GB2196375A - Diametrically opposed hooked dead bolt lock - Google Patents

Abstract

A cylinder lock 18 mechanism wherein two diametrically opposed hooked swing dead bolts 14, 29 are operated simultaneously and grasp a long strike plate attached to the door frame thus preventing movement of the lock, and hence the door. The mechanism may be used on a swing door, sliding door, roll up door or push up door, and may also be elongated in length such that the hooked swing dead bolts may be placed as far apart as is required by various specifications. <IMAGE>

Description

SPECIFICATION Diametrically opposed hooked dead bolt lock BACKGROUND OF THE INVENTION Various dead bolt lock mechanisms are available which provide a sliding dead bolt to hold the door closed. However, all sliding dead bolts are limited in that by inserting a car jack across the door frame in the vacinity of the cylinder mechanism the door frame members may be jacked apart, thus moving the strike plate on the frame away from the lock bolt and so allowing the door to be pushed open.

These standard dead bolt locks have a second limitation in that the machine screws holding the cylinder on to the lock mechanism are in line with any applied force on the cylinder and so it is possible to pull the cylinder out of the lock mechanism simply by stripping the threads of two number eight, or 4BA, screws by using lever grips.

Other dead bolt locks provide a single hooked bolt which helps prevent door frame spreading but whose lock mechanism is exposed outside its housing in such a manner that by drilling a one-eighth inch hole below the cylinder the lock mechanism can be sprung. This same single hooked bolt lock when used on a sliding door may be lifted out of its strike plate by simply lifting the door out of its track.

A final limitation on most types of dead bolt lock is that very little attention has been paid to the design of the strike plate. Strike plates should be an integral part of the design of the lock and not just an auxiliary item. Impact forces applied to a door, such as a kick or a shoulder charge, are usually applied above the bolt. These forces are intended to push the door inwards, but, because the lock bolt prevents inward movement, the impact force is converted into a torque with the lock bolt acting as a fulcrum point. The results is that most of the impact force is concentrated on th! top screw of the strike plate causing this screw to tear through the frame causing the door frame to split and allowing the strike plate to be ripped out of the frame.

A locking system made in accordance with this invention prevents door frame spreading, cylinder pulling and because of the long strike plate used, reduces by four times the torque effect on the strike plate.

SUMMARY OF THE INVENTION This lock assembly consists of a profile cylinder which is retained in the lock assembly by means of a door edge mounted quarter inch machine screw which is supported along its length by support and guidance angle plates. The profile cylinder has a sintered steel pawl which rotates in conjunction with the key such that when the key is withdrawn the pawl remains located within the metal chassis of the lock assembly. Both of these items, i.e.

the retaining machine screw and the pawl being located within the lock assembly housing, working in conjunction with an external cylinder guard prevent the cylinder from being pulled from the lock assembly.

The cylinder pawl engages upon either of two steel pins located on a spring controlled angled sliding plate bearing upon a guide plate which is welded to a sliding drive plate, such that this assembly operates as an integrated unit. Two angled slots, cut into the drive plate, engage upon a second pair of pins inserted and held in holes drilled into the two swinging hooked dead bolts such that when the drive plate moves up or down the hooked swing bolts rotate out of or into the lock mechanism housing. Thus, the rotation of the key, and so the cylinder pawl, causes a drive upon either of the pins on the angled slide plate which, in turn, causes the drive plate to move up or down thus rotating the hooked swing bolts by means of the angled slots acting upon the bolt drive pins.

An object of this invention is the provision of a locking mechanism whose hooked swing bolts will catch and hold on to a long strike plate attached to a door frame thus preventing the frame from being spread.

An object of this invention is the provision of a locking mechanism whose cylinder mounting screw is encased within and therefore strengthened by the lock housing and also within which housing the cylinder pawl is located when the cylinder key is removed, the whole of which assembly preventing the pulling of the cylinder from the said lock housing.

An object of this invention is the provision of a locking mechanism which may be used on any type of door whether they be swing, sliding, pull up or roll up doors.

An object of this invention is the provision of a locking mechanism which will dissipate or reverse most of a force couple, or lever action, due to any impact force applied to the door, and thus obviate or reduce the concentration of this force at one point on the door frame.

An object of this invention is the provision of a locking mechanism which can be elongated such that the hooked swing dead bolts may be placed as far as is required by various specifications.

The above stated and other objects and advantages of the invention will become apparent from the following description when taken with the accompaning drawings and descriptions. It will be understood, however, that the drawings are for purposes of illustration and are not to be construed as defining the slope or limits of the invention, references being had for the latter purpose to the claims appended hereto.

BRIEF DESCRIPTION OF THE DRA WINGS In the drawings wherein like reference characters denote like parts in the several views: Figure 1 is a side view of the lock mechanism and cylinder with the top cover removed Figure 2 is a front view of the lock mechanism with the front plate removed. This view also shows the version of the lock as used on steel or aluminium doors where no front plate is used.

DESCRIPTION OF THE PREFERRED EMBODI MENT Referring to Fig. 1, the front plate (1) to which the rest of the assembly is attached via screws (5) and (32), is the means by which the lock assembly is attached to the edge of the door. On steel doors the front plate (1) is removed and the assembly as shown in Fig. 2 is inserted into the channel riser of the door and matched with precut holes on the door edge, thus the steel door edge takes the place of the front plate (1).

The angled base and back plate (8) is welded to the mounting blocks (4) and (33) such that it wraps around these mounting blocks and so forms two sides of the lock mechanism housing. The two hooked swing bolts (14) and (29) are attached to the base and back plate (8) by means of the headed rivets (13r and (28) in such a manner that they swing easily on the said rivets.

Hardened steel drive pins (11) and (26) are inserted into two holes cut in the respective hooked swing bolts (14) and (29) such that they protrude through the thickness of the drive plate (9). Two right angled drive slots (10) and (25) are cut into the drive plate (9) such that they correspond to the two hardened steel drive pins (11) and (26) and bear upon these said drive pins when the drive plate (9) is moved.

The drive plate (9) slides between two 'u' shaped guide plates (15) and (16) which latter perform several functions. Firstly, they guide the drive plate (9) in its up and down move meSnt such that there is no horizontal play.

Secondly, they provide a stop for the movement of the drive plate in the operated or locked position, as shown in Fig. 1. Guide plate (16) strikes one end of the slot cut into the front of drive plate (9) and so prevents any further upward movement of the said drive plate in its locked position. Conversely, guide plate (15) strikes the opposite end of the said slot in the drive plate (9) in the unlocked position, i.e. bolts inboard, and so prevent any further downward movement of drive plate (9). Thirdly, both guide plates (15) and (16) guide the cylinder retaining screw (19) directly into the tapped hole in the cylinder body and so strengthen this screw by supporting it along most of its length.And fourthly, the said guide plates bear upon the top plate (36) in such a manner that this said top plate is prevented from bearing upon the drive plate (9) and is so inhibiting its up and down movement.

Plate (24) is welded to the drive plate (9) and holds the spring (17) in place such that it bears upon the spring plate (21) thrusting it towards the cylinder body. Plate (24) also guides the spring plate (9) such that it can move in only the one plane, horizontally. Attached to the spring plate (21) are two hardened steel pins (20) and (23) which lie on either side of the cylinder pawl (22) in the locked (shown) position.

When the pawl (22) of the lock cylinder (18) is rotated by means of the key, it bears upon either pin (23) or (20) depending upon the direction of rotation. The lock mechanism is shown in its locked position. To unlock the mechanism the key and hence the cylinder pawl (22) is rotated counter-clockwise. The cylinder pawl (22) bears upon pin (23) causing the spring plate (21) to slide towards front plate (1) and thus compressing spring (17) as well as forcing the drive plate (9) to slide downwards. The drive slots (10) and (25) slide vertically along the drive pins (11) and (26) unlocking the swing hooked bolts (14) and (29). The hooked swing bolts only begin to move when drive pins (11) and (26) bear upon the topmost surfaces of the horizontal sections of drive slots (10) and (25).At this point the bolts (14) and (29) become completely unlocked from their outboard (locked) condition since the drive pins (11) and (26) are not longer held in position by the vertical sections of the drive slots (10) and (25).

When the drive pins (11) and (26) enter the horizontal sections of drive slots (10) and (25) they apply a downwards force to the hooked swing bolts (14) and (29) causing them to rotate inward into the body of the lock. The lock mechanism is then in its unlocked condition.

To lock the lock mechanism the reverse procedure to the above is carried out. The key in the lock cylinder is turned clockwise causing the cylinder pawl (22) to bear upon pin (20) thus sliding the spring plate (21) towards the front plate (1) and then also applying an upwards force to the drive plate (9) and so causing as upwards motion of this said plate.

This upwards motion of the drive plate (9) causes the drive slots (10) and (25) to bear upon drive pins (11) and (26) which, in turn applies a force to the hooked swing bolts (14) and (29) hence causing these said bolts to rotate outwards. The drive pins (11) and (26) enter the vertical sections of the drive slots (10) and (25) about three-quarter of the way through their complete displacement thus locking the hooked swing bolts (14) and (29) in the outboard (locked) position.The lock remains locked because (A) the cylinder pawl takes up the fixed position shown in Fig. 1 between pins (20) and (23) when the lock key is removed, thus preventing any further movement of the drive plate (9), and (B) because the drive pins (11) and (26) are located within the vertical section of the drive slots (10) and (25) thus preventing any lateral movement of the said drive pins and so the hooked swing bolts, which movement is required before the said hooked swing bolts can rotate. Even with the lock cylinder removed the hooked swing bolts cannot rotate with the drive pins located within the vertical section of the drive slots, hence the hooked swing bolts are double locked in the locked position of the lock mechanism.

All of the above mechanism contained within the housing (8) and (36) may be elongated, i.e. lengthened by increasing the length of housing (8) and (36) and also the length of the drive plate (9) such that the hooked swing dead bolts (14) and (29) may be spaced further apart to any dimension required by various specifications.

Claims (7)

1. A locking system of the class which is operated by a profile cylinder to effect operation of two diametrically opposed hooked swing dead bolts; the improvement wherein these said hooked swing dead bolts clasp the strike plate mounted on the door frame and so prevent movement of the door in any plane about the door frame, and wherein these said hooked swing dead bolts are locked in the locked position by means of the driving mechanism drive pins, and wherein the driving mechanism is held in either the locked or unlocked position by means of the cylinder pawl bearing upon either of two pins located in the said driving mechanism.

2. The invention as recited in claim 1 wherein the said dead bolts are mounted on a base plate by means of headed pins such that the said dead bolts are free swinging around the said headed pins.

3. The invention as recited in claim 2 wherein a drive pin is inserted into a hole strategically located and drilled into each of the hooked swing dead bolts which said drive pins ride within right angled slots machined into a drive plate these said right angled slots being located on the drive plate such that they coincide with the location of the said drive pins mounted on the said hooked swing dead bolts.

4. The invention as recited in claim 3 wherein a guide plate is welded on to the drive plate such that it guides a right angled spring plate on to the cylinder pawl.

5. The invention as recited in claim 4 wherein two pins inserted into a right angled spring plate engage upon the cylinder pawl in such a manner that the movement of the said cylinder pawl applies a driving force upon the said pins causing the said right angled spring plate to proscribe an elliptical movement and so cause the said drive plate to move vertically.

6. The invention as recited in claim 5 wherein the movement of the drive plate caused the drive pins mounted on the hooked swing dead bolts to slide through the complete area of the right angled slots cut into the drive plate and so cause the dead bolts to deflect into a locked or unlocked position.

7. The invention as recited in claims 1 through 6 wherein the lock mechanism is located within a housing which can be expanded in length in conjunction with the drive plate such that the bolts can be placed apart at any distance specified by various requirements.