The present invention relates to garage door operating apparatus and methods, and more particularly, to apparatus and methods for influencing the force needed to raise and lower a garage door.
The present invention is an improvement upon the invention disclosed in U.S. Pat. No. 6,983,785, issued on Jan. 10, 2006, and titled DOOR OPERATING MECHANISM AND METHOD OF USING THE SAME, which is hereby incorporated in its entirety by reference.
Most systems for operating garage doors utilize torsion springs to assist in lifting the garage door. Such torsion-spring-based systems function as follows. A shaft is normally located above the door opening. A pair of door drums are attached to the shaft. Cables connect the door drums to the garage door. As the garage door is raised, the cables wind around the drums; as the door is lowered, those cables unwind. A torsion spring is positioned along the shaft. One end of the torsion spring is connected to the shaft and the opposite end of the spring is anchored to the door opening. The torsion spring is preloaded during the installation process. This preloading provides the necessary torque to counterbalance or offset the torque that the garage door imposes on the shaft by its connection to the door drums. When the garage door is raised, the shaft rotates in a first direction, and the torsion spring releases stored energy, thus assisting in lifting the door. When the door is lowered, the shaft rotates in the opposite direction, and the torsion spring is reloaded with energy, thereby, assisting in offsetting the weight of the door and slowing its decent.
However, the use of torsion springs to assist in the lifting and lowering of garage doors offers disadvantages. For example, since torsion springs must be preloaded at installation, a technician performing that installation is exposed to risk of injury. If the technician overloads the torsion spring or the torsion spring includes a material defect, the spring may fail suddenly. Due to the preload, such a failure of a spring is unpredictable and may cause the spring to strike the technician or a garage surface with great force, causing significant bodily injury or property damage. In addition, the very process of preloading a torsion spring is difficult and laborious, and many individuals are physically incapable of completing such a task. Therefore, there is a need to replace torsion springs commonly used for garage door mechanisms with safer and easier apparatus and methods.
U.S. Pat. No. 6,983,785 discloses the use of gas springs as an alternative to torsion springs. A gas spring is fixed at one end and slideably mounted along a track on the opposite end. A cable connects the gas spring to a side drum, which is attached to the shaft above the garage door. As the door is lowered, the cable winds around the side drum, causing the gas spring to compress and store energy. This compression serves to counterbalance the weight of the door and slow the decent of the door. As the door is raised, the compressed gas spring extends and releases energy, pulling the cable attached to the side drum and assisting in lifting the door.
The present invention provides alternatives to the use of torsion springs in assisting the operation of a garage door. The elimination of torsion springs overcomes disadvantages in the prior art. In addition, the present invention provides for novel arrangements of apparatus and methods for using these alternatives to torsion springs.
The present invention provides apparatus and methods for operating a garage door. An embodiment of an operating assembly for a door includes a shaft, a graduated drum, and an energy storing member. The shaft is coupled to the door such that the shaft rotates in a first direction as the door is opened and rotates in a second direction as the door is closed. The coupling of the shaft to the door is typically accomplished by a cable. The graduated drum is coupled to the shaft, and the energy storing member is coupled to the graduated drum by another cable. The energy storing member is arranged such that the energy storing member stores energy as the door is closed and releases stored energy as the door is opened to assist in the raising and lowering of the door.
While the present invention is described with reference to embodiments described herein, it should be clear that the present invention is not to be limited to such embodiments. Therefore, the description of the embodiments herein is merely illustrative of the present invention and will not limit the scope of the invention as claimed.
The present invention provides novel arrangements and methods for assisting in the raising and lowering of garage doors. An embodiment of the present invention utilizes an energy storing device, preferably a gas spring, coupled to a drum to provide resistance force to counterbalance the weight of a door as it is lowered and to provide an assisting force to counterbalance the weight of door as it is raised. Another embodiment optionally utilizes an at least partially graduated drive drum to relay forces from an energy storing device to the garage door. Yet another embodiment arranges the gas spring so as to gain a mechanical advantage and limit the stoke needed by the spring to move the door between the open and closed positions.
As best seen in
The gas spring 24 is fixed on a first end 30 and slideably coupled to a rail 32 on a second end 34. A pulley wheel 36 is attached to the slideable end 34 of the spring 24 to engage the gas spring 24 with the rail 32. The spring cable 26 is secured to the graduated drum 28 at one end. The spring cable 26 extends from the graduated drum 28, around the pulley wheel 36, and is secured to the rail 32 by a hook 38.
The gas spring 24 is arranged such that as the door 10 is lowered, the spring cable 26 winds around the graduated drum 28, and the spring 24 compresses and pressurizes to store energy. As the door 10 is raised, the spring cable 26 unwinds from the graduated drum 28 and the gas spring 24 extends and releases stored energy. As the electric motor 22 is actuated to raise the door 10, the shaft 16 begins to rotate, which unwinds the spring cable 26 from the graduated drum 28. This movement allows the gas spring 24 to extend and release stored energy. The release of this energy assists the shaft 16 in rotating, thus assisting in lifting the door 10. Conversely, when the door 10 is in an open or raised position, the spring cable 26 is unwound from the graduated drum 28 and the spring 24 is extended. As the electric motor 22 is actuated to lower the door 10, the shaft 16 begins to rotate in the opposite direction, which winds the spring cable 26 on the graduated drum 28. This movement compresses the gas spring 24, which stores energy. This storing of energy resists the rotation of the shaft 16, thereby slowing movement of the door 10 as it is lowered.
Although the present disclosure generally describes embodiments as including a gas spring that compresses to store energy and extends to release energy, it will be readily understood by those skilled in the art that energy storing devices practiced with the present invention are not limited to compression gas springs. Generally, the present application can be practices with any energy storing device that can store and subsequently release energy. For example, the present invention may be practiced with a gas spring that is arranged to extend when storing energy and contract (or compress) when releasing energy.
Exemplary embodiments of alternative energy storing apparatus are illustrated in
As shown in FIGS. 5 though 8, the slideable carriage 43 is coupled to tracks or rails 48 by a series of rollers 49, to assist in aligning the carriages 42, 43 and the spring 45, 46. However, as one skilled in the art will readily recognize, such systems may be arranged to be self-aligning and may be implemented without the need for any rails 48 or rollers 49 to align the energy storing device or carriages.
As illustrated in
Whether a garage door is operated by an electric motor, opened and closed manually, or by some other mechanism, there are force profiles (i.e., the force required to move the door as a function of the door position) that produce preferred behavior. For example, when manually opening a door, it is preferable that the force needed to raise the door from the closed to the open position is constant for the first 90% to 95% of the travel of the door, and the final 5% to 10% of the travel of the door requires no additional force from the operator. In other words, the door pulls itself up the last 5% to 10% of the travel distance. This arrangement provides the operator with confidence that the door will not fall back down, thereby avoiding physical injury or property damage.
This preferred force profile may be achieved through the use of the nonlinear graduated drum 28 illustrated in
Optionally, the nonlinear graduated drum 28 is used with a gas spring 24 that has a force ratio of 1.37 (i.e., a 200 lbs. spring creates a 274 lbs. force when fully compressed). The drum 28 is arranged such that 6.5 revolutions of the drum 28 move the door 10 between fully open and fully closed positions.
The height of the door will determine the displacement needed to move a door from a closed to an open position. Most commonly, garage doors are manufactured in 7 foot and 8 foot heights. In implementing a drive drum system, whether the drum is nonlinear, linear, graduated, flat or any combination thereof, maintenance of a constant number of shaft rotations in moving a door from the closed to the open position is preferred. Otherwise, a different drive drum would need to be manufactured for each door height, which may lead to the need for different lengths of gas springs. It is preferable to maintain a consistent graduated drum and gas spring. Door drums are typically 4 inches in diameter, which requires approximately 6.5 revolutions to open a 7 foot door and 7.5 revolutions to open an 8 foot door. To maintain consistent drive drums and gas springs, the 4 inch door drum is used with 7 foot doors and a 4.58 inch door drum is used with 8 foot doors. This results in the shaft rotating 6.5 times regardless of whether the height of the door is 7 or 8 feet. It will be immediately recognized that the door drum may be adjusted for doors of any size to maintain 6.5 shaft revolutions to move a door from a closed to an open position.
It is preferable to use a spring with more stroke available than needed. For example, with the graduated drum 28 illustrated in
As shown in
Referring again to
As shown in
The assembly 100 comprises at least one guide rail 112, a stationary carriage 114, a slideable carriage 116, and an energy storage device 118, preferably a gas spring, however, any energy storing device can be used. The stationary 114 and slideable 116 carriages are interconnected by the gas spring 118. In the preferred embodiment, each carriage 114, 116 utilizes sheaves 120 as a pulley system to accommodate a cable 122 therebetween. The slideable carriage 116 is attached to the guide rail 112 by at least one roller 126, although two or more rollers may be optionally used. As such, the modular assembly 100 can be mounted to a guide track of the garage door with a cable connection between the sheaves 120 and a graduated drum attached to a shaft, such as the one disclosed herein. This arrangement provides a compact, modular, and easy-to-install garage door counterbalance system.
Specific features of the modular assembly 100 are pointed out to fully describe the inventions disclosed herein. For example, to reduce friction in both the gas springs and the track and carriage system, a hinge connection at both ends of the gas springs has been provided to prevent an undesirable binding or friction effect that occurs within the gas spring components. A ball stud 124 is located on both slideable and stationary carriages. A mating socket is threaded onto the ends of the gas spring. The height of the ball stud 124 creates an offset from its mounting location. If the system uses, for example, a 3 to 1 or 5 to 1 mechanical advantage, the slideable carriage 116 may need to be balanced to reduce the normal forces in the rollers 126, thus reducing friction and wear. The combination of an odd mechanical advantage (i.e., 3 to 1, 5 to 1, etc.) and a ball stud requires the designer to pay attention to dimensions so as not to unnecessarily add the frictions previously mentioned.
Further, as best shown in the exploded view in
As an example utility of the system, using a 5 to 1 mechanical advantage with two 250 lbs gas springs with a ratio of 1.37, the forces in the various components are as follows: the two springs, when fully compressed provide 685 lbs; each cable wrap provides 137 lbs; and, since four of the wraps apply their force to the carriage through the sheave pin, the sheave pin applies 548 lbs to the carriage. Due to the multiple cable wraps, the last wrap that ends on the slideable carriage must be offset to prevent the cable from rubbing with other wraps. If the carriage is not properly balanced, a torque will be created, and the reaction to this torque will be applied to the rollers as they make contact with the track. Torques about other axes should also be minimized, i.e. the torque created from the cable fleet angle as the drive cable walks down the torque control device.
The combination of the modular garage door counterbalance assembly 100 with the connection block 134, motor 130, and lead screw 132 creates a second assembly 200. This second assembly 200 may be used to retrofit manually operated garage doors or may be used to replace an existing garage door operating system where the motor or lead screw have failed.
While the invention has been described with reference to the preferred embodiment, and other alternate embodiments also have been disclosed, additional embodiments, modifications, and alternations would be obvious to one skilled in the art upon studying the disclosure and drawings. All of the additional embodiments, modifications, or alterations encompassing the spirit of the invention are claimed by the applicants to the extent that they are within the scope of the appended claims.
This application claims priority from U.S. Provisional Patent Application No. 60/727,933, titled TORQUE CONTROL SYSTEM AND METHOD, filed on Oct. 18, 2005; U.S. Provisional Patent Application No. 60/735,914, titled GARAGE DOOR LIFT SYSTEM AND METHOD, filed on Nov. 10, 2005; and U.S. Provisional Patent Application No. 60/785,510, titled GARAGE DOOR COUNTERBALANCE SYSTEM, filed on Mar. 24, 2006; all of which are hereby incorporated in their entirety by reference.
Number | Date | Country | |
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60727933 | Oct 2005 | US | |
60735914 | Nov 2005 | US | |
60785510 | Mar 2006 | US |