WO1994009236A1

WO1994009236A1 - Sliding door lock

Info

Publication number: WO1994009236A1
Application number: PCT/US1993/009314
Authority: WO
Inventors: Richard J. Richardson; Charles E. Crown; Gary E. Paugh; Fernando Calderon
Original assignee: Anthony's Manufacturing Company, Inc.
Priority date: 1992-10-09
Filing date: 1993-09-30
Publication date: 1994-04-28
Also published as: CN1089680A; MX9306279A

Abstract

A sliding door lock (10) having a latch plate (28, 74), which slidably engages a channel (30) in one leg of a corner piece (22). The corner piece (22) is mounted in a door frame (20). A stud (44, 78) is attached to the latch plate (28, 74) so that a person may grasp the stud (44, 78) and slide the plate (28, 74) up and down. The stud (44, 78) has internal threads (52, 90). A screw (54, 86) is threaded into the internal threads (52, 90) of the stud. The sliding door lock (10) is used by grasping the stud (44, 78), which extends through an elongated slot (50) in the door frame (20), and using the stud (44, 78) to move the latch plate (28, 74) upward so that it extends past the top of the door frame (20). The screw (54, 86) is then used to hold the latch plate (28, 74) in an upward position.

Description

SLIDING DOOR LOCK

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of applica- tion, Serial No. 07/988,301, filed October 9, 1992, and entitled "SLIDING DOOR LOCK."

BACKGROUND OF THE INVENTION

The present invention relates generally to door locks, and more particularly to a sliding door lock which may be used to lock a sliding door and to hold the door open.

In the past, a variety of different locks have been used to lock a sliding door or window. For example, U.S. Patent No. 4,514,996, issued to Sjogren on May 7, 1985, discloses a sliding door lock mounted to the end of a sliding door frame. A handle attached to a bolt is used to move the bolt upward until it engages one of several apertures in a door frame casement. The bolt may be locked in an upward position using a barrel lock, thus preventing the door frame from moving.

U.S. Patent No. 4,475,313, issued to Governale on October 9, 1984, describes two different locking devices used for sliding doors. One device uses knobs at the top and bottom of a door frame to move sliding bolts into openings at top and bottom portions of a surrounding frame sill structure. Slots in the door frame allow vertical movement of the knobs, which are locked in place by compres¬ sion springs. The second device uses a lever operated swinging latch bolt, pivotally mounted in a bolt housing mounted on a door frame. An extension of the bolt removably engages a slot in an adjacent door.

A latch used for windows or doors is disclosed in U.S. Patent No. 4,066,284, issued to Ikemura on January 3, 1978. A latch bolt is slidably mounted in a housing, which may be attached to a window or sliding door. A handle is used to move the bolt longitudinally along the length of the housing until the end of the bolt engages a recess in the surround¬ ing door or window structure. The handle removably engages one of the channels in a plate member of the housing. A spring biases the handle into a channel, keeping the end of the bolt in the recess.

Another lock used for locking sliding windows or doors is disclosed in U.S. Patent No.. 3,975,041, issued to Edison on August 17, 1976. A screw is used to clamp members to one of the legs of a channel guide on which a window or door is slidably mounted. The members are in contact with the frame of the window or door, effectively preventing sliding movement of the window or door. U.S. Patent No. 3,944,266, issued to Weaver on March

16, 1976, discloses a locking latch for sliding doors. The latch has a housing which is attached to the outside of a door frame. A plate is free to move vertically along the length of the housing. The plate has two upward extensions at its upper end. A thumb screw is threaded into a threaded aperture in the plate. A slot in the housing allows a person to grasp the screw and move the plate up and down. A sliding door may be locked in place by moving the exten¬ sions of the plate upward, using the screw, until the extensions engage apertures in a surrounding structure.

U.S. Patent No. 3,347,585, issued to Chmura on October

17, 1967, discloses a sliding window lock using an elongated member EE, having a number of notches along the length thereof. Member EE is mounted on a sliding window. A U- shaped locking member LE may be attached to elongated member EE at different locations along the length of the member EE by selectively using different notches. A lock screw is used to attach members EE and LE together. The locking member LE limits sliding movement of an adjacent window. Other locking devices used for doors and windows are disclosed in U.S. Patent Nos. 5,127,685, issued to Dallaire, et al. on July 7, 1992 (a window latch); 4,971,374, issued to Lovell, et al. on November 20, 1990 (window and door clamps and anti-liftoff plate for sliding glass door) ; 2,431,178, issued to Keane on November 18, 1947 (window lock); and 692,047, issued to Bronson on January 28, 1902 (window sash fastener) .

SUMMARY OF THE INVENTION

It is an object of this invention to provide a sliding door lock that may be used to lock a sliding door and to hold the sliding door open.

It is another object of this invention to provide a sliding door lock that is mounted inside a door frame.

It is still another object of this invention to provide a sliding door lock that is easy to install and to remove.

It is still another object of this invention to provide a sliding door lock that is economical to manufacture and easy to use.

These and other objects and advantages are attained by a sliding door lock having a latch plate, which slidably engages a channel in one leg of a corner piece. The corner piece is mounted in a door, frame. A stud is attached to the slider plate so that a person may grasp the stud and slide the plate up and down. The stud has internal threads. A small screw is threaded into the internal threads of the stud.

The sliding door lock is used by grasping the stud, which extends through an elongated slot in the door frame, and using the stud to move the latch plate upward so that it extends past the top of the door frame. Upward movement of the latch plate is stopped when the bottom end of an elongated slot in the plate contacts a screw used to fasten the corner piece to the door frame. The small screw is then used to hold the latch plate in an upward position. A tool is used to thread the small screw past the end of the stud so that the end of the small screw is in frictional contact with the corner piece, thus holding the latch plate in the upward position.

When the latch plate is locked in the upward position, the door cannot be slid open because the upper end of the plate will come into contact with a block positioned above the door frame and mounted on a supporting structure surrounding the door frame. The latch plate may also be used in conjunction with other blocks for the purpose of holding the sliding door open. The sliding door may be unlocked by using the tool to thread the end of the small screw away from (or out of frictional contact with) the corner piece, so that the stud may be grasped and the latch plate may be moved downward.

In another embodiment of the sliding door lock, a screw is threaded past the end of the stud and into an elongated slot in the corner piece. The latch plate is held in an upward position by the end of the screw, which contacts the bottom end of the elongated slot in the corner piece. The screw is trapped inside a cylindrical portion of the stud. The stud has an outside plate, which slides on the outside of the door frame, and covers the elongated slot in the door frame.

The various features of the present invention will be best understood together with further objects and advantages by reference to the following description of the preferred embodiment when taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a display case having sliding doors, showing a sliding door lock of the present invention mounted on one of the doors; FIG. 2 is a cross-sectional view taken in the direction of arrows 2-2 of FIG. 1, showing a latch plate of the sliding door lock locked in an upward position;

FIG. 3 is a cross-sectional view taken in the direction of arrows 3-3 of FIG. 2, showing how the sliding door lock is mounted inside a door frame;

FIG. 4 is an exploded perspective view of the sliding door lock and a portion of the door frame;

FIG. 5 is an enlarged perspective view of an upper left-hand corner of a sliding door and of another embodiment of the sliding door lock shown mounted on a door; and

FIG. 6 is a cross-sectional view taken in the same direction as FIG. 3, showing how the sliding door lock of FIG. 5 is mounted inside a door frame.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following specification taken in conjunction with the drawings sets forth the preferred embodiments of the present invention in such a manner that any person skilled in the art can make and use the invention. The embodiments of the invention disclosed herein are the best modes contemplated by the inventors for carrying out their invention in a commercial environment, although it should be understood that various modifications can be accomplished within the parameters of the present invention. FIG. 1 shows a sliding door lock 10 of the present invention mounted on a sliding door 12 of a display case 14. The sliding door lock 10 may be used for the sliding doors of a refrigerated display case used in supermarkets, or other retail establishments. However, the sliding door lock 10 may be used for any type of sliding doors such as sliding doors used in a residence. Also, lock 10 may be used for sliding windows.

As shown in FIG. 2, the sliding door 12 may be mounted in a channel support 16 attached to a supporting structure 18 of the display case 14. The sliding door lock 10 is mounted inside a door frame 20 of the sliding door 12, as shown in FIG. 3. As a result, lock 10 fits conveniently inside the door frame 20, and does not require a housing typically used for prior art locking devices. Such housings are usually attached to the outside of door frames, and present a bulky, unattractive appearance for sliding doors.

The sliding door lock 10 has a corner piece 22 with two legs 24 and 26. A latch plate 28 slidably engages a channel

30 in leg 24 of the corner piece 22 (see FIG. 4) . Screws 32 through 36 engage threaded apertures 38 through 42, respectively, in the corner piece 22, and are used to attach the corner piece 22 to the door frame 20. Aperture 42 is preferably countersunk. Corresponding threaded apertures are used in the door frame 20 for the screws 32 through 36. As shown in FIG. 3, the apertures at the outside of the door frame 20 are preferably countersunk and flat screw heads are preferably used for screws 32 through 36 to provide flat, flush surfaces.

A stud 44 is attached to the latch plate 28 by threaded end 46, which engages internal threads 47 of aperture 48 in the plate 28. However, the stud 44 may be press-fitted, or otherwise attached to the plate 28. The stud 44 extends through an elongated slot 50 in the door frame 20. As a result, a person may grasp the stud 44 and move the latch plate 28 up and down.

The stud 44 has internal threads 52. A small screw 54 is threaded into the internal threads 52 of the stud 44. The screw 54 has an engaging recess 56, such as a hex-shaped recess, at one end. However,' any shaped recess may be used. The latch plate 28 has an elongated slot 58 in the upper portion thereof. Screw 34 passes through slot 58 as shown in FIG. 3. The sliding door lock 10 is used by grasping the stud 44, and using the stud 44 to move latch plate 28 upward so that it extends through aperture 21 in the door frame 20, and past the top of the door frame 20. Upward movement of the latch plate 28 is stopped when the bottom end of elongated slot 58 in plate 28 comes into contact with screw 34. The small screw 54 is then used to hold the latch plate 28 in an upward position. This is accomplished by inserting a tool 60 into recess 56 of screw 54, and threading the screw 54 past the threaded end 46 of the stud 44 so that the end of the screw 54 is in frictional contact with the corner piece 22, thus holding the latch plate 28 in the upward position.

When the latch plate 28 is locked in the upward position, the door 12 cannot be slid open (moved to the left as shown in FIG. 3) because the upper end of plate 28 will come into contact with a block 62 positioned above the door 12, and attached to the supporting structure 18 by screws 64. A plate 66 may be used as shown in FIG. 3, if desired. The door 12 shown in FIG. 3 is opened by sliding the door 12 to the left. The supporting structure 18 prevents the door 12 from being slid to the right when the door 12 is closed, or positioned as shown in FIG. 3. As a result, the lock 10 keeps the sliding door 12 from being opened. The door 12 may be unlocked by using the tool 60 to thread the screw 54 to the left (see FIG. 3) , or so that the end of the screw 54 is no longer in frictional contact with the corner piece 22. Plate 28 may then be lowered.

Another block 68 may be positioned over the door 12 as shown in FIG. 3, so that the block 68 is located above a pulley 70 used for the door 12. When the door 12 is locked as shown in FIG. 3, block 68 prevents the door 12 from being lifted out of its bottom track, or bottom channel support 16, because lifting of the dOOr 12 will cause the pulley 70 to come into contact with block 68. The sliding door lock 10 may also be used to hold the door 12 open. This may be accomplished by attaching additional blocks (not shown) to the supporting structure 18, above the door 12 and to the left of the door 12 (as shown positioned in FIG. 3), or to the left of block 62. Therefore, when the door 12 is slid to the left, latch plate 28 may be locked in an upward position, using lock 10, and positioned to the left of one of the additional blocks, thus preventing the door 12 from closing or sliding to the right. As a result, the door 12 may be held open at different positions by selectively locating the additional blocks.

Downward movement of the stud 44 may be limited by the bottom end of slot 50, or by the top end of slot 58 coming into contact with screw 34. Also, if desired, upward movement of the latch plate 28 may be restricted by the top end of the plate 28 coming into contact with the supporting structure 18, or by the stud 44 contacting the top end of elongated slot 50. In addition, instead of using screw 54 to hold plate 28 in an upward position, the stud 44 may be screwed into the internal threads 47 of aperture 48 in plate 28 so that the end of the stud 44 is in frictional contact with the corner piece 22. As such, screw 54 may be elimi¬ nated, if desired. Also, note that the door frame 20, at the corner of the door 12 where the lock 10 is mounted, consists of horizontal and vertical portions (only the vertical portion is shown in FIG. 4) . This facilitates mounting the lock 10 inside the frame 20. As mentioned above, the recess 56 may have any shape that matches tool 60. For example, recess 56 may be an aperture having indentations at the bottom of the aperture. The matching tool 60 would then have extensions at the end thereof that fit into the indentations of the aperture. Any special tool may be fabricated for use with screw 54. Finally, bolts or other types of fasteners may be used instead of screws. Another embodiment of the sliding door lock 10 is shown in FIGS. 5 and 6. In this embodiment, the sliding door lock 10 is mounted inside the door frame 20 of the sliding door 12. The lock 10 has a corner piece 72 with two legs 24 and 26. A latch plate 74 slidably engages channel 30 in leg 24. The legs 24 and 26 and channel 30 for corner piece 72 are the same as shown for the embodiment in FIG. 4. The corner piece 72 may be attached to the door frame 20 by a screw 76 used to attach the pulley 70 to the door frame 20. Alterna¬ tively, one or more of screws 32 through 36 may be used to attach the corner piece 72 to the door frame 20. It is intended that any desirable means may be used for fastening the corner pieces 22 and 72 of the present invention to the door frame 20.

A stud 78, passing through an aperture 80 in an outside plate 82, is attached to the latch plate 74 by threaded end 46, which engages internal threads 47 of aperture 48 in the plate 74. The threaded end 46 of stud 78 and internal threads 47 in aperture 48 of plate 74 are like end 46, threads 47 and aperture 48 of the embodiment shown in FIG. 4. However, any desirable means may be used to attach the stud 78 to the latch plate 74.

The stud 78 extends through elongated slot 50 in the door frame 20. The corner piece 72 also has an aperture 84 therein. The aperture 84 preferably is an elongated slot 84. As explained below, slot 84 is used to hold the latch plate 74 in an upward position.

A person may grasp stud 78 and move the latch plate 74 up and down so that the plate 74 may be extended through aperture 21 in the door frame 20, and past the top of the door frame 20. The stud 78 has internal threads 90 (like internal threads 52 of stud 44) . A screw 86 with a head 88 is threaded into the internal threads 90 of the stud 78. As shown in FIG. 6, the stud 78 has a cylindrical portion 94 with an open end or aperture ^"98 formed by a bent or crimped end 96 of portion 94. Cylindrical portion 94 is preferably formed as an integral part of stud 78. Aperture 98 is sized so that head 88 of screw 86 is larger than or cannot pass through the aperture 98. As a result, screw 86 is trapped inside stud 78, because the screw 86 cannot pass through aperture 98. The sliding door lock 10 is used by first grasping the stud 78 and moving the latch plate 74 upward so that the upper end of plate 74 extends through aperture 21, and past the top of the door frame 20. Upward movement of the latch plate 74 is stopped when the stud 78 comes into contact with the top end of slot 50. Alternatively, upward movement of the latch plate 74 may be stopped when the top end of the plate 74 contacts the supporting structure 18. Also, if desired, the latch plate 74 may have an elongated slot 58, like slot 58 used for latch plate 28, and upward movement of the plate 74 may be stopped when the bottom end of slot 58 contacts a screw 34, like screw 34 used with plate 28 (see FIG. 3) .

The latch plate 74 may be locked in an upward position after moving the plate 74 upward as shown in FIG. 6, by inserting the tool 60 through aperture 98, into cylindrical portion 94, and into a recess 92 in head 88 of the screw 86. The tool 60 is then used to thread the screw 86 into the internal threads 90 of the stud 78, so that head 88 rests against internal surface 95 of the stud 78, and the end of the screw 86 extends past the end of the stud 78 and into elongated slot 84 of the corner piece 72. The stud 78 and latch plate 74 may then be lowered until the end of screw 86 comes into contact with the bottom end of elongated slot 84 in the corner piece 72. Thus, downward movement of the latch plate 74 is prevented and the plate 74 is held or locked in the upward position.

The screw 86 is preferably sized so that the end of the screw 86 does not come into frictional contact with the door frame 20. However, the lock 10 will still work even if the end of screw 86 contacts the door frame 20. As discussed above, the door 12 cannot be slid open when the latch plate 74 is locked in the upward position. The sliding door lock 10 may be unlocked by inserting the tool 60 once again into recess 92, and unscrewing screw 86 so that the end of the screw 86 no longer extends past the end of stud 78. This may be accomplished by unscrewing the screw 86 until head 88 comes into contact with crimped end 96 of cylindrical portion 94. The latch plate 74 may then be lowered until stud 78 comes.into contact with the bottom end of elongated slot 50. Alternatively, downward movement of plate 74 may be stopped by using an elongated slot 58 in plate 74 and a screw 34 as shown in FIG. 3 and discussed above.

As discussed above, the recess 92 in head 88 of screw 86 may be any shape, and the end of tool 60 may be fabricat¬ ed to engage any shaped recess 92.

The outside plate 82 is preferably L-shaped and fits around one edge or corner of the door frame 20 as shown in FIG. 5. However, the plate 82 may be a flat plate, a U-shaped plate, or have any desirable shape or configura¬ tion. The plate 82 is coupled or attached to stud 78 and moves up and down with the stud 78, sliding along the door frame 20. The plate 82 is sized to cover elongated slot 50 in the door frame 20. Outside plate 82 covers slot 50 when the lock 10 is locked and the latch plate 74 is in the upward position, and when the lock 10 is unlocked and stud 78 is in contact with the bottom end of slot 50.

Plate 82 prevents contaminants or other undesirable materials from entering the door frame 20 through slot 50. Also plate 82 protects against a person getting his or her fingers caught or injured in slot 50 when using the lock 10.

As discussed above, the latch plate 74 of the sliding door lock 10 shown in FIG. 6 may be used with blocks 62 and

68 to lock a sliding door 12 shut, or to keep a door 12 open. The above description discloses the preferred embodi¬ ments of the present invention. However, persons of ordinary skill in the art are capable of numerous modifica¬ tions once taught these principles. Accordingly, it will be understood by those skilled in the art that changes in form and details may be made to the above-described embodi¬ ments without departing from the spirit and scope of the invention.

Claims

WE CLAIM:

1. A locking device for use with a frame slidably mounted in a supporting structure comprising: a corner piece having two legs mounted inside said frame; a latch plate slidably engaging said corner piece; and means engaged to said latch plate for releasably holding said latch plate in aη upward position.

2. The locking device of Claim 1 further comprising a plate coupled to said means for releasably holding said latch plate in an upward position, said plate located outside said frame.

3. The locking device of Claim 1 further comprising a block mounted on said supporting structure and positioned above said door frame, said latch plate adapted to contact said block when in said upward position in order to prevent movement of said door frame.

4. The locking device of Claim 1 wherein said means for releasably holding said latch plate in an upward position comprises a stud engaged to said latch plate and a screw engaging said stud and adapted to releasably be in frictional contact with said latch plate.

5. The locking device of Claim 4 further comprising a tool adapted to engage and apply torque to said screw.

6. The locking device of Claim 1 wherein said means for releasably holding said latch plate in an upward position comprises a stud, said latch plate having an aperture with internal threads, said stud engaging said internal threads.

7. The locking device of claim 1 wherein said means for releasably holding said latch plate in an upward position comprises a stud engaged to said latch plate and a screw engaging said stud, said corner piece having an aperture therein, said screw adapted to releasably engage said aperture in said corner piece.

8. The locking device of Claim 7 further comprising a tool adapted to engage and apply torque to said screw.

9. A locking device for use with a frame slidably mounted in a supporting structure comprising: a corner piece mounted inside said frame; a latch plate slidably engaging said corner piece; a stud engaging said latch plate; and a screw engaging said stud and adapted to releasably hold said latch plate in an upward position.

10. The locking device of Claim 9 further comprising a block mounted to said supporting structure and positioned above said frame, said latch plate adapted to contact said block when in said upward position in order to prevent movement of said frame.

11. The locking device of Claim 10 further comprising a tool adapted to engage and apply torque to said screw.

12. The locking device of Claim 11 wherein said frame has an elongated slot therein, said stud extending through said elongated slot.

13. The locking device of Claim 12 wherein said corner piece has two legs.

14. The locking device of Claim 13 wherein one of said legs of said corner piece has a channel therein, said latch plate slidably engaging said channel.

15. A locking device for use with a frame slidably mounted in a supporting structure comprising: a corner piece mounted inside said frame, said corner piece having an aperture therein; a latch plate slidably engaging said corner piece;

a stud engaging said latch plate; and a screw engaging said stud and adapted to releasably engage said aperture in said corner piece.

16. The locking device of Claim 15 further comprising a block mounted to said supporting structure and positioned above said frame, said latch plate adapted to contact said block when in said upward position in order to prevent movement of said frame.

17. The locking device of Claim 15 further comprising a plate coupled to said stud, said frame having an elongated slot therein, said stud extending through said elongated slot, said plate covering said elongated slot.

18. The locking device of Claim 15 wherein said corner piece has two legs.

19. The locking device of Claim 18 wherein one of said legs of said corner piece has a channel therein, said latch plate slidably engaging said channel.

20. The locking device of Claim 19 wherein said stud has a cylindrical portion, said screw being trapped inside said cylindrical portion.