1. Field of the Invention
This invention relates to latch assemblies and, more particularly, to a latch assembly that can be used to releasably maintain a movable closure element in a desired position relative to a support therefor.
2. Background Art
Movable closure elements are used in many industries in both static environments and on moving equipment. These closure elements are commonly pivoted, or translated, between different positions, normally opened and closed positions, to selectively block and allow access to, a space fronted by the closure element.
An exemplary latch assembly, utilized on the above type of closure element, is shown in U.S. Pat. No. 6,158,787, to Kutschat. Kutschat employs two throated rotors 16 which are repositionable to cooperatively engage with a strike element 4. The rotors 16 are designed to be selectively maintained in secondary latched positions, as shown in
Additionally, the impeding rotor 16 must be mounted to permit the additional pivoting movement required to disengage the arm 28. This could put constraints on the manner in which the rotors 16 are mounted to the supporting housing 8.
Still further, the arcuate path traveled by the arm free end may, depending upon the particular cooperating arrangement between the arm and rotors 16, place unwanted restrictions on, or complicate, the design of the cooperating portions of the rotors 16 and arm 28.
Designers of this type of latch assembly strive to simplify design, without compromising functionality. In the interest of simplifying design, it is common to reduce the number of component parts. This may contribute to efficiency from the standpoint of inventory control, number of manufacturing steps, etc. The industry is constantly looking for ways to make designs of these latch assemblies more economically feasible while at the same time improving operating characteristics thereof.
In one form of the invention, a latch assembly is provided for a movable closure element. The latch assembly has a housing and a first rotor that is movable relative to the housing selectively between a) a first latched position and b) a release position. The first rotor is biased towards the release position and has a first throat to receive a strike element. The latch assembly further consists of an operating assembly having a latched state and an unlatched state The operating assembly in the latched state releasably maintains the first rotor in the first latched position. The operating assembly has a catch arm that is movable relative to the housing from a first position into a second position to thereby change the operating assembly from the latched state into the unlatched state. The operating assembly further has a catch block that is movable floatingly relative to the catch arm from a) an engaged position with the catch arm in the first position into b) a disengaged position as an incident of the catch arm moving from its first position into its second position. The catch block in the engaged position causes the first rotor to be maintained in the first latched position.
In one form, with the catch block in the engaged position, the catch block directly engages the first rotor to maintain the first rotor in the first latched position.
The catch block may be mounted for pivoting movement relative to the catch arm.
In one form, the catch block has an angular orientation relative to the housing. The catch block is maintained in substantially the same angular orientation relative to the housing as the catch block changes between the engaged and disengaged positions.
In one form, the catch block is biased towards an operating angular orientation relative to the housing.
A single spring element may be used to both bias the catch block towards the operating angular orientation and bias the first rotor towards the release position. In one form, the single spring element is a formed wire.
In one form, the latch assembly includes a second rotor movable relative to the housing selectively between a) a first latched position and b) a release position. The second rotor has a second throat to receive a strike element. The first and second rotors in their respective first latched positions are arranged so that the first and second throats cooperatively define a receptacle for a strike element.
The second rotor may likewise be biased toward its release position.
In one form, the catch block in the engaged position causes the second rotor to be maintained in its first latched position.
In one form, a bias force is exerted on the catch block at first and second spaced locations to thereby bias the catch block towards the operating angular orientation.
In one form, the single spring element exerts a bias force on the catch block at the first location to thereby bias the catch block towards the operating angular orientation and biases the first rotor towards its release position.
In one form, a second single spring element exerts a bias force on the catch block at the second location to thereby bias the catch block towards the operating angular orientation and biases the second rotor towards its release position.
In one form, the catch block is pivotable relative to the catch arm around a first axis, with the first rotor being pivotable relative to the housing around a second axis. The first and second axes are substantially parallel to each other.
In one form, the catch block and catch arm cooperate to limit pivoting of the catch block relative to the catch arm to a predetermined range.
In one form, the formed wire has a first free end and a second free end, and the first free end is engaged with the catch block, with the second free end engaged with the first rotor.
In one form, the housing has first and second parts joined by an axle, with the formed wire being wrapped around the axle.
In one form, the latch assembly is provided in combination with a movable closure element.
The latch assembly and movable closure element may further be provided in combination with a support for the closure element, with the closure element movable relative to the support between first and second positions. A strike element on the support is received by the first throat on the first rotor with the closure element in its first position.
In one form, the first rotor is movable relative to the housing into a second latched position and the operating assembly has a second latched state wherein the operating assembly maintains the first rotor in the second latched state.
The invention is further directed to the combination of a) a closure element, b) a support for the closure element which is mounted for selective movement relative to the support between first and second positions, c) a strike element on the support, and d) a latch assembly on the movable closure element, as described above.
The operating assembly may include a first actuator element that is movable relative to the catch arm to move the catch arm from its first position into its second position.
The actuator element may include a graspable handle to facilitate movement of the first actuator element.
The operating assembly may further include a second actuator element movable relative to the catch arm to move the catch arm from its first position into its second position.
In one form, the second actuator element is movable relative to the catch arm without causing movement of the first actuator element.
The present invention is directed to a latch assembly, as shown generically at 10 in FIG. 1. The latch assembly 10 is associated with a closure element 12 which is mounted for movement relative to a support 14 between first and second positions. The first and second positions may be closed and opened positions between which the closure element 12 is moved to selectively block, and permit access to, a space associated with the support 14. However, it is not necessary that the closure element 12 be movable between the first and second positions strictly for that purpose. The support 14 can be virtually any structure. As just an example, the support 14 might be part of a static environment, such as on a building, or a cabinet. Alternatively, the support 14 could be on a moving vehicle, such as a tractor. In the latter case, the closure element 12 might be a door or window structure that is either pivotably mounted, or mounted for translational movement between first and second positions. The support 14 has an associated strike element 16, which cooperates with the latch assembly 10 to releasably maintain the closure element 12 in one of the first and second positions therefor.
Referring now to
In the embodiment shown, the housing parts 20, 22 are formed from metal sheet material. However, the housing parts 20, 22 could be made from virtually any material and could be molded in the shape shown, as opposed to being formed.
In addition to their function of interconnecting and spacing the housing parts 20, 22, the axles 24, 26, 28, 30 serve as a support for certain of the internal components of the latch assembly 10. More specifically, the axles 26, 28 support rotors 46, 46′ for pivoting movement between a release position, shown in dotted lines in
The rotor 46′ is reversed from the rotor 46 and mounted on the axle 28 for pivoting movement relative to the housing 18 about an axis 66, that is parallel to the axis 64. With this arrangement, the legs 54, 56 on the rotor 46, and corresponding legs 54′, 56′ on the rotor 46′, move relative to each other in a scissors-type action, parallel to a reference plane 67, as the rotors 46, 46′ are changed between their release positions and primary latched positions.
With the rotors 46, 46′ in their release positions, as shown in dotted lines in
The rotors 46, 46′ are maintained in their primary latched positions by an operating assembly at 78. The operating assembly 78 consists of a catch arm 80 on which a catch block 82 is mounted. The catch arm 80 has an L-shaped configuration with a long leg 84 and a short leg 86. The catch arm 80 is pivotably connected to the housing 18 at the juncture of the long and short legs 84, 86, for pivoting movement around an axis 88, that is generally parallel to the axes 64, 66.
The catch block 82 is connected at the free end 90 of the longer leg 84 of the catch arm 80 through a pin 92. Through the pin 92, the catch block 82 is pivotable relative to the catch arm leg 84 about an axis 94, which is generally parallel to the axes 64, 66, 88.
The operating assembly 78 is changeable between a primary latched state, shown in solid lines in
The catch block 82 is mounted “floatingly” to the catch arm 80, and can be angularly reoriented relative to the catch arm 80 and housing 18 around the axis 94, and translated relative thereto transversely to the axis 94, within a predetermined range, as described hereinbelow. Under the influence of two wire spring elements 96, 96′, described in detail hereafter, the catch block 82 is biasably maintained in a predetermined, operating, angular orientation relative to the housing 18 and catch arm 80. The spring elements 96, 96′ biasably urge the catch block 82 consistently into this orientation.
In the engaged position, the catch block 82 resides between facing stop surfaces 98, 98′ on the rotors 46, 46′, to thereby prohibit the rotors 46, 46′ from pivoting out of their primary latched positions, i.e. by movement of the rotor 46 in a clockwise position around the axis 64 from its solid line position in FIG. 4 and the rotor 46′ in a counterclockwise direction about the axis 66 from its solid line position in FIG. 4. By shifting the catch block 82 to the disengaged position, the catch block 82 is caused to clear out of the path of the rotors 46, 46′, so that the rotors 46, 46′ can move substantially unimpededly from their primary latched positions into their release positions. Because the catch block 82 is floatingly mounted upon the catch arm 80, the catch block 82 can move while maintaining the same angular orientation in substantially a straight line path, as indicated by the double-headed arrows 100, between the engaged and disengaged positions. This allows the catch block 82 to slide from between the stop surfaces 98, 98′ with minimal resistance from the rotors 46, 46′. In the absence of this floating arrangement for the catch block 82, the arcuate path traveled by the catch block would force a certain amount of clockwise pivoting of the rotor 46′ to allow the catch block 82 to clear away from the rotor 46′ as the catch block 82 moves from the engaged position into the disengaged position.
The catch block 82 has thickened portions 102,104 with surfaces 106,108 which engage the rotors 46, 46′ with the catch block 82 in the engaged position. Thus, a relatively large contact area between the rotor surfaces 98, 98′ and catch block surfaces 106,108 can be established. This large contact area assures that the catch block 82 and rotors 46, 46′ firmly abut to each other and also reduces potential wear resulting from the repetitive contact between the rotor and catch block surfaces 98, 98′, 106, 108. At the same time, the fact that the catch block 82 slides from between the rotor surfaces 98, 98′ in the same operating angular orientation accounts for relatively little resistance between the catch block 82 and rotors 46, 46′, compared to what the resistance would be between these same sized surfaces if the catch block 82 were required to pivot the rotor 46′, as previously described, as the catch block 82 moves out of the engaged position.
As noted above, by reason of the relatively large interactive surface areas between the catch block 82 and rotors 46, 46′, wear on the cooperating parts can be controlled. This arrangement lends itself to the construction of both the rotors 46, 46′ and catch block 82 from moldable material, such as plastics, composites, etc. While the rotors 46, 46′ and catch block 82 may be made from metal, preferably these elements are made from a non-metal material. The non-metal material has numerous advantages. First of all, a material such as plastic can be readily and economically molded to desired shapes. Plastic material is generally lower in cost and lighter in weight than metal. Further, the plastic material is not prone to being corroded upon being exposed to moisture and chemicals commonly encountered in environments in which this type of latch assembly 10 is used. Still further, there will normally be a lower coefficient of friction between the plastic and cooperating parts than that between like cooperating metal parts. Additionally, the need to lubricate between the plastic rotors 46, 46′ and parts against which they act may be obviated.
The rotors 46, 46′ are biased by the spring elements 96, 96′ towards their release positions. The spring elements 96, 96′ also bias the catch block 82 towards its engaged position. Both spring elements 96, 96′ have the same construction. Exemplary spring element 96 will be described in detail herein.
As seen most clearly in
The spring element 96′ is mounted around the axle 30 and has corresponding free ends 114′, 116′, which bear respectively on a shoulder 128 on the catch block 82 and a shoulder 130 on the rotor 46′, to thereby urge the catch block 82 towards the engaged position and the rotor 46′ towards its release position.
The spring elements 96, 96′ produce a balanced, biasing force on the catch block 82 at spaced locations on opposite sides of the pivot axis 94 to thereby urge the catch block 82 into its desired operating angular orientation relative to the housing 18 and catch arm 80. At the same time, the spring elements 96, 96′ exert a force on the catch arm 80, through the catch block 82, urging the catch arm to its first position, as shown in solid lines in FIG. 4.
The rotors 46, 46′ have stop surfaces 132,132′, which function in the same manner as the stop surfaces 98, 98′, previously described, in conjunction with the catch block 82. The stop surfaces 132, 132′ engage the catch block 82 with the rotors 46, 46′ in a secondary latched position, shown in FIG. 5.
In operation, with the rotors 46, 46′ in their release positions, repositioning of the closure element 12 causes the strike element 16 to bear upon the cam surfaces 70, 70′. Continued movement of the closure element 12 causes the strike element to pivot the rotors 46, 46′ towards their primary latched positions. As this is occurring, the catch block 82 is constantly biasably urged against the rotors 46, 46′. Eventually, the catch block 82 moves between the stop surfaces 132, 132′ into engaged position with the rotors 46, 46′, thereby maintaining the rotors 46, 46′ in the secondary latched position of FIG. 5. Continued movement of the closure element 12 wedges the catch block 82 out of engagement with the stop surfaces 132, 132′ and drives the rotors 46, 46′ further toward the primary latched positions therefor, at which point the catch block 82 moves between the stop surfaces 98, 98′, to releasably maintain the rotors 46, 46′ in their primary latched positions.
When it is desired to release the strike element 16, an actuator 134 is operated to change the catch arm 80 from its first position to its second position, thereby moving the catch block 82 from its engaged position into its disengaged position. As this occurs, the catch block 82 moves out of the path of the rotors 46, 46′, whereupon the spring elements 96, 96′ drive the rotors 46, 46′ back into their release positions.
The actuator 134 is shown in this embodiment as an arm 136 which is pivotably connected through a pin 138 to a tab 140 on the housing part 20. The resulting pivot axis 142 for the arm 136 is orthogonal to the pivot axis 88 for the catch arm 80. The arm 136 has an extension 144 with a cam edge 146 which bears on an inset cam edge 148 on the catch arm 80. Pivoting movement of the arm 136 in the direction of the arrow 150 around the axis 142 pivots the catch arm 80 between the first and second positions therefor. The actuator 134 may be directly graspable or operated through a linkage or other mechanism 152, which may in turn have an actuator element 154 that is directly operable by the user.
A secondary actuator 156 (
A through bore 168 is provided in the actuator 156 at a location remote from the actuating tab 164. The bore 168 receives the pin 92 on the catch block 82. By pivoting the actuator 156 about its axis 166, the catch block 82 can be selectively moved between the engaged and disengaged positions therefor.
In
In both embodiments described above, the catch block 82 cooperates with the pin 92 so as to be translatable transversely to the pin axis. More specifically, as shown in
To avoid excessive repositioning of the catch block 82, as might cause binding of the catch block 82 with the rotors 46, 46′, the floating movement of the catch block 82 is confined by structure cooperating between the catch block 82 and the catch arm 80 and actuator 156. Referring initially to
The catch block 82 cooperates with the catch arm 80 in the same manner, as shown in FIG. 12. The longer leg 84 of the catch arm 80 has a tab 200 with the same configuration as the tab 186, and performing the same function. The tab 200 has oppositely facing edges 202, 204 which reside between, and cooperate with, facing surfaces 206, 208 on thickened portions 210, 212, corresponding in shape and function to the oppositely projecting thickened portions 102, 104 on the opposite side of the catch block 82. The tabs 186, 200 thus redundantly perform the function of confining both translatory and pivoting movement of the catch block 82 relative to the actuator 156 and catch arm 80.
The foregoing disclosure of specific embodiments is intended to be illustrative of the broad concepts comprehended by the invention.
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Number | Date | Country | |
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20040113433 A1 | Jun 2004 | US |