US 3704908 A
A door chain lock wherein a headed connector is detachably engageable with its head passing removably through an enlarged portion of a receiver slot, there being provided a guard for occupying the space adjacent to the connector to prevent entry of a tampering tool.
Description (OCR text may contain errors)
I United States Patent [151 3,704,908 Schwartz 1 Dec. 5, 1972  DOOR CHAIN LOCK  References Cited Inventor: Jerome Schwartz, 1 Assignee! Taylor Lock p y Philadel- 2,076,605 4/1937 West ..292/264 phia, Pa. 3,493,256 2/1970 Ramler ..292/264 Wade X [2!] Appl. No.: 134,360 Primary Examiner-Richard E. Moore AttorneyRobert K. Youtie  US. Cl. ..292/264, 70/93, 70/418,  ABSTRACT A door chain lock wherein a headed connector IS  Int. Cl ..E05c 17/36 d etachabiy engageable with its head passing  Flew Search 292/264 70/416 25/ 9 3: removably through an enlarged portion of a receiver slot, there being provided a guard for occupying the space adjacent to the connector to prevent entry of a tampering tool.
6 Claims, 5 Drawing Figures noon CHAIN LOCK BACKGROUND OF THE INVENTION As is well known to those versed in the art, door chain locks are frequently subject to jimmying or tampering, as by a wire coat hanger or other elongate tool being inserted between the chain and receiver to urge the connector toward the, enlarged slot receiving portion, thereby permitting surreptitious removal or disengagement of the connector from the receiver.
While certain prior devices have been proposed to overcome this lack of security, such devices have not found general acceptance, as by reason of their complexity, added expense, unreliability, and difficulty in operation and installation. A door chain lock has a headed connector which is detachably engageable with its head passing removably through anenlarged portion of a receiver slot, there being provided a guard element for occupying the space adjacent to the connector to prevent entry of a tampering tool.
SUMMARY OF THE INVENTION It is, therefore, an important object of the present invention to provide a door chain lock of the type described which overcomes the above-mentioned difficulties, automatically precluding the insertion of a jimmying or tampering tool, which adds little or nothing to manufacturing and sales costs, is staunch and durable in construction, and entirely reliable throughout a long useful life.
Other objects of the present invention will become apparent upon reading the following specification and referring to the accompanying drawings, which form a material part of this disclosure.
The invention accordingly consists in the features of construction, combinations of elements, and arrangements of parts, which will be exemplified in the construction hereinafter described, and of which the scope will be indicated by the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partial elevational view showing the interior of a door having associated therewith a door chain lock of the present invention in a locked or engaged condition.
FIG. 2 is a partial elevational view similar to FIG. 1, but illustrating the chain in its fully straightened or extended condition, as when effecting engagement or disengagement of the chain connector with the door mounted receiver.
FIG. 3 is a top plan view taken generally along the line 3--3 of FIG. 2. t
FIG. 4 is a horizontal sectional view taken generally along the line 4--4 of FIG. 2.
FIG. 5 is an enlarged plan view illustrating a component part of the door chain assembly of the instant invention, apart therefrom.
BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now more particularly to the drawings, and specifically to FIG. 1 thereof, a door is there generally designated 10, and may be of a conventional swinging type, having a manually actuable operating member or knob 11 located adjacent to the swinging or movable edge 12 of the door. The building wall adjacent to the door is generally designated 13, and may terminate at the door jamb l4.
The door chain assembly is generally designated 20, and may include a receiver 21, which may be essentially conventional in construction. The receiver 21 may be suitably fabricated, as by die casting or otherwise, and include a hollow body 2.2 of elongate configuration. The receiver body 22 includes an outer wall 23 of elongate configuration and formed therethrough with a longitudinally extending, elongate slot 24. The slot 24 may be essentially of a constant width, except at one end where it is provided with an enlarged region 25.
The hollow receiver body 22 further includes a pair of side walls 26 extending longitudinally on opposite sides of the front wall 23, being normal thereto, and is each provided with a longitudinally extending flange 27.
In association with the door 10, the flanges 27 are disposed in facing engagement with the inner door surface, and suitably affixed thereto, as by fasteners 30 ex tending through respective corners of the flanges. Thus, the outer wall 23 of the body 22 is spaced from the door 10. Further, the body 22 is arranged on the door 10 so that the enlarged slot region 25 is remote from the swinging door edge 12, in the conventional manner.
In addition, there is provided. a flexible, elongate member or chain 35 having one end securely fastened to the wall 13. That is, one end link 36 may be circumposed about a fastener 37, which may be impaled or otherwise suitably secured to the wall.
The other end of chain 35, remote from the secured link 36, is provided with a connector, generally designated 40. The connector 40 is detachably connectable to the receiver20 for locking the door within the limits imposed by the length of the chain 35.
In particular, the connector 40 includes a shank or pin 41 having on one end an enlargement or head 42. The head 42 is sized so as to conformably pass through the enlarged slot region 25, while being incapable of passing through the remainder of slot 24. That is, the head 42 effectively retains the connector pin 41 in the slot 24, except in the enlarged end] region 25.
A link 43 of chain 35, remote from the link 36 is suitably secured to the connector 40. Specifically, the link 43 is circumposed about the: pin or shank 41. As best seen in FIG. 4, the pin may be provided with a circumferential shoulder or ledge 44 adjacent to a spaced from the head 42, and facing away from the head.
In addition, a pair of guard members or shoulder plates 45 and 46 are each circumposed about the connector pin on opposite sides of the attached link 43. The guard member or plate 45 may be seen in FIG. 5, and may be identical to the guard. member or plate 46.
It will there been seen that the plate 45 is of an elongate configuration, having a through aperture 47 adjacent to and spaced inwardly from one plate end. A notch or cutout 48 extends inwardly from the opposite plate end extending toward and terminating short of the aperture 48.
In the assembled connector 40, the plate 45receives the pin 41, the shoulder or ledge 44 abutting against one face of the plate; and the other guard plate 46 is similarly engaged about the pin 41, but on the opposite side of link 43. A retaining element or head 50 is provided on the end of pin 41 remote from the head 42, to positively secure in a relatively rigid relationship, the plates 45 and 46, and interposed link 43. Further, as best seen in FIG. 4, the guard member or plate 45 is of a thickness approximately equal to the distance between the outer wall 23 of receiver body 22 and the link 43.
As best seen in FIGS. 2 and 3, the guard members or plates 45 and 46, being substantially congruent to each other, are arranged in substantially completely overlying relation with respect to opposite sides of the intermediate or sandwiched link 43. Further, the cutouts of guard plates 45 and 46, such as the cutout 48 of plate 45 and the corresponding cutout of plate 46, are in registry with each other and serve to receive portions of the next adjacent link 51 passing through the link 43.
Thus, as best seen in FIGS. 3 and 4, the space between end link 43, receiver 21, pin 41 and link 51 is effectively completely occupied by the guard member or shoulder plate 45, so that a jimmying or tampering tool is precluded from entry.
From the foregoing, it is seen that the present invention provides a door chain assembly which is of greatly enhanced security, extremely simple, staunch, durable and reliable, and which otherwise fully accomplishes its intended objects.
Although the present invention has been described in some detail by way of illustration and example for purposes of clarity of understanding, it is understood that certain changes and modifications may be made within the spirit of the invention.
What is claimed is:
1. In a door chain, the combination comprising a hollow receiver having an elongate slot formed with an enlarged region, a headed connector having its head removably engageable through said enlarged region and slidably retained in the remainder of said slot, a chain having a link attached to said connector, said link being in facing spaced relation with said receiver when said connector is retained in said slot, and a guard extending from said connector along said link for interposition between said facing link and receiver and shaped to substantially completely occupy the space therebetween when said connector is in said slot, whereby a tampering tool is precluded from insertion between said link, receiver and connector for urging the latter toward said enlarged region.
2. The combination according to claim 1, said connector comprising a pin, said link being circumposed about said pin, and said guard comprising a shoulder extending from the pin and spaced from said head approximately the thickness of said receiver, said shoulder having a thickness to substantially completely occupy the space between said link and receiver.
3. The combination according to claim 2, said shoulder extending from said pin to substantially completely overlie said link.
4. The combination according to claim 1, said receiver being adapted for attachment to a door at a location adjacent to the swinging door edge and with its enlarged slot region remote from said door edge, said chain having a remote link adapted for attachment to a wall adjacent to said door edge so that the connector ust reaches said enlarged region when the door IS closed, and said guard comprising a plate of a thickness approximately equal to the distance between said link and receiver when said head is in said slot.
5. In a door chain, the combination comprising a hollow receiver having an elongate slot formed with an enlarged region, a headed connector having its head removably engageable through said enlarged region and slidably retained in the remainder of said slot, a chain having a link attached to said connector, said link being in facing spaced relation with said receiver when said connector is retained in said slot, and a guard extending from said connector along said link for interposition between said facing link and receiver to substantially completely occupy the space therebetween when said connector is in said slot, whereby a tampering tool is precluded from insertion between said link, receiver and connector for urging the latter toward said enlarged region, said connector comprising a pin, said link being circumposed about said pin, and said guard comprising a shoulder extending from the pin and spaced from said head approximately the thickness of said receiver, to effectively occupy the space between said link and receiver, said shoulder being configured to substantially completely overlie said link and having a cutout passing the received portion of the next adjacent link.
6. The combination according to claim 5, in combination with an additional shoulder on said pin substantially completely overlying said link on the side thereof opposite to said first mentioned shoulder, said first mentioned and additional shoulders being fixed to said pin to securely position said link on said pin.