Patent Grant
6928694
1. Field of the Invention
The present invention relates to opening closing and holding devices, systems and methods for doors and more particularly to holding devices for the doors of vehicles and most particularly for automobile and truck doors and the like. Door holding devices of the kind provided by this invention are often referred to as infinite-position holding devices or infinite position door checks because they act to hold the door in any open position to which it is moved and left standing, but still permit the door to be readily moved to any other desired position.
2. Description of the Prior Art
A door check mechanism is usually present on each vehicle door on all automobiles, recreational vehicles, vans, trucks, and virtually all other vehicles. In many designs, the door check mechanism provides two open detented positions, one at which the door is partially open and the other at which the door is fully open. In some cases, the door check mechanism for a vehicle door provides only one open retention position.
Door check mechanisms of the fixed detent type are quite common and have been used for many years. However, they are far from uniform in construction or in application. In many vehicles, the manufacturer provides a check mechanism that is separate from the door hinges and it is typically mounted at a location midway between the two hinges. In other instances, one of the hinges incorporates a check mechanism in the hinge structure itself.
Attempts have been made to incorporate an infinite door check mechanism into a vehicle and a number of patents have been issued covering such devices (discussed below). None has yet achieved commercial success due to the cost and complexity and well as the short service lives of these prior art mechanisms.
Door check mechanisms have in general exhibited some substantial difficulties over the years including: (i) the need in some designs for frequent lubrication without which they tend to make undesirable noises; (ii) inadequate operating life; (iii) corrosion; (iv) the inability to endure vehicle body processing temperatures associated with the curing of external finishes (400° F.); (v) the inability to be easily separated from the vehicle after painting to permit the door to be separately trimmed and then reassembled to the body; (vi) the occurrence of unacceptable stress and wear on the door hinges caused by loading from the door check; and (vii) the requirement for frequent post installation adjustment during the vehicle life. Each of these problems has been addressed in one or more of the prior art fixed detent door checks but there is no infinite door check that has solved all of these problems.
The tendency for an automobile door to swing open or closed when not desired is frequently caused by factors such as the transverse curvature or crown of a pavement or road, by the slope of a hill, or by a gust of wind. Such a tendency, when in the closing direction, causes the door to strike the legs or other parts of a person entering or leaving the automobile. When in the opening direction, it can cause the door to impact into other people or objects inflicting harm or damage thereto. A particularly costly problem, as reported by automobile insurance companies, happens in parking lots where the opening door of one vehicle bangs into an adjacent vehicle causing damage to the finish that can lead to an insurance claim. This increases the cost of insurance to all automobile owners.
To partially solve this problem, vehicle doors are frequently provided with an inclined hinge axis incident to body design that biases the door to close. This is a desirable feature since it aids in the closing of the door especially by older or physically impaired people and should not be defeated as is done by some infinite position door checks which maintain a friction drag on the vehicle door at all times.
As discussed below, this tendency of a vehicle door to swing in an unwanted manner is prevented or minimized by the infinite door check means of the present invention which is effective to hold the door in any open position in which it is left standing, while permitting a relatively free manual movement of the door to any other desired position and a free self closing action when that is desired. This invention also provides an infinite position door checking mechanism that solves all of the problems of prior art infinite position door checks listed above in a simple and cost effective design. In the context of automobile manufacturing, for example, most of the design implementations of this invention permit the door to be easily removed from the vehicle for trimming and then reassembled entailing only the removal and replacement of a single pin.
The infinite position door check mechanism for regulating pivotal movement of a vehicle door between a closed position and any open position, which mechanism is sometimes incorporated in a hinge, includes an elongated strip member having a flat or curved surface; a cam, or other locking member, which engages one of the strip surfaces with varying amounts of pressure contact depending on whether the door is in the freely opening or closing mode, checked against movement in one direction or checked against movement in both directions. Either the cam or the strip member typically has a resilient plastic, brake material or other non-metallic surface, the other surface generally being metal. The engaging portions of the cam and strip member surfaces are thus preferably dissimilar materials, usually a metal and a non-metal.
Pertinent prior art includes the following:
U.S. Pat. No. 406,840 to Jones describes a door check for doors of buildings and like structures and includes a check-rod and a sliding sleeve containing two springs between which the check-rod is fitted. The springs bear or press constantly on opposite sides of the check-rod, and when they ride over inclined surface of the rod at a point of its greater diameter, they are compressed and serve to retard rapid movement of the door.
U.S. Pat. No. 2,232,986 to Westrope describes a door check device having a check arm provided with spaced abutments providing a recess therebetween. The check device includes a retainer through which the arm extends and a pair of bearings in the retainer for engaging opposite sides of the arm and having socket-engaging portions. The bearing members are movable away from each other so that one of the abutments may pass therebetween. The socket-engaging portions engage that abutment when the bearing members are positioned in the recess. Yieldable means are provided to hold the bearing members in engagement with opposite sides of the arm.
U.S. Pat. No. 2,268,976 to Westrope describes a door check for a vehicle including an arm pivoted to either the door or the vehicle supporting structure. The arm has a projection and a cushion thereon. The projection is adapted to engage a tiltable cam mounted upon the other structure and supported upon a resilient member. When the door is opened, the projection engages the cam and pushes it downward as the projection slips over the cam. Thereafter, the cushion on the arm engages the housing of the cam and cushions the halting motion of the door. After the projection on the arm has slipped over the cam, the cam acts as a yielding abutment to hold the door open.
U.S. Pat. No. 2,268,977 to Westrope describes a door check for a vehicle including a housing attached to the body of the vehicle and a strap or link attached to the door or vice versa. The housing contains a tiltable cam engageable with a projection on the strap or link and having a spring member for maintaining this engagement. Optional means are provided for adjusting the tension of the spring member.
U.S. Pat. No. 2,882,548 to Roethel is one of the early patents on door checks. The checking is done by friction drag that is increased at two checking positions. The effectiveness of this system is degraded when the coefficient of friction changes, and the system has a limited life.
U.S. Pat. No. 2,992,451 to Schonitzer et. al. describes a design that uses continuous sliding friction of a nylon plunger spring loaded against a ramp member. Some viscoelastic effect, or static/dynamic friction, takes place when the door is held in a particular position slightly increasing the resistance to further motion. Problems arise with regard to dirt, moisture, temperature, wearing etc. This may be the first infinite door check patent. The holding power is stronger when the door is in the open position. The continuous friction defeats the automatic door closing system. The holding force is designed to exactly counter-balance the tendency of the door to close by itself. The system is also dependent on sliding friction and therefore strongly affected by the surface condition that may have a coating of oil, grease, moisture etc. or be dry.
U.S. Pat. No. 3,345,680 to Slattery describes a friction type door checking device that is designed to hold the door in discrete positions. It has the same problems as Schonitzer et al.
U.S. Pat. No. 3,461,481 to Bachmann describes an infinite position door checking device based on a frictional locking mechanism. The frictional locking mechanism is held in contact with the friction surfaces by means of a biasing spring that exerts its maximum torque and thus creates the maximum wear when the mechanism is in the unlocked position.
U.S. Pat. No. 3,584,333 to Hakala describes an infinite position door check system in which a contact edge of the detent member digs into the friction member to provide a wedging restraint to hold the door. It is thus a friction-based system. The torque spring has its maximum force in the non-detented positions, thus, maximum drag. The system requires careful alignment and is subject to wear. Thus the characteristics will change over time. It does not have an intermediate detenting position. The normal tendency of the door to close under gravity causes the detenting action. The frictional drag works to prevent the door from closing under its own weight thus defeating that desirable function.
U.S. Pat. No. 3,643,289 to Lohr describes a device including an infinite position hold open hinge. This device is a totally sliding friction dominated system using a plastic brake. A greater force is required to close the door than is required to open the door. There is drag on the door in both directions and higher drag in the closing direction. The brake is made of a material such as nylon or polyurethane that the inventor claims has both a high static coefficient of friction and low sliding coefficient of friction. Although this is the goal, this cannot be achieved due to surface contamination.
U.S. Pat. No. 3,969,789 to Wize describes a system with four detents thus providing multiple locations for the door. The detenting mechanism slides smoothly over the detents as long as torque is applied to the door. When motion is stopped, the detent falls into the closest spot. This may cause significant motion of the door to get to the nearest door detent. There also is an alignment problem with this device. The detenting is done with rollers, however, so there is no sliding friction except for the friction spring associated with the mechanism that carries the detents over the detenting holes or slots.
U.S. Pat. No. 3,965,531 to Fox et al. describes an infinite position door hold open using continuous sliding friction to wedge a brake to create a much larger friction. The device is complicated, requires adjustment, is sensitive to dirt, and has no positive intermediate position. Thus, as with all other infinite door checks discussed thus far, the door is either in a position where it will move relatively easily toward a more open position but is checked against closing or else it is in a position where it will move freely toward the closed position but is checked against opening. The friction surfaces are knurled and adjustment is required during the life of the vehicle due to wear of brake surfaces.
U.S. Pat. No. 4,069,547 to Guionie et. al. describes a device using a four-bar linkage structure that has the advantage of keeping the detenting system aligned. Otherwise, it is a single position door checking mechanism. The checking motion is rather small, probably resulting in significant variation in the checked position from vehicle to vehicle.
U.S. Pat. No. 4,332,056 to Griffin et. al. describes an infinite position door check that does not have an intermediate position. It uses a roller that rubs continuously on the friction surface resulting in a wear problem. It can also defeated by moisture, oil, or other contaminant etc. on the rubbing surfaces. For this reason, the hard rubber chosen as the friction surface is a poor choice since the friction coefficient is strongly influenced by surface films. The roller moves from one position to another based on differences in the friction coefficients between the biasing plunger and the hard rubber coated arcuate friction surface. This system requires adjustment when installing on vehicle.
U.S. Pat. No. 4,532,675 to Salazar describes a door hold open door check which is only engaged when the door is in the filly open position. Therefore, the parts are not under continual cyclical stress as which reduces the wear problem.
U.S. Pat. No. 4,628,568 to Lee et. al. describes an infinite position door check system based on a difference between a high static coefficient of friction and low sliding coefficient of friction such as nylon or polyurethane. This is unsustainable as surface films will radically change the friction coefficients. Since significant friction is always present, there is a wear problem resulting in a device with a short life without adjustment.
U.S. Pat. No. 4,720,895 to Peebles describes a quick disconnect door hinge with an integral discrete position door check. It solves the problem of being able to paint the door on the body and then disassembling it for trimming and later reassembling it to the vehicle in an easy manner.
U.S. Pat. No. 5,018,243 to Anstaugh et al. describes the use of a polyester urethane material for coating the roller. This material is good from −40° to 400° F. and lasts substantially longer than nylon if it is backed up by metal. Additionally, it is substantially quieter than the nylon on metal system used in the prior art.
U.S. Pat. No. 5,074,010 to Gignac et al. describes a detent system and shows the many different geometries that have been adopted by various vehicle manufacturers. It claims advantages in either the roller or the track having a resilient elastomer core, preferably an elastomer material (e.g., a silicone polymer) that retains its elastic properties over a wide temperature range.
U.S. Pat. No. 5,173,991 to Carswell addresses some of the force components that can cause noise and premature failure of door check mechanisms. The design described in this patent is a discrete door check that is claimed to be quite and have a long life. Once again, the contacting materials are discussed and this patent recommends coating the link arm with Milon by DuPont that is moldable material. The bearing ball purportedly provides three degrees of freedom where as the prior art devices with rollers allow for only two degrees of freedom with the result of a fair amount of grinding of the housing adjacent the edges or shoulders of the link member. The ball system gives point contact, therefore higher forces and therefore greater wear. It has not been realized that this problem can and has been solved in prior art devices by placing the rollers with their axes in a vertical direction. Although the ball rolls in the groove, on which the patent makes a great issue, it is sliding on the elastomeric spring that pushes it down. This sliding friction will cause wear and shorten the life of the door check.
U.S. Pat. No. 5,346,272 to Priest et al. describes a door hinge with infinitely adjustable detent or door check. It is significant since it is the first attempt to apply electronics to this problem. There is no obvious advantage to this overly complicated system since to deactivate the door holding system, the door must be moved which requires a force. The same force can be used to remove the detent in a pure mechanical system.
U.S. Pat. No. 5,452,501 to Kramer et al. describes a device in which the detent force acts vertically so as to not load the pivot pin. However, in this case, the hinge pin is still loaded when the door is moved into and out of the detented positions and thus the problem is only partially solved. Any detenting system will put a couple onto the hinge pin.
U.S. Pat. No. 5,474,344 to Lee describes a device which is almost a duplicate of the Carswell patent (U.S. Pat. No. 5,173,991) except rollers are used instead of balls. In this patent, the body as well as the cover are all made from plastic. Significantly, there is a pad disclosed for the prevention of the introduction of foreign substances into the locking unit.
Although each of the above references attempts to solve one or more of the problems listed above, in contrast to the infinite position door check described herein, in no case is there provided an infinite door check mechanism which solves substantially all of these problems. As a result, there is no successful infinite door check in high volume commercial use at this time although the desire for such a device is well known in the industry.
Accordingly, it is an object of the invention to provide new and improved door check mechanisms for regulating movements of a vehicle door, or doors of other structures.
It is another object of the present invention to provide new and improved door mechanisms which enables the door to be moved to a plurality of different open positions and held in those open positions.
It is still another object of the present invention to provide new and improved door check mechanisms which provide positive retention of the vehicle door in an infinite number of open positions without interfering with the normal opening and closing movements of the doors, yet exhibit long life and are essentially unaffected by high or low temperatures.
Further objects and advantages on this invention include, to provide an infinite position door check mechanism which does not require lubrication; has an operating life equivalent to that of the vehicle; does not corrode; is able to endure vehicle body processing temperatures associated with the curing of external finishes (about 400° F.); is able to be easily separated from the vehicle after painting to permit the door to be separately trimmed and then reassembled to the body; is simple and inexpensive to manufacture and install; does not result in unacceptable stress and wear on the door hinges caused by loading from the door check; does not require post installation adjustment during the vehicle life; and has the capability to be released electrically permitting the vehicle door to close under its own weight.
Accordingly, to achieve at least some of the objects above, one embodiment of a vehicle including a door movable from a closed position in a door frame to any one of a plurality of different open positions and held in the different open positions includes a strip connected to the door or door frame and a braking mechanism connected to the other of the door or door frame to provide relative movement between the strip and the braking mechanism when the door is moved relative to the door frame. The braking mechanism engages with the strip at a plurality of locations and prevents movement of the strip when the braking mechanism is in engagement therewith. The braking mechanism is preferably biased against the strip. The vehicle also includes an electrical system, such as a motor or solenoid, coupled to the braking mechanism to disengage it from the strip to thereby permit relative movement between the strip and the braking mechanism and thus movement of the door relative to the door frame. When the strip is connected to the door and the braking mechanism is connected to the door frame, the strip would move relative to the braking mechanism while on the other hand, when the strip is connected to the door frame and the braking mechanism is connected to the door, the braking mechanism moves relative to the strip.
In one embodiment, a motor automatically moves the door relative to the door frame. As such, a depressible switch may be coupled to the electrical system and the motor for initiating the electrical system to disengage the braking mechanism from the strip and for initiating the motor to automatically move the door relative to the door frame upon depression of the switch. The switch may be arranged on the steering wheel of the vehicle. In the alternative, a capacitive sensor defining a sensing area may be coupled to the electrical system and the motor for initiating the electrical system to disengage the braking mechanism from the strip and for initiating the motor to automatically move the door relative to the door frame upon detection of the presence of a hand in the sensing area. The capacitive sensor may be arranged on the door and/or such that when removal of the hand is detected, the electrical system is arranged to cease the disengagement of the braking mechanism from the strip and the motor is arranged to cease movement of the door relative to the door frame.
In this regard, two capacitive sensors can be provided, one for initiating the electrical system to disengage the braking mechanism from the strip and for initiating the motor to automatically move the door in a first direction relative to the door frame upon detection of the presence of a hand in the sensing area of the first capacitive sensor and the other for initiating the electrical system to disengage the braking mechanism from the strip and for initiating the motor to automatically move the door in a second direction relative to the door frame, opposite to the first direction, upon detection of the presence of a hand in the sensing area of the second capacitive sensor.
In another embodiment, a voice activation module for processing verbal commands may be provided whereby the electrical system and motor are controlled by the voice activation module to initiate the electrical system to disengage the braking mechanism from the strip or allow engagement of the braking mechanism with the strip and to initiate the motor to move the door upon detection of specific commands.
A related method for controlling movements of a vehicle door from a closed position in a door frame to any one of a plurality of different open positions involves connecting a strip to one of the door or the door frame, arranging a braking mechanism in the other of the door or the door frame to enable relative movement between the strip and the braking mechanism when the door is moved relative to the door frame, engaging the braking mechanism with the strip at one of a plurality of possible locations to prevent relative movement between the strip and the braking mechanism, biasing the braking mechanism against the strip and providing an electrical system to selectively disengage the braking mechanism from the strip to thereby permit relative movement between the strip and the braking mechanism and thus movement of the door relative to the door frame. The same enhancements to the vehicle and door movement system described above can be utilized with the method.
Another vehicle including a door movable from a closed position in a door frame to any one of a plurality of different open positions and held in the different open positions includes a hinge mechanism for hingedly connecting the door to the door frame and a motor for pivoting the door about the hinge mechanism to enable the door to move between its closed position and any one of the plurality of open positions. The motor can include a rotatable motor armature controlled to freely stop its rotation to thereby fix the door at any one of the plurality of open positions. A depressible switch may be used to initiate the motor to automatically pivot the door upon depression of the switch. Also, a capacitive sensor or voice activation module can be used to initiate the motor to automatically pivot the door upon detection of the presence of a hand in the sensing area.
Other embodiments of a door check mechanism in accordance with the invention comprise a rack adapted to be coupled to and extend outward from the frame, a gear adapted to be arranged on the door, the gear having teeth and being arranged in engagement with the rack and a detent mechanism arranged in engagement with the rack and the gear for enabling the door to be positioned in a plurality of fixed positions and for preventing movement of the door to a different fixed position when a force exerted upon the door is below a threshold. A housing may be provided to house or support the gear and all or only a portion of the detent mechanism.
In the alternative, the rack can be attached to the door and the gear and detent mechanism attached to the door frame.
The detent mechanism usually includes a member having a portion in engagement with the rack, e.g., an irregularly shaped cam with a pawl, and some sort of pressure applying component(s) to press the gear against the rack, e.g., a detent and a spring for biasing the detent against the gear to, in turn, press the gear against the rack.
The detent mechanism is designed to prevent rotation of the gear relative to the member when a force exerted on the door is less than a threshold and allow rotation of the gear relative to the member when the force exerted on the door is greater than the threshold. Rotation of the gear relative to the member is necessary in order for the gear to roll along the rack which translates into movement of the door relative to the rack, i.e., relative to the door frame. That is, only when the gear is allowed to rotate relative to the member will the position or degree of opening of the door be able to be changed from one initial fixed position to another fixed position. Although the door can move when the gear rotates relative to the rack, so long as the gear rotates simultaneously with the member, it will revert to the initial fixed position and will not change fixed positions.
The detent mechanism is also designed to prevent movement of the member, and thus any movement of the gear, when a force exerted on the door is below a threshold. Thus, slight nudges of the door will not result in movement of the door. The thresholds can be set by the design of the components of the detent mechanism.
The member or cam is preferably held in a stationary position when the door is in a fixed position, for example, by a movable piston member having a roller arranged in connection therewith and which engages an indentation on a side of the cam opposite the pawl. The piston member is biased by a spring to thereby force the roller into engagement with the cam to prevent movement of the cam.
The rack may be guided between guide members arranged in connection with the door or housing for the detent mechanism. Stops are provided for stopping rotational movement of the member above a threshold to allow the gear to be able to rotate relative to the member.
The invention will be described with reference to the following non-limiting drawings:
FIG. 21A and
Referring to the accompanying drawings wherein like reference numerals refer to the same or corresponding parts throughout the several views;
The door portion shown in
Door 117 includes a vertical support member 119 that is preferably an integral part of the door. Door check mechanism 118 is mounted on the support member 119 by fastening means indicated generally as 121. Upper hinge 106 is mounted on door 117, preferably as indicated at mounting locations 122, by fastening means and more particularly on support member 119. Similarly, the lower hinge 109 is mounted on the support member 119 at mounting locations 123 by fastening means. The hinges 106,109 have a common pivotal axis 125 for enabling pivotal movement of the door. The fastening means may be screws, nails, welds, rivets, adhesive, etc.
In one preferred form of the door check mechanism 118 that is shown in
At this juncture, it should be appreciated that the locking member may be other than the irregularly shaped cam shown in
If sufficient force is applied to overcome the forces described above in, for example, the direction to open the door 117, then the cam 130 will rotate to the position as shown in
When the cam 130 is in the position as shown in FIG. 4B and sufficient force is applied to the left on the door 117 to stop the opening momentum of the door 117, the door 117 will remain in position absent additional forces. If the door 117 is designed to be biased toward closing, then even a slight force toward further opening the door 117 will not cause it to move until the bias is overcome. In this position, a small force will cause the door 117 to open further but a much larger force in the closing direction is required to move the strip member 116 to the position as shown in FIG. 4A. The magnitude of this force is determined by the geometry of the cam profile portions 134 and 135, the magnitude of spring force 150 and by the coefficient of friction between the strip member 116 and support member 160.
A slight drag must be exerted onto the strip member 116 by the cam surface profile 136 if the cam 130 is to be engaged by the strip member 116 and caused to rotate without slipping to bring the cam 130 to the position shown in
An elastica spring was chosen for its simplicity. Many other types of springs or combinations of springs and other mechanisms such as cams and linkages could also be designed to perform the desired function. The preferred function for the spring 140 is one that exerts little or no torque on the cam 130 when the cam 130 is in the position as shown in FIG. 4A. As the cam 130 rotates from this position, the spring 140 should exert a force that opposes the motion of the cam 130 and reach a maximum value at some angle between the positions shown in
An elastica spring is a spring that acts like a buckled column where when both ends are freely supported, the force does not increase significantly with greater deflection once a minimum deflection is obtained. In the cantilevered implementation used here, the force will increase with increased deflection. As best seen in
The checking mechanism as illustrated here has been designed for a coefficient of friction of about 0.1 or greater between the cam profile surfaces 135, 134 and the strip member 116. As long as the friction coefficient exceeds this value, the strip member 116 will not slip on the cam 130 and the torque chosen will not cause the cam 130 to slip on the strip member 116. The mechanism can be designed for a lower friction coefficient such as about 0.05 with the result that the tolerances on the parts would become tighter which would increase the manufacturing cost. An alternate preferred design that can be used even when lubrication is present is described below. Most material combinations exhibit a friction coefficient of greater than about 0.1 providing the surfaces are not contaminated with a lubricant. The possible presence of a lubricant can be compensated for by providing a slight texture to the cam profile portion surfaces 134 and 135. Since there will only be rolling contact between surface 126 of the strip member 116 and the cam profile portions 134 and 135, such a texturing will not cause undue wear to the strip member surface 126. In order to reduce noise, the surface of strip member 116 is preferably made of a plastic such as a filled Nylon or with Milon by DuPont, or a similar polymer. In some applications, an elastomer may be used and in others brake material can be used. A properly designed and made textured surface will defeat the lubricating action of most lubricants by cutting through the surface lubricant film or forcing the lubricant to flow out of the space between the contacting surfaces.
A coil spring 150 is illustrated to create the contact pressure between the cam 130 and strip member 116. Naturally, other types of springs could be used including those made from an elastomer or from a cantilevered beam.
The mechanism described above is illustrated in an exploded view in FIG. 3 and in cross section in FIG. 5. Like reference numbers represent the same parts in each of the views in
Checking device 118 includes an external box-like housing 170 which is closed by a cover 176 both of which may be formed of sheet metal and mounted upon door support element 119 by bolts, screws or other fasteners 123. The configuration of housing 170 is not particularly critical. Housing 170 does include two apertures through which the strip member 116 passes. The fastening means 121 connects the housing 170 to the structure to which the door check mechanism 118 is mounted. The housing 170 provides a firm mounting for the cam 130 and cam holder 180. Cam 130 is preferably made by a powder metal or forging or coining technology. Cam holder 180 can also be made from sheet metal. Cam 130, as shown in detail in
The use of metal for the cam 130 and support 160 is predicated upon the assumption that strip member 116 and its surfaces 126 and 127 are formed of a hard, durable resin material such as nylon, so that when the two engage each other, as seen in
In explaining the operation of vehicle door check mechanism 118, it is most convenient to start from the closed position of door 117. In the closed position, the cam 130 is most likely to be in the position shown in FIG. 4C. To open the door 117, the cam 130 must be rotated past the detented position illustrated in
To open door 117, the door latch (not shown) is released and the door 117 is pivoted toward an open position with respect to car body 101 and particularly its frame member 104. The direction of this movement is counter clockwise about hinge axis 125, viewed from above. This pivotal movement of the door 117 drives door check mechanism 118 along strip member 116, in the direction generally indicated by the arrow B in
To close door 117, of course, it is pivoted back toward body 101 and frame member 104 (FIG. 1). On the return motion, if desired, door 117 can again be stopped and held at any intermediate position by applying a force in the opening direction until the detent is engaged.
The cam 130 is preferably solid steel providing that the strip member 116 has a polymeric or other non-metallic coating. If the strip member 116 has instead a metallic surface then the cam can be molded of a hard, relatively non-resilient plastic such as a glass-fiber-filled heat stabilized nylon or otherwise have a non-metallic surface. The purpose, as before, is to assure that where the cam surfaces 134, 135, the support surface 160 and the strip surfaces 126,127 engage there are dissimilar materials, avoiding any tendency toward “freeze-up” in operation or unnecessary noise. Also, lubrication is not generally required except on the cam shaft 132. In some applications it may be possible to use metal for both the surfaces of the cam 130 and strip member 116 providing consideration is provided elsewhere to acoustically dampen the resulting noise.
In part due to the distortable nature of the cam 130 (
The preferred embodiment illustrated above is for the case where the checking mechanism is separate from the hinge. Naturally, the infinite door check mechanism of this invention can be integrated into the hinge itself as is common in the prior art with fixed detect door checks. One example of such a mechanism is illustrated in
A strip of bent spring material 250 is used in this embodiment instead of the coil spring 150 to force the cam 230 against the outer surface of hinge member 216. Although other constructions of biasing means for forcing the cam 230 against the outer surface of hinge member 216 are possible, this design was selected to reduce the space required for the checking mechanism.
A variation of this design is illustrated in
In some implementations where there is sufficient space, two opposing cam mechanisms 130a, 130b can be used in place of the single cam structure as described above as illustrated in
A common complaint among older and disabled people is that once they are in the vehicle and the door is detented open, closing the door can be a difficult chore. What is desired is a feature where with the push of a button, the door will close automatically. This feature can be readily added to the instant invention as shown in
In many cases, doors are designed to be gravity biased to close automatically except for the detenting system. If the detent can be removed in these cases, the door will close automatically under its own weight unless the vehicle is tilted significantly to the side or pointing down a hill. An electrical release mechanism 450 is illustrated in
Usually, the momentum of the door closing as described is insufficient to fully close the door and an additional mechanism is required for pulling the door to its completely closed and latched position. Such a device is illustrated schematically as 500 in FIG. 10. Naturally, although
The invention as implemented in
In some cases, the door is so strongly biased toward closing that an intermediate checking position is not required.
Up until now, a cam type wedging mechanism has been illustrated. Alternate systems can also be used as illustrated in
A detailed discussion of the operation of the conventional sprag roller system can be found in U.S. Pat. No. 5,482,144 to Vranish which is incorporated by reference herein in its entirety as if it all words and figures were literally inserted here. The sprag disclosed as prior art in the '144 patent has been modified here to permit a certain maximum torque to be transmitted between the driving member (strip member 116) and the driven member (member 634) by means of roller 630 before a snap through to the detent position and then to free motion in the other direction is permitted. In the normal operation of a sprag, the transmitted torque is considered infinite and no snap through feature is provided. The mechanism of
Still another wedging system is illustrated in
Several of the features of the above designs are combined in the preferred design illustrated in
An alternate embodiment of the invention is shown in perspective generally at 1000 in FIG. 18. In this embodiment of the invention, a rack and pinion gearing system replaces the friction system of the earlier designs. More specifically, a rack 1020, or other elongate member with teeth adapted to mesh with those of a pinion or gearwheel, is attached to a frame or strip 1015 and engages a pinion gear or cogwheel 1022. Strip 1015 is guided into engagement with the gear 1022. A frame or housing structure 1030 retains or supports the various parts as described below. Spring 1025 provides the force to check the motion of the door. Bracket 1010 is attached to the door frame and the remaining mechanism, i.e., the frame 1030, is housed within the door or arranged on or in connection with the door.
The spacing and/or number of teeth on the rack 1020 determines the number of different open positions of the door relative to the door frame because the space between each adjacent pair of teeth corresponds to one open position of the door.
Instead of the gear 1022, another movable and/or rotatable member having teeth or projections may be used. The teeth or projections should be designed to engage with the teeth of the rack 1020 to prevent movement of the rack 1020 when the movable/rotatable member is stationary.
A side view of the mechanism is illustrated in
In order for cam 1040 to rotate, a roller 1050 must be forced to move, in a downward direction in the drawing, causing piston member 1060 to depress spring 1025. Otherwise, roller 1050 is pressed by the spring 1025, via the piston member 1060, into an indentation in a surface of the cam 1040 opposite the pawl 1024. The spring 1025 is designed to prevent movement of the piston member 1060 and roller 1050 unless a force above a threshold is exerted on the door, to open or close the door, thereby forcing rotation of the cam 1040 relative to the rack 1020. Such a force above the threshold causes rotation of the cam 1040 and thus downward movement of the roller 1050, piston member 1060 and spring 1025.
The non-detented position of the mechanism is illustrated in
In
To summarize, in the initial detented position, both the pawl's tooth and the gear 1022 are meshed with the rack 1020. To start opening or unlocking the detent 1044, it is necessary to apply the appropriate force along the rack 1020 to overcome the cam's fixation that is provided by the roller 1050, piston 1060 and flat spring assembly 1025. During the rack translation, the cam 1040 and gear 1022 rotate simultaneously due to the spring-loaded detent 1044 until the edge of the cam 1040 contacts one of the stops 1035. Thereafter, the gear 1022 is able to rotate relative to the cam 1040 as the rack 1020 continues to move.
The rack 1020 continues its movement in the same direction and the cam shoulder rests against its stop 1035 and the detent 1044 jumps from slot to slot between the teeth in gear 1022 thus maintaining the connection between the cam 1040 and the gear 1022.
To once again engage the door check at the desired position of the door, the motion of the rack 1020 is stopped and a slight movement backward causes the gear 1022 to drive the cam tooth into a meshing engagement. The cam 1040 catches the roller 1050 and locks the rack 1020 with its tooth ready to bare the detenting loads.
As described above, the rack 1020 is mounted in the frame 1015 which is connected to a bracket 1010 which in turn is mounted to the door frame. The detent mechanism is thus arranged in connection with the door. A reverse arrangement is also possible, i.e., the rack being arranged on the door and the detent mechanism being arranged in connection with or housed within the door frame.
In all of the implementations described above, the detenting mechanism has been mechanical. With the trend to add more electronics to automobiles, the door detent system can similarly be accomplished electrically. Such a system can be implemented in numerous ways generally involving a brake mechanism that engages a strip with the force of the brake against the strip being provided typically with a spring and an electrical system such as a motor or solenoid used to remove the brake from strip. Thus, the implementation of an electrical system is relatively simple and the switching system used to activate the electrical system now permits additional comfort and convenience features to be incorporated into the automobile. Additionally, the motion of the door itself can now be motorized. In such a case, a separate brake may not be required as the resistance to rotation of the motor armature itself will serve as the detent system.
In one implementation of such a system, a capacitive sensing area is placed on the door and when the hand of the occupant touches this area, provided the vehicle is not moving and the parking gear engaged, the door will unlock and a motor will begin to open the door. As long as the occupant's hand is adjacent the capacitive surface, the door continues to open with no significant force provided by occupant. Thus, this system is particularly useful to older or disadvantaged people do not have significant strength to open a typically heavy vehicle door. Through touching a second capacitive sensing surface on the door, the door can also be caused to close.
Many other systems can be used to control the doors as well as another vehicle components in addition to switches and mouse pads. These include track balls, sequentially pressing of one or more switches to cause the selection of desired function to change followed by a depression of a second switch that selects the action. In this latter case, the switches can be located on the steering wheel near the edge where the driver hands normally rest to permit easy operation of these switches using driver's thumbs. For example, a switch can be located near the right side of the steering wheel for activation by the right thumb which could be used to select the function (e.g., open the passenger door) and a switch located on the left side causes the function to be executed (e.g., the passenger door is opened). In general, any of the conventional and even unconventional input devices that are used for manual input of information to a computer can be used in this case. A joystick coupled with a mouse button where the joystick can also be located on the steering wheel is another alternative.
Many other types of switching systems can be used. For example, a mouse pad can be adapted to a steering wheel, as disclosed in U.S. patent application Ser. No. 09/645,709 filed Aug. 14, 2000 (incorporated by reference herein in its entirety), as part of the vehicle's component control system. Activating the mouse pad and a heads-up or other type display, the driver can cause any of the doors of the vehicle to open or close. Such a device can be located at other locations in the vehicle as illustrated in
In one preferred embodiment of the system, the door opening capability can be provided to a driver to open, unlock, close and lock any of the doors, including the trunk, of the vehicle from driver seat location. Generally, the other doors of the vehicle can only be operated from the seat adjacent that door except in case of the driver who can operate all of the vehicle doors.
With power-operated doors, it is desirable to sense objects or obstructions that may prevent the door from closing and to stop motion of the door when such an obstruction occurs. This can be accomplished in numerous ways such as optically, as described in U.S. provisional patent application Ser. No. 60/292,386 filed May 21, 2001, ultrasonically as described in U.S. Pat. Nos. 5,629,681 and 5,829,782 (all of which are incorporated by reference herein in their entirety), or through sensing the current and/or voltage in the motors used to open and close the door. When that current increases above a threshold, it is assumed that the door has encountered an obstruction and motion is stopped and in some cases reversed.
Similarly during the opening process of the door and in order to prevent impacts of the door with another vehicle in a parking lot, for example, or a tree or other external object, when the current in the drive motor exceeds a threshold, the motion of the door can be stopped. An override can be provided to account for cases where vehicle is tilted or the door is encountering resistance caused by brush or snow, for example, or other obstruction where the driver desires to continue motion of the door in spite of the obstruction.
More sophisticated sensors can also be used to stop the opening motion of the door to prevent an impact with another object. Such sensors include but are not limited to capacitive sensors, ultrasonic sensors, laser radar sensors, lidar, radar or vision sensors using either visual, infrared, ultraviolet, or any other part of electromagnetic spectrum. For vehicles which have blind spot detectors or anticipatory side impact sensors, for example, the sensing of an obstruction to a powered opening door can become part of such a system.
When a person approaches his or her vehicle from the exterior, a variety of systems can be provided to aid the driver in opening the vehicle door. In one case, for example, the driver can depress a key fob to unlock the door and by holding the button down the door can be opened while the occupant is still some distance from the vehicle. Alternatively, the operator may possess an RFID tag in his pocket, for example, and as he or she approaches the vehicle, the vehicle system interrogates and recognizes the identification on the RFID tag and automatically unlocks and begins opening the door. In another preferred embodiment, the owner will merely touch the door or door handle and the vehicle can recognize the owner through a biometric sensing system, such as a fingerprint, voice print, facial scan, iris scan etc. or through an RFID as mentioned above. Achieving a positive identification, the vehicle can then proceed to open the door. This process in the cases above can be reversed if the owner exerts a threshold force on door opposing its motion.
In the event of an accident, where the occupants are incapable of operating the doors, a voice request to an ONSTAR™ operator, for example, can initiate a remote action to unlock and open the vehicle doors. Similarly, if the ONSTAR™ operator, or other observer, can remotely determine that vehicle occupants have become incapacitated by virtue of an accident, or otherwise, and that the occupants would be aided through opening of the doors or windows, a camera placed within the passenger compartment which sends a view of the compartment could provide sufficient information for such an operator to initiate door or window opening.
Although there have been a few vehicle models with unusual door hinging structures, generally the front driver and passenger doors hinge on A-pillar and rotate about an approximately vertical axis. Other door opening schemes have been attempted but are difficult for a driver or other vehicle occupant to operate. Although power sliding doors have the used in some vans, they have heretofore not been adopted for the front vehicle doors. Utilizing the teachings of this invention, this new capability now exists. In fact, there are now many options for the path of the front driver and passenger doors that are now possible. For example, the door can slide forward after first moving laterally outward from the car. In this case, the maximum space becomes available for the driver or passenger to enter or leave the vehicle permitting the entire opening to be available. It also prevents the vehicle door from banging into the sides of other vehicles in a parking lot, for example.
Since the door is operated by electric motors, the path taken by the door is limited only by the imagination of the designer. Instead of going out and then forward for example, the door could be designed to move vertically either straight upward or in a curved path to a position above the vehicle roof. The door could also be made to move toward the rear, however, in some cases this could interfere with the rear doors. It would certainly be possible for a two door vehicle. Finally, the door could even be designed to rotate downward and underneath the vehicle and even provide a step for easy entry and exit from the vehicle. This would be particularly desirable in some high vehicles such as SUVs.
Thus, the addition of electric power to control the opening and closing of the front doors offers many new options for the vehicle designer. The actual path taken by door can be controlled through slide mechanisms or through various linkage designs including four-bar, five-bar, or other spatial linkage mechanisms.
In most or all of the various door configurations discussed above, it is desirable to replace the current wire harness system that brings power and information to and from the door with a similar system. Such systems include a one wire pair system such as described in U.S. Pat. No. 6,326,704 or a wireless system as described in U.S. provisional patent application Ser. No. 60/231,378 filed Sep. 8, 2000 and U.S. patent application Ser. No. 09/765,558 filed Jan. 19, 2001 as desired by the designer (the patent and these applications being incorporated by reference herein in their entirety).
The microprocessor 1180 may include determining means for determining the location of the head of the driver and/or passenger for the purpose of adjusting the seat to position either occupant so that his or her eyes are in the eye ellipse or to adjust the HUD 1140, 1145 for optimal viewing by the occupant, whether the driver or passenger. The determining means would use information from the occupant position sensors such as 1110, 1111, 1113 or other information such as the position of the vehicle seat and seat back. The particular technology used to determine the location of an occupant and particularly of his or her head is preferably based on neural networks or neural fuzzy systems, although other probabilistic, computational intelligence or deterministic systems can be used, including, for example, pattern recognition techniques based on sensor fusion. For the case where a neural network is used, the electronic circuit may comprise a neural network processor. Other components on the circuit include analog to digital converters, display driving circuits, etc.
The interior of a passenger vehicle is shown generally at 1600 in
In any of the various embodiments of the invention described above, the door check mechanism should afford excellent performance characteristics over the full vehicle life. These door check mechanisms provide quiet operation over the full range of door movement, require little or no lubrication and have a minimum of moving parts; they are light in weight and adaptable to use with bolts, butt welding, or virtually any other; mounting arrangement. Corrosion is effectively avoided and adjustment of operational force requirements is readily achieved.
The infinite door check mechanism in accordance with the invention may be used for doors other than vehicular doors, although its use in vehicular doors is of primary importance as the need for such a door check mechanism is most prominent in this regard. There are additionally other non-door applications for the mechanisms disclosed herein.
Thus, disclosed above is an embodiment of the invention which relates to an infinite position door check mechanism for regulating movement of a vehicle door, pivotally mounted on a first support element comprising part of a vehicle frame, between a closed position and an open position that is displaced from the closed position by an angle, the vehicle door including a second support element. The door check mechanism comprises a strip member, including an elongated substantially flat smooth surface, a detent cam or other locking member, and mounting means for mounting the strip member on one of the support elements and for mounting the detent cam member on the other of the support elements with the detent cam member aligned with the strip surface. The detent cam member has a rigid surface with a varying radius about its rotation axis that engages the strip member. The strip member preferably has a coating of a polymeric or other non-metallic material on those surfaces that engage the cam. Either a second detent cam member or a support member is provided on the opposite side of the strip from the first cam member. The strip surface and the external surface of the detent cam are preferably formed of dissimilar materials. The detent cam is mounted so that when engaged in a detenting relationship with the strip, it is resiliently pressed against the strip. The resilient cam mounting means and the support means conjointly maintain the detent cam member in pressure rolling engagement with the strip surface during the detenting operation. During other motions of the door, the detenting cam slides on the strip with very little force. The alignment of the cam member and the strip surface cause the detent cam member to detentingly engage with the strip when the door is pivoted to any partially open position and a force is exerted in the opposite direction so that the detent cam member and the strip member releasably maintain the door in any desired open position.
In one embodiment, the infinite door check mechanism comprises a door check housing adapted to be mounted on the door, a support member arranged in the housing, a rotatable locking member arranged in the housing and an arcuate member adapted to be mounted to and extend outward from the frame. The arcuate member is arranged at least partially in the housing and at least partially interposed between the locking member and the support member. Also, the arcuate member and locking member are movable relative to one another. The door check mechanism further includes biasing means for selectively pressing the locking member against the arcuate member to force the arcuate member against the support member and thereby retain the arcuate member in a fixed position (resulting in checking of the door) and releasing pressure of the locking member against the arcuate member and thereby enable movement of the arcuate member, and torque means for applying a variable torque to the locking member to thereby vary a force necessary to cause movement of the arcuate member relative to the locking member. It can also prevent the locking member from slipping on the arcuate member when the checking is occurring. The arcuate member may be adapted to be pivotally mounted to the frame and have opposed longitudinally extending surfaces, one engaging the locking member and the other engaging the support member.
One disclosed locking member is a cam including an integral cam shaft defining a rotational axis for the cam. The cam has an irregular shape and is arranged to press the arcuate member against the support member with a variable force depending on the position of the cam. For example, the cam can have a first flat surface having edges and second and third arcuate surfaces alongside a respective edge of the first flat surface such that the radial distance at the edges is greater than the radial distance of the first flat surface. A cam holder is connected to the cam and has an edge adapted to contact the support member once the second or third arcuate surface contacts the arcuate member such that the biasing means press the cam holder against the support member. In this manner, there is a release of the pressure applied by the biasing means to force the cam against the support member with the arcuate member interposed between the cam and the support member and enabling the arcuate member to move.
A locking member holder may be connected to the locking member for holding the same and whereby the biasing means comprise an elastic spring operative at one end against the housing and operative at an opposite end against the locking member holder.
The torque means may comprise one or more elastica springs, each mounted at one end to the locking member holder and bearing against the locking member at an opposite end. More particularly, each elastica spring can be arranged to bear against a respective recessed arcuate surface of the locking member. In the alternative, the torque means may comprise a cantilevered spring mounted at one end to the locking member holder and having its opposite end movable between two projections arranged on the locking member
An automatic door closing apparatus can be provided for enabling the door to close automatically under its own weight. This may comprise a motor coupled to the housing, and a rod extending into engagement with the support bracket and actuatable by the motor to pull the locking member away from the arcuate member.
Another embodiment of an infinite door check mechanism in accordance with the invention comprises a door check housing adapted to be mounted on the door, a support member arranged in the housing, a rotatable locking member arranged in the housing, a strip member adapted to be mounted to and extend outward from the frame, biasing means for urging the locking member in a direction toward the strip member, and means for increasing a drag force upon rotation of the locking member beyond predetermined limits. The means for increasing the drag force may comprise a cantilevered spring mounted at one end to a locking member holder and having its opposite end movable between projections on the locking member. The cantilevered spring applies a variable torque to the locking member to thereby vary a force necessary to cause movement of the strip member relative to the locking member. The strip member may be serrated on a surface engaging the locking member to thereby form alternating teeth and grooves whereby the locking member has a tip positionable in the grooves.
Another embodiment of an infinite door check mechanism in accordance with the invention comprises a door check housing adapted to be mounted on the door, a support member arranged in the housing, a rotatable locking member arranged in the housing and an elongate strip member adapted to be mounted to and extend outward from the frame. The strip member extends at least partially through the housing and is at least partially interposed between the locking member and the support member. A first spring selectively presses the locking member against the strip member to force the strip member against the support member and thereby retain the strip member in a fixed position resulting in checking of the door and releases pressure of the locking member against the strip member and thereby enable movement of the strip member. One or more additional springs engage with the locking member and apply torque to the locking member to prevent the locking member from slipping on the strip member when the checking is occurring. The locking member and springs may be as described above,
Another embodiment of a door check mechanism in accordance with the invention comprises a door check housing adapted to be mounted on the door, a support member and a movable locking member arranged in the housing, a strip member adapted to be mounted to and extend outward from the frame, and biasing and torque means for biasing the locking member against the strip member and applying a variable torque to the locking member to thereby vary a force necessary to result in movement of the strip member relative to the locking member. The strip member is arranged at least partially in the housing and is at least partially interposed between the locking member and the support member. The locking member may comprise a cam in which case, a shaft is provided for supporting the cam in the housing. The cam has a groove through which the shaft passes. The biasing and torque means may comprise one or more springs each coupled at one end to the housing and at an opposite end to the locking member. The strip member has a first surface in contact with the locking member and a second surface opposite the first surface. If the second surface of the strip member includes a groove, the support member has a conical portion engaging with the groove of the strip member to thereby constitute a sprag wedging system.
Yet another embodiment of an infinite door check mechanism disclosed above comprises an elongate strip member mounted to the frame and directed outward from the frame, a door check housing adapted to be mounted on the door, the strip member extending at least partially through the housing, a support member arranged in the housing, a movable locking member arranged in the housing such that the strip member is interposed between the locking member and the support member, and biasing means for selectively pressing the locking member against the strip member to force the strip member against the support member and thereby retain the strip member in a fixed position and releasing pressure of the locking member against the strip member and thereby enable movement of the strip member. The strip member may be arcuate and fixedly or movably mounted to the frame, e.g., pivotally mounted by means of a clevis attached to the frame. The strip member has opposed longitudinally extending surfaces, one of which engages the locking member and another of which engages the support member. The door check mechanism may be mounted either horizontally or vertically in the door.
In certain embodiments, the locking member is a cam including an integral cam shaft defining a rotational axis for the cam or the cam shaft may be fixed in the housing or cam holder and pass through a slot in the cam. The cam has an irregular shape and is arranged to press the strip member against the support member with a variable force depending on the position of the cam. The main door check force is thus the frictional sliding resistance between the strip and the cam or locking member. With respect to the irregular shape of the cam, it may include a first flat surface having edges and second and third arcuate surfaces alongside a respective edge of the first flat surface such that the radial distance at the edges is greater than the radial distance of the first flat surface. If a cam holder is fixedly connected to the cam, the cam holder has an edge adapted to contact the support member once the second or third arcuate surface contacts the strip member such that the biasing means presses the cam holder against the support member thereby releasing pressure applied by the biasing means to force the strip against the support member and enabling the strip member to move, i.e., to any number of different positions relative to the door check housing and thus enable the door to be opened to any desired degree. The cam also includes fourth and fifth recessed arcuate surfaces on an opposite side of the cam from the first flat surface, and rotation limiting means arranged in the housing for limiting rotational movement of the cam, e.g., a tab at least partially extending into one of the fourth and fifth recessed surfaces.
If the locking member is fixed to a locking member holder, an edge of the locking member is adapted to contact the support member upon rotation of the locking member such that the biasing means press the locking member holder against the support member thereby releasing pressure applied by the biasing means to force the locking member against the support member with the strip member interposed between the locking member and the support member and enabling the strip member to move, i.e., to any number of different positions relative to the door check housing and thus enable the door to be opened to any desired degree. Rotation limiting means may be arranged in the housing for limiting rotational movement of the locking member, e.g., a tab at least partially extending into a recessed surface of the locking member. The biasing means may comprise an elastic spring operative at one end against the housing and operative at an opposite end against the locking member holder.
It is an important feature of some embodiments of the invention that torque means are present for applying torque to the locking member to prevent the locking member from slipping on the strip member when the checking is occurring. This may comprise one or more elastica springs, each mounted at one end to the locking member holder and bearing against the locking member at an opposite end. If the locking member is a cam, the elastic springs bear against the fourth and fifth recessed arcuate surfaces, thereby exerting a torque on the cam urging it back to the checked position. In the alternative, the torque means comprise a cantilevered spring mounted at one end to the locking member holder and having its opposite end movable between two projections arranged on the locking member.
In some embodiments, the support member comprises an additional movable locking member arranged such that the strip member is interposed between the two locking members. In this case, the torque means may comprise elastica springs, each pivotally mounted at one end to the locking member holder and bearing against the locking member at an opposite end, e.g., against a respective recessed arcuate surface thereof.
In other embodiments, the strip member is serrated on a surface engaging the locking member to thereby form alternating teeth and grooves and the locking member has a tip positionable within one of the grooves. Thus, the locking member may include a pair of arcuate surfaces adapted to be pressed against the strip member and a pointed tip defined between the arcuate surfaces. In any of the embodiments disclosed herein, the locking member may have a beveled edge and the strip member has a groove for at least partially receiving the beveled edge of the locking member. This creates a sprag effect and increases the frictional force of the locking member against the strip and results in some additional ware.
The door check mechanism in accordance with any of the embodiments of the invention disclosed herein may be incorporated together with an automatic door closing apparatus for enabling the door to close automatically under its own weight or by electric motor. Such an apparatus may comprise a motor coupled to the housing, and a rod extending into engagement with a support bracket associated with the locking member and actuatable by the motor to pull the locking member away from the strip member.
In another embodiment, the infinite door check mechanism in accordance with the invention comprises a door check housing adapted to be mounted on the door, a support member adapted to be mounted to the frame, the support member including a hinge pin defining a rotational axis about which the support member is rotatable, a hinge member arranged around the hinge pin, a movable locking member arranged in the housing to engage the hinge member, and biasing means arranged in the housing for selectively pressing the locking member against the hinge member to force the locking member against the hinge member and thereby retain the hinge member and thus the door in a fixed position and releasing pressure of the locking member against the hinge member and thereby enable rotation of hinge member and thus the door. The mechanism may include a locking member holder fixedly connected to the locking member whereby the biasing means comprise a strip of bent spring material arranged in the housing to exert pressure against the locking member holder and thus the locking member. Drag exerting means may be provided for exerting a drag force onto the hinge member to enable the locking member to rotate without slipping, e.g., at least one elastica spring structured and arranged to apply a torque to the locking member, each mounted at one end to a locking member holder and bearing against the locking member at an opposite end.
The infinite door check mechanism may be arranged opposite to that described immediately above in that the door check housing is mounted on the frame of the vehicle and the support member is mounted to the door, the support member including a hinge pin or member defining a rotational axis about which the support member is rotatable. In this case, the hinge member is arranged around the hinge pin and connected to the door to enable the door to rotate about the axis.
Design and Analysis of Door Check Device (
The cam pivots about a point O. A line from O perpendicular to the strip intersects the plane of the strip at a point V, fixed in space. In the locked position, a line from O to V intersects the cam surface at a point C, fixed on the cam. Since the system must perform equally for motion of the strip in either directionfrom the locked position, the cam should be symmetric about the line OC. Motion of the strip to the right, with counter-clockwise rotation of the cam, will be analyzed but the results for motion of the strip to the left will be the same with some obvious changes in sign. The following parameters are defined (CW stands for clockwise, CCW for counter-clockwise):
the subscript i indicates initial values, with the system in the locked position and the strip just beginning to move.
For a point fixed on the cam surface θ R are fixed and as the cam rotates dξ=R cos(Ψ−θ) dΨ and dη=dy+R sin(Ψ−θ)dθ. For the point instantaneously at Q dη=0 and dy=Rq sin(φ) dΨ. If the cam does not slip on the strip then dξ=dx and dx=Rq cos(φ)dθ. Thus dy/dx=−tan(φ).
A moment balance on the cam about the point O leads to T=F y tan(φ)+Fty. Since |Ft|must be ≦μF the torque T must be between Tmin and Tmax where Tmin =Fy (tan(φ)−μ) and Tmax =Fy(tan(φ)+μ). Or, if T, F, y, and μ are specified then tan(φ) must be between T/(Fy)−μ and T/(Fy)+μ.
Note that Ft=T/y−F tan(φ) can become negative after φis positive.This means that the cam action is pushing the door farther in the direction of its initial motion. It might be necessary to limit this pushing action to a value Ftmin to keep the door from getting out of control.
When the strip first begins to move it could be moved in either direction, and by symmetry the torque T must be zero. Then Fti=−F1 tan(φI)=Fiw/yi and, for specified Fti yi, w should be as large as possible to minimize the required Fi. Since Fti must be less than or equal to μFi, w must be less than or equal to μyi. In the design w is set equal to μyi and then Fi is equal to Fti/ μ.
The system is completely unlocked when the pivot O rests on its support, when O has been lowered by δy. For this to occur with as small a strip motion x as possible, tan(φ) should be as large as possible. Initially φis negative (tan(φI)=−w/yi=−∥), but as the strip moves φincreases:
dφ/dx=d(Ψ−θq)/dx=(dΨ/dx)(1−dθq/dΨ)=(1−dθqdΨ)/y. Now dθqdΨcannot
be negative, so to increase φas quickly as possible dθq/dΨshould be zero as long as possible, that is the same point on the surface of the cam should remain in contact with the strip. This is possible if the tangent to the surface of the cam just left of the initial Q makes a positive angle with the strip. The current Q can be kept at the initial Q until tan(φ)=T/(Fy)+μor tan(φ)=T/(Fy)−Ftmin/F, whichever comes first. After that the increase in φmust be controlled so that tan(φ) does not become greater than the current value of T/(Fy)+μor T/(Fy)−Ftmin/F, whichever is smaller.
φ can be controlled by controlling the curvature of the cam surface. If the contact point Q is on a portion of the cam surface with a smooth curvature, then the location of the contact point could be determined as follows. Consider again the general point P on the cam surface. If θis varied without changing Ψ, then y is constant and dη−dR cos(Ψ−θ)−R sin(Ψ−θ)dθ. At the contact point Q dηis zero, R=RQ, Ψ−θ=φ, and dR/dθ=−RQ tan(φ).
After the cam pivot is resting on its support, if the strip is moved farther then the slips under the cam and the cam does not rotate any more. The cam then exerts a normal force FN on the strip and this causes a tangential force Ft=μa FN, is the actual coefficient of friction which may be greater than the design value μ. A moment balance about the hinge pivot leads to FN=T/(μa y+RQ sin(φ)) where T, Y, RQ, φare the values when the pivot reaches its support.
Design steps
1. Specify the holding force Fti, the initial distance yi of the pivot from the strip, the amount δy that the pivot must be moved toward the strip until it is supported, the design coefficient of friction μ, and the maximum pushing force−Ftmin.
2. Calculate the distance w=μyi and the initial external force Fi=Fti/μ. The initial contact point is a distance w, parallel to the strip, from the center point V. A mirror contact point is on the other side of V. The cam surface may be flat between these points or bowed away from the strip.
3. Specify an external force F(y) and an external torque T(Ψ). F(yi)must be Fi and T(0)must be zero. After T becomes non-zero it should be positive, and should decrease as y approches yi−δy.
4. Initially, as the cam rotates to Ψ, RQ2=yi2+w2, tan(θQ)=w/yi φ=Ψ−θQ, y=RQ cos(φ),x =w+RQ sin(φ), F=F(y), T=T(Ψ), Ft=(T/y)−F tan(φ), Tmin=Fy (tan(φ)−μ), Tmax=Fy(tan(φ)+μ).
5. This initial motion cam continue until tan(φ)=T/(Fy)−Ftmin/F or tan(φ)=T/(Fy)+μ, whichever comes first.
6. After the initial motion is ended, the cam surface is shaped so that tan(φ) is equal to or less than the smaller of T/(Fy)+μor T/(Fy)−Ftmin/F. This is done by making tan(φ)=−(1/RQ) d RQ/θQ =-d log(RQ)/dθQ. At a given Ψ, the parameters RQ, T, F, y, φhave been found. Then choose a new Ψand
7. Calculate the new T(Ψ).
8. Estimate the new θQ.
9. Calculate the new φ=Ψ−θQ.
10. Calculate (tan(φ)avg≅(tan(φold)+tan (φnew))/2.
11. Calculate the new RQ=RQgold exp(−(tan(φ))avgΔθQ).
12. Calculate the new y=RQcos(φ).
13. Calculate the new F=F(y).
14. Check tan(φ)=min[T/(Fy)+μ, T/(Fy)−Ftmin/F].
15. Repeat steps 8 to 14 until agreement.
16. If the new θQ is less than the old θQ, set the new θQ and RQ equal to the old values and repeat and 9, 12, and 13 (a discontinuity of slope occurs here).
17. Continue stepping Ψuntil y=yi−δy. Then the cam pivot is resting on its support.
18. Calculate FN and the drag force Ft=μa FN for further motion of the strip.
19. New relations F(y) and T(Ψ) may be specified, and steps 4 to 18 repeated to improve the design.
Two design goals are to minimize the strip travel from lock to unlock, and to minimize the final drag force on the strip after unlocking.
Analysis of torque
The torque is produced by two elastica strips mounted on either side at the top of the cam. The analysis will be for the one at the upper left that exerts the torque when the cam is rotated counter-clockwise. The other strip and its mounting are the mirror image of the one analyzed and the results are the same, with the necessary changes of sign.
In the following analysis some of the same symbols as above are used, but in most cases the meanings of the symbols are different.
The elastica has a fixed end at the upper left. If the elastica were undeformed (stress-free) it would be straight. In the locked position (Ψ=0) the elastica is deformed so that its non-fixed end contacts the cam surface, but does not exert a torque about the cam pivot. After the cam has rotated a certain amount a projection on its surface contacts the end of the elastica, and additional rotation moves this end so that it remains in the same position relative to the cam.
Note that when Ψ is greater than ΨT φe=φei+(Ψ−ΨT) and that ΨT generally will be less than φei.
Equations
M=Mf+Fxy−FyX (3)
(moment balance about point F; Mf is the moment at F)
(Differentation of 1 and 3 and use of 2)
At F, s=x=y=θ=0. At E, M=0, s=L,x=xe, y=ye (Boundary conditions) (5)
The following solutions to differential equation 4 with the boundary condition θ=0 at s=0 and M=0 at s=L may be verified by direct substitution:
In these equations, cd stands for the elliptic function cd(w|m), cdo cd(wo|m), nd for the elliptic function nd(w|m), ndo for nd (wo|m), sd for the elliptic function sd(w|m). m is the parameter, a constant of integration, and w and wo are
Equations 6 and 7 may be integrated to get
Here E stands for the elliptic integral E(w|m) and sn for the elliptic function sn(w|m). The constants in 11 and 12 may be found by requiring that x and y vanish at s=0. Then the following relations are found for x and y at the end point E:
In these equations Eo stands for E(wo|m), sno for sn(wo|m), and sdo for sd(wo|m).
From the geometry of the system the end coordinates are
Xe=Rf cos(φf−φu)−Recos(φe−φu) (15)
Ye=Rf sin(φf−φu)−Resin(φe−φu) (16)
Now when Xe and Ye are calculated, equations 13 ang 14 can be used to find wo and m. Then F=EI(wo/L)2 and equations 9 can be used to find Fx and Fy.
When Fx and Fy are determined the clockwise torque T about the pivot that the elastica exerts on the cam is given by
T=Re[Fxsin(φe−φu)−Fycos(φe−φu)] (17)
Procedure
1. Specify Rf, φf, φu, Re, ΨT, (φei−ΨT),EI.
2. Calculate φei and Fy/ Fx=sin(φei−φu)(equation 17 with initial T=0).
3. Divide equations 9 and set equal to sin(φei−φu) to get a relation between m and wo.
4. Calculate initial Xe and Ye from equations 15 and 16.
5. Divide equations 13 and 14 and set to Xe/Ye to get another relation between m and wo.
6. Solve the two relations to get the initial m and wo.
7. From equation 13 and Xe calculate L.
Now for any Ψ
8. If Ψ<ΨT T=0. Else φe=Ψ+(φei−ΨT).
9. From equations 15, 16, and L calculate Xe/L and Ye/L.
10. Use equations 13 and 14 to determine m and wo for this Ψ.
11. Use equations 9 to calculate Fx and Fy.
12. Use equation 17 to calculate the torque T for this Ψ.
Analysis of door-check device (
The current door check device shown in
For this analysis the strip moves a distance x to the right from its locked-up configuration. Motion to the left is completely symmetric to this.
The compressive force in the spring is FS. If FSO is its value in the locked-up configuration and the spring rate of the spring is KS, then FS=FSO−kSL(1−cos θ), where L(1−cos θ) is the downward motion of the pin from its locked-up configuration. Two more forces are introduced: FN is the normal force downward on the strip from the prong, and FT is the horizontal force to the left on the strip from the prong. In addition, through some mechanism, a clockwise torque T is acting on the prong at the pin. While the pin is above the bottom of its slot FN will equal FS. A moment balance on the prong leads to T=FNL sin θ+FTL cos θ. The horizontal force needed to move the strip is Fstr=FT+μBFN.
In the initial motion from the locked up position the prong is required not to slip on the strip. This requires that |FT|≦μTmFN and so FNL(sin θ−μTm cos θ)≦T≦FNL(sin θ+μTm cos θ). During this motion x=L sin θ,
FN=FS=FSO−kSL(1−cos θ), FT=T/(L cos θ)−FN tan θ, and T will be some function of θ and, perhaps, FS. When L, kS, FSO, and μB are known, then for any x sucessively θ, FS, FN, T, FT and then Fstr can be calculated. In the locked-up configuraion where x and θ are zero, by symmetry T should be zero and Fstr=μBFSO.
When the pin has moved to the bottom of its slot, θ has reached its maximum value, θD, where cos θD=1−δP/L, and
Further motion of the strip requires dragging it under the prong, and then FT=μTFN,
where TD is the value of the torque when the pin has bottomed out and θ is θD, and Fstr=Fstr,drag=(μT+μB)FN,drag. Just before the pin bottoms out the spring force and thus FN is FN=FS=FSO−kSδP, and the torque T must be at least T≧(FSO−kSδP)L(sin θD−μTm cos θD). If the torque does not change after the pin bottoms out and θ reaches θD, then TD will satisfy the same inequality, and the force needed to move the strip further will be
Note that if Tdoor is the torque on the door needed to move it and if rDC is the horizontal distance from the center of the force FN to the center of rotation of the door hinge, then Tdoor=rDCFstr. Thus if Tdoor is specified for the locked position and for the continuously moving configuration, and if rDC is known, then the required Fstr for these configurations can be determined.
Example: suppose that L=0.5 inches and δP=0.1 inches. Then θD=36.87 degrees and xD=0.30 inches. If the required locked-up door torque is Tdoor=400 inch-pounds, rDC=2 inches, and μB=0.4, then the locked-up strip force must be Fstr,lock=400/2=200 pounds, and the locked-up spring force must be FSO=200/0.4=500 pounds. Suppose that μT=0.2 and μTm=0.1. Then
and if this ratio should be, say about 0.2, then the spring force just before the pin bottoms out must be only about 20% of the initial locked-up spring force.
This application is a divisional of U.S. patent application Ser. No. 10/043,556 filed Jan. 11, 2002, now U.S. Pat. No. 6,681,444, which is a continuation-in-part of U.S. patent application Ser. No. 09/576,065 filed May 22, 2000, now U.S. Pat. No. 6,349,448, which is a continuation of U.S. patent application Ser. No. 09/040,206 filed Mar. 17, 1998, now U.S. Pat. No. 6,065,185, which claims priority under 35 U.S.C. §119(e) of U.S. provisional patent application Ser. No. 60/040,977 filed Mar. 17, 1997.
| Number | Name | Date | Kind |
|---|---|---|---|
| 406840 | Jones | Jul 1889 | A |
| 2232986 | Westrope | Feb 1941 | A |
| 2268976 | Westrope | Jan 1942 | A |
| 2268977 | Westrope | Jan 1942 | A |
| 2882548 | Roethel | Apr 1959 | A |
| 2992451 | Schonitzer et al. | Jul 1961 | A |
| 3345680 | Slattery | Oct 1967 | A |
| 3461481 | Bachmann | Aug 1969 | A |
| 3584333 | Hakala | Jun 1971 | A |
| 3643289 | Lohr | Feb 1972 | A |
| 3965531 | Fox et al. | Jun 1976 | A |
| 3969789 | Wize | Jul 1976 | A |
| 4069547 | Guionie et al. | Jan 1978 | A |
| 4332056 | Griffin et al. | Jun 1982 | A |
| 4532675 | Salazar | Aug 1985 | A |
| 4628568 | Lee et al. | Dec 1986 | A |
| 4658543 | Carr | Apr 1987 | A |
| 4720895 | Peebles | Jan 1988 | A |
| 5018243 | Anspaugh et al. | May 1991 | A |
| 5074010 | Gignac et al. | Dec 1991 | A |
| 5173991 | Carswell | Dec 1992 | A |
| 5346272 | Priest et al. | Sep 1994 | A |
| 5452501 | Kramer et al. | Sep 1995 | A |
| 5474344 | Lee | Dec 1995 | A |
| 5482144 | Vranish | Jan 1996 | A |
| 5563483 | Kowall et al. | Oct 1996 | A |
| 5629681 | DuVall et al. | May 1997 | A |
| 6065185 | Breed et al. | May 2000 | A |
| 6105208 | Westerdale et al. | Aug 2000 | A |
| 6108866 | Waynick, Jr. | Aug 2000 | A |
| 6176040 | Sugihara | Jan 2001 | B1 |
| 6237190 | Grumm et al. | May 2001 | B1 |
| 6314352 | Kunimatsu et al. | Nov 2001 | B1 |
| 6349448 | Breed et al. | Feb 2002 | B1 |
| 6370732 | Yezersky et al. | Apr 2002 | B1 |
| 6467126 | Yezersky et al. | Oct 2002 | B1 |
| 6607236 | Mooy et al. | Aug 2003 | B2 |
| 6719356 | Cleland et al. | Apr 2004 | B2 |
| 20020068158 | Breed et al. | Jun 2002 | A1 |
| Number | Date | Country |
|---|---|---|
| 614441 | Feb 1961 | CA |
| 4207706 | Sep 1993 | DE |
| 833844 | May 1960 | GB |
| Number | Date | Country | |
|---|---|---|---|
| 20030182759 A1 | Oct 2003 | US |
| Number | Date | Country | |
|---|---|---|---|
| 60040977 | Mar 1997 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 10043556 | Jan 2002 | US |
| Child | 10397950 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 09040206 | Mar 1998 | US |
| Child | 09576065 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 09576065 | May 2000 | US |
| Child | 10043556 | US |
