US3446524A - Link and lever operated toggle latch mechanism - Google Patents

Description

J. K. BARRY May '27, 1969 LINK AND LEVER OPERATED 'IOGGLE LATCH MECHANISM Filed Nov. 5, .1967

Sheet INYENTOR. John K. Barry ATTORNEYS.

LINK AND LEVER OPERATED TOGGLE LATCH MECHANISM Filed Nov. 5, 1967 J- K. BARRY May 21, 1969 Sheet 2 of 2 INVENTOR v John K. Barry BY v o m 3 4 u M 'l'lflll4 I 2 4 I m \xw m ATTORNEYS United States Patent US. Cl. 292-223 12 Claims ABSTRACT OF THE DISCLOSURE A latching device is provided, for mounting on a door or .the like and engaging a keeper mounted on a door frame, the device being actuated by a manually engageable lever which is operative through an over-center toggle-link mechanism to actuate a locking pawl into locking engagement with the keeper mounted on the door frame. The lever may be spring-biased into a locking position of the locking pawl. The pawl is especially configured for camming engagement with a plate carried by the door frame to facilitate the application of leverage for prying open the door by means of the lever, the lever being useable as a door handle.

Background of the invention Latching devices of the prior art types are not capable of providing a high degree of gasket compression for such applications as sealing doors and furthermore do not provide a high degree of locking force, in that they are principally constructed on the simple lever principle. Also, latching devices of the prior art types are not adapted for providing a high degree of leverage to loosen a stuck or frozen door.

Handle-levers of prior art latching devices are generally secured in latched positions by external latching means, such that, if sufiicient forces are present against a door which is latched in position, tending to open the door, disengagement or ineffectual operation of the external latching means will leave the handle-lever free to become unlatched from its keeper.

Summary of the invention The present invention seeks to obviate the above and other undesirable features to prior art types of latching devices, in providing a latching device which utilizes a toggle-link operable onthe over-center principle to provide a high degree of locking force and leverage for sealing applications and the like, such as when the device is utilized for securing doors in closed positions. The high degree of leverage available by the device of this invention also facilitates the function of loosening a stuck or frozen door by prying the same open.

Still further, because the latching device of this invention uses an over-center principle, forces which may tend to force a door open only tend to further secure the device in a latched position.

Accordingly, it is a primary object of this invention to provide a latching device for securing structures together, such as, doors to their frames, wherein the device is capable of a high degree of leverage, and operates on a toggle-link principle.

It is another object of this invention to accomplish the above object, wherein the toggle-link structure is operable in different over-center positions, corresponding to locking and unlocking positions of the device.

It is a further object of this invention to provide a latching device which is adapted for use in latching structures such as doors to their frames, the device operating on a toggle-link principle and being capable of providing a high degree of leverage for latching a pawl against its keeper, the device further being operable for prying open the door.

It is another object of this invention to provide a latching device operable on the toggle-link over-center principle, the device including a lever-handle which may be locked in a latched position.

It is yet another object of this invention to provide a latching device, for doors and the like, utilizing the toggle-link over-center principle, wherein the lever-handle has an end portion which is bent inwardly toward a door to preclude the accidental disengagement of the leverhandle by external means.

Other objects and advantages of this invention will be apparent to those skilled in the art from the following detailed description, drawings, and appended claims.

Brief description of the drawing FIGURE 1 is a top perspective view, fragmentally illustrated, and partially in section, of a door and frame embodying the latching device of this invention, the door being illustrated in a latched closed position.

FIGURE 2 is a top plan view of a portion of the door and frame illustrated in FIGURE 1, with the latching device 'being illustrated in approximately its full size.

FIGURE 3 is a longitudinal sectional view of the latching device of FIGURE 2, taken generally along the line III-III of FIGURE 2, and wherein the various latching components are illustrated in their respective positions with the latching device in a fully latched state, the locking device and the door and frame structure being illustrated in phantom.

FIGURE 4 is a longitudinal sectional view similar to that of FIGURE 3, but with the latching device being illustratedin a unlatched state wherein the components may be utilized to pry open the door from its frame.

FIGURE 5 is a transverse sectional view through the latching device of this invention, taken generally along the line VV of FIGURE 3.

Description of the preferred embodiment Referring now to the drawings in detail, reference is first made to FIGURE 1, wherein there is illustrated a frame 10, door 11, and latching device 12 of the invention.

The frame 10 includes a jamb generally designated by the numeral 13, of rectangular configuration, and as illustrated, having a first vertical jamb portion 14, a first horizontal jamb portion 15, a second vertical jamb portion 16 and a second horizontal jamb portion 17, terminating in a free edge 18, which describes a rectangular opening inwardly of the door 11. The jamb 13 may be constructed of the same material as an outer surface 20 of the frame 10, such material being of thermoplastic, metal, or other materials which facilitate bending or otherwise providing the various jamb portions.

The door 11 is constructed of an outer surface member 21 of rectangular configuration, having inwardly bent lips 22 extending in a rectangular configuration receiving a compressible insulating material 23 therein. The insulating material 23 may be of foam rubber or plastic foam consruction, as desired, having a stepped periphery 24 comprising first and second horizontal portions 25 and 26 respectively connected by a generally vertically extending portion 27. The first horizontal portion 25 of the insulating material 23 is adapted to sealingly engage the first horizontal jamb port-ion 15. correspondingly, the second horizontal portion 26 of the insulating material 23 is adapted to sealingly engage the second horizontal jamb portion 17, whereby the door 11 may be tightly sealed against the frame 10 by the application of a desired sealing force through the latching device 12.

The door 11 is connected to the frame by means of a suitable hinge 28. A keeper 30 is provided, secured to the outer surface of the frame 10 by means of bolts 32, or other suitable fastening means. The keeper includes a plate 31 having a generally planar upper surface and a keeper latching portion 33 which projects upwardly from the plate 31, and is integral therewith. A recess 34 is provided in the latching portion 33 of the keeper 30 on that side which is adjacent to the door 11. The upwardly projecting latching portion 33 terminates in an arcuate upper surface 36. The uppermost portion of the recess 34 of the keeper 30 terminates in a pawl-engaging lip 35.

A frame is provided, for carrying the latching device 12, and securing the same to the upper surface 21 of the door 11 by means of bolts 39, or other suitable fastening devices extending through a mounting plate 38 of the frame 37, and fastened to the door 11. The frame 37 also includes upstanding frame sides 40 and 41 which carry a latching pawl 42 therebetween, one end of the latching pawl 42 being generally bifurcated into pawl mounting flanges 43 and 44. The mounting flanges 43 and 44 of the pawl 42 define a recess 45 therebetween, the flanges 43 and 44 being pivotally carried between the upstanding frame sides 40 and 41 of the frame 37 by means of a mounting pin 46 extending through the flanges 43 and 44 of the pawl 42, and engaged within the frame sides 40 and 41.

The pawl 42 terminates at its left-most end, as viewed in FIGURE 3 on an upper surface thereof with a keeperengaging lip 47, for engaging against the surface of the keeper 30. The pawl 42 is also provided with an arcuate camming surface 48, opposite the keeper-engaging surface 47, for camming the pawl 42 against an upper surface of the plate 31 of the keeper 30, for loosening a stuck door or the like, in a manner later to be described.

The pawl flanges 43 and 44 are connected by means of a pin 50, extending therebetween, across the recess 45.

A lever 51 is provided, secured to the upstanding sides and 41 of the frame 37. The level 51 terminates in a left-most end, as viewed in FIGURE 2, in a bifurcated end, having spaced mounting flanges 52 and 53 which define a recess 54 therebetween. The lever flanges 52 and 53 are respectively, pivotally carried by the frame sides 40 and 41 by means of mounting pins 55 and 56.

Another mounting pin 57 is provided, extending across the recess 54 between the lever mounting flanges 52 and 53, the mounting pin 57 pivotally carrying one end of a link 58. The link 58 is disposed within the recess 54, at one end, its other end being disposed within the recess of the pawl 42, and being carried by the pin 50. The link 58 thus provides a connection between the lever 51 and the pawl 42, for transmitting force and motion, in a manner later to be described.

A pin 60 extends across the recess 54, between the lever flanges 52 and 53, to which is secured one end of an extension spring 62, the other end of the spring being secured to a pin 61 which is carried by and extends between the frame sides 40 and 41, as viewed in FIGURES 3 and 4.

A pair of clearance holes 63 and 64 are provided in respective lever flanges 52 and 53, the holes 63 and 64 are being adapted to receive a padlock 65 (illustrated in phantom in FIGURE 3), for locking the lever 51 in the latched position illustrated in FIGURE 3.

The lever 51 also includes a graspable portion 66 which terminates in a free end portion 67, the free end portion 67 extending inwardly toward the door 11, to prevent accidental unlatching of the device 12 by extraneous members becoming wedged between the door 11 and the lever 51.

A bumper 68 is provided, secured to the lever 51 by means of a suitable fastener 70, the bumper 68 being adapted to prevent damage to the latching device 12 by external means as well as being adapted to prevent damage to external members by opening the latching device in a manner illustrated in FIGURE 4, if a bumper 68 were not provided. The bumper 68 may be of suitable rubber or plastic construction, or the like, as desired.

The frame 37 is provided with sloping upper surfaces 71 and 72 on its sides 40 and 41, respectively, the surfaces 71 and 72 having respective recesses 73 and 74, for receiving the padlock 65 partially therein, when the latching device 12 is in the latched condition illustrated in FIG- URE 3.

In order to effect latching engagement of the pawl 42 with the keeper 30, the lever 51 is grasped at its portion 66, and moved in a generally counter-clockwise direction, as viewed in FIGURE 3, until the keeper-engaging lip 47 of the pawl 42 is disposed within the recess 34 of the keeper 30. The lever 51 is then moved in a clockwise direction as viewed in FIGURE 3, until the keeper-engaging lip 47 of the pawl 42 tightly abuts against the pawl-en gaging lip 35 of the keeper 3%, in which position the lever 51 is in the extreme clockwise position illustrated in FIG- URE 3, with the door 11 being clamped against the frame 10, the sealing portions 25 and 26 of the insulating material 23 being tightly clamped against the jam portions 15 and 17. This clockwise movement of the lever 51 moves the link 58 from a position disposed above the axis of the pins 55 and 56, to a position slightly below the axis of the pins 55, thereby providing an over-center movement of the link 58. It will be noted, that in the fully latched position in FIGURE 3, a straight line passing through the centers of the pins 50 and 57 passes below the center line of the pins 55 and 56.

A force from inside the door 11 tending to urge the door 11 outwardly would be operative through the pawl 42, to tend to pivot the pawl 42 in a countenclockwise direction about its pin 46, thereby tending to further urge the portion of the link 58 which is disposed about the pin 50 toward counter-clockwise pivotal movement about the pin 57, thereby further urging the link 58' toward a greater over-center position, and preventing the opening of the latching device 12.

When it is desired to unlatch the device 12, the lever 51 is pivoted in a counter-clockwise direction against the force of the spring 62 until the arcuate camming surface 48 of the pawl 42 engages against the upper surface of the plate 31 of the keeper 30, during which movement the link 58 is moved to an unlatching over-center position, whereby a straight line between the pins 50 and 57 would pass above the axis of the pins 55 and 56, as illustrated in FIGURE 4. Further counter-clockwise movement of the lever 51, pivoting about the pins 55 and 56, urges the link 58 leftward, as viewed in FIGURE 4, thereby tending to pivot the pawl 42 in a counter-clockwise direction about its pin 46, the forces created by such leverage being applied to the surface of the plate 31, through the arcuate camming portion 48 of the pawl 42, and acting to pry open the door 11 from the jamb 13. In those instances when the door 11 may become jammed or frozen shut, the desirability of the device 12 is readily apparent.

That portion of the device 12 of this invention which embodies the toggle-link principle comprises those portions of the link flanges 52 and 53 between the pin 57 and the respective pins 55 and 56, in combination with the link 58 disposed between the pins 50 and 57.

The inwardly bent free end portion 67 of the lever 51 is particularly desirable when the latching device 12 of the invention is used for locking doors 11 to frames 10 on the sides of trucks and the like, in preventing the accidental opening of a door 11, by tree branches and the like becoming engaged between the door 11 and the lever 51.

The device of this invention may be used with or without the spring 62; in the latter instance, when the door 11 is swung toward a closed position the latching device 12 will be operative to permit the keeper-engaging lip 47 of the pawl 42 to always become disposed adjacent to the recess 34 of the keeper 30, the pawl 42 then being cammed further into the recess 34 by the plate 31 contacting against the arcuate edge 48 of the pawl 42, such that the device 12 will be partially latched. The lever 51 may then be pivoted in a clockwise direction to completely latch the device 12.

The lever 51 is particularly adapted to be grasped by hand, at its portion 66, for operation. However, it is to be noted that the latch is also designed to be open and closed by remote means, such as by a pole of predetermined length which is adapted to engage the lever 51. It may also be desirable to utilize a wire, rope or cable looped around the graspable portion 66 of the lever 51 to open the door 11, particularly in those instances when the door 11 is disposed in an environment of radiation or high temperature.

It is apparent that when the spring 62 is utilized in the device 12 of the invention, the lever 51 will always be urged toward a position closely adjacent the door 11, a feature which is particularly desirable in many applications of a latching device.

With the insertion of a padlock 65 across the recess 54 between the padlock-receiving holes 63 and 64, movement of the link 58 to an unlatching over-center position is clearly prevented, by engagement of an upper edge of the link 58 against a portion of the padlock 65 which extends between the holes 63 and 64, across the recess 54.

The latching device 12 is constructed having pivotal means, or pins which are not removable, thereby preventing undesirable tampering with the device 12.

The varous components may be made of malleable iron or steel, in order to preclude component breakage in cold environments.

The keeper 31 may be adjustable such that its pawlengaging lip 35 may be selectively positionable either toward or away from the frame surface 20, for those applications where an adjustable keeper is desirable.

It will be understood that various changes and modifications in the details, materials, and arrangements of parts of this invention may be made by those skilled in the art without departing from the scope of the invention as defined in the appended claims.

What is claimed is:

1. A latching device for door-like structures comprising keeper means, pawl means for locking engagement with said keeper means and movable between locking and unlocking positions of said pawl means, toggle-link means operatively connected to said pawl means for applying leverage to, and moving, said pawl means, and second class lever means for actuating said toggle-link means, wherein said toggle-link means is operatively connected to said lever means for selective movement of said togglelink means between over-center positions of said togglelink means corresponding to locking and unlocking positions of said pawl means, upon actuation of and pivotal movement by said lever means.

2. The device of claim 1, wherein a first portion of said toggle-link means and said lever means comprise a unitary lever member.

3. The device of claim 1, wherein said keeper means and pawl means are carried respectively by first and second relatively movable structures and means are provided on said pawl means and keeper means for camming said second structure into a removed position relative to said first structure upon said lever means being moved into an over-center position remote from the lever means position in a locked position of said pawl means.

4. The device of claim 3, wherein said camming means comprises a plate member mounted on said first structure and a portion of said pawl means is configured for sliding engagement against said plate.

5. The device of claim 1, wherein spring means are provided for biasing said toggle-link means toward a position corresponding to a locked position of said pawl means and for constantly biasing said lever means toward a posi- 5 tion corresponding to a locked position of said pawl means.

6. The device of claim 2, wherein said lever member includes an elongated second portion, movable toward and away from a structure which carries said member and is.

adapted to be latched, said elongated second portion of said lever member having a free end remote from said first portion; said free end extending toward the structure which carries said member.

7. A latching device comprising a keeper having a pawlengaging portion and a cam plate portion, said cam plate portion being spaced from said pawl-engaging portion and defining a pawl-receiving void therebetween and the keeper being adapted for mounting on a first of two relatively movable structures; a frame having a baseplate and sidewalls extending transversely of said baseplate, said frame being adapted for mounting with said baseplate secured to a second of two relatively movable structures; a pawl being mounted in pivotal relation to frame sidewalls, said pawl having a keeper-engaging portion and a link-engaging portion; a second class lever having a pivotal mounting portion carried by frame sidewalls, said lever having a link-engaging portion and an extended manually engageable portion; and a link having a pawl-engaging portion and a lever engaging portion, said link portions being respectively pivotally carried by said link-engaging portion of said pawl member and said link-engaging portion of said lever member for transmitting force and motion from said lever member to said pawl member, wherein said link is mounted for selective movement of its said portions between over-center link positions relative to said lever pivotal mounting portion upon actuation by said lever member.

8. The device of claim 7, wherein spring means are provided for continually urging said lever member toward an over-center position of said link corresponding to latched engagement of said pawl and latch.

9. The device of claim 7, wherein pins are provided for pivotally mounting said pivotal portions.

10. The device of claim 7, wherein said keeper is mounted on a structure adjacent to and fixed relative to a door, and said frame is carried by a door.

11. The device of claim 10, wherein said manually engageable lever portion includes a free end extending toward said door.

12. The device of claim 10, wherein bumper means is provided, carried by said manually engageable lever portion; said bumper extending away from said door.

References Cited UNITED STATES PATENTS 567,621 9/1896 Smith 292-97 1,153,514 9/1915 North et al. 292-210 2,149,375 3/1939 Wiebe 292347 2,256,447 9/1941 Burke 292 223 2,469,113 5/1949 Hooker 292-332 FOREIGN PATENTS 793,975 4/ 1958 Great Britain.

RICHARD E. MOORE, Primary Examiner,

US. Cl. X.R- 29.2347

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