US2764443A - Door lock - Google Patents

Description

Sept. 25, 1956 w, BENNETT 2,764,443

DOOR LOCK Filed May 4, 1955 4 Sheets-Sheet l IN V EN TOR.

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Sept. 25, 1956 w, BENNETT 2,764,443

DOOR LOCK Filed May 4, 1953 4 Sheets-Sheet 5 fire 5- W44 TEE BEA/N577; INVEN TOR.

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United Sttes Patent DOOR LOCK Walter Bennett, Los Angeles, Calif, assignor to Utility Trailer Manufacturing Company, Los Angeles, Calif., a corporation of California Application May 4, 1953, Serial No. 352,925

7 Claims. (Cl. 292-240) The present invention has reference to locks, and, although applicable to any relatively movable member, is particularly applicable and effective when used on swinging doors. The invention also has certain features which make it particularly effective when applied to the swinging door or doors commonly used to close the rear end of a van-type transport body. The invention will be described and its action explained with particular reference to such doors and body; but without implying that the invention is limited to any such specific use.

A primary objective feature of the present invention lies in its provision of a locking means, operable by a manual handle, which applies an increasing torque to the door as it approaches more and more closely to its final closed position; so that the door may be, by easy manual actuation, forced closed or open, under heavy pressure. And, in connection with that feature, it is also a characteristic of the locking mechanism of my invention that, in its final position in which it holds the door closed under great force, the operating handle is not subject to any force tending to move it in an opening direction. When the door is being held closed under pressure, the operating handle is dead.

There are many other objective features and corresponding accomplishments of the invention, all of which will be best understood as they are explained in connection with the specific and preferred illustrative embodiments of the invention set out in illustrative detail in the followingidescription and shown in the accompanying drawings in which:

Fig.1 is a fragmentary elevation showing one illustrative preferred form of my present invention, with the parts'shown in their closed positions;

' Fig. 2 is an enlarged horizontal section on line 2-2 of Fig. 1, with the parts in their closed positions;

Fig. 3 is a further enlarged detail section on line 33 of Fig. 2;

Fig. 4 is a detail section on line 44 of Fig. 3;

Fig. 5 is a schematic view similar to Fig. 2 but showing the parts in positions approaching the closed position;

Figs. 6 and 7 are diagrammatic views showing other progressive positions of the locking mechanism;

Figs. 7a, 7b and 70 show details of progressive positions of the locking mechanism;

Fig. 8 is a fragmentary elevation showing a modified form of the invention with the lock in closed position;

Fig. 9 is a plan section of the parts shown in Fig. 8;

and

' Figs. 10 and 11 are diagrams showing progressive positions of the locking mechanism of Figs. 8 and 9.

In the drawings a typical swinging door is shown at 20, hinged at one vertical edge on hinges 22 (see Fig. 7) in a door framing 24 which may be of any type and structure. The door itself is shown as having a rabbeted flange 26'Which may either serve to trap another door of a pair, or may, through packing 28, seat directly on a shoulder 30 in the door frame structure 24. The present lock mechanism is applicable to any such door. As explained later, the door here shown, whether it is a single door or the right hand door of a pair, acts as a gusset to brace the door frame.

The physical structure of the presently preferred form of the lock mechanism is best shown in Figs. 1 to 5 and will first be explained with reference to those figures. As there shown, a vertical lock shaft 34, preferably formed of tubing or pipe, is rotatively mounted in two journal members 36 which are rigidly secured to the outer face of the door at its swinging side near its top and bottom. A collar 38 or other shoulder formation rigidly attached to the shaft rests on one of the journals to support the shaft and its carried parts in proper position to cooperate with other parts mounted on the door frame structure. That door frame structure may, for instance, be the rear end framing of a vehicle body.

Two curved locking tongues 40 are rigidly mounted on the upper and lower ends of shaft 34 in positions respectively just above and below the upper and lower edges of the door. These locking tongues, in their locking position, engage in keepers 42 which are mounted on the door frame structure just above and below the door opening. The two tongue and keeper units are duplicates, so a detailed showing and description of the lower unit will suffice for both. As here shown in preferred form, the shaft-mounted hub 44 of the lower tongue 40, in addition to carrying the tongue also carries one element of the lock operating cam mechanism. However the lower tongue 40 might have its own hub 44 like the upper tongue; and the cam mechanism element could be mounted on its own individual hub on shaft 34 and that hub and the cam mechanism could be spaced alongthe shaft from the lower tongue just as it is spaced from the upper tongue. This is spoken of particularly for the purpose of pointing out later that, in finally locked condition, the shaft 34 may be put in torsional stress between the camming mechanism and both locking tongues,

as well as only the upper locking tongue as here specifically shown.

As will appear, the camming mechanism rotates the shaft and its tongues between such an open position as shown in Fig. 6, and the final locked position shown in Figs. 1 and 2, passing through intermediate positions such as shown in Figs. 7 and 5. The shaft and tongues are rotated through about between the open position of Fig. 6 and the finally locked position of Fig. 2; and as will appear from the successive positions shown in Figs. 6, 7, 5 and 2, the tongue enters the box-like keeper 42 by a swinging movement from the right to the left in the drawings. In thus entering the keeper the tongue has a component of movement toward the left in the keeper as well as a component of movement outward, away from the door frame. Those two movement components are indicated by arrows in Figs. 3 and 4.

The keeper 42 is a box -like structure with an outer wall 50 presenting an inner face 51 that is convex as viewed in horizontal section as in Fig. 4. The tongue- 40 is curved as viewed in plan (Figs. 2 and 4) and has an outer concave face 41 which, in the final locked position of Figs. 2 and 4, fits the convex keeper face 51. In that final locked position the tongue is being forced in the direction of the arrow A of Fig. 4 and its concave face is therefore pressing against keeper face 51 not only in direction A but also in direction B. In consequence, the tongue, thus engaging the keeper, is forcibly pressed in the door closing direction, opposite to A; and is also I relation to the frame.-

The box-like keeper has upper and lower walls that Patented Sept. 25, 1956} present inner faces converging toward the left; and the tongue, in the aspect of Fig. 3, is correspondingly tapered. Consequently, as the tongue forcibly enters the keeper in the direction of the arrow in Fig. 3, the interengagement of the tapering and converging faces will correct any relative vertical displacement that may exist between the tongue and keeper. This action is of some practical importance where the door and/ or door frame structure are liable to become deformed. For instance, the rear end framing of a transport body which has a rear door opening substantially as large as the body itself, may be very liable to warpage to rhomboidal shape when the vehicle is standing on uneven ground. The frame door opening then, at the swinging edge of the door, stands vertically displaced from that edge of the door. Assuming that the door itself is stiff in its own plane and held at its hinged edge with no loosenesses either horizontally or vertically, and assuming that shaft 34 and the tongues are vertically immovable on the swinging end of the door then the forcible entry of the tapered tongues into the tapering keeper boxes will force the vertically displaced door framing into its proper rectangular shape as the tongues move to their final locked positions of Figs. 2, 3 and 4.

As stated before, collar 38 or an equivalent shoulder holds shaft 34 up in the bearings 36. Another such shoulder under either journal 36 could be used to hold shaft 34 and the tongues from moving up relative to the door. But the camming mechanism now to be described provides the necessary upwardly bearing thrust in the specific design here shown.

In this specific illustrative embodiment of the invention the lower journal member 36 carries a rigid pivot pin 60 projecting downwardly from mounting lug 62. Pivoted on that pin and confined vertically between lug 62 and a cam slot member 64, is the pivoted end 66 of a manual lever handle 6%. Cam slot member 64 is rigidly mounted on shaft 34. In this particular design, as mentioned before, it is mounted on and integral with hub 44 of the lower locking tongue. The confinement of 66 between 64 and 62 makes those parts perform a thrust function to hold shaft 34 down in its journals.

Attention is now directed particularly to Figs. 2 and 5. For convenience of description the line C--C on Fig. 2, parallel to the face of the door, will be used as a datum. With the parts in the final locked position of Fig. 2, with tongue 40 projecting to the left of shaft 34 into keeper 42, the cam slot 70 of member 64 in this illustrative embodiment stands at an angle of about 60 to C--C. Pivoted handle 68 carries a cam pin 72 which projects down into cam slot 70 and plays between the two opposite walls 74 and 76 of that slot. In the final locked position of the parts, the line D, determined by the axes of pivot pin 69 and cam pin 72, lies preferably at right angles to the length of slot 70, and thus in this particular illustrative embodiment makes an angle of about 30 with C-C. In that position the main length of handle 68 lies back flatly against or close to the door face and is held against accidental displacement by a suitable keeper, such as the one shown at 78 pivoted on an extension of one of the bolts 80 that bolt the lower journal member 36 to the door.

Referring now to the relative magnitudes indicated by a, b, c and d in Fig. 5, it can be shown that 4 represented by L which has such relationship with said slot wall. Then the (2) input torque t=Fa where a is the perpendicular distance between pivot point 60 and line of force L.

The opposite and equal reaction force F acts, of course, along line L, and the (3) output torque T of shaft 34=Fc where c is the perpendicular distance between the shaft center and line L. From (2) it follows that and from (3) it follows that Therefore T T T 0 T? Or r-a If we now introduce the friction factor, We have, in place of Equation 2 (7) t=F(a+ub) and, in place of Equation 3 (8) T=F(c+ud) Substituting (a-i-ub) for a and (c-l-ub) for c, in Equation 6, we have T c+ud 15 c -hub Assuming u to be 0.40 the ratio T/ t from such a position as shown in Fig. 6 to the final closed position of Fig. 2, varies from about 0.3 to 2.75. That is assuming pin 72 to be of full round shape (no flat as shown). However the presence of the fiat face '73 on pin 72 does not materially change the torque ratios. Of course, if u is neglected, or is made to be very small (as it can be by, for instnace, using an anti-friction bearing sleeve around pin 72) the ratio T/ t will approach infinity as the closed position of Fig. 2 is reached.

That changing ratio of the torques of course means that, from a starting position of the handle such as in Fig. 6 substantially parallel to the plane of the door, a given small angular movement of the handle (e. g. to the position of Fig. 7) throws the locking tongue through a relatively large angle; approximately 60 as seen by comparing Fig. 6 with Fig. 7. The remaining large angular throw of the handle from the position of Fig. 7 to the finally closed position of Fig. 2 (approximately moves the locking tongue through a very small angle (compare Fig. 7 with Fig. 2) under relatively great torque with the result of finally forcing the door closed with great force.

As the door is finally forced closed, the relative positions of the locking parts may be such that shaft 34 is finally put under torsional strain to keep the door tightly closed in spite of slight variations in the relative locations and dimensions of parts of the locking mechanism, and of the door and its frame. The overhanging portions of the shaft, between bearings 36 and the tongues 40 at the shaft ends, may also at the same time be put under elastic bending stress. Elastic deformation of other parts of the mechanism may also have the same effect, but the elastic deformation of the shaft is the greater factor. That deformation also is effective in pressing the door tightly closed even though pin 72 is provided with the flat 73 which functions the same as if, in the final locked position of Fig. 2, pin '72 (with no flat) were moved to a position over center with relation to slot wall 74; that is, to a position where line D (Fig. 2) were angularly rotated about 60 in counter-clockwise direction. As will be explained, the flat has that same handle locking action and at the same time provides a broad surface for the pressure action between pin 72 and the slot wall.

The functioning of the flat 73 as the parts approach final locked position is illustrated particularly in Figs. 7, 7a, 7b and 70. In the positions of Figs. 7 and 5 the fiat is inoperative or substantially so; the cylindric surface of pin 72 hearing against wall 74. Beginning with about the position of Fig. 7 and through the progressive positions shown in Figs. 7a and 7b the fiat 73 is moving more nearly into fiat contact with wall 74, until, in the position of Fig. 70, with line D normal to the face of wall 74, the flat fully engages that wall. From approximately the position of Figs. 7b to that of 7c, cam slot member 64 moves slightly in a retrograde direction, that is, clockwise about the axis of shaft 34 as flat 73 reaches its final position. Just before that position is reached the cam member 64 is in its furthest position counter-clockwise and shaft 34 and the other parts of the locking mechanism are under their greatest stress and elastic deformation. When cam member 64 has finally backed off to the position of Fig. 7c, that stress and deformation are slightly relieved, but the locking tongues are still held in heavy pressurable engagement with the keepers, and the door held tightly closed, by the elastic deformation which still exists. Slot wall 74 is pressed against fiat 73 by the same elastic stresses, and holds pin 72 and handle in the position of Fig. 2, without any torque being exerted on the handle. In fact, positive torque in a clockwise direction must be exerted on the handle to move it from the fully locked position of Fig. 2. Thus, the handle is not only dead in that position but requires positive force to move it out of that position and to start the movement of the lock mechanism toward open position.

It will be noted that when the locking tongue 40 is in full pressural engagement with keeper 42, as in Fig. 2, pivot pin 60 lies below the line R which represents a radius from shaft 34 extended to the then effective surface of cam interengagementthat is, point B where pin 72 engages slot wall 74. On the other hand, in Fig. 5 pivot pin 60 lies above line Ra which represents a radius from shaft 34 extended to the then effective surface of cam interengagementthat is point Ea where pin 72 engages slot wall 74.

The relative movements of the parts from locked to unlocked condition, and the stresses, strains and torques involved, are in general simply the reverse of those involved in movement from open to locked condition. That would be exactly true if pin 72 were fully round and fitted slot 70 tightly. Exactly the same high torque ratio which facilitates forcible closing of the door would be applied to opening the door against any condition tending to stick it closed--ice in the space between the door edge and the frame, for instance. And the same is true generally when pin 72 has the flat 73. In approximately the position of Fig. 7a or 7b the pin comes into contact with the face of slot wall 76, and from that position on the handle exerts a high torque on member 64 to force or break the door open if necessary.

To securely lock the mechanism in closed position against unauthorized opening, it is sufficient to lock handle 68 in the position of Fig. 2 in any suitable manner. For example the swinging keeper 78 can be padlocked; or a padlock can be inserted and locked in the opening 71 in the member 64 to prevent pin 72 from moving in the opening direction.

In the modification shown in Figs. 8 to 11, the shaft 34a may be the same and have the same relation to door 20a as in Figs. 1 to 7; and tongues 40a and keepers 42a may be the same in structure, location and function as in Figs. 1 to 7. The tongue and keeper shown in Figs. 8-1l are somewhat modified in form, but are functionally the same as in Figs. 1-7. The modification of Figs. 8-11 is in the camming mechanism which operates the lock shaft and tongues.

tion indicated with relation to 62a; so that, in the relative positions of Figs. 10 and 11, the arm 62a swings with handle 68a. Handle-lever 68a carries a cam formation 72a adapted to enter and to cooperate with the cam receiving member 70a which is mounted on the door- The operation of this modification will be understood from Figs. 10, 11 and 9. In the open position of Fig. 10, the door can be pulled open or pushed toward closing position by pulling or pushing on handle 68a. In closing, upon tongue a reaching a position where by rotation it will enter keeper 42a, handle 68a, and with it the arm 62a and the tongues, is swung counter-clockwise through such a position as shown in Fig. 11 and into approximately the position indicated in broken lines for 68a and 62a in Fig. 9. In that last mentioned positionthe tongues 4001 are well within their keepers and the cam member 72a is entering the box 70a. Then, from that position shown in broken lines in Fig. 9, handle 68a and its cam member 72a are now thrown around clockwise through approximately 180, to the final position shown in full lines in Fig. 9. The shape of cam member 72a is such that, by engagement with the inner face of box 70a, it forces arm 62 a through a total angle of about 30, for 180 movement of the handle; and also such that the mechanical advantage of the handle over arm 62a and tongue 40a increases as the final locked position is reached. And in that final position a flat cam face 72b may bear flatly against a flat box face 70b, so that the parts are all held in their final locked positions with no rotative forces being exerted on the then dead handle. And in the final locked position 1 the several parts and particularly the shaft may be under the same distortion stresses and with the same functional actions as in the form first described. A padlock inserted in hole 71a in a lug 71b projecting from journal member 36a will prevent handle 68a from being swung out from its position of Fig. 9 and thus prevent the lock mechanism 40' from being thrown open.

.A brief comparison of the two forms will bring out their similarities both as to function and structure. In Fig. 2, the lever-handle is pivoted on a pivot (60) which is stationary with reference to the door, and carries a camming member (72) which operates on a camming member (64) that is carried by the tongue operating shaft (34). In Fig. 9, the relative carriages of handle pivot (60a) and of camming member (70a) are simply reversed; the bandle pivot 60a now being carried by shaft 34a and the camming member 70a being stationary with reference to the door. In the final action of forcing the door closed by movement of the handle between the two positions of Fig. 9, the functionings of the two forms are very similar to each other. However, the form of Figs. 8-11 has one functional detail that the first form does not have. In the last figures the tongues are first moved into their keepers and into positions close to their final locked positions by swinging the handle counter-clockwise to the broken line position of Fig. 9. Then from that position the handle may be swung through approximately clockwise to give the tongues their final locking movement. In the form of Fig. 2 etc. the maximum movement of handle 68, both to enter the tongue in the keeper and then to force the tongue to final position,.is 180.

It will be noted by reference to Fig. 9, that when the locking tongue 40a is in full pressural engagement with keeper 42a (at which time the cam member 72a is in the full line position) pivot pin 60a lies above the line Rb which represents a radius from shaft 34a extended to the then effective surface of cam interengagement-that is point Eb where cam 72a engages cam face 72b; whereas, when cam 72a is in the dot-dash position of Fig. 9, said pivot pin 60a lies below the extended radius Rb.

Both forms of the locking mechanism have a further advantageous feature. It is not necessary to rivet or weld the journals 36 or 36a to the door to prevent unauthorized tampering. If all the bolts that hold the parts to' the door should be removed, it is still impossible to remove tongue 40 from keepers 42, if the parts are locked in their relative closed positions by padlocks in the openings 71 and 71a. To remove the tongues from the keepers it is necessary to rotate the whole assembly clockwise about a vertical axis located, in Fig. 2 for instance, somewhere to the right of the left hand ends 36b of the mounting lugs 360 of journals 36. The extension of those lugs in contact with the door to the left of that axis makes that rotation impossible. In Fig. 9 the same mounting lugs may be similarly extended; or, in that form of the mechanism, the locked handle 68a extending to the left performs the same function.

The lock mechanism disclosed herein, as distinguished from the lock operating mechanism disclosed and claimed herein, is the subject matter of my application, Serial Number 602,369, filed August 6, 1956.

I claim:

1. In a locking mechanism for a door or the like which is movable with relation to a doorway frame, a shaft rotatably mounted on the door in a position with its axis substantially parallel to the plane of the door, a locking tongue rigidly carried by the shaft and projecting laterally from the shaft, said tongue being pressurally engageable with and disengageable from a keeper on the frame by virtue of shaft rotation in opposite directions, and cam mechanism comprising two relatively movable inferengaging camming members, one mounted on the shaft and the other on the door and adapted by camming action to rotate the shaft and the locking tongue, one of the members being pivotally mounted, the effective surface of cam intenengagement being radially spaced more distantly from the shaft than is the point of pivotal mounting of said one member, said point of pivotal mounting lying at one side of a radius extended from the shaft to the then effective surface of cam interengagement when the locking tongue is in a position of full pressural engagement with the keeper and lying at the other side of a radius extended from the shaft to the then effective surface of cam interengagement when the tongue is in positions of lesser pressural engagement. 7

2. Locking mechanism as in claim 1; wherein said effective surface stands substantially at right angles to a radius through the pivot point when the members are in the position they occupy when the locking tongue is in full pressural engagement with the keeper.

3. Locking mechanism as in claim 1; wherein the pivotally mounted member is mounted on a pivot which is fixed with relation to the door and the other camming member is rigidly mounted on the shaft.

4. Locking mechanism as in claim 1; and in which the shaft-mounted camming member comprises an element rigidly mounted on the shaft and having a slot formation which has its length lying in a direction tangential of the shaft, and the other camming member comprises a manually operable handle having one end pivoted on a pivot axis parallel to and spaced from the shaft axis, and a cam pin mounted on said handle at a point spaced from the pivot and entered in said cam slot, said cam pin having a fiat face on one side in a plane tangential to the pivot axis, and the parts being so positioned that said fiat face flatly engages a wall of the cam slot when the locking tongue is in full pressural engagement with the keeper.

5. Locking mechanism as in claim 1; and in which the shaft-mounted camming member comprises an element rigidly mounted on the shaft and having a slot formation which has its length lying in a direction tangential of the shaft, and the other camming member comprises a manually operable handle having one end pivoted on a pivot axis parallel to and spaced from the shaft axis, and a cam pin mounted on said handle at a point spaced from the pivot and entered in said cam slot, said cam pin being engageable exclusively with slot walls which extend lengthwise of the slot formation.

6. Locking mechanism as in claim 1; wherein the shaft mounted camming member is pivotally mounted on a pivot which is fixed with relation to the shaft.

7. Locking mechanism as in claim 6; wherein the two camming members interengage on a surface which stands substantially at right angles to a radius through the pivot when the locking tongue is in full pressural engagement with the keeper.

References Cited in the file of this patent UNITED STATES PATENTS

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