US 1896363 A
Description (OCR text may contain errors)
Patented Feb. 3 E833 aaeaa nnvm n. Jamison, or wanna, rnmnois BUILDEES HAIR-DWE ipplication filed. March 14, 1980. Serial No. 435,719.
My invention relates to builders hardware and includes among its objects and advantages the provision of an improved secret door latch having positive action independ-.
cut of the speed of movement.
In the accompanying drawing, Fig. 1 is a side elevation of a lock, according to the invention, with the cover of the housingremoved.
Fig. 2 is a section on line 2-2 of Fig. 1.
Fig. 3 is a view similar to Fig. l with the parts in position for withdrawal, and
Fig. 4 is a section on line 4 4 of Fig. 1.
Housing and ejector In the embodiment of the invention selected for illustration, is a movable element such as a door or lid, and 12 is a fixed element such as a door jamb or the side of a box or cabinet. The retaining hook .14 is mounted on movable element 10, and the housing 16 and parts carried thereby are mounted on the fixed element 12. In the lower portion of the housing I provide a cast partition 18 spaced from the bottom'wall 20 of the housing to define a channel receiving the ejector 22. The ejector comprises a cylindrical body slidable through the hole 24 in the front of the casing and a head 26 to limit the outward movement. The coil spring 28 tends to move the ejector against the movable element 10. The spring 28 may be adjustably tensioned by the abutment nut 30 to give the correct action under a wide variety of loadings.
Retaining means The latch 32 is pivoted on the pintle 34 and terminates in a retaining toe 36. The outer face of the toe 36 and the inner face of the hook 14 are sloped so that movement of the hook inwardly to the position of Fig. 1 will push the latch up above the position of Fig. 1 until the hook has passed under the toe 36, when the latch will move down to the position of Fig. 1, and the parts are firmly held against separation. To secure the prompt return of the latch I provide suitable biasing means such as a wire spring 38 housed in a kerf in the latch member and wound around the pintle 34. The stop pin 40 limits the downward movement of the latch when the parts are'not' engaged.
Release The latch 32 has a cylindrical recess 42 with its lower side open. The release dog comprises a pintle member 44 and a dog proper 46. The connection between the pintle member 44.and the dog 46 is of such width that the parts may rotate almost thirty degrees, being limited by the engagement between the dog and the toe 36 in one direction, and in the other direction by engagement of the shoulder 47 with the body of the latch 32. The faces of the dog 46 are at such angles that it will ride over the hook 14 during movement in either direction. They diverge much less by reason of the lost motion permitted by rotation around the pintle 44. This tipping always increases the slope of the surface with which the hook happens to be engaged at the time.
To release the door 10 it need only be pushed further into the position of Fig. 3. During this inward movement the advancing face of the hook 14 will engage the front face of the dog and push the latch up until the dog rides over the hook 114 and the parts move down again to the position of Fig. 3. There is now 30 no impediment to withdrawal of the hook, and the ejector 22 will open the door. The inner face of the dog 46 will ride over the hook 14 and again lift the latch. ,The tip of the dog 46 projects just a trifle below the lower end of the toe 36 so that the tip of the hook 14 will be safely guided under the too 36 during its outward movement.
Reversibility screws 50 have their center lines just a little clear of the casing cover 52. This sets the wood screws well in from the edge of the door. By making the hook 14 symmetrical about a. horizontal median plane, the hook casting can be rotated 180 about a horizontal axis from the osition of Fi 1 and assembled on either le hand or' rig t hand doors, with equal facility and with the offset in the right direction.
In either position, the base plate 48 extends far enough to function as an abutment or strike plate for the end of the ejector 22. In either position the, lower prong of the hook 14 moves just above the wall 18. If the hinges permit the door to sag, this lower prong will slide on the wall 18 and prevent the door from sagging enough to interfere with proper operation'of the lock.
The cover plate 52 completes'the housing for the ejector 22 and spring 28, and is apertured to receive wood screws which may also pass through the apertures 54 in the bottom of the casing to fasten the cover plate and housin in place on the cabinet wall 12. A pair 0 bosses 56 are formed in the housing casting to enter registering holes in the cover ate. a
P Without further elaboration, the foregoing will 'so fully explain my invention that others may, b applying-knowledge current at the time 0 application, readily adapt the same for use under various conditions of service.
1. The combination with a fixed member and a movable member, of a housin carried by said fixed member, a hook carrie by said movable member, a s ring pressed latch member, said latch mem r and hook having inwardly facing hook surfaces for holding the hook against withdrawal, and means mounted upon said latch member and actuated by movement of said hook inwardly beyond latched position for lifting said latch member to clear said hook and release it upon subsequent outward movement of said hook, said hook being symmetrical about a median plane and having a portion positioned substantially in contact with one surface of the housing.
2. An automatic latch holder including a hook, a housing, a spring pressed latch member carried by said housing, said latch member and hook having outwardly facing cam surfaces to deflect said latch member and permit entry of said hook, said latch member and hook having flat surfaces defining hook portions for permitting said latch member to return and for holding said hook against withdrawal thereafter, a cam dog tiltably mounted on said latch member behind the hook surface thereof and shaped to deflect the latchmember and ride over the hook in either. direction, said cam dog having a flat face facing the fiat surfaces upon said latch member, said hook being wedged between the flat faces. upon the cam dogA and the latch when sald latch member and e hook are in latched relation said dog when'tilted in the direct1on of the flat surface u on the latch member, having its flat surface yin against the flat surface upon the latch mem r and extending coming wed ed between said first-mentioned hook and t e movable element associated therewith, said wedged connection resisting normal forces on the door, but yieldable upon the a plication of an abnormal force to permit t e second hook to be moved to a position upon the opposite side of the said movable element, whereby the latter will prevent said second hook from becoming wedged between the movable element and said first mentioned hook when withdrawn therefrom.
In testimony whereof I hereunto aflix my signature.
ELVIN H. JOHNSON.