US 3451704 A
Description (OCR text may contain errors)
June 24, 1969 L. B. COTHRON 3,451,704
COMBINATION LATCH AND DEAD BOLT LOCK Filed Jan. 31. 1967 Sheet I of 2 Lill 38 64 INVENTOR. 72 v 3 LAWSON B. COTHRON 60 Fig. 3
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June 24, 1969 1 BJCOTHRON 3,451,704
COMBINATION LATCH AND DEAD BOLT LOCK I Filed Jan. 51, 1967 Sheet 2/ of 2 X so 4 a4 8 as 82 6 as J [l' 54 9 00 so 7 o4 94 7 38 A 8% I06 54 7 "*I I08 I g 94 s 'l02 e 60 92 'L ,J'? Fig.7 73 l 92 INVENTOR.
LAWSON B. COTHRON BY 6 143mm: & 14mm United States Patent 3,451,704 COMBINATION LATCH AND DEAD BOLT LOCK Lawson B. Cothron, 4886 Jewel, San Diego, Calif. 92109 Filed Jan. 31, 1967, Ser. No. 612,919 Int. Cl. Ec 3/06; E05b 65/06 US. Cl. 292198 4 Claims ABSTRACT OF THE DISCLOSURE The lock utilizes a pair of orthogonally inter-fitting elements, each of which is slotted at one position to allow the other to move, one element comprising an indexed latch operated by movement of the door and the other being a dead bolt type locking element.
Background of the invention The present invention relates to locks, primarily for doors, and specifically to a combination latch and dead bolt lock. Existing dead bolt locks are generally of two basic types. One type uses a latch for normal operation with a separate dead bolt for security. The other type uses a single bolt with latch action and some complex arrangement of pawls, cams, springs and the like to secure the latch as a dead bolt.
Summary of the invention Brief description of the drawings FIGURE 1 is a top plan view of the lock assembly, with the top portion of the lock casing cut away to reveal the mechanism in locked position;
FIGURE 2 is a sectional view taken on line 2-2 of FIGURE 1;
FIGURE 3 is an end elevation view as taken from the right hand side of FIGURE 2;
FIGURE 4 is a view similar to FIGURE 1, with the mechanism unlocked;
FIGURE 5 is a sectional view taken on line 5-5 of FIGURE 4;
FIGURE 6 is a vie-w similar to a portion of FIGURE 1, showing adaptation to a sliding door; and
FIGURE 7 is a sectional view taken on line 7-7 of FIGURE 6.
Similar characters of reference indicate similar or identical elements and portions throughout the specification and throughout the views of the drawings.
Description of the preferred embodiments The lock 10 is shown in FIGURE 1 as being installed in a door jamb or wall, indicated in broken line at 12, but could be installed in a door of suitable thickness, the location depending on the size of the lock and the operating requirements. Lock 10 is contained in a frame, illustrated as a generally rectangular box-like casing 12, having protective walls including side walls 14 and 16, a top wall 18 and a bottom wall 20. At the exposed end the end wall 22 has a set back jamb wall 24 which forms a stop shoulder 26, against which the swinging door 28 closes. On the edge of door 28 is a striker 30 illustrated here as a simple striker plate, with an opening 32, behind which is a cavity 34.
Inside casing 12 is a horizontally disposed latch element 36, illustrated as a disc, but which may be of other configurations to suit particular purposes. Latch element 36 is rotatable about a vertical post 38 fixed between top and bottom walls 18 and 20 and projects through a slot 40 in the jamb wall 24 which continues into stop shoulder 26. In the periphery of latch element 36 is a latching notch 42 in which the door is held. The small portion of the door 28, between cavity 34 and the face of the door which confronts stop shoulder 26, forms a latching bar 44 which fits into notch 42 when the door is against the stop shoulder. When door 28 is opened the motion of the striker is substantially tangential to the rotation of the latch element 36, so the latching bar 44 engages one side 46 of notch 42 and rotates the latch element until the door is released, as indicated by the solid line arrows in FIG- URE 4. Side 46 thus constitutes the opening face, the other side of the notch 42 being the closing face 48, which latching bar 44 engages when the door is closed and rotates the latching element to the latched position, as indicated by the broken line arrows in FIGURE 4. The edge portion of latch element 36 projecting into cavity 34 thus acts as a door retaining tongue 49.
Latching disc 36 is thus actuated by the door itself and holds the door in the closed position. To keep the door in place and to maintain alignment of latching notch 42 for re-engagement by the door in the unlatched position, latching element 36 is provided with a pair of appropriately spaced sockets 50 and 52, which are engaged by a detent 54. As illustrated, the sockets are in the periphery of the latching element 36 and the detent is a. simple ball element 56 biased by a spring 58, but other arrangements may be equally suitable.
Deadbolt locking action is provided by a locking element 60, also shown as a disc for simplicity, which is rotatably mounted on a horizontal post 62 between side Walls 14 and 16, substantially in the plane of latch element 36. The latch element has a locking notch 64 in its periphery, through which the locking element 60 passes, the two elements thus interfitting orthogonally, as in FIGURE 1. In this position the latch element 36 is securely held against rotation, the locking element 60 acting as a dead bolt. In the edge of locking element '60 is a clearance notch 66 through which the latch element 36 can pass, when the locking element is rotated to the correct position. To ensure proper alignment the locking element 60 has a pair of appropriately spaced sockets 68 and 70 for engagement by a detent 72, which may be similar to detent 54. In the unlocked position of locking element 60, latch element 36 is free to turn, through clearance notch 66, with its open and shut latching action.
Locking element 60 can be operated by a variety of means, such as a knob or handle coupled directly thereto, a slide bar type of mechanism, or locks of different types. The arrangement shown utilizes the high degree of security offered by the mechanism and includes a pair of barrel type locks 74 and 76, one on each side, for operation of the lock from either side of the door. It will be obvious that a single lock will sufi'ice if the door is required to be locked from one side only. Each lock is operated by a key and has an extended shaft 78 which is rotated by the key, the end of the shaft carrying a radially extending dog 80. Locks .74 and 76 are mounted in side walls 14 and 16, respectively, with their shafts 78 coaxial and substantially parallel to post 62. Dogs: 80 project into an actuating slot 82 in the edge of locking element 60 in the manner of intermeshing gears, so that operation of either lock will rotate the locking element to the limits imposed by detent 72. The full line positions of dogs 80 in FIGURES 2 and show the actual engagement with the locking elements when being turned by key. In the locked position of each lock with the key removed, the dog would be turned upwardly clear of the locking element, so that either lock could be used without interference by the other. To provide ample clearance, actuating slot 82 may be fitted with laterally extending plates 84 for engagement by One dog 80. This will avoid the necessity for undue thickness of the locking element.
It should be noted that the detent 72 can easily be made firm enough to prevent operation by the usual delicate lock picking tools. Thus without the proper key, the door could not be opened except by destruction of the lock or the door.
With very little modification the lock is adaptable to a sliding door, as in FIGURES 6 and 7. The locking element and its actuating means are unchanged and the only alteration to the latch element is in the configuration of the latching notch. Since the sliding door 86 does not require a stop shoulder, the casing 88 has a flat end wall 90 with a slot 92, in which a portion of the edge of modified latch element 94 is exposed. Latching notch 96 is elongated and disposed at an angle to the radius from post 38, the door 86 having a striker 98 projecting from the edge to fit into the notch. Striker 98 is in the form of a U-shaped loop with an opening 100 into which the latch element 94 enters, and a latching bar 102 which is actually held in the latching notch. The inside face of latching notch 96, or the face nearest post 38, comprises the closing face 104 and the outside face of the notch becomes the opening face 106, comparable to the arrangement of latching notch 42.
When latching bar 102 engages the closing face 104 as the door is closed in a direction generally radial to the latch element, the inclined face acts as a ramp and the pressure causes rotation of latch element 94. The tongue portion 108 of the latch element, outside notch 96, enters the striker opening 100 and the latching bar 102 is seated at the closed end of the notch. When the door is pulled open, the latching bar bears against the inclined opening face 106 and rotates the latch element in the opposite direction until the striker is released. The closed position is indicated in full line and the open position in broken line in FIGURE 6. The latch element 94 is actuated entirely by opening and closing the sliding door, just as latch element 36 is operated by the swinging door. With looking element 60 in locked position, as in FIGURE 7, latch element 94 is held securely against rotation and striker 98 is trapped in latching notch 96 with complete security. A channel to receive the door edge, or weatherproofing seals may be added in the usual manner and would serve to conceal the small gap between the door and jamb, so preventing cutting of the striker, which is the only method of forcing entry without considerable destruction.
Apart from the actuating means for the locking element, which can vary, the actual lock mechanism utilizes only two moving parts, the latch element and the locking element. Yet this simple arrangement provides all the con venience of a door actuated retaining latch and release and the security of a dead bolt. The two elements can be made very rugged to resist damage, as opposed to the delicate cams, springs and the like in other locks of comparable type.
It is understood that minor variation from the form of the invention disclosed herein may be made without departure from the spirit and scope of the invention, and that the specification and drawings are to be considered as merely illustrative rather than limiting.
It is claimed:
1. A combination latch and dead bolt lock assembly, comprising:
a lock unit for attachment to one portion of a structure and a striker for attachment to another portion of a structure to be locked to the first portion;
said lock unit having a frame;
a disc latch element mounted in said frame for rotation about an axis substantially perpendicular to the direction of motion of the striker relative to and adjacent to the lock unit;
an edge portion of said latch element having a latching notch therein to receive and retain a portion of said striker, said latching notch being disposed at an angle to the corresponding radius of the disc latch element and defining a tongue portion between the latching notch and the adjacent edge portion of the latching element to engage said striker in the locked position;
a disc locking element rotatably mounted in said frame and having a portion engageable with said latch element to lock the latter against rotation;
and means to move said locking element selectively into and out of engagement with said latch element.
2. The structure according to claim 1, wherein said locking element is mounted for rotation about an axis substantially perpendicular to the axis of said latch element and overlaps the latch element in orthogonal inter-fitting relation therewith;
said locking element having a clearance notch through which said latch element can pass in an unlocked position;
and said latch element having a locking notch into which said locking element fits in a locked position.
3. The structure according to claim 1, wherein the direction of motion of said striker relative to said latch element is substantially radial to the axis of rotation thereof;
said latching notch being inclined to the radius and the faces of said latching notch being ramps engageable by said latching bar to rotate the latching element when unlocked and retaining the functionality of said tongue portion to engage said striker when in locked position.
4. The structure according to claim 1, wherein said frame has protective side walls and an end wall having an opening in which is exposed a portion of said latch element having said latching notch therein for engagement with said striker, said end wall at one side of said opening therein having a stop shoulder against which said another portion of the structure abuts when in locked position.
References Cited UNITED STATES PATENTS 1,462,684 7/1923 Clum 20044 2,217,098 10/1940 Brownne 2922l0 2,910,859 11/1959 Allen 135 MARVIN A. CHAMPION, Primary Examiner.
E. J. MCCARTHY, Assistant Examiner.
US. Cl. X.R. 70135