US3439948A

US3439948A - Door latch assembly

Info

Publication number: US3439948A
Authority: US
Inventors: Vernon O Smith
Original assignee: Overhead Door Corp
Current assignee: Overhead Door Corp
Priority date: 1967-10-16
Filing date: 1967-10-16
Publication date: 1969-04-22
Anticipated expiration: 1986-04-22

Description

DOOR LATCH ASSEMBLY Filed Oct. 16, 1967 of 3 v Sheet INVENTOR.

K Z/VOA/ 0. 5/7/27 $22M, w gw April 22, 1969 v. 0. SMITH 3,439,948

DOOR LATCH ASSEMBLY Filed Oct. 16, 1967 Sheet 3 of s 4 INVENTOR.

VfE/VO/V 0. 577/7 6 66 2; XI/BY ATTOEA [YS April 22, 1969 v. 0. SMITH 3,439,948

DOOR LATCH ASSEMBLY Filed Oct. 16, 1967 Sheet 3 of 3 Elli Illl INVENTOR.

VcK/VOA/ 0. 5/7/77/ i/wiawgw United States Patent US. Cl. 2922]l6 5 Claims ABSTRACT OF THE DISCLOSURE A shallow housing, open on one side, has narrow edges adapted for securement to the side of a sliding door adjacent the closing edge thereof which engages a casing. A latch mechanism within the housing has a latch with first hook means engageable with a catch mounted upon the casing, and second hook means engageable by third hook means on a lever which holds the latch in its catch-engaging position. A cam is arranged to move the lever out of its latch-holding position and lock means controls movement of the cam. An arm on the lever is engageable from the interior side of the door to move the lever out of the latch-holding position.

BACKGROUND OF THE INVENTION This invention relates in general to a latch assembly for a door which slides or moves substantially within a plane as it approaches the closed position and, more particularly, to a latch for an upwardly acting truck door wherein said latch is automatically moved into the latched position as the door is lowered into its closed position, said latch being adapted for normal release from the ex ternal side of the door and emergency release from the interior side of the door.

It has been common practice for many years to use upwardly acting doors on the access openings of truck vans wherein each door comprises a plurality of horizontally hinged, relatively narrow sections. Said doors are guided in their movement between a substantially vertical, closed position and a substantially horizontal open position by means of rollers mounted on the ends of the sections and engaged in suitable tracks, which extend along the opposite edges of said doors. Many types of latch and lock assemblies have been developed for such doors and, in general, have served their purposes. However, there has been a need for a lightweight, inexpensive latch assembly capable of latching automatically as the door is moved into the closed position, but which is constructed so that additional features, such as lock tumblers and the like, can be added without modification of the basic latch assembly.

Further, many trucks having closed vans are equipped with one access opening to such van. Accordingly, there are known instances when personnel have been trapped within the van because the door closed accidentally and because the latch mechanism was not accessible from within the van. For this reason, the use of latch assemblies which are automatically latched when the door moves into the closed position have not received widespread acceptance for use in certain types of truck applications.

It is common knowledge that valuable merchandise is often removed from locked truck vans largely because it is frequently necessary to park trucks for extended periods of time where they cannot be watched. Accordingly, it is standard practice to fabricate the latch and/or lock mechanisms from exceptionally heavy-duty materials which cannot be easily tampered or broken to gain access to the interior of the truck van. However, by placing the entire latch mechanism upon the interior side of the door,

"ice

a relatively lightweight and inexpensive latch mechanism can be made to serve as effectively as the ponderous structures presently used on the external side of the door, and with less chance of permitting unauthorized entry.

Accordingly, a primary object of this invention is the provision of a latch assembly which is adapted for mounting upon the interior side of an upwardly acting truck van door, which is capable of latching automatically as the door is moved into the closed position, which can be fabricated from a minimum number of lightweight, but adequately strong, and relatively inexpensive parts, which can be quickly and easily mounted upon the door, which can be opened from within the van of the truck, and which can be easily equipped with a lock for positively preventing opening of the latch mechanism from the exterior of the door.

A further object of the invention is the provision of a latch assembly, as aforesaid, which is constructed so that it Will not interfere with the movement of the door, which will not become jammed against the load within the truck van, which will not interfere with or destroy the effectiveness of the weatherseal along the closing edge of the door and which eliminates the need for any structure extending beyond the exterior surface of the door upon which it is mounted.

Other objects and purposes of the invention will become apparent to persons familiar with this type of equipment upon reading the following descriptive material and examining the accompanying drawings, in which:

FIGURE 1 is a front elevational view of the latch assembly of the invention attached to fragments of an upwardly acting truck door and the threshold therefor.

FIGURE 2 is a sectional view taken along the line II II in FIGURE 1 with the latch assembly in the closed position.

FIGURE 3 is a sectional view taken along the line III-III in FIGURE 2.

FIGURE 4 is a sectional view taken along the line IV-IV in FIGURE 1.

FIGURE 5 is a fragmentary, sectional view taken along the line VV in FIGURE 2.

FIGURE 6 is a sectional view taken along the line VIVI in FIGURE 2 showing the latch mechanism shortly after it has been manually released.

FIGURE 7 is a sectional View taken along the line VIIVII in FIGURE 3.

FIGURE 8 is a fragment of FIGURE 5 showing the latch mechanism shortly after it has been unlatched by the normal procedure.

FIGURE 9 is a sectional view taken along the line IX-IX in FIGURE 3 with a lock mechanism added.

FIGURE 10 is a sectional view taken along the line XX in FIGURE 9.

For purposes of convenience in description, the terms upper, lower, front, rear and words of similar import will have reference to the latch assembly of the invention as appearing in FIGURE 1, which shows the front side of the assembly. The terms inner, outer and derivatives thereof will have reference to the geometric center of said latch assembly and parts thereof.

Specific reference is made herein to an adaptation of the invention for use with an upwardly acting door of a truck van because it was from a need in this field that the invention developed. However, it will be recognized that said latch mechanism is equally applicable to other types of door constructions and other specific uses.

latch assembly comprised of a latch mechanism disposed within a housing mounted upon the interior surface of a door near the closing edge thereof, and a catch mounted upon the casing of threshold of the door for engagement by the latch mechanism so that the assembly is automatically latched when the door is closed. While the disclosed embodiment is particularly designed for use with an upwardly acting door on a truck van, the assembly can be used on any type of door structure wherein the final portion of the closing movement of the door against a casing or threshold is substantially planar. The housing is provided with an opening through which an arm on the latch mechanism can be reached for unlatching the mechanism from within the van, even when the door is locked.

DETAILED DESCRIPTION The latch assembly of the invention, a preferred embodiment of which is shown in FIGURES 1 and 3, is comprised of a housing 10, in which the latch mechanism 11 is mounted, and a catch unit 12 which the latch mechanism 11 is adapted to engage.

The catch unit 12 is comprised of a substantially rectangular mounting plate 13 which is secured upon the surface 14 of the bed 16 of a conventional truck van having an upwardly acting door 17 consisting of a plurality of horizontally hinged door sections 18. The mounting plate has a substantially rectangular opening 19 which is produced by striking out two

adjacent portions

22 and 23 from the central part of the plate 13. The portion 22 is preferably bent so that it is approximately perpendicular to the plane of the plate 13 and extends downwardly into an aligned opening 24 in the bed 16. The portion 23 at the opposite end of the opening 19 is bent downwardly slightly into the opening 24 and the inner edge 27 of portion 23 is folded upon itself to form a catch, which is engaged by the latch mechanism 11. The mounting plate 13 may be secured to the truck bed 16 by rivets 28, by welding or the like.

The housing 10 is comprised of a substantially planar front wall 31 and a narrow peripheral wall 32 which extends rearwardly from the front wall 31 and defines therewith a shallow cavity 36. The upper portion 33 of the peripheral wall 32 slopes downwardly and frontwardly to avoid jamming with a load adjacent to the door 17 when it is opened. The peripheral wall 32 has outwardly extending

flanges

34 and 35 on the upper leftward and rightward sides thereof, as appearing in FIGURE 3, through which the

openings

37 and 38, respectively, are pierced for the purpose of receiving rivets 41 (FIGURE 1) by which the housing 10 is rigidly secured to the lowermost door section 18.

As shown in FIGURE 4, said lowermost door section 18 has an enlarged lower edge portion 42 containing a downwardly opening groove 43 of irregular cross section for receiving the upper lateral edge of an elongated sealing element 44 having a corresponding cross section. As shown in FIGURE 2, parts of the enlarged edge portion 42 and the sealing element 44 are cut off or recessed to blend with the front surface 46 on the section 18, which is engaged by the recessed rear edge 47 of the lower portion of the peripheral wall 32.

The housing 10 has an integral, downwardly projecting latch guard 48 which opens upwardly and rightwardly, as appearing in FIGURE 3. The width of the latch guard 48 is slightly less than the distance between the adjacent edges of the

portions

22 and 23 of the catch unit 12, and the thickness of the latch guard 48 is slightly less than the distance between the 'front and rear edges 51 and 52 of the opening 19 in the plate 13. Thus, the latch guard 48 can move freely through th opening 19 during a latching or unlatching operation, as discussed hereinafter.

A latch 55 having upper and lower sidewardly projecting

hooks

56 and 57 on the rightward side thereof, as appearing in FIGURE 3, is pivotally supported between said hooks upon the pivot pin 58 which is rigidly mounted upon the front wall 31 slightly above the latch guard 48. The lower hook 57 is disposed within the latch guard 48 when the latch mechanism is in the unlatched position, as shown in FIGURES 6 and 8. However, when the latch 55 is in the latched position, as shown in FIGURES 3 and 5, the hook 57 projects from the latch guard 48 so that the catch element 27 is snugly disposed within the recess defined by the upper edge 60 of the hook 57 and the opposing lower edge 63 of the latch 55. Part of the lower edge of the peripheral wall 32 is omitted to provide a latch opening 62 therein adjacent the latch guard 48.

A latch-retaining lever 65, which is substantially inverted U-shaped, is pivotally supported near the upper end thereof upon the pivot pin 66 which is rigidly secured to the front wall 31 of the housing 10. The rightward leg 67 (FIGURE 3) of the lever 65 has a hook 68 which is engageable with the upper hook 56 of latch 55 so as to positively oppose clockwise rotation of the latch 55. The upper edge 63 of hook 56 and the lower edge 64 of hook 68 are curved to facilitate their engagement when the latch 55 moves into engagement with the catch 27.

A spring 69, which encircles the pivot pin 58 (FIGURE 2), has its upwardly projecting ends 72 and 73 engaged respectively with and bearing against adjacent sides of the left leg 74 of the retaining lever 65 and the latch 55 above the pivot pin 66. Accordingly, the spring 69 continuously urges the

hooks

56 and 68 into or toward engaged positions.

The housing 10 has an integral flange 76 which projects rightwardly (FIGURE 3) from the flange 34 to a point adjacent the leg 74 of the retaining lever 65'. The flange 76 has an opening 77 coaxial with an opening 78 in the front wall 31 (FIGURE 1) for rotatably receiving the shaft 79 upon which the actuating cam 82 is rigidly secured between the flange 76 and the front wall 31. The cam 82 has a downwardly and rightwardly facing arcuate edge 83 which is snugly but slideably engageable with the substantially upright leftward edge 84 of the left leg 74 on the retaining lever 65. The cam 82 also has an upwardly projecting integral element 86 with a flat right edge engageable with said edge 84 to prevent clockwise rotation of the cam 82 beyond its FIGURE 3 position.

The shaft 79 has an out-of-round, substantially central opening 87 into which the shank 88 of a handle 89 (FIG- URE 2) can be removably received for turning th actuating cam 82 in a counterclockwise direction (FIGURE 3) away from its position of FIGURE 3 into its position of FIGURE 8. The spring 69 continuously urges the left leg 74 against the adjacent edge of the actuating cam 82.

The housing 10 has a finger opening 92 near the flange 35, and the latch-retaining lever 65 has an integral arm 93 which extends over the opening 92 where it can be manually engaged to move the lever 65 out of its latchretaining position.

As shown in FIGURES 9 and 10, a lock tumbler 96 can be rigidly secured to the door section 18 so that its locking cam 97 can be moved between its solid line, unlocked position (FIGURE 10) and its broken line locking position with respect to the upwardly projecting element 86 on the actuating cam 82.

OPERATION The operation of the above-described latch assembly will be apparent to persons skilled in the art from such description. However, for convenience, such operation will be summarized. Under normal circumstances, the latch mechanism 11 will be in the unlatched condition of FIGURE 1 or 6 when the door is open, and said latch mechanism will be in its latched position of FIGURES 3 and 5 when the door is closed.

As the door 17 (FIGURE 1) is moved downwardly toward the closed position, the latch guard 48 (FIGURE 6) moves through the opening 19 in the mounting plate 13 after which the edge 63' of the latch 55, engages the catch element 27. Since the edge 63' is rightwardly of the pivot pin 58, continued downward movement of the door 17 pivots the latch 55 in a counterclockwise direction, as appearing in FIGURE 6, until the upper arcuate edge 63 of the upper hook 56 engages the lower arcuate edge 64 of the hook 68 on the lever 65. The spring 69 constantly urges the left leg 74 of the lever 65 against the actuating cam 82, whereby the lower edge 64 of the hook 68 is held in the path of the upper edge 63 of the hook 56 when the latch 55 is moved in a counterclockwise direction. As the latch 55 continues its counterclockwise movement (due to further downward movement of door 17), the hook 56 slides along the hook 68 and the lever 65 is urged in a counterclockwise direction contrary to the urging of the spring 69. When the lower edge of the hook 56 passes the upper edge of hook 68, the lever 65 is pivoted in a clockwise direction by spring 69 and the hook 68 moves into locked engagement with the hook 56 as appearing in FIGURE 3, such movement being limited by engagement of the left leg 74 with the substantially fiat right side 85 of the actuating cam 82.

While the latch 55 and lever 65 are moving into latched engagement, as discussed in the foregoing paragraph, the catch 27 is being received into the recess 59 where it is firmly engaged by the hook 57 until the latch 55 is released by the lever 65 for clockwise rotation.

As shown in FIGURE 2, the rearward edge of the sealing strip 44 is compressed substantially by the mounting plate 13. However, appropriate allowance is provided in the structure of the sealing element 44 to permit this while maintaining a firm seal elsewhere, as seen in FIGURE 4. If the mounting plate 13 is flush mounted, then the engagement between the rearward edge of sealing strip 44 and the upper surface 14 of the deck 16 will be as appearing in FIGURE 4 throughout the length of the sealing strip.

When it becomes desirable to open the door 17 in the normal manner, the handle 89 is turned so that it pivots the actuating cam 82 (FIGURE 3) in a counterclockwise direction whereby the arcuate edge 83 engages the left edge 84 of the leg 74 on lever 65 and thereby pivots said lever 65 in a counterclockwise direction into the position thereof appearing in FIGURE 8. As sooon as the hook 56 is released from its engagement with the hook 68, due to the pivotal movement of the lever 65, the latch 55 is rotated in a clockwise direction by the spring 69 into the position of FIGURE 8 wherein the tip of the hook 56 bears against the portion of the peripheral wall 32 adjacent the opening 62 therein and the closed end of the hook 57 bears against the extension of the peripheral wall 32 in the latch guard 48.

As shown in FIGURE 8, the left leg 74 of the lever 65 will be urged by spring 69 against the adjacent edge of the actuating cam 82 as soon as the hook 56 releases the hook 68. Thus, when the handle 89 is released, the leg 74 (FIGURE 8) will urge the counterclockwise rotation of the actuating cam 82 into its detent position of FIGURE 3. That is, the latch mechanism 11 will automatically reset itself, in the solid line position of FIGURE 6, for latching engagement with the catch 27 when the door 17 is again moved toward the catch unit 12.

When the latch mechanism 11 is in latched engagement with the catch unit 12, as appearing in FIGURE 3, an unlatching operation can also be performed by engaging the arm 93, either manually or by an instrument, through the opening 92 and thereafter raising the arm 93 until the hook 56 releases the hook 68 after which the subsequent operation of the latch mechanism may be identical with that discussed above following the normal operation of the latch mechanism by the handle 89. As soon as the engagement of the arm 93 is released, the latch mechanism 11 will move toward its solid line position of FIG- URE 6, so that it is set for a subsequent latching operation when the door 17 is moved downwardly. The left edge 84 of the left leg 74 is shaped so that the lever 65 can be rotated in a counterclockwise direction, as appearing in FIGURE 3, without interference from or movement of the actuating cam 82.

As shown in FIGURES 9 and 10, it may be desirable to provide a tumbler and locking cam in association with the latch mechanism 11 to prevent unauthorized opening of the door 17 by turning the handle 89. When the locking cam 97 is in its broken line position of FIGURE 10, it is substantially perpendicular to the initial direction of movement of the adjacent outer end of the element 86 on the actuating cam 82. Accordingly, counterclockwise unlatching movement of the actuating cam 82 is positively prevented by said cam 97, Clockwise unlatching movement of the actuating cam 82 is positively prevented by engagement between the edge of the cam 82 and the edge 84 of lever leg 74.

By moving the locking cam 97 into its solid line position of FIGURE 10, it no longer obstructs the counterclockwise movement (FIGURE 10) of the actuating cam 82 in effecting an unlatching operation of the latch mechanism 11. Moreover, since it is unnecessary to move the actuating cam 82 when the latching mechanism 11 is manually operated by the arm 93, an emergency opening of the latch mechanism 11 by the arm 93 can be effected when the cam 82 is locked in its FIGURE 3 position by cam 97.

Under some circumstances, it may be desirable to indicate that there has been an emergency operation of the latch mechanism 11 by the arm 93, particularly where there is another means of gaining access to the interior of the truck van. In such case, the opening 92 may be covered with a sealing material which must be broken or otherwise mutilated in order to achieve access to the arm 93.

Although particular preferred embodiments of the invention have been disclosed above for illustrative purposes, it will be understood that variations or modifications of such disclosure, which come within the scope of the appended claims, are fully contemplated.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A latch assembly for a sliding door on a truck van, said door being movable within a plane substantially toward and away from a jamb and having an edge engageable with said jamb when said door is in the closed position, said door further having an inside surface con fronting the interior of said truck van and an outside surface on the side thereof opposite said inside surface, comprising:

housing means having a sidewall and a peripheral wall defining a shallow cavity, said peripheral wall having the free edge thereof adapted for securement to the inside surface of said door near said edge thereof whereby said cavity is covered; catch means mounted upon said jamb; latch means supported upon said housing means and coacting between said catch means and said door for maintaining said door in the closed position, said latch means including a latch member pivotally supported upon said housing means within said cavity and having first and second hook portions thereon, said first hook portion being adapted to engage said catch means when said edge of said door is closely adjacent said jamb, disengagement of said latch means from said catch means being effected by pivotal movement of said latch member in one direction from a latched position to an unlatched position, said latch member further having a cam surface thereon coacting with said catch means for effecting pivotal movement of said latch member in the opposite direction from said unlatched position toward said latched position when said edge of said door is moved into a position adjacent said jamb,

first resilient means continuously yieldably urging said latch member in said one direction toward said unlatched position;

lever means pivotally supported upon said housing within said cavity, said lever means having a third hook portion engageable with said second hook portion when said lever means is in a retaining position for positively maintaining said latch member in said latched position and preventing pivotal movement thereof in said one direction;

second resilient means continuously yieldably urging said lever means toward said retained position wherein said third hook portion is engageable with said second hook portion;

actuating cam means pivotally supported upon said housing means within said cavity and coacting with said lever means for moving same out of said retain ing position whereby said third hook portion disenigages said second book portion for permitting said first resilient means to pivotally move said latch member in said one direction toward said unlatched position;-

manually actuatable handle means positioned adjacent the outside surface of said door for permitting said latch member to be moved in said one direction from said latched to said unlatched position, said handle means including a portion extending through said door and fixedly connected to said cam means for pivotally moving same;

means defining a small opening in the sidewall of said housing for permitting communication between the cavity within said housing and the interior of said truck van; and

said lever means further having a manually actuatable portion positioned adjacent to and in substantial alignment with said opening when said lever means is in said retaining position, said manually engageable portion being accessible and manually engageable through said opening for permitting said lever means to be moved away from said retaining position whereby said latch member can be disengaged from within the interior of said truck van.

2. A latch assembly according to claim 1, wherein said housing is substantially narrow and the sidewall thereof is substantially planar, and wherein said peripheral wall means has an upper portion which slopes downwardly and outwardly from the inside surface of said door so as to avoid jambing of said door with a load positioned within the truck van when the door is being opened,

3. A latch assembly according to claim 1, wherein said housing has a latch guard integrally fixed thereto and projecting beyond the edge of said door, said latch guard having substantially parallel front and rear Wall members defining a cavity therebetween in which is received said first hook portion when said latch member is in said unlatched position, whereby said latch member is thus protected when the door is in the open position.

4. A latch assembly according to claim 1, including lock means pivotally supported within said cavity for movement into and out of a position with respect to said cam means for positively preventing movement of said cam means When said cam means is holding said lever means in said retaining position.

5. A latch assembly according to claim 1, wherein said lever means comprises a substantially U-shaped lever member having a pair of legs integrally joined by abase portion with said base portion being pivotally connected to said housing, one of said legs having said third hook portion integrally formed thereon, the other of said legs coacting with and being contacted by said cam means for permitting said cam means to move said lever means away from said retaining position; and a spring means coacting between said latch member and the other leg of said lever member, one end of said spring constituting said first resilient means and be ing connected to said latch member for biasing same in said one direction, the other end of said spring constituting said second resilient means and being connected to the other leg of said lever means for biasing same into said retaining position.

References Cited UNITED STATES PATENTS 2,153,102 4/1939 Smith 292-180 2,194,408 3/ 1940 Sluss 292-101 2,727,774 12/1955 Marple et al 292-216 3,023,804 3/1962 Howell 49-488 X 3,103,805 9/1963 Crosswell -142 3,170,722 2/1965 Schutte 292-216 X 3,236,551 2/1966 Nash 292-216 X RICHARD E. MOORE, Primary Examiner.