US3526423A - Toggle latch with preloaded drawhook - Google Patents

Description

2 Sheets-Sheet 1 J. R. NEWCOMER ETAL TOGGLE LATCH WITH PRELOADED DRAWHOOK Sept. l, 1970` Filed May 5, 1968 MKM ' .4 T 70E/Veys Sept 1Q 1970 J. R. NEwCoMER -12T/u. 3,526,423

TOGGLE LATCH WITH PRELOADED DRAWHOOK Filed Hay 3, 1968 2 SheetsSheefc 2 VIJIIIIIIIIIIIIIIIIIIII,\\

IN VENTOR Ti 7 un coa R. Ne wao/MSR `C3 HTTORNEYS United States Patent O Fice 3,526,423 TOGGLE LATCH WITH PRELOADED DRAWHOOK Jacob R. Newcomer, Wyckol, and Leonard A. Bayer, Ridgefield Park, NJ., assignors to Rex Chainbelt Inc., Milwaukee, Wis., a corporation of Wisconsin Filed May 3, 1968, Ser. No. 726,478 Int. Cl. EOSc 5/04, 19/14 U.S. Cl. 292-113 13 Claims ABSTRACT OF THE DISCLOSURE BACKGROUND OF THE INVENTION Various forms of toggle latches are known in the prior art. 'Most of these latches include a handle mounted for swinging movement on one of two members to be joined for movement between an open position and a closed position. The handle pivotally supports a drawhook for movement around an axis displaced from the handle mounting axis. As the handle moves from open to closed position, the drawhook is brought into engagement with the strike on the other of the bodies and upon continued movement of the handle, the bodies are drawn together and, finally, the drawhook pivot moves to a position beyond dead center with respect to the handle pivot to lock the latch.

While latches of the type described above are generally satisfactory, they do not vmeet many special requirements. For example, in many instances it is desirable to impart a high load to the joint between the two bodies as soon as deiiection of the drawhook starts as the latch is being locked. In latches of the prior art this load is relatively low. Owing to the fact that the locking force in latches of the type described above is a result of stresses inthe material of which the parts themselves are made, the drawhook cannot withstand excessive vibration and the latch has a relatively short life of operating cycles. Some special latch mountings have projecting parts over which the drawhook must move in order to engage the strike. In the prior art no latch having a preloaded drawhook is known which can accommodate such a mounting.

We have invented a toggle latch which overcomes the defects of toggle latches of the prior art pointed out hereinabove. The drawhook of our toggle latch is preloaded so as to impact a high load on the joint as soon as the drawhook begins its deection upon locking up of the latch. Our latch has a high capability of withstanding vibrations. It has an extremely long life as contrasted with toggle latches of the prior art. Our latch has a preloaded drawhook and yet can accommodate special mountings having upwardly projecting parts. Our latch is simple in construction and compact for the results achieved thereby. It is inexpensive to construct.

SUMMARY OF THE INVENTION One object of our invention is to provide a toggle latch with a preloaded drawhook which overcomes the defects of toggle latches of the prior art.

Another object of our invention is to provide a toggle latch which imparts a high load on the joint being made 3,526,423 Patented Sept. 1, 1970 immediately upon the start of deflection of the drawhook as the latch is locked up.

A further object of our invention is to provide a toggle latch having a high capacity for absorbing vibrations without damage.

A still further object of our invention is to provide a toggle latch which has a long life.

Yet another object of our invention is to provide a toggle latch having a preloaded drawhook which can accommodate special mountings having upwardly projecting parts.

A still further object of our invention is to provide a preloaded toggle latch which is simple in construction and compact.

Yet another object of our invention is to provide a preloaded toggle latch which is relatively inexpensive to construct.

Other and further objects of our invention will appear from the following description.

In general our invention contemplates the provision of a toggle latch having a preloaded drawhook in which a handle supported for swinging movement on one of two members to be joined around a irst axis between an open position and a/closed position pivotally supports a link for movement around a second axis displaced from the irst axis. The link carries a drawhook for translatory movement between a retracted position and an extended position relative thereto. Preloaded springs bias the drawhook to its retracted position. In locking the latch up, the underside of the drawhook engages an upstanding part on the mounting to hold the drawhook out of engagement with the strike. The link and the end of the drawhook are pushed toward the strike to rock the drawhook on the mounting part to cause it to move relative to the link to a position at which the hook can 'engage the strike. Upon continued movement of the handle the springs are loaded as the link moves relative to the drawhook and the latch is locked up.

BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings which form part of the instant specification and which are to be read in conjunction therewith and in which like reference numerals are used to indicate like parts in the various views:

FIG. 1 is a top plan view of our toggle latch with parts broken away and with other parts shown in section.

FIG. 2 is a sectional view of our toggle latch taken along the line 2-2 of FIG. l.

FIG. 3 is a side elevation of our toggle latch.

FIG. 4 is a sectional view of our toggle latch with parts removed taken along the line 4-4 of FIG. 1.

FIG. 5 is a sectional view of our toggle latch drawn on an enlarged scale and showing the relative position of the parts just prior to engagement of the drawhook with the strike.

FIG. 6 is a sectional view of our toggle latch similar to FIG. 5 showing the relative position of the parts when the drawhook has been brought to a position at which it can engage the strike.

FIG. 7 is a sectional view of our toggle latch similar to FIG. 5 showing the relative position of the parts in locked up condition.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, our toggle latch includes two members 10 and 12 which are to be joined along a line such as is the case with a container having a top hinged to a base or the like. Conveniently the two members 10 and 12 are provided with respective edge extrusions 14 and 16. In one form of extrusion 14 which we may employ, we provide the extrusion with a channel 18 having respective lips 20 and 22 running along the edges thereof. It is to be noted that the lip 22 extends above the surface of the extrusion 16. Channel 18 is formed with a groove 24 extending along itsbase. The extrusion 16 forms a strike 26 along the edge thereof which may be of an arcuate configuration so as to permit it to receive a hook to be described hereinafter. As is known in the art, extrusion 14 may be formed with a tongue 28 adapted to cooperate with a complementary groove 30 formed in the extrusion 16.

Our latch assembly, indicated generally by the reference character 32, has a mounting bracket provided with a base 34 and respective upright supports 36 and 38. Base 34 carries respective edge flanges 40 and `42 adapted to be inserted in the channel 18 below the respective lips and 22. Locating tabs or tongues 43 struck out of the base 34 cooperate with the channel groove 24 to locate the mounting bracket properly in the channel. Since this structure per se does not form a part of our invention, it will not be discussed in further detail.

Our latch 32 includes a handle 44 having sides 46 and 48 which are attached to the uprights 36 and 38 on the mounting bracket by respective rivets 50 and 52 so as to mount the handle for swinging movement between an open position and a closed position as will be described hereinafter.

A `U-s-haped loading link of our latch includes legs 54 and 56 connected by a web 58. A pivot pin 60 extends through the legs 54 and 56 of the link and through the handle sides 46 and 48 pivotally to mount the link on the handle. If desired, we may also provide a spacer sleeve 62 carried by the pin 60 and extending between the legs 54 and 56. If it is found necessary or desirable, we may also dispose washers 64 between the ends of the legs 54 and 56 on the pin 61B and the sides 46 and 48 of the handle.

The drawhook 66 of our latch 32 has a hook portion 68 adapted to engage the strike 26. We form the end of the drawhook 66 remote from the hook portion 68 with a flange 70. Hook 66 also is provided with offsets 72 and 74 extending outwardly from the body of the hook so as to engage the upper surfaces of the link legs 54 and 56 to limit movement of drawhook 66 in a counterclockrwise direction around strike 26 as the latch assembly is locked up. We may also form reinforcing tabs 73 on the drawhook to reinforce the flange 70.

Our latch assembly includes a plurality of loading spring guide rods 76 which extend from heads 82 on the rods through openings 78 in the link web 58 and through openings 84 in flange 70 to upset heads 86 on the other ends of the rods. We may form the web 58 with retaining flanges 80 for holding the heads 82. A plurality of preloaded compression springs 88 carried by the rods 76 normally urge the drawhook 66 to the left as viewed in FIG. 2 until flange 7 0 abuts the heads 86.

Referring now to FIG. 5, we have shown the Open position of the parts just before the drawhook 68 has been brought to a position at which it can engage strike 26. It will be seen in this position of the parts that the underside of the hook rests on the lip 22 and that further movement of the handle toward closed position without more will not bring the drawhook into engagement with the strike. With the parts in this position and while holding the handle 44, we push downwardly on the link and drawhook to rock the drawhook on the lip 22 to a position at which it can engage the strike. In the course of this movement, the drawhook moves out of alignment with the link to the position shown in FIG. 6. In this manner we have accommodated the special mounting having the upstanding lip 22 while at the same time providing a preloaded drawhook.

From the positions of the parts shown in FIG. 6 handle 44 is rotated in a counterclockwise direction to the position shown in FIG. 7. Owing to the preload of springs 72 a very high initial force s applied tending to draw parts 14 and 16 together. Moreover, when the link pivot 60 lhas moved to its beyond dead center position with respect to handle pivot 52, a high lockup force is maintained. To open the latch handle 44 is merely moved in a clockwise direction from the position shown in FIG. 7.

It will be seen that we have accomplished the objects of our invention. We have provided a toggle latch having a preloaded drawhook. Our latch can accommodate special mountings having upstanding parts over which the drawhook must be moved to engage the strike while having a relatively low silhouette. It exerts a high initial force on the joint being made and maintains a relatively high force in locked up condition. It can withstand vibration and has a long life. It is simple and compact in construction. It is relatively inexpensive to fabricate.

It will be understood that certain features and subcombinations are of utiltiy and may be employed without reference to other features and subcombinations. It is further obvious that various changes may be made in details without departing from the spirit of our invention. It is, therefore, to be understood that our invention is not to be limited to the specific details shown and described.

Having thus described our invention., whatwe vclaim is:

`1. A latch assembly including in combination a handle, a drawhook, means mounting said drawhook on said handle for pivotal movement around a first axis on said handle while permitting translatory movement of said drawhook relative to said first axis between a retracted position and an extended position, means biasing said drawhook toward said first axis, a support having a base, means mounting said handle adjacent one end thereof on said support for pivotal movement around a second axis spaced from said base, said handle mounting means mounting said handle for movement between an open position at which the other end thereof is remote from the drawhook and a closed position at which the other end thereof is adjacent the drawhook, the distance between said second axis and said base being greater than the distance between said axes to permit said first axis to swing through the space between said second axis and said base as said handle moves from open to closed position.

2. A latch assembly as in claim 1 in Which said drawhook mounting means comprises a link, means mounting said link for pivotal movement around said first axis and means mounting said drawhook on said link for translatory movement between a retracted position and an extended position relative to said link.

3. A latch assembly as in claim 2 including interengageable means on said drawhook and on said link.

4. A latch assembly as in claim 2 in which said means mounting said drawhook on said link comprises a pin.

5. A latch assembly as in claim 2 in which said means mounting said drawhook on said link permits limited pivotal movement of said drawhook relative to said link.

6. A latch assembly as in claim 2 in which said link comprises a first flange, said drawhook comprises a second flange and said biasing means is a preloaded compression spring extending between said flanges.

7. A latch assembly as in claim 2 in which said means mounting said drawhook on said link comprises a first flange on said link, a second flange on said drawhook and a rod engaging said flanges and being slidable with relation to one of the flanges.

8. A latch assembly as in claim 2 in which said means mounting said drawhook on said link comprises a flange on said link, a flange on said drawhook and a rod engaging said flanges and being slidable with relation to one of said flanges, said biasing means comprising a spring carried by said rod and bearing between said flanges.

9. A latch assembly as in claim 2 in which said link is generally U-shaped having legs and a connecting web, said link mounting means comprising a pin passing through said legs, said drawhook comprising a hook portion at one end thereof and a flange at the other end thereof, said drawhook mounting means comprising a rod passing through said flange and being slidable with relation to said flange and a spring carried by said rod and bearing between said flange and said web.

10. A latch assembly as in claim 2 in ywhich said drawhook comprises a laterally olset tab, said tab adapted to engage said link in the closed position of said handle.

11. A latch assembly as in claim 2 in which said link is generally U-shaped having legs and a connecting Web, said link mounting means comprising a pivot pin passing through said legs adjacent ends thereof remote from said web, said drawhook hiving a hook portion at an end thereof adjacent to said web and having a ange at the other end thereof, said drawhook mounting means comprising a rod passing through said web and said flange, said biasing means comprising a spring carried by said rod and bearing between said web and said ange, and respective offset laterally extending tabs on said drawhook overlying said legs.

12. A latch assembly for securing a rst body to a second body having a strike thereon including in combination, a handle, means mounting said handle on said first body lfor swinging movement of said handle around a iirst pivotal axis between an open position and a closed position, a link, a drawhook having a hook portion for engaging said strike, means mounting said drawhook on said link for translatory movement between a retracted position and an extended position relative to said link, means for biasing said drawhook toward its retracted position and into alignment with said link, means mounting said link on said handle for pivotal movement around a second axis spaced from said rst axis for movement of said drawhook from a position corresponding to said handle-open position at which said drawhook is out of engagement with said strike to a second position corresponding to the handle-closed position at which said drawhook engages said strike, said drawhook adapted to pivot on said strike as said handle moves to its closed position and interengageable means on said drawhook and on said link for engaging each other upon said pivotal movement of said drawhook to limit said pivotal movement.

13. A latch assembly for securing a iirst body to a second body having a strike thereon including in combination, a handle, means mounting said handle on said rst body for swinging movement of said handle around -a rst pivotal axis between an open position and a closed position, said mounting means comprising an upstanding part located between said rst pivotal axis and said strike, a link, a drawhook having a hook portion for engaging said strike, means mounting said drawhook on said link for translatory movement between a retracted position and an extended position relative to said link, means for biasing said drawhook toward its retracted position and into alignment with said link, means mounting said link on said handle for pivotal movement around a second axis spaced from said rst axis, said drawhook in an intermediate position of said handle resting on said Iupstanding part with said hook portion out of engagement with said strike, said drawhook rocking on said upstanding part and to move out of alignment with said link and to a position at which said hook portion can engage said strike in response to force exerted on the end of said link remote said second pivotal axis, said springs being compressed as said link moves relative to said drawhook upon movement of said handle from said intermediate to said closed position.

References Cited UNITED STATES PATENTS 2,605,123 7/ 1952 Claud-Mantle 292-113 2,63 5,910 4/ 1953 Celeste 292-247 3,034,817 5/ 1962 Willis 292-113 3,088,623 5/1963 Parker 220-46 3,193,314 7/1965 Johnson 292-113 RICHARD E. MOORE, Primary Examiner R. L. WOLFE, Assistant Examiner

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