US3519298A - Positive lock for toggle latch - Google Patents

Description

July 7, 1970 P. R GLEY ET AL 3,519,298

POSITIVE LOCK FOR TOGGLE LATCH Filed Feb. 24, 1967 2 Sheets-Sheet 1 VENTORS H T TO RNE vs E. rman S. Johnson o m m m] Pa u No BY July 7, 1970 p, GLEY ET AL 3,519,298

POSITIVE LOCK FOR TOGGLE LATCH Filed Feb. 24, 1967 2 Sheets-Sheet 2 III INVENTO Pau/ E G/ey R5 MOr/Wafl S. Jo/7/750/7 MwaW F? TTORNEYS United States Patent O 3,519,298 POSITIVE LOCK FOR TOGGLE LATCH Paul R. Gley, Hillsdale, and Norman S. Johnson, New

Milford, N.J., assignors, by mesne assignments, to Rex Chainbelt Inc., Milwaukee, Wis., a corporation of Wisconsin Filed Feb. 24, 1967, Ser. No. 618,456 Int. Cl. Ec 5/04 US. Cl. 292-113 6 Claims ABSTRACT OF THE DISCLOSURE A toggle latch in which the drawhook assembly carries a movable catch biased toward the handle pivot and which passes through an opening in the latch handle and snaps into engagement therewith as the handle moves to its closed position to engage the drawhook with the strike. The spacing between the catch and the free end of the handle and the direction of biasing of the catch are such as to permit concomitant release of the catch and movement of the handle to open position to release the latch.

BACKGROUND OF THE INVENTION One type of latch in wide use in the prior art for securing two members together is a toggle latch comprising an operating handle which is moved from an open to a closed position first to engage a drawhook on one of the parts with a strike on the other part and then to draw the parts together by moving the drawhook pivot to a position beyond dead center with reference to the handle pivot. While latches of this type successfully perform their function of holding parts in assembled relationship and of being relatively readily operable, only a small movement of the handle is required completely to release the latch. As a result, the danger exists that a small accidental movement of the handle will cause the latch to fall to a released position. In many installations the latch handle is above the surface of the member carrying the latch and thus is in a position at which it may accidentally be caught and pulled. All of these latches must be readily operable with one hand even under adverse conditions, such as extreme cold.

SUMMARY OF THE INVENTION We have invented a tog-gle latch which overcomes the defects of toggle latches of the prior art pointed out hereinabove. Our latch includes a positive lock for preventing such accidental movement of the latch handle as would result in releasing the latch. Our construction is such that the positive lock can be released and the latch can be uncoupled with the use of only one hand. This operation can be accomplished by a person wearing heavy mittens. Our positive locking toggle latch is readily interchangeable with existing toggle latch installation. It is simple in construction and is easy to operate.

One object of our invention is to provide a toggle latch assembly having a positive lock for preventing accidental movement of the handle to open position.

Another object of our invention is to provide a toggle latch having a positive lock which permits the lock to be released and the latch to be uncoupled with one hand.

A further object of our invention is to provide a toggle latch having a positive lock which can be operated by a person wearing heavy mittens.

A still further object of our invention is to provide a toggle latch having a positive lock, which latch is readily interchangeable with already installed toggle latches.

Yet another object of our invention is to provide a toggle latch having a positive lock which is simple in construction and in operation.

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

In general our invention contemplates the provision of a catch mounted on the latch drawbar for movement between 21 position at which it locks the latch handle in the closed position thereof and a position at which the handle is released. We provide means for biasing the catch to its locking position and provide the handle with an opening which receives the catch. As the handle moves from its open to its closed position, interenga-geable cam means on the handle and on the catch cam the catch out of its locking position to permit it too pass through the handle opening and then snap back to handle locking position.

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 plan view of a toggle latch provided with one form of our positive lock.

FIG. 2 is a side elevation of the latch shown in FIG. 1 with parts broken away and with other parts shown in section.

FIG. 3 is a plan view of a toggle latch provided with another form of our positive lock.

FIG. 4 is a side elevation with parts broken away and with other parts shown in section of the toggle latch shown in FIG. 3.

FIG. 5 is a perspective view of the form of our locking element shown in FiGS. 3 and 4.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to FIGS. 1 and 2, the toggle latch indicated generally by the reference character 10 shown therein is adapted to join two members 12 and 14 along a line 16. The member 14 carries a hook or strike 18 adapted to be engaged to draw the parts 12 and 14 together in a manner to be described. Hook 18 may be secured to the member 14- by any suitable means such, for example, as by rivets 20 or the like.

We employ any suitable means such, for example, as rivets 22 for securing a bracket base 24 to the member 12. Bracket 24 includes respective sides 26 and 28 carrying pivot pins 30 and 32. Our latch 10 includes a handle 34 provided with respective side flanges 36 and 38 through which the pins 30 and 32 extend pivotally to support the handle for movement from the full-line position illustrated in FIG. 2 to the dot-dash line position. For purposes of convenience and clarity in exposition, we have termed the fullline position the closed position of the handle and have designated the dot-dash line position as the open position of the handle.

Our latch includes a drawbar assembly indicated generally by the reference character 40. The drawbar assembly 40 includes a first portion 42 formed from sheet metal or the like and shaped and bent to provide a bearing sleeve 44 which receives a pin 46 carried by the handle side flanges 36 and 38 pivotally to support the drawbar assembly 40 on the pin 46. We also shape the member 42 to provide a threaded socket 48 which receives the shank 50 of the hook portion 52 of the drawbar assembly. It will readily be appreciated that the effective length of the drawbar can be adjusted by screwing the shank 50 into or out of the socket 48.

The form of our positive lock shown in FIGS. 1 and 2 includes a cast locking element 54 having a bore 56 through which the shank 50 extends. We provide the element 54 with a hook 58 and with a cam surface 60. A spring 62 surrounding the shank 50 bears between a collar 64 on the shank and the base of a recess 66 formed in the element 54 normally to urge the element to the left, as viewed in FIGS. 1 and 2, into engagement with the end of the member 42. The cast element 54 includes a bottom flange 68 which cooperates with the underside of the member 42 to constrain the element 54 to slide along the shank 50 and to prevent cocking thereof. We provide handle 34 with an opening 70 for receiving the head of the element 54. As the handle moves from the dot-dash line position shown in FIG. 2 to the full-line position, an edge of the opening 70 engages the cam surface 60 to urge the element 54 to the right against the action of spring 62 to permit the catch to move through the opening and then back to a position at which the hook 58 overlies the handle.

Referring now to FIGS. 3 to 5, as many of the parts shown therein are similar to the parts of the form of latch shown in FIGS. 1 and 2. This form of our latch includes the bracket having the base 24 and sides 26 and 28 for pivotally supporting the handle 34 by means of the pins 30 and 32. Similarly it includes the drawbar assembly comprising the portion 42 which receives the pivot pin 46 carried by the handle and which is formed with the threaded socket 48 for receiving the shank 50 of the hook 52.

In the form of our positive lock shown in FIGS. 3 to 5, we form the catch indicated generally by the reference character 72 from a unitary piece of sheet metal. Catch 72 includes a retainer 74 which engages the bearing sleeve 44 of the drawbar holder 42 to hold the catch 72 on the drawbar assembly. A web 76 of metal connects the retainer to one leg of a U-shaped spring 78, the other leg of which forms a hook 80 providing a cam surface 82. We form the spring legs with slots 84 and 86 and provide the web 76 with a rib 88 to permit passage of the shank 50 to the holder 42. This arrangement also ensures that the catch 72 will move with the drawbar assembly 40 while permitting hook 80 to move relative to the assembly against the action of spring 78. The form of our handle 34 shown in FIGS. 3 and 4 has an opening 90 which cooperates with the hook 80.

In each form of our invention we provide the base 24 with an opening 92 to permit movement of the drawbar holder bearing sleeve 44 through the space between the axis of pins 30 and 32 and the surface of the member 12. It is to be noted further that in the form of toggle latch shown, the distance between the axis of pins 30 and 32 and the upper surface of member 12 is greater than the distance between the axis of those pins and the axis of pivot pin 46.

In operation of our toggle latch provided with the positive lock, prior to operation of the latch the parts are in the positions shown in dot-dash lines in FIG. 2. With the parts in this position the member 14 carrying hook 18 is brought to a position adjacent member 14 at which the hook 52 is adapted to engage hook 18. With the parts in this position handle 34 is rotated in a clockwise direction to cause the pivot pin 46 to move from the dot-dash line position of FIG. 2 toward the full-line position. In the course of this movement, hook 52 engages hook 18 to draw the members 12 and 14 together along the line 16. As the handle approaches its closed position, an edge of the opening 70 engages cam surface 60 to move catch 54 to the right as viewed in FIG. 2. The flange 68 constrains the catch to slide along the shank 50 and prevents cocking and rotation of the catch around the shank. Upon continued movement of the handle, ultimately it rides under hook 58 and spring 62 moves the catch to the full-line position at which the hook overlies the handle. In this position of the parts, if an attempt is made to move the handle to its open position without releasing the catch, that force will be transmitted to the drawbar assembly which resists the force.

We have so arranged our positive lock as to permit the catch 54 to be released and the handle to be operated in what is substantially a single operation. Moreover, this can be done even by a person wearing heavy mittens. To

open the latch, the operator grasps the end of the handle 34 with his fingers while pushing on the cam surface 60 with his thumb to move the catch 54 to a position clear of the edge of opening '70. With the parts in this relative position, handle 34 can be moved to its open position with relative ease.

The operation of the form of our lock shown in FIGS. 3 to 5 is analogous to that of the form of our lock shown in FIGS. 1 and 2. With the handle in its open position, as it moves toward closed position the hook 52 engages hook 18 to draw members 12 and 14 together. Ultimately, an edge of the opening 90 engages cam surface 82 to move hook clear of the opening against the action of the spring 78. After the hook has cleared the handle, it snaps into locking position over the handle. This form of our lock is released in the same manner as is that of FIGS. 1 and 2, by grasping the handle end with the fingers while squeezing with the thumb against surface 82 to move hook 80 clear of the handle. Handle 34 can then be moved to its open position.

It will be seen that we have accomplished the objects of our invention. We have provided a toggle latch with a positive lock for preventing the handle from accidentally being actuated to release the latch. Our positive lock can be released concomitantly with the operation of opening the handle. Release can be achieved even by a person wearing heavy mittens. It is relatively simple in construction for the result achieved thereby.

It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of our claims. It is further obvious that various changes may be made in details within the scope of our claims 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, what we claim is:

1. A toggle latch for joining two members in assembled relationship including in combination, an engageable element on one of said members, an operating handle having an opening therein, means mounting said handle adjacent one end thereof on one of said members on a pivot spaced outwardly from the surface of said one membet for movement between an open position and a closed position, the other end of said handle being a free end, a drawbar having means thereon for engaging said element, means comprising a movable pivot connecting said drawbar to said handle adjacent one end thereof, said handle overlying said drawbar in the closed position of the handle, a catch adapted to project outwardly through and beyond said handle opening intermediate the ends thereof to an accessible location and to engage a portion of said handle adjacent said opening in the closed position of the handle and means mounting said catch on said drawbar for movement between a release position remote said handle pivot out of engagement with the handle and a locking position sufficiently relatively adjacent the handle pivot and remote from the free end thereof to permit an operator concomitantly to release said catch and to move said handle to its open position with one hand by pulling on said handle and squeezing said catch.

2. A latch assembly as in claim 1 including means responsive to movement of said handle for camming said catch out of said locking position in response to movement of said handle into its closed position.

3. A latch assembly as in claim 1 in which said catch mounting means mounts said catch for sliding movement on said drawbar, said catch comprising a hook for engaging said handle, a cam surface adapted to be engaged by said handle, guide means for constraining said catch for sliding movement and a spring for biasing said catch to handle locking position.

4. A latch assembly as in claim 1 in which said catch i a unitary member of resilient material, said catch comprising a hook for engaging said handle, a cam surface adapted to be engaged by said handle, a retainer for holding said catch on said drawbar, and a U-shaped spring portion connecting said retainer to said hook.

5. A toggle latch for joining two members in assembled relationship including in combination, an engageable element on one of said members, an operating handle, means mounting said handle on one of said members for movement around a pivot spaced from the surface of one of said members between an open position and a closed position, a drawbar having means thereon for engaging said element, means comprising a movable pivot connecting said drawbar to said handle adjacent one end thereof, the distance between said pivots being less than the shortest distance between said handle pivot and said surface whereby in response to movement of said handle from said open position to said closed position said movable pivot moves through the space between said handle pivot and said surface and said drawbar means engages said element, a catch adapted to engage said handle, means mounting said catch on said drawbar for sliding movement between a handle locking position and a release position and means biasing said catch to said locking position.

6. A toggle latch for joining two members in assembled relationship including in combination, an engageable element on one of said members, an operating handle, means mounting said handle on one of said members for movement around a pivot spaced from the surface of one of said members between an open position and a closed position, a drawbar having means thereon for engaging said element, means comprising a movable pivot connecting said drawbar to said handle adjacent one end there f, the distance between said pivots being less than the short est distance between said handle pivot and said surface whereby in response to movement of said handle from said open position to said closed position said movable pivot moves through the space between said handle pivot and said surface and said drawbar means engages said element, and a unitary member formed of resilient material, said member having a first portion attached to said drawbar and a catch portion extending from said first portion and adapted to engage said handle.

References Cited UNITED STATES PATENTS 1,153,514 9/1915 North et a1. 292-210 1,311,102 7/1919 Thompson 292113 3,070,395 12/1962 Morrison et al. 292-113 3,259,411 7/1966 Grfiiths 292113 FOREIGN PATENTS 27,980 12/1908 Great Britian.

RICHARD E. MOORE, Primary Examiner U.S. Cl. X.R. 292---l08

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