US3920110A

US3920110A - Self-tightening door lock

Info

Publication number: US3920110A
Application number: US488399A
Authority: US
Inventors: Stuart M Douglas
Original assignee: Individual
Current assignee: Individual
Priority date: 1973-09-19
Filing date: 1974-07-15
Publication date: 1975-11-18
Anticipated expiration: 1992-11-18
Also published as: CA976582A

Abstract

A self-tightening lock on a door to prevent movement of the door in relation to the door jamb and eliminate any play in the lock mechanism. The door and door jamb may be connected by either a pivotable bar or by a chain. In the former case the bar is connected by means of sliding member in a vertical slide passage with a hole in the sliding member engaging an upturned end of the bar. In the latter case, one end of the chain is connected to a securely fastened hook. The bar or chain is connected to a pivotable member connected to the door or door jamb. A tightening member is mounted on the pivotable member to tighten the bar or chain. When the door is locked, the tightening member moved downwardly under gravitational force when the pivotable member is pivoted downwards to a downward position and wedges the pivotable member in the downward position. This tightens the bar or chain. With the use of the chain the door may be secured from the outside as well as the inside.

Description

United States Patent 1191 Douglas Nov. 18, 1975 SELF-TIGHTENING DOOR LOCK 314,195 5/1956 Switzerland 292/240 [76] Inventor: Stuart M. Douglas, Grange Street, I Smiths F lls, O t i C d Primary Examiner-Paul R. Gilliam Filed y 15 1974 Assistant ExaminerVictor N. .Sakran 21 A 1. No.: 488 399 I pp 57 ABSTRACT [30] Foreign Application Priority Data A self-tightening lock on a door to prevent movement Se t I 9 1973 Canada 181 41 1 of the door In relation to the door amb and ellmlnate p any play in the lock mechanism. The door and door jamb may be connected by either a pivotable bar or by 292/207 ag a chain. In the former case the bar is connected by [58] Fieid 292/207 6 240 241 means of sliding member in a vertical slide passage 2 /2 41 with a hole in the sliding member engaging an upturned end of the bar. In the latter case, one end of the chain is connected to a securely fastened hook. [561 References Cited The bar or chain is connected to a pivotable member 1 UNITED STATES PATENTS connected to the door or door jamb. A tightening 847,345 3/1907 Leach 292/207 member is mounted on the pivotable member to ,988 10/ 1919 Good 292/34l.13 1 tighten the bar or chain. When the door is locked, the Anderson member moved under gravita. g f y' tional force when the pivotable member is pivoted 11/1932 w: r gg downwards to a downward position and wedges the 210941547 9/1937 Mcculiii't'QITIIIIIIII1365/1516.30 Pivotable member the ,downward Thls 2,554,455 5/1951 Casey et a1. 292/207 hghtehs the bar or Chalh- Wlth the use of the Chalh the 3,158,908 12/1964 Springer 292/1310. 30 5 9 y be Secured from the Outside as as the FOREIGN PATENTS OR APPLICATIONS 13,440 l/19l6 United Kingdom 292/341.13 8 Claims, 6 Drawing Figures US. Patent Nov. 18, 1975 Sheet 1 of3 3,920,110

US. Patent Nov. 18, 1975 Sheet 2 of3 3,920,110

FIG.4

US. Patent Nov. 18, 1975 Sheet3of3 3,920,110

BACKGROUND TO THE INVENTION It is common to lock doors or gates with theme of a sliding or pivotable bar which can be moved manually from an open position where the door or gate is unlocked to a closed position where the door or gate is locked. Usually devices are provided for preventing the bar from being moved or tampered with by those attempting to enter the door or gate. Thus a simple chain and padlock could be used to prevent a bar from being moved but padlocks are relatively expensive and give rise to the need for keys which may be lost or the need to remember combinations which can easily be forgotten.

It is also well known in the case of sliding bar locks for doors to mount the bar in a tubular slide having a lengthwise opening in one side to permit the passage of an outwardly projecting handle for the bar. This opening is fitted with at least one groove to permit the handle and bar to be pivoted in the slide when the bar is in the locked position. Thus when the handle is inserted into the groove the bar is prevented from sliding to an unlocked position. The problem with a lock such as this is that there is often considerable play left between the bar, the door, and the door jamb. This play may be so great as to permit those attempting to enter the door from the side of the door opposite the bar to either break the lock or to manipulate the bar into an open position. In the case of the bar lock discussed above, having a pivotable handle and a groove, the only manipulation required is the pivoting of the bar so that the handle is removed from the groove and the sliding of the bar into the open position. The play in locks can often be increased easily by jiggling the door or pressing against it. Once the intruder has sufficient play in the lock, it is relatively simple for him to unlock simple bar locks from the outside in the above stated manner.

Another common type of lock is the simple chain door lock wherein one end of the chain is rigidly fastened to a door or door jamb and the other end is fitted with a sliding member. Fitted rigidly to the door or door jamb (whichever does not have the chain attached to it), there is a metal slide into one end of which the sliding member may be inserted to lock the door. When someone attempts to open the door from the outside, the chain is pulled tight by the door and the sliding member is in such a position with respect to the 'slide that it-cannot be removed therefrom. The difficulty with such locks is that there is normally considerable play between the door and the door jamb, permitting the lock to be forced and broken or simply unlocked from the outside as in the case of the simple bar lock already discussed.

It is an object of the present invention-to overcome the disadvantages of the above known locks by having tightening means to tighten the lock after it has been placed in the locked position. When the door is rattled or otherside distrubed, the tighteningmeans takes up slack in the parts which comprise the. lock. Thus play 2 tightly or solidly the door is secured in the door jamb by the lock.

It is a further object of the invention to provide a lock for a door whereby the door cannot easily be forced open and it is difficult, if not impossible, to unlock the lock from the outside because play is prevented between the door and the door jamb.

SUMMARY OF THE INVENTION Thus a self-tightening lock according to one aspect of the present invention for preventing movement of a door in relation to an adjacent structure, the door and the adjacent structure comprising two parts, includes a pivotable member and connecting means for releasably connecting said pivotable member to one of the two parts. The pivotable member is pivotably fastened by pivot and fastening means to the other of the two parts. Tightening means including a tightening member slidably mounted on the pivotable member are provided to tighten the lock. When the lockis mounted on the two parts and the pivotable member is connected to the one part to prevent movement of the door, the tightening member slides downwardly under gravitational force, when the pivotable member pivots downwards to a downward position and wedges said pivotable member in said downward position. The lock is tightened by this downward movement of the pivotable member. In a preferred embodiment of the lock according to the present invention, the pivotable member comprises a single U-shaped member having a base portion and two legs.

According to another aspect of the invention, the tightening means is a pawl pivotably connected to said pivotable member and a series of notches to prevent one end of the pawl from moving upwardly.

BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings which illustrate embodiments of the invention,

FIG. 1 is a front elevation of one embodiment of the lock according to the present invention showing a portion of the door and door jamb to which the lcok is attached, I

FIG. 2 is a sectional side view taken along the line 22 of FIG. 1,

FIG. 3 is a sectional view taken along the line 3-3 of FIG. 1, i

FIG. 4 is a sectional side view similar to FIG. 2 showing the lock in the unlocked position,

FIG. 5 is a front elevation of another embodiment of the lock according to the present invention again showing a portion of the door and door jamb to which the lock is attached,

FIG. 6 is a right side view of the embodiment shown in FIG. 5.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS The self-tightening lock shown in FIG. 1 is connected to two

parts

10 and 12 comprising a door 10 and an adjacent structure or door jamb 12, part only of the door and adjacent structure being shown in the drawings. The lock 11 has a pivotable member 14 which connects the door 10 to the adjacent structure 12 when the door is closed and the lock is in the locked position shown in FIG. 1. In the lock of FIG. 1, the pivotable member 14 is a U-shaped member having two

legs

18 and 20 located at

ends

15 and 13 respectively. The leg 18 isrelatively short with a circular cross-section while leg 20 is relatively long and is formed with two flat parallel sides 22 on opposite sides of the leg 20. The remaining portion of the sides of the leg 20 is curved and the outer end of leg 20 is formed or fitted with a knob 24 to permit the leg 20 to be gripped manually with relative ease and safety. The outer end 26 of leg 18 is rounded or bevelled to permit easy insertion of the end 26 in a hole 28 shown in FIG. 2.

Connecting means 30 for connecting the leg 18 of the pivotable member 14 to one of the two parts and 12 are provded. The preferred connecting means shown in FIGS. 1 to 3 are connected to the door jamb 12 but it will be understood that they could just as easily be connected to the door 10 by reversing the lock 11. The connecting means comprise a sliding member 32 having the aformentioned hole 29 contained therein and channel-like slide guide 34 for slidably connecting the member 32 to the door jamb. The sliding member 32 has a base portion 36 and a fiat outward porjection 38 having the hole 28 therein. The slide guide means include a bottom 40 and two outwardly projecting sidewalls 42, one wall extending along the length of each side edge of the bottom 40. These sidewalls 42 are bent first outwardly and then away from the bottom 40 to provide a recess for the nuts 72 and the ends of the bolts 50. Projecting from the outer edge of each sidewall 42, parallel to the bottom 40, there is a lip 44 (see FIG. 3) extending the length of the sidewall. A gap or space 46 is formed between the two lips 44 and the projection 38 extends therethrough. Between the bottom 40 and the lips 44 a slide passage 48 is formed, a passage which is closed at each end by an end wall 47. The base portion 36 of the sliding member 32 can slide freely up and down in the slide passage but is otherwise fastened securely to the door jamb by the slide guide 34 which is attached by bolts or screws 50, to the door jamb. The bolts 50 may be two carriage bolts.

The pivotable member 14 pivots about pivot and fastening means 51 which comprise a tubular member 52 and attachment means for rigidly attaching the tubular member to either the door or the door jamb. FIG. 1 shows the tubular member attached to the door but, as mentioned earlier, the lock may be reversed and the tubular member attached to the door jamb. The attachment means shown include a plate 54 and two bolts 56. Corner screws 58 may also be used at each corner of the plate 54 if desired. The tubular member has a short projection 60 on the side adjacent the plate 54 connecting the member to the plate. This projection 60 may simply be formed by a weld connecting the tubular member to the plate 54. The pivotable member 14 extends through the tubular member 52 and is free to pivot in the member 52 when the door is unlocked.

Tightening means 60 for tightening the lock mechanism comprises a tightening member 62 mounted on the leg 20. The preferred embodiment of the tightening member shown in FIGS. 1 and 2 is a V-shaped member having two diverging legs 64, each leg having a hole 66 therein and being slidably mounted on the leg which extends through each hole 66. The flat sides 22 of leg 20 prevent the tightening member from rotating about the leg.

The lock 1 1 is operated by closing the door and raising the U-shaped pivotable member, the sliding member 32, and the tightening member 62 to the positions shown in FIG. 4. Thus the sliding member 32 is raised to the top of the vertical slide passage 48, the tightening member 62 is raised to the top of the leg 20, and the pivotable member is pivoted upwards, towards the door 10. The upper end of leg 18 must be pivoted to a position immediately below the hole 28 and then the sliding member is lowered over the leg 18 in the direction indicated by the arrow in FIG. 4 to the position shown in FIG. 2. The tightening member 62 is then lowered in the direction indicated by the arrow in FIG. 4 causing the leg 20 to be pivoted slightly downwardly away from the door. The pivotable member and tightening member are thus brought to the locked position shown in FIG. 2 where the door is effectively locked.

If a person attempts to gain entry through the door by shaking the door or otherwise disturbing it, the pivotable member will tend to be pivoted slightly downwards away from the door being prevented from pivoting in the other direction by the tightening member 62 wedged between the leg 20 and the door 10. If the U- shaped pivotable member does pivot downwards so as to increase the distance between the leg 20 and the door, the tightening member moves downwardly under gravitational force to a position where it is again wedged between the leg 20 and the door. Thus the lock is tightened, any play in the lock mechanism and between the door and the door jamb being reduced. This self-tightening feature of the lock makes it more difficult for an intruder to force the door and lock open or to manipulate the lock from the outside.

An added feature of the present lock, which makes it very difficult for an intruder to force the lock open is the use of bolts extending completely through the door and door jamb to fasten the plates 54 and the slide guide 34 to the door and door jamb as shown in FIG. 3. After drilling the necessary holes, the two bolts 50 are inserted through holes in the door jamb 12 and a' metal plate or plates 70 adjacent the outer wall of the door jamb. The ends of the bolts 50 may be secured by means of the nuts 72 as shown or suitably threaded holes in the bottom 40 of the slide guide or keeper 34. In either case the keeper must be fastened in such a way that vertical movement of the sliding member 32 is not interfered with. The ends of the bolts or the fastening nuts 72 should not project into the slide passage 48. Bolts 50 are shown with smooth rounded heads 68 which merge at their sides with the plate or plates 70. This helps to prevent each bolt from being unscrewed from the outside. Moreover the bolts 50 can be flathead bolts without slotted heads, such bolts being pulled into the door as the nuts are threaded onto their ends until their flatheads are flush with the wood surface. Their flatheads can then be covered by the facing trim of the door frame so that they are not visible to anyone trying to force the door. If a steel door frame exists, the bolts can be countersunk and similarly covered. The bolts 50 can also be keyed into the steel frame by a small protuberance under the head.

Alternatively the slide guide or keeper can be fastened to the door jamb with a threaded tube and corresponding fully threaded bolt which can be threaded into the tube. The tube would then extend through a hole in the bottom of the slide guide and a suitable hole in the door jamb. A nut can be welded to the inner end of the tube to permit the tube to be held in place as the bolt is screwed into the tube and to engage the bottom 40 of the slide guide. A sharp projection can be provided next to the head of the bolt and this projection is drawn into the wood so as to prevent the bolt from being turned from the outside. As suggested above, the

projection can engage a hole drilled in the frame where a steel door is encountered.

Similarly the bolts 56 extend completely through the door and metal plate or plates 74 to fasten the plate 54 securely to the door by means of nuts on their ends. The bolts 56 are fitted with heads 76 similar to the heads 68 of the bolts 50.

A second embodiment of the present invention is shown in FIGS. 5 and 6 where the same numerals represent the same or similar parts as the embodiment shown in FIGS. 1 to 4. In this embodiment the connecting means 84 include a chain or cable 78 which has two ends 80 and 82 and attachment means for connecting the end 80 to one of the two

parts

10 and 12 of the door structure are provided. The preferred attachment means shown in FIGS. 5 and 6 are connected to the left hand opening door 10 but it will be understood that they could just as easily be connectedto the door jamb 12 in the case of a right hand opening door. In the case of a right hand opening door the plate member 54 and the parts attached thereto would be fastened to the door rather thanthe door jamb as shown in FIGS. 5 and The attachment means comprise aghook 86,, a nut 88 to the bottom side of which the hook 86 is fastened preferably by a weld, a plate member or washer 90 and a bolt 92. The plate member ,or washer 90 should be large enough to provide a secure base for the nut and hook and is located between the nut 88' and the door 10. The bolt 92 extends through the door and plate 90 and is screwed into nut 88. It will be understoodthat Preferably the pivotable member 94 shown in FIGS. 5 and 6 has a handle 120 whichis rigidly connected to the Ushaped member for manually pivoting member 94 to lock and unlock the door. ln the' embodiment shown the handle extends at a right angle from one end 122 of the base portion 100 of the U-shaped' member. Obviously the handle could just as easily extend from the other end of the base portion. The handle forms an This type of lock may be operated fromthe inside by closing the door and disengaging the pointed end 110 from the notches 118 bypivoting pawl 108 away from the notched surface area 116. The handle 120 is then raised in the direction indicated by the arrow in FIG. 7 which causes the legs 98 to be pivoted towards the door structure. During the pivoting of the legs 98, the pointed end 110 must of course be held away from the notches 118. The legs must be pivoted sufficiently to permit the end 80 of chain 78 to beconnected to the hook 86. Once the chain is connected to the lock 86, the handle 120 may then be lowered, causing the legs 98 to be pivoted away from the door structure and the chain 78 to be tightened. When the chain has been tightened asmuch as possible, the pawl 108 is pivoted towards the notched surface area 116 so that end 1 10 engages one of the notches, 118. Alternatively the pawl may simply be allowed to wedge itself by gravitational force as the chain is tightened. The door 10 is then effectively locked and can be unlocked by following a bolt 92 is secured on the outside in a manner similar to that of

bolts

50 and 56 already explained.

The pivotable member 94 connected to the end 82 of the chain 78 pivots about pivot and fastening means 96.

The pivot and fastening means comprise 'the'tubular member 52 and attachment means, which may be simichain is connected to theend102 of the leg 98 which is closest to the door by means of a bolt 104 or other procedure for locking the door except that the end 80 of chain 78 is removed from hook 86 rather than connected to it when the legs 98 are pivoted towards the door structure. I

As with the first embodiment, if a person attempts to gain entry through the door by shaking the door or otherwise disturbing it, the pivotable member 98, together with the handle 120, will tend to be pivotedslightly suitable connecting ineans. Bolt 104 may be threaded and screwed into a threaded hole in the leg 98 or may be fastened by means of a nut.

Pivotably connected to the end 106 of the leg 98 which is furthest from the door 10, there is a tightening member comprising pawl 108 which is pointed at end 110 and connected to the leg 98 at its opposite end 112. Pawl 108 which is approximately equal in length to each leg 98 is connected to the leg 98 by means of pin member 114. The pin member 114 may comprise a threaded bolt and nut or simply a threaded bolt screwed into a threaded hole in either leg 98 or plate member 108 or any other suitable connecting member such as a hinge which permits the plate member to pivot with respect to the leg 98.

The plate member 54 connected to the door jamb 12 has a notched surface area 1 16 which acts as holding or ratchet means to engage the pointed end 110 of the tightening member. In the drawings this area 116 is downwards being prevented from pivoting upwards by the pawl 108 wedged between one of the legs 98 and plate member 54. If the pivotable member 94 does pivot downwards so as to increase the distance between the end 106 of leg 98 and the notched surface area 1 16, the pawl member 108 moves downwardly under gravitational force to a position where the pointed end 110 engages a lower notch 118 and the pawl 108 is again tightly wedged between the leg 98 and the plate member 54. Thus the chain 78 is tightened and play in the lock mechanism and between the door and the door jamb is reduced.

The type of lock shown in FIGS. 5 and 6, unlike that shown in FIGS. 1 to 4, may be used to secure the door from the outside of the door as well as from the inside. The same procedure as described earlier is employed to lock the door from the outside up to the time the end of chain 78 is connected to the hook 86 except that the door is not closed until after end 80 is connected. The door is held open a sufficient amount to permit the end 80 of the chain to be held in the hand of a person outside the door and connected to the hook 86 on the door. The door is then closed and the pivotable member 94 pivots downwardly due to gravitational force and tighten the chain 78. Once the chain becomes tight, downward movement of member 94 is arrested. The pawl 108 again wedges itself by force of gravity between the leg 98 and the plate member 54, efiectively locking the door.

obtuse angle with the adjacent leg 98 as shown in FIG.

it will be understood that the various parts of the lock are constructed of a suitably strong material such as a metal or metal alloy and preferably iron or steel.

Locks according to the present invention may also be adapted for use in connection with sliding doors as well as swinging doors or, indeed may be used on windows, particularly the easement type. It whould also be noted that the pivot and fastening means for the pivotable member need not necessarily be connected to the door or the door jamb but may be rigidly fastened to the floor beside the door. This is particularly true with locks for sliding doors.

Thus it is apparent that there has been provided, in accordance with the invention, a self-tightening lock that fully satisfies the objects, aims, and advantages set forth above. While the invention has been described in conjunction with specific embodiments thereof, it is evident that alternatives, modifications and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications and varia tions as fall within the spirit and broad scope of the appended claims.

What I claim as my invention is:

l. A self-tightening lock for preventing movement of a door in relation to an adjacent structure, said door and said adjacent structure comprising two parts, said lock comprising a pivotable member, connecting means for releasably connecting said pivotable member to one of said two parts, pivot and fastening means for pivotably fastening said pivotable member to the other of said two parts, tightening means for tightening said lock including a tightening member slidably mounted on said pivotable member whereby when said lock is mounted on said two parts and said pivotable member is connected to said one of said two parts to prevent movement of said door, said tightening member slides downwardly under gravitational force when said pivotable member is pivoted downwards to a downward position, wedges said pivotable member in said downward position, and thus tightens said lock.

2. A lock according to claim 1 in which said pivotable member comprises a U-shaped member having a base portion and two legs.

.3. A lock according to claim 2 in which said tightening member has two diverging legs, each leg having a 8 hole therein and being slidably mounted on one leg of said pivotable member which extends through each hole.

4. A lock according to claim 2 in which said connecting means comprise a sliding member having a hole therein and holding the slide means for slidably connecting said sliding member to said one of said two parts, whereby when said lock is mounted on said two parts said one of said two legs is pivotable to an upward-extending position and then is insertable in said hole by sliding said sliding member downward from an upper position.

5. A lock according to claim 3 in which said pivotable member and at least one of the holes in said tightening member are formed with co-operating flat sides to prevent rotation of said tightening member with respect to said pivotable member.

6. A self-tightening lock for preventing-movement of a door in relation to an adjacent structure, said door and said adjacent structure comprising two parts, said lock comprising a pivotable member, connecting means for releasably connecting said pivotable member to one of said two parts, pivot and fastening means for pivotably fastening said pivotable memberto the other of said two parts, tightening means for tightening said lock including a pawl pivotably connected to said pivotable member and a series of notches to prevent one end of said pawl from moving upwardly and thereby preventing said pivotable member from pivoting towards the other of said two parts, whereby when said lock is mounted on said two parts and said pivotable member is connected to said one of said two parts to prevent movement of door, said pawl pivots downwardly under gravitational force when said pivotable member is pivoted downwards to a downward position, wedges said pivotable member in said downward position, and thus tightens said lock.

7. A lock according to claim 6 in which said pivotable member includes a handle to pivot said pivotable memher.

8. A lock according to claim 4 in which said pivot and fastening means include a horizontal tubular member fastened to the other of said two parts and in which said base protion extends through said tubular member.

Claims

1. A self-tightening lock for preventing movement of a door in relation to an adjacent structure, said door and said adjacent structure comprising two parts, said lock comprising a pivotable member, connecting means for releasably connecting said pivotable member to one of said two parts, pivot and fastening means for pivotably fastening said pivotable member to the other of said two parts, tightEning means for tightening said lock including a tightening member slidably mounted on said pivotable member whereby when said lock is mounted on said two parts and said pivotable member is connected to said one of said two parts to prevent movement of said door, said tightening member slides downwardly under gravitational force when said pivotable member is pivoted downwards to a downward position, wedges said pivotable member in said downward position, and thus tightens said lock.

3. A lock according to claim 2 in which said tightening member has two diverging legs, each leg having a hole therein and being slidably mounted on one leg of said pivotable member which extends through each hole.

6. A self-tightening lock for preventing movement of a door in relation to an adjacent structure, said door and said adjacent structure comprising two parts, said lock comprising a pivotable member, connecting means for releasably connecting said pivotable member to one of said two parts, pivot and fastening means for pivotably fastening said pivotable member to the other of said two parts, tightening means for tightening said lock including a pawl pivotably connected to said pivotable member and a series of notches to prevent one end of said pawl from moving upwardly and thereby preventing said pivotable member from pivoting towards the other of said two parts, whereby when said lock is mounted on said two parts and said pivotable member is connected to said one of said two parts to prevent movement of door, said pawl pivots downwardly under gravitational force when said pivotable member is pivoted downwards to a downward position, wedges said pivotable member in said downward position, and thus tightens said lock.

7. A lock according to claim 6 in which said pivotable member includes a handle to pivot said pivotable member.