1. Field of the Invention
This invention relates to latch assemblies as used on repositionable elements, such as closure elements, and, more particularly, to a latch assembly having a catch assembly which is releasably engageable with a strike element to maintain the closure element in at least one predetermined position relative to a support for the closure element.
2. Background Art
Latch assemblies are utilized in myriad different environments for both static and dynamic applications. In one exemplary latch assembly, a catch assembly is provided within a component space defined by a housing. The catch assembly has at least first and second different states. The catch assembly includes a rotor that is in a first, primary latched position with the catch assembly in the first state and a second position with the catch assembly in the second state. In the first position, the rotor engages a strike element so as to prevent separation of the strike element from the latch assembly. With the rotor in the second position, the strike element, which is held by the latch assembly with the rotor in the first position, is permitted to be separated from the latch assembly. The rotor commonly has a third, secondary latched position, between the first and second rotor positions. With the rotor in the third position, the latch assembly is in a third state, wherein the rotor engages the strike element to prevent separation of the strike element from the latch assembly.
The rotor has a U-shaped opening to receive the strike element. With the rotor in the first position, and the strike element within the rotor opening, escape of the strike element is prohibited by a strike surface on a strike plate which blocks the rotor opening by bridging two spaced legs between which the strike element moves. With the strike element engaged by the latch assembly, and a closure element with which the latch assembly is associated in a first position, attempted movement of the closure element from the first position into a second position therefor causes a force to be imparted by the strike element through the rotor and strike plate to the housing. It is important that the housing does not respond to this force by bending/deflecting to the point that the strike element might escape from between the rotor and strike plate. In certain applications, such as on moving vehicle doors, the forces tending to compromise the connection of the latch assembly and strike element may be substantial. Aside from the fact that the magnitude of these forces may be quite large, governmental regulations often impose stringent requirements on the ability of these latch assemblies to resist forces even greater than those typically encountered.
Conventionally, the relationship between a strike element and rotor, with the rotor in the first position therefor, is characterized as being either “in pocket” or “out of pocket”. The in pocket relationship occurs with the captive strike element bearing against one arm on the rotor and remaining spaced from the strike surface on the strike plate. That is, the strike element penetrates the U-shaped opening sufficiently that with the rotor in the first position therefor, the strike element remains spaced from the strike surface on the strike plate. As the force generated on the first arm by the strike element increases, as in the event that the closure element is urged forcibly from the first position towards the second position therefor, a deflection/bending of the housing may occur to the point that the strike element bears simultaneously against the first arm of the rotor and the strike surface on the strike plate. This results in the strike element being out of pocket. For a typical construction, the ability of the latch assembly to withstand additional loading is greater with the strike element in the in pocket state then in the out of pocket state. Thus, ideally, the latch assembly design takes into consideration the maintenance of the in pocket state to the highest loading anticipated. This objective, however, may compete with that of rigidifying the housing without increasing its perimeter dimensions. The industry continues to seek out designs which improve overall strength without dimensional variations for the housing.
In one form, the invention is directed to a latch assembly having a housing and a catch assembly on the housing and having first and second states. The catch assembly has a rotor that is movable selectively relative to the housing between first and second positions. The rotor has a mounting portion and a receiving portion. The receiving portion has a U-shaped opening between spaced first and second legs. The U-shaped opening is configured to receive a strike element. The latch assembly further has a strike plate with a strike surface that projects across the U-shaped opening to block a strike element in the U-shaped opening with the rotor in the first position and the catch assembly in the first state. The U-shaped opening is bounded by an edge with a portion of the edge defined by the first leg against which a strike element within the U-shaped opening bears under a force tending to separate the latch assembly from the strike element. A portion of the edge has a first substantially straight length that extends to adjacent the strike surface with the rotor in the first position. The rotor is in the second position with the catch assembly in the second state to allow a strike element in the U-shaped opening, with the latch assembly in the first state, to be separated form the latch assembly.
In one form, the strike surface extends along a reference line and the straight length of the edge portion is spaced from the reference line a distance not greater than on the order of 0.04 inches with the rotor in the first position.
In one form, the first leg defines a confronting edge which faces and is at or adjacent the strike surface with the rotor in the first position. The conforming edge has a second substantially straight length, with the first and second substantially straight lengths converging towards a corner.
In one form, the corner is convexly radiused.
The corner may be defined by an arc of a circle having a radius of from 0.024 to 0.04 inches.
In one form, the radius of the arc is not greater than on the order of 0.032 inches.
In one form, the first leg has a confronting edge at or adjacent to the strike surface with the rotor in the first position and the confronting edge and the portion of the edge meet at a corner having a convex shape approximated by an arc of a circle having a radius that is substantially less than 0.125 inch.
The latch assembly may be provided in combination with a repositionable element to which the latch assembly is attached. The repositionable element has a strike element thereon and is movable between first and second positions relative to a support. With the repositionable element in the first position, the latch assembly is in the first state and the strike element captively resides within the U-shaped opening.
In one form, the first leg is abuttable to the strike surface.
The invention is further directed to a latch assembly having a housing and a catch assembly on the housing and having first and second states. The catch assembly has a rotor that is movable selectively relative to the housing between first and second positions. The rotor has a mounting portion and a receiving portion. The receiving portion has a U-shaped opening between spaced first and second legs. The U-shaped opening is configured to receive a strike element. The latch assembly further has a strike plate with a strike surface which projects across the U-shaped opening to block a strike element in the U-shaped opening with the rotor in the first position and the catch assembly in the first state. The U-shaped opening is bounded by an edge with a portion of the edge defined by the first leg against which a strike element with a U-shaped opening bears under a force tending to separate the latch assembly from the strike element. The first leg has a confronting edge at or adjacent to the strike surface with the rotor in the first position. The portion of the edge and the confronting edge meet at a corner having a convex shape approximated by a radius that is substantially less than 0.125 inch. The rotor is in the second position with the catch assembly in the second state, to allow a strike element in the U-shaped opening, with the latch assembly in the first state, to be separated from the latch assembly.
In one form, the edge portion on the first leg extends to within 0.04 inches of the strike surface.
The confronting edge may have a substantially straight length extending along a first line.
In one form, the strike surface extends along a reference line and the first line is substantially parallel to the reference line.
The convex shape of the corner may be approximated by an arc of a circle having a radius that is not greater than 0.04 inches.
In one form, the convex shape of the corner is approximated by an arc of a circle having a radius that is in the range of 0.024 to 0.04 inches.
The convex shape of the corner may be approximated by an arc of a circle having a radius that is on the order of 0.032 inches.
The latch assembly may be provided in combination with a repositionable element to which the latch assembly is attached. The repositionable element is movable between first and second positions relative to a support. With the repositionable element in the first position, the latch assembly is in the first state and the strike element captively resides within the U-shaped opening.
The first leg may be abuttable to the strike surface.
The invention is further directed to a rotor for use in a latch assembly having a housing and a strike plate with a strike surface. The rotor is movable between first and second positions to respectively hold a strike element and allow separation of a strike element from the rotor. The rotor has a body with a mounting portion and a receiving portion. The receiving portion has first and second legs between which an opening is defined that is bounded by a U-shaped edge. The U-shaped edge is defined by an edge portion on the first leg. The first leg has a confronting edge which is repositionable at or adjacent to a strike surface with the rotor in the first position. A portion of the edge and the confronting edge meet at a corner having a convex shape approximated by a radius that is substantially less than 0.125 inch.
In one form, the edge portion has a substantially straight length that extends to the corner.
In one form, the confronting edge has a substantially straight length.
The convex shape of the corner may be approximated by an arc of a circle having a radius that is not greater than 0.04 inches.
In one form, the convex shape of the corner is approximated by an arc of a circle having radius that is in the range of 0.024 to 0.04 inches.
The convex shape of the corner may be approximated by an arc of a circle having a radius that is on the order of 0.032 inches.
In
According to the invention, the repositionable element/closure 14 has a latch assembly 16 carried thereon with a catch assembly 18 that cooperates with a strike element 20 on the support/frame 12. The latch assembly 16 is designed to releasably maintain the repositionable element/closure 14 in its first position with the latch assembly 16 in a first state. By changing the latch assembly 16 into a second state, the strike element 20 can be released from the catch assembly 18 to allow the repositionable element/closure 14 to be placed in its second position. The latch assembly 16 has a latch element 22 that is movable between a latched position and a release position through an operator 24 to respectively a) maintain the catch assembly 18 in the first state and b) allow the catch assembly 18 to be changed from the first state into the second state.
As shown more specifically in
The housing parts 32, 34 are maintained in fixed relationship by, in this embodiment, three similarly configured axles 40, 42, 44. Exemplary axle 42 has a cylindrical body 46 and axially spaced, reduced diameter ends 48, 50, as shown most clearly in
The reduced diameter ends 48, 50 define oppositely facing, annular shoulders 64, 66 which are spaced a distance D to establish the desired spacing between a flat surface 68 on the base wall 54 and a facing flat surface 70 on the cover wall 58, with the latter abutting to the shoulder 64 with the housing 30 assembled. The axle ends 48, 50 are radially deformed, through a swaging process, or otherwise, to conform them to the beveled surfaces 60, 62 in such a manner that the base wall 54 and cover wall 58 are drawn tightly towards each other and against the shoulders 64, 66, respectively, to unitize the axle 42 and housing parts 32, 34.
The axle 40 has a stepped outer diameter and reduced diameter ends 48′, 50′ which extend through bores 56′, 52′, with surrounding bevels 60′ (one shown), on the cover wall 58 and base wall 54, respectively.
The axle 44 also has a stepped outer diameter with reduced diameter ends 48″, 50″ extending through bores 56″, 52″, with surrounding bevels 60″ (one shown) on the cover wall 58 and base wall 54, respectively.
Spacing rings 76, 78, formed separately from, or as one piece with, the base wall 54, define bearing support surfaces 80, 84. Separate, cooperating, components 86, 88, with the latter a pivotable rotor, are mounted to the housing part 32. The component 86 is a strike plate that bears directly against the housing surface 68. The rotor 88 is moved guidingly against the bearing support surface 80. The latch element 22 is moved guidingly against the bearing support surface 84.
The rotor 88 has a body 90 with a mounting portion 92 and a receiving portion at 94 for the strike element 20. The mounting portion 92 of the body 90 has a through bore 96 to receive a reduced diameter portion 98 of the axle 42. An annular shoulder 100 between the reduced diameter portion 98 and a larger diameter portion 102 is spaced a distance D2 (
The reduced diameter portion 98 of the axle 42 is dimensioned to be closely received within the rotor bore 96 so as to guide pivoting movement of the rotor 88 about the axis 104 between a first, primary latched position, shown in
The receiving portion 94 of the rotor 88 has an opening 106 which bifurcates the receiving portion 94 so as to define spaced legs 108, 110 between which a throat is defined to accept the strike element 20. The opening 106 is bounded by a U-shaped edge 112.
As seen in
In the first position for the rotor 88, the strike element 20 within the rotor opening 106 resides fully within the width dimension of the housing 30. This is permitted by having U-shaped, coincident openings 116, 118 in the base wall 54 and cover wall 58, respectively. With the rotor 88 in the first position therefor, escape of the strike element 20 from the rotor opening 106 is blocked by a strike surface 120 on a strike plate 122, which bridges the legs 108, 110 on the rotor 88 and resides in close proximity thereto, or abuts thereto.
The strike plate 122 has a through bore 124 which receives a reduced diameter portion 98′ of the axle 40. The strike plate 122 is keyed against movement around the axle 40 by a tab 126 which projects into a receptacle 128 through a side wall 130 on the housing part 32. Additional keying is afforded by a tab 132 defining part of an opposite side wall 134 which seats in an undercut 136 on the strike plate 122.
The rotor 88 is normally biased towards its second position by a coiled torsion spring 138 which surrounds the larger diameter portion 102 of the axle 42. A first offset 140 on one cantilevered end arm 142 on the spring 138 bears against an edge 144 on a return wall 146, projecting from the side wall 130 towards the opposite side wall 134. A second offset 148 on an end arm 150 on the torsion spring 138 nests in a receptacle 152 on the rotor 88. The torsion spring 138 is loaded between the edge 144 on the return wall 146 and the edge bounding the receptacle 152 on the rotor 88 to bias the rotor 88 towards its second position. The second position for the rotor 88 is consistently maintained by the abutment of an edge 154 on the rotor 88 to a tab 156 that defines a part of the side wall 134.
The latch element 22 has a through bore 158 to accept a reduced diameter portion 98″ of the axle 44, which guides movement of the latch element 22 around an axis 160 between a latched position, and a release position, shown in phantom lines in
With the rotor 88 in the first position therefor, and the latch element in its latched position, the free end 182 on the latch element 22 abuts to an undercut stop surface 184 on the rotor 88 to maintain the rotor 88 in its first position. By pivoting the latch element 22 in the direction of the arrow 185 in
The latch element 22 is repositionable from its latched position into its release position through a release assembly, including a latch lever 188, which is mounted to an offset tab 190 on the cover wall 58 by a pin 191 for pivoting movement around an axis 192. Pivoting movement of the latch lever 188 in the direction of the arrow 194, around the axis 192, causes an actuating leg 196 to bear against the operating arm 164 on the latch element 22 to the point that the stop arm 166 bears against the wall surface 180, representing the release position for the latch element 22. As previously noted, the latch lever 188 can be repositioned either at the site of the latch lever 188, or remotely therefrom, by any type of operator 24, known to those skilled in the art or that might be readily devised by someone skilled in the art.
The present invention is concerned primarily with the specific configuration of the rotor 88 and its cooperation with the strike plate 86, as shown in detail in
With the rotor 88′ in its first position, the leg 110′ abuts, or is adjacent, to the strike surface 120′, corresponding to the strike surface 120 on the strike plate 86, as previously described. The leg 110′ has a confronting edge 200 which resides against, or is in close proximity to, the strike surface 120′ with the rotor 88′ in its first position. With the rotor 88′, strike element 20, and strike plate 86′ in the
In one embodiment, currently commercially offered by the assignee herein, the confronting edge 200 is defined by an arc of a circle centered on the point C. The arc has a radius R which is on the order of 0.125 inches. The confronting edge 200 blends into the edge portion 202 at a convexly radiused corner 206, which has the same radius R from the point C. The edge portion 202 has a portion at 208 which is substantially straight and projects generally along a reference line L in
As the magnitude of the force applied by the strike element 20 on the rotor 88′, in the direction of arrow 204, increases, ultimately the housing 30′ with which the rotor 88′ is associated begins to deflect/bend. This bending/deflection causes the rotor 88′ to reposition by moving slightly in the direction of the arrow 216 around the mounting axis 218. As a consequence of this, the strike element 20 bears on the arm 110′ closer to the free end of the arm 110′. By so doing, the strike element 20 encounters the arm edge with the radius R at the end of the edge portion 208, and eventually the corner 206. This action tends to wedge the rotor 88′ further in the direction of the arrow 216 to the point that the strike element 20 slides against the corner 206 into engagement with the strike surface 120′ so as to bear simultaneously against the rotor 88′ and the strike surface 120′. This represents the “out of pocket” state for the strike element 20. With the rotor 88′ out of pocket, the application of an increasing force on the rotor 88′ and strike plate 86′ through the strike element 20 causes a force to be applied in the direction of the arrow 204 to the strike plate 86′, which causes the strike plate 86′ to in turn deflect/bend the housing so that the strike plate 86′ shifts out in the direction of the arrow 220 in
In most constructions, the housing has a lesser ability to withstand an increasing loading force in the out of pocket state, shown in
As seen in
The arm 110 has an edge portion 228 against which the strike element 20 bears, with the rotor 88 in the first position, that is straight or slightly concavely curved so that the extent of the edge portion 228 can be approximated by the reference line L3. The confronting edge 226 and arm portion 228 meet at a radiused corner at 230 having a surface that is approximated by an arc of a circle with a center C1 and having a radius R1, on the order of 0.032 inches. The radius R1 may vary, preferably in a range between 0.024 and 0.04 inches. With this configuration of the corner 230, the strike element 20 is allowed to slide into and out of the opening 106 without hanging up on the arm 110 in normal operation with the rotor 88 in the second position. At the same time, the corner 230 does not guide the strike element 20 to the out of pocket position as does the corresponding corner 206 and convexly curved end of the edge portion 208 on the prior art rotor 88′ in
Accordingly, the strike element 20 has the capability of being in the in pocket position longer, as loading forces increase, with the configuration in
The tendency of the strike element 20 to move into the out of pocket state is even greater in the prior art construction with the rotor 88′ in a third, secondary latched position, as shown in
As seen with the inventive structure in
Even at the stage that the strike element 20 encounters the corner 230, the inventive rotor 88 will produce a lesser wedging action than occurs with the rotor 88′. That is because the corner 230 has a smaller radius of curvature than the corner 230′. The smaller radius will have a smaller contact area with the strike element 20. The force of the corner 230 on the strike element 20 will be more localized than the force of the corner 230′ on the strike element 20. The rotor will thus tend to hang up on the corner 230 so that it will not shift toward the out of pocket position until the force produced by the strike element 20 thereon is increased significantly.
Since the inventive rotor 88 functions similarly with the rotor in the first, primary latched and third, secondary latched positions therefor, the first position for the rotor, as recited in the claims herein, is intended to mean either the primary latched position or the secondary latched position therefor.
The foregoing disclosure of specific embodiments is intended to be illustrative of the broad concepts comprehended by the invention.