US2696999A

US2696999A - Double toggle latch mechanism

Info

Publication number: US2696999A
Application number: US271301A
Authority: US
Inventors: James O Rop
Original assignee: Jervis Corp
Current assignee: Jervis Corp
Priority date: 1952-02-13
Filing date: 1952-02-13
Publication date: 1954-12-14
Anticipated expiration: 1971-12-14

Description

2 Shee ts-Sheet 1 J. O. ROP

DOUBLE TOGGLE LATCH MECHANISM Dec. 14, 1954 Filed Feb.

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DOUBLE TOGGLE LATCH MECHANISM Filed Feb. 13, 1952 2 Sheets-Sheet 2 United States Patent DOUBLE TGGGLE LATCH MECHANISM James 0. Rop, Grandville, Mich assignor to Jervis Corporation, Grandville, MiChi, a corporation of Michigan Application February 13, 1952, Serial No. 271,301

12 Claims. (Cl. 292-332) This invention relates to a latch mechanism having toggle means for holding it alternately in a keeper engaging or locked position and in a cocked or unlocked position. It is an object of the invention to provide an improved latch mechanism of that character.

It is another object of the invention to provide a latch mechanism which is held rigidly in its keeper engaging and cocked positions.

It is another object of the invention to provide an improved latch mechanism which is held rigidly in its keeper engaging and cocked positions while being readily releasable therefrom by the application of proper forces.

It is another object of the invention to provide an improved cocking latch mechanism which requires a relatively light tripping force and which moves positively into cocked position when Withdrawn from a cooperating keeper while permitting substantial leeway in the positioning and dimensions of such keeper.

It is another object of the invention to provide an improved latch mechanism having the characteristics prescribed above while being simple, reliable, and economical to manufacture.

In accordance with one embodiment of the invention two bolt members are provided, corresponding ends of which are interconnected by toggle joints. The bolt members are pivotable about points intermediate their ends and are so spaced apart relative to the dimensions of the toggle joints that when the bolt members are in their keeper engaging positions one toggle joint is toggled while the other is collapsed, and when the bolt members are in their cocked posit-ion the other toggle joint is toggled while the first-mentioned joint is collapsed. Spring means are provided for urging both toggle joints toward their toggled positions whereby neither toggled joint is readily collapsed by inadvertent jarring. Nevertheless the toggled joint, whether it be the one holding the bolt members in cocked position or the one holding the bolt members in keeper engaging position is readily collapsed by a relatively small force applied directly against the center of the toggle joint. Additional spring means are preferably employed for urging the bolt members toward their keeper engaging positions. The latter spring means are effective, barring the application of external forces, to drive the bolt members forcibly into their keeper engaging posit-ions under all conditions except when the latch mechanism is in or nearly in full cocked position.

Accordingly, it is another object of the invention to provide an improve-d latch mechanism having a pair of bolt members and toggle means interconnecting corresponding ends of the bolt members, the latter being pivotable about points intermediate their end-s.

This invention, together with further objects and advantages thereof, will best be understood by reference to the following description taken in connection with the accompanying drawings, and its scope will be pointed out in the appended claims.

In the drawings, in which like parts are designated by like reference numerals,

Fig. 1 is a plan view of a latch mechanism illustrating one embodiment of the invention, the external housing of the latch mechanism being broken away.

Fig. 2 is a cross-sectional view taken along the line 22 of Fig. 1;

Fig. 3 is a cross-sectional view similar to Fig. 2 but illustrating the latch mechanism in a different operating position;

Patented Dec. 14, 1954 "ice Fig. 4 is a cross-sectional view taken along the line 44 of Fig. 3;

Fig. 5 is a cross-sectional view taken along the line 55 of Fig. 3;

Fig. 6 is a cross-sectional view taken along the line 66 of Fig. 3; and

Fig. 7 is a partial plan view of an alternative embodiment of the invention.

A latch mechanism constructed in accordance with the invention is well adapted for use on refrigerators and the embodiment of the invention illustrated in the drawings is shown in such an application.

-In Fig. 1 the latch mechanism 10 is shown as being secured to a refrigerator door 11, a keeper or strike 12 for cooperating with the latch mechanism 10 and associated cover member 12a being secured to the door frame 13 of the refrigeraton The door 11 is shown in its closed position in Fig. l, a suitable gasket, not shown in the drawings, normally being employed to form a tight joint between the door 11 and the door frame 13. It will be appreciated that the door 11 is mounted on suitable hinges not shown in the drawings and that the initial opening movement of the door 11 is downwardly as viewed in Figs. 1, 2 and 3.

The latch mechanism includes a housing 15 best seen in Figs. 4, 5 and 6, various operating parts of the latch being supported on said housing. A pair of bolt members 16 and 17 are provided for engaging the keeper 12 to hold the door shut. In the embodiment of the invention illustrated, each bolt member 16 and 17 is actually a channel-shaped member as may be seen best in Fig. 5. Both legs of each channel-shaped bolt member are employed in securing the respective bolt members to various pins subsequently to be described. This results in a strong, rigid construction in which the bolt members are restrained from bending and from wobbling.

The bolt member 16 is pivot-ally mounted near its center point on a pin 18 which passes through both legs of the channelshaped bolt member and through opposed walls of thehousing 15. The bolt member 17 is similarly mounted on a pin 19.

At the upper end of the bolt member 16, as viewed in Figs. 2 and 3, a toggle link 20 is pivotally secured thereto by a pin 21. It will be noted by reference to Fig. 4 that the link 20 actually comprises a pair of arms. Since these arms act in concert they are referred to herein as comprising a single link. Another toggle link 22 is similarly secured to the upper end of the bolt member 17 by a pin 23 and the two

toggle links

20 and 22 are pivotally connected to each other by a pin 24.

Similar toggle links 26 and 27 are pivotally secured to the respective bolt members 16 and 17 at their lower ends by

pins

28 and 29 respectively, and are pivotally secured to each other by a pin 30.

A roller 31 is rotatably mounted on the pin 21 intermediate the two arms forming the toggle link 20, and a similar roller 32 is rotatably mounted on the pin 23 intermediate the two arms forming the toggle link 22. These rollers are adapted to engage the keeper 12 and serve to hold the latch mechanism in fixed position relative to the keeper when they enter

corresponding depressions

35 and 36 of the keeper 12. It will be noted in Fig. 2 that when the rollers 31 and 32 are so engaged with the keeper, the toggle links 26 and 27 are substantially aligned and are n toggled position. More specifically, any force tendngto move the rollers 31 and 32 outwardly of each other 1s rigidly resisted by the toggle joint formed by the toggle links 26 and 27. When the latch mechanism is in its cocked position illustrated in Fig. 3, the rollers 31 and 32 are spaced apart by a sufficient distance that they are removed from the

depressions

35 and 36 in the keeper 12 with the result that the latch mechanism is free of the keeper. With the latch mechanism in this cocked position, the toggle jOlIlt formed by the toggle links 26 and 27 is collapsed while the toggle joint formed by the

toggle links

20 and 22 is in toggled position, the

links

20 and 22 being substantially aligned. When the latch mechanism is in this toggled position any force applied to straighten the toggle joint 26, 27 is rigidly resisted by the

toggle joint

20, 22.

The latter toggle joint may, however, be readily collapsed to permit the bolt members 16 and 17 and more spec1fically therollers 31 and 32 to assume their keeper engaging positions by application of a relatively light force d rected against the center of the

toggle joint

20, 22. This force may be obtained by moving the refrigerator door 11 to its closed position wherein the center of the

toggle joint

20, 22 is brought into engagement with a depression 39 at the outer end of the keeper 12. Slight pressure exerted by the keeper against the pin 24 readily collapses the

toggle joint

20, 22 to permit the bolt members 16 and 17 to move into their keeper engaging positions illustrated in Fig. 2.

A spring bar 40 is pivotally connected at one end to the p1n'24 joining the arms of the

toggle links

20 and 22, and is pivotally and slidably connected at its other end to the pin 3% joining the arms of the toggle links 26 and 27. A slot 41 at the lower end of the link 40 as viewed in Fig. 2 permlts sliding movement of the spring bar 40 with respect to the pin 30, such movement being provided for since the distance between the

pins

24 and 30 is greater when the latch mechanism is in either of its extreme positions than when it is in an intermediate position, as will be well understood by those skilled in the art. Also pivotally connected to the pin 30 is a U-shaped actuator 42, the two legs of which engage the pin 30 outwardly of the spring bar 40 and immediately inwardly of the arms of the toggle links 26 and 27.

The spring bar 40 serves to support a pair of compression springs 43 and 44. The spring 43 at its upper end engages a shoulder 40a on the spring bar 40 and at its lower end engages the upper end of the actuator 42. This spring thereby serves to urge the

pins

24 and 30 apart. This means that the spring 43 urges both

toggle joints

20, 22 and 26, 27 toward their toggled positions. However, when the latch mechanism is in or near either of its extreme positions, namely the keeper engaging position or the cocked position, the initial movement of the latch mechanism away from that extreme position involves a greater movement of the

24 or 30 of the toggled joint than of the pin of the collapsed joint. More specifically, when the latch mechanism is in the cocked position as is illustrated in Fig. 3, movement of the latch mechanism away from that position and toward the keeper engaging position illustrated in Fig. 2 will initially involve a more rapid movement of the pin 24 than of the pin 30. As a result of this fundamental characteristic of the apparatus, the spring 43 urges the toggled joint to remain in its toggled position, regardless of whether it is the toggle joint 20, 22 holding the bolt members in their cocked positions or the toggle joint 26, 27 holding the bolt members in their keeper engaging positions. The spring 43 therefore tends to maintain in its toggled position whichever toggle joint may be toggled and thereby minimizes the possibility that the toggled joint may be collapsed by any inadvertent jarring of the mechanism.

The spring 44 bears at its lower end against the actuator 42 and at its upper end against a pair of ears 46 which are rigid with respect to the housing 15 and preferably struck therefrom. The spring 44 therefore operates directly against the toggle joint 26, 27 and urges that toggle joint toward its toggled position, corresponding to the keeper engaging position of the latch mechanism. The spring 44 is relatively powerful as compared to the spring 43 and when the toggle joint 20, 22 is collapsed it urges the rollers 31 and 32 forcefully into the

depressions

35 and 36 whereby the latch mechanism may serve to draw the refrigerator door 11 toward the door frame 13 and compress a gasket therebetween with substantial force in the event that the operator fails to slam the door with proper force but only moves the door toward closed position far enough to trip the toggle joint 20, 22.

The apparatus for operating the latch mechanism may be of any suitable form and does not constitute a part of the present invention. The operating apparatus disclosed in Fig. 1 will therefore be described only briefly.

A handle 50 is pivotally mounted on the door 11 through a pair of cars 51 and a pin 52. Also pivotally mounted on the pin 52 is a bar 53, the free end of which is positioned to bear against the outer end of the actuator 42. A spring 54 is Wound around the pin 52, the ends of this spring pressing against the outer surface of the door 11 and the inner surface of the bar 53. The spring therefore urges the bar 53 and hence the handle 50 in a'clockwise direction as viewed in Fig. 1

counterclockwise movement of the handle 50 by an operator forces the bar 53 to press against the end of the actuator 42. Assuming that the latch mechanism is in its keeper engaging position, the pressure of the bar 53 against the actuator 42 collapses the toggle joint 26, 27 and continued pressure further compresses the spring 44 and forces the latch mechanism into the cocked position illustrated in Fig. 3. Once this position has been assumed the toggled

links

20, 22 prevent the spring 44 from returning the latch mechanism to keeper engaging position even after the handle 50 has been released.

One of the problems in providing a cocking latch which operates reliably is to assure the cocking of the latch when the latch is so operated as to release it from the keeper. Normally this requires very accurate setting of the keeper in order to assure that when the latch bolt is in such position that it will just barely clear the keeper, it will be in cocked position. At the same time it is desired that the latch mechanism not be driven substantially beyond a minimum cocked position since such movement ordinarily means that a substantial uncocking force is required to move the latch mechanism into keeper engaging position.

In the illustrated embodiment of the invention, the bolt members 16 and 17 need not be moved completely into cocked position in order to clear the keeper. If the bolt members are close to their cocked positions when the bolt rollers clear the keeper the spring 43 will exert a powerful outward thrust on the

pins

21 and 23 and snap the toggle links 20 and 22 into toggled position because of the mechanical advantage resulting when the bolt members 16 and 17 approach the cocked position and the toggle links 20 and 22 approach alignment. Because of this feature of the latch, substantial leeway is permissible in the dimensions of the keeper and in its position on the door frame without danger that the latch mechanism may be drawn free of the keeper without being moved completely into cocked position.

The spring 43 therefore assures that the bolt members 16 and 17 will move to their cocked positions whenever the latch mechanism is withdrawn from the keeper 12 in spite of substantial leeway in the dimensions and positioning of the keeper. The spring 43 also serves to maintain the latch bolts in their cocked positions against the effect of any substantial jarring action and against the effect of any force other than one directed downwardly, in Figs. 2 and 3, against the center of the toggle joint 20, 22.

Where the described latch is applied to a refrigerator door it is desirable, as indicated above, that the latch mechanism exert a substantial closing force over an appreciable distance in order that the latch mechanism, once tripped, may serve to compress a sealing gasket which may be arranged between the refrigerator door and the facing portion of the door frame. This assures that the gasket will be properly compressed regardless of the force with which the door is closed, that is, the gasket will be properly compressed provided only that the door is shut with sufficient force to trip the latch mechanism.

Accordingly, it is preferred that the latch mechanism be tripped just as the rollers 31 and 32 reach the lateral high points of the keeper. As the rollers 31 and 32 then approach each other, under the influence of the heavy spring 44, the rollers draw the door shut and compress a sealing gasket as the rollers enter the recessed

portions

35 and 36 of the keeper.

In the embodiment of the invention illustrated in Figs. 1-6 a problem sometimes arises in attempting to attain maximum closing movement of the door by forces stored in the spring 44 in that if the door is closed with just sufficient force to trip the latch mechanism, the rollers 31 and 32 may strike the lateral peaks of the keeper on dead center thereof. In other words the rollers may not have passed by the dead center position so that they will positively enter

recesses

35 and 36 and draw the door shut to compress the sealing gasket. This is particularly likely to happen where, because of manufacturing tolerances, one of the rollers 31 or 32 may be minutely to one side of the corresponding lateral peak of the keeper while the other roller is minutely to the other side, whereby one roller will urge the door inwardly while the other roller tends to ride down the outer sloping surface of the keeper and move the door in an opening direction.

This possibility of the latch coming to rest on the dead center position may be avoided by permitting the latch mechanism to trip only after the rollers 31 and 32 are substantially past the lateral peaks of the keeper. The latter procedure may however reduce the amount of door closing and gasket compressing movement which may be obtained by the latch mechanism. The difficulty can also be eliminated by providing a shallower slope on the outer portions of the keeper recesses 35 and 36, that is by moving the lateral peaks of the keeper outwardly away from the casing 13 and elongating the

recesses

35 and 36 in the direction of opening and closing movement of the door 11. The latch mechanism can then be made to trip when the rollers 31 and 32 are past or inwardly of the lateral peaks of the keeper and will still have the same amount of closing movement after tripping of the latch mechanism as is provided in the arrangement disclosed in Figs. 1-6. However, a shallower sloped keeper will eventuate a Weaker closing force than is obtained with the illustrated keeper; accordingly, the sealing gasket may not be adequately compressed unless the latch spring 44 were made more powerful.

The preferred arrangement for substantially eliminating the possibility of the latch mechanism coming to rest with the rollers engaging the lateral peaks of the keeper, Without affecting the other desirable characteristics of the latch mechanism of Figs. 1-6, is illustrated in Fig. 7. Most of the operating parts of the latch of Fig. 7 are identical to those of the latch mechanism disclosed in Figs. 1-6 and are designated by the same reference numerals with the exception that a prime marking is added thereto. Accordingly, the latchmechanism of Fig. 7 need not be described in its entirety. The difference between the two latch mechanisms disclosed is that in Fig. 7 the pins 21' and 23 supporting the rollers 31' and 32 pass through slots 60 and 61 in the toggle links and- 22' rather than through circular openings such as are employed in the latch mechanism of Figs. 1-6.

When the latch mechanism is in its cocked position corresponding to the position illustrated in Fig. 3 the spring 44' urges the bolt members 16 and 17' together at their upper'or inner ends and accordingly the roller pins 21' and 23' engage the inner ends of the slots 60 and 61. As the door is moved toward its closed position with the latch mechanism in cocked position the rollers 31' and 32' will strike the outer sloping faces of the keeper 12'. If the door is closed with sufiicient force the rollers 31 and 32' will be forced outwardly, further compressing the latch spring 44, until the rollers may pass' over the lateral peaks of the keeper 12.

As in the latch mechanism of Figs. l-6, this latch mechanism is intended to be tripped just as the rollers 31" and 32 lie alongside the lateral peaks of the keeper. However, since an appreciable force must be applied to bring the latch mechanism to its tripping position, with the rollers 31 and 32' directly alongside the lateral peaks of the keeper, the possibility that the door and the latch mechanism will come to a stop on this dead center position is extremely small. t would be next to impossible for an operator deliberately to trip the latch mechanism with the rollers 31 and 32 in the dead center position 'with respect to the lateral peaks of the keeper since the resistance offered by the latch mechanism to a steady applied closing force suddenly reduces to zero as the rollers 31 and 32' reach the lateral peaks of thekeeper.

In the event that the closing force is insuificient to force the rollers 31 and 32 apart such that they may pass over the lateral peaks of the keeper, the rollers will draw together again under the influence of the spring 44 and to the extent permittedby the slots 60 and 61. In so doing the rollers roll along the sloping outer surfaces of the keeper 12 and move the door toward its open position. Accordingly, it will be readily detected by the operator that the. door has failed to close.

Both of the latch mechanisms disclosed herein have been found to have excellent operating characteristics,

--the embodiment illustratedin Fig. 7 ofiering one solution to a detail problem faced in the designing of the latch, mechanism. As pointed out above this same problem may be avoided by using the latch mechanism of Figs. l-6' with a slightly modified keeper which causes tripping of the latch mechanism after the rollers 31 and 32 have passed inwardly of the lateral peaks of the keeper.

The latch mechanism in general is one which is rigidly held in either cocked or keeper engaging position while being tripped by a properly directed force of relatively small magnitude. are well' protected against inadvertent application of 6 tripping forces since both toggle. joints are at all times contained within the housing 15. Also the toggle joints form a very rugged construction while at the same time being easily operated and economical to manufacture.

It will be apparent that the invention may be varied in its physical embodiment without departing from the spirit of the invention, and it is desired, therefore, that life invention be limited only by the scope of the appended c anns.

The invention having thus been described, what is claimed and desired to be secured by Letters Patent is:

1. In a latch mechanism for cooperating with a keeper having a pair of opposed latch engaging hooks; a body member, a pair of elongated bolt members having keeper engaging ends, said bolt members being pivotally mounted on said body member intermediate their ends for pivotal movement between keeper engaging positions and cocked positions, first toggle means interconnecting said bolt members adjacent said keeper engaging ends, second toggle means interconnecting said bolt members adjacent their other ends, said first toggle means being toggled and said second toggle means being collapsed when said bolt members are in said cocked positions, said second toggle means being toggled and said first toggle means being collapsed when said bolt members are in said keeper engaging positions, and bolt actuating means for collapsing said second toggle means to permit movement of said bolt members from said keeper engaging positions to said cocked positions, said first toggle means being collapsible by striking said keeper to permit movement of said bolt members from said cocked positions to said keeper engaging positions.

2. In a latch mechanism for cooperating with a keeper having a pair of opposed latch engaging hooks; a body member, a pair of elongated bolt members having keeper engaging ends, said bolt members being pivotally mounted on said body member intermediate their ends for pivotal movement between keeper engaging positions and cocked positions, first toggle means interconnecting said bolt members adjacent said keeper engaging ends, second toggle means interconnecting said bolt members adjacent their other ends, said first toggle means being toggled and said second toggle means being collapsed when said bolt members are in said cocked positions, said second toggle means being toggled and said first toggle means being collapsed when said bolt members are in said keeper engaging positions, bolt actuating means for collapsing said second toggle means to permitmovement of said bolt members from said keeper engaging positions to said cocked positions, said first toggle means being collapsible by striking said keeper to permit movement of said bolt members from said cocked positions to said keeper engaging positions, and spring means urging both of said toggle means toward toggled position 1 whereby an appreciable force is required to collapse said It will be noted that the toggle joints .8

toggle means.

3. In a latch mechanism for cooperating with a keeper having a pair of opposed latch engaging books; a body member, a pair of elongated bolt members having keeper engaging ends, said bolt members being pivotally mounted on said body member intermediate their ends for pivotal movement between keeper engaging positions and cooked positions, first toggle means interconnecting said bolt members adjacent said keeper engaging ends, second toggle means interconnecting said bolt members adjacent their other ends, said first toggle means being toggled and said second toggle means being collapsed in a direction toward said keeper when said bolt members are in said cocked positions, said second toggle means being toggled and said first toggle means being collapsed in a direction away from said keeper when said bolt members are in said keeper engaging positions, bolt actuating means for collapsing said second toggle means to permit movement of said bolt members from said keeper engaging positions to said cocked positions, said first toggle means being collapsible by striking said keeper to permit movement of said bolt members from said cocked positions to said keeper engaging positions, and a compression spring interconnecting said first and second toggle means and urging both toward toggled position.

4. In a latch mechanism for cooperating with a keeper having a pair of opposed latch engaging hooks; a body member, a pair of elongated bolt members having keeper engaging ends, said bolt members being pivotally mounted on said body member intermediate their ends for pivotalmovement between keeper engaging positions and cocked positions, first toggle means interconnecting said bolt members adjacent said keeper engaging ends, second toggle means interconnecting said bolt members adjacent their other ends, said first toggle means being toggled and said second toggle means being collapsed in a direction toward said keeper when said bolt members are in said cocked positions, said second toggle means being toggled and said first toggle means being collapsed in a direction away from said keeper when said bolt members are in said keeper engaging positions, bolt actuating means for collapsing said toggle means to permit movement of said bolt members from said keeper engaging positions to said cocked positions, said first toggle means being collapsible by striking said keeper to permit movement of said bolt members from said cocked positions to said keeper engaging positions, a compression spring interconnecting said first and second toggle means and urging both toward toggled position, and spring means urging said bolt members toward said keeper engaging positions.

5. In a latch mechanism for cooperating with a keeper having a pair of opposed latch engaging books; a body member, a pair of elongated bolt members having keeper engaging ends, said bolt members being pivotally mounted on said body member intermediate their ends for pivotal movement between keeper engaging positions and cocked positions, first toggle means interconnecting said bolt members adjacent said keeper engaging ends, second toggle means interconnecting said bolt members adjacent their other ends, said first toggle means being toggled and said second toggle means being collapsed in a direction toward said keeper when said bolt members are in said cocked positions, said second toggle means being toggled and said first toggle means being collapsed in a direction away from said keeper when said bolt members are in said keeper engaging positions, bolt actuating means for collapsing said second toggle means to permit movement of said bolt members from said keeper engaging positions to said cocked positions, said first toggle means being collapsible by striking said keeper to permit movement of said bolt members from said cocked positions to said keeper engaging positions, a bar interconnecting said first and second toggle means and slidable with respect to at least one of said toggle means, a compression spring surrounding said bar and urging both of said toggle means toward toggled position, and spring means surrounding said bar and urging said second toggle means toward toggled position.

6. In a latch mechanism for cooperating with a keeper having a pair of opposed latch engaging hooks; a body member, a pair of elongated bolt members having keeper engaging ends, said bolt members being pivotally mounted on said body member intermediate their ends for pivotal movement between keeper engaging positions and cocked positions, a first pair of toggle links pivotally connected at one end each to the other and pivotally connected at their other ends respectively to said bolt members adjacent said keeper engaging ends, a second pair of toggle links pivotally connected at one end each to the other and pivotally connected at their other ends respectively to said bolt members adjacent their other ends, said second pair of links being substantially aligned and toggled and said first pair of links forming an acute angle when said bolt members are in said keeper engaging positions, and said first pair of links being substantially aligned and toggled and said second pair of links forming an acute angle when said bolt members are in said cocked positions, and bolt actuating means for collapsing the toggle joint formed by said second pair of links when said bolt members are in said keeper engaging positions to permit movement of said bolt members from said keeper engaging positions to said cocked positions, the toggle joint formed by said first pair of links when said bolt members are in said cocked positions being collapsible by striking of said links against said keeper to permit movement of said bolt members from said cocked positions to said keeper engaging posions.

7. In a latch mechanism for cooperating with a keeper having a pair of opposed latch engaging hooks; a body member, a pair of elongated bolt members having keeper engaging ends, said bolt members being pivotally mounted on said body member intermediate their ends for pivotal movement between keeper engaging positions and cocked positions, a first pair of toggle links pivotally connected at one end each to the other and pivotally connected at their other ends respectively to said bolt members adjacent said keeper engaging ends, a second pair of toggle links pivotally connected at one end each to the other and pivotally connected at their other ends respectively to said bolt members adjacent their other ends, said second pair of links being substantially aligned and toggled and said first pair of links forming an acute angle opening toward said keeper when said bolt members are in said keeper engaging positions, and said first pair of links being substantially aligned and toggled and said second pair of links forming an acute angle opening away from said keeper when said bolt members are in said cocked positions, bolt actuating means for collapsing the toggle joint formed by said second pair of links when said bolt members are in said keeper engaging positions to permit movement of said bolt members from said keeper engaging positions to said cocked positions, the toggle joint formed by said first pair of links when said bolt members are in said cocked positions being collapsible by striking of said links against said keeper to permit movement of said bolt members from said cocked positions to said keeper engaging positions, and a compression spring interconnecting said pairs of links and urging both pairs toward toggled position.

8. In a latch mechanism for cooperating with a keeper having a pair of opposed latch engaging hooks; a body member, a pair of elongated bolt members having keeper engaging ends, said bolt members being pivotally mounted on said body member intermediate their ends for pivotal movement between keeper engaging positions and cocked positions, a first pair of toggle links pivotally connected at one end each to the other and pivotally connected at their other ends respectively to said bolt members adjacent said keeper engaging ends, a second pair of toggle links pivotally connected at one end each to the other and pivotally connected at their other ends respectively to said bolt members adjacent their other ends, said second pair of links being substantially aligned and toggled and said first pair of links forming an acute angle opening toward said keeper when said bolt members are in said keeper engaging positions, and said first pair of links being substantially aligned and toggled and said second pair of links forming an acute angle opening away from said keeper when said bolt members are in said cocked positions, bolt actuating means for collapsing the toggle joint formed by said second pair of links when said bolt members are in said keeper engaging positions to permit movement of said bolt members from said keeper engaging positions to said cocked positions, the toggle joint formed by said first pair of links when said bolt members are in said cocked positions being collapsible by striking of said links against said keeper to permit movement of said bolt members from said cocked positions to said keeper engaging positions, a compression spring interconnecting said pairs of links and urging both pairs toward toggled position, and spring means urging said bolt members toward said keeper engaging positions.

9. In a latch mechanism for cooperating with a keeper having a pair of opposed latch engaging hooks; a body member, a pair of elongated bolt members having keeper engaging ends, said bolt members being pivotally mounted on said body member intermediate their ends for pivotal movement between keeper engaging positions and cocked positions, a first pair of toggle links pivotally connected at one end each to the other and pivotally connected at their other ends respectively to said bolt members adjacent said keeper engaging ends, a second pair of toggle links pivotally connected at one end each to the other and pivotally connected at their other ends respectively to said bolt members adjacent their other ends, said second pair of links being substantially aligned and toggled and said first pair of links forming an acute angle opening toward said keeper when said bolt members are in said keeper engaging positions, and said first pair of links being substantially aligned and toggled and said second pair of links forming an acute angle opening away from said keeper when said bolt members are in said cocked positions, bolt actuating means for collapsing the toggle joint formed by said second pair of links when said bolt members are in said keeper engaging positions to permit movement of said bolt members from said keeper engaging positions to said cocked positions, the toggle joint formed by said first pair of links when said bolt members are in said cocked positions being collapsible by striking of said links against said keeper to permit movcxnent of said bolt members from said cocked positions to said keeper engaging positions, a bar interconnecting said pairs of links and slidable with respect to at least one pair thereof, a compression spring surrounding said bar and urging both of said pairs of links toward toggled position, and spring means surrounding said bar and urging said second pair of links toward toggled position.

10. In a latch mechanism for cooperating with a keeper, an elongated bolt member having a keeper engaging end, said bolt member being pivotable about a point intermediate its ends between a keeper engaging position and a cocked position, first toggle means connected to said bolt member adjacent said keeper engaging end, second toggle means connected to said bolt member adjacent its other end, said first toggle means being toggled and said second toggle means being collapsed when said bolt member is in said cocked position, said second toggle means being toggled and said first toggle means being collapsed when said bolt member is in said keeper engaging position, and bolt actuating means for collapsing said second toggle means to permit movement of said bolt member from said keeper engaging position to said cocked position, said first toggle means being collapsible by striking said keeper to permit movement of said bolt member from said cocked position to said keeper engaging position.

11. In a latch mechanism for cooperating with a keeper, an elongated bolt member having a keeper engaging end, said bolt member being pivotable about a point intermediate its ends between a keeper engaging position and a cocked position, first toggle means connected to said bolt member adjacent said keeper engaging end, second toggle means connected to said bolt member adjacent its other end, said first toggle means being toggled and said second toggle means being collapsed in a direction toward said keeper engaging end of said bolt member when said bolt member is in said cocked position, said second toggle means being toggled and said first toggle means being collapsed in a direction away from said keeper engaging end of said bolt memher when said bolt member is in said keeper engaging position, and spring means interconnecting said first and second toggle means and urging both of said toggle means toward toggled position whereby an appreciable force is required to collapse either of said toggle means.

12. In a latch mechanism for cooperating with a keeper having a pair of opposed latch engaging hooks; a body member, a pair of elongated bolt members having keeper engaging ends, said bolt members being pivotally mounted on said body member intermediate their ends for pivotal movement between keeper engaging positions and cocked positions, first toggle means interconnecting said bolt members adjacent said keeper engaging ends, second toggle means interconnecting said bolt members adjacent their other ends, said first toggle means being toggled and said second toggle means being collapsed when said bolt members are in said cocked positions, said second toggle means being toggled and said first toggle means being collapsed when said bolt members are in said keeper engaging positions, and bolt actuating means for collapsing said second toggle means to permit movement of said bolt members from said keeper engaging positions to said cocked positions, said first toggle means being collapsible by striking said keeper to permit movement of said bolt members from said cocked positions to said keeper engaging positions, said first toggle means being slotted at its connections with said bolt members whereby said keeper engaging ends of said bolt members may be moved resiliently outwardly of said cocked positions when said first toggle means is toggled.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,574,023 Compton et al Feb. 23, 1926 2,001,443 Williams May 14, 1935 2,342,250 Burke Feb. 22, 1944 2,559,068 Doeg July 3, 1951 FOREIGN PATENTS Number Country Date 41,578 Austria Mar. 25, 1910