Security lock

Abstract

A security lock for a window including a keeper and a latch, with a housing rotatably seating a bolt carrying the latch and with the bolt having a shaped end disposed within the housing with a bearing plate slidably mounted on the shaped end and urged against an internal face of a front wall of the housing by a spring disposed between the bearing plate and a flange on the bolt, with lock means on the bearing plate and housing front wall for holding the bolt and latch in rotated position. An opening in the housing front wall for entry of a tool to engage the shaped end of the bolt and depress the bearing plate against the spring to free the bolt for rotation, the front wall opening having at least one radial slot and with the tool having a first end with an opening to fit on the shaped end of the bolt for rotation of the bolt, and the other end of the tool having a similarly shaped end with an ear to pass through the radial slot and engage behind the front wall after the bolt is rotated whereby the tool can function as a handle. Additionally, the housing includes a separate back plate having an arcuate slot co-acting with a lug on the bolt to limit rotation of the bolt and the latch carried thereby and with the back plate being reversible to adapt the security lock for either right-hand or left-hand assembly. In a modification of the security lock, there are a plurality of units for each window requiring two persons to operate all the locks to unlocked position whereby one person can not remove the window.

Parent Case Text

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of Bates et al Ser. No. 355,055, filed Apr. 27, 1973.

Description

BACKGROUND OF THE INVENTION

This invention pertains to security locks for a window wherein one person can not remove the window and a special tool is required for operation of each security lock and with the tool having provision for use solely as a key for the lock or for use as a key as well as a handle for operation of the window to which the lock is secured.

A number of prior art patents show window locks wherein a spring-loaded bolt is engageable by a tool or key to rotate the bolt between locked and unlocked position. Examples of this prior art are Bulkley U.S. Pat. No. 184,501, Anderson U.S. Pat. No. 788,389, and Bacon U.S. Pat. No. 1,480,338.

Additionally, it is old to have a tool for use with a lock wherein the tool may be retained for use as a handle. This is shown in Lovatt U.S. Pat. No. 1,997,528. A tool usable as a handle is also shown in Wheaton U.S. Pat No. 2,191,902.

Patents, such as George U.S. Pat. No. 3,524,335 and Glass U.S. Pat. No. 3,661,001, show locks with a spring-loaded member within the lock housing which functions to eject the key.

SUMMARY

The security lock disclosed herein provides for use of a special tool to release the bolt carrying the latch of the security lock from either of two positions, either in engagement with or out of engagement with, a keeper. The structure embodies the use of a spring-loaded bearing plate within a housing of the security lock which coacts with structure on the front wall of the housing to retain the bolt in either of its two rotative positions, with the insertion of the tool moving the bearing plate away from the front wall to release the coacting structure and permit rotation of the bolt and latch. The tool has two ends, with each end having an internal chamber shaped to engage on a shaped end of the bolt and with one of the tool ends additionally having an ear to pass through a radial slot formed as part of the opening in the front wall of the housing whereby upon rotation of the tool and the bolt the ear is captured behind the front wall of the housing whereby the tool may function as a handle. Additionally, the bolt carries a lug coacting with an arcuate slot in a back plate of the housing to limit rotation of the bolt and latch and with the back plate being mountable to the housing in either of two positions whereby the security lock may be adapted for use either as a right-hand or left-hand assembly.

An object of the invention is to provide a new and improved security lock having a spring-loaded bearing plate providing for retention of the rotatable bolt of the lock in either of two rotative positions and with a tool insertable through an opening in the front wall of the housing to shift the bearing plate and release it from its locked position with the housing and also to engage a shaped end of the bolt for rotation thereof and with the tool having an opposite end for performing the above functions and additionally having structure to coact with the housing to function as a handle.

Still another object of the invention is to provide a security lock, as defined in the preceding paragraph, wherein the bearing plate is urged against the inner face of the housing front wall with a pair of lugs on the front wall coacting with either of two pairs of notches on the bearing plate to lock the bearing plate and bolt against rotation and with the coaction therebetween being released by depression of the bearing plate to free the bolt and bearing plate for rotation, and with the bearing plate then functioning to lock the bolt in the other rotative position when the bearing plate is free to move back into engagement with the front wall and bring the notches and lugs into coacting relation.

Still another object of the invention is to provide a security lock which may be used in either right-hand or left-hand assembly by provision of a back plate for the housing carrying an arcuate slot coacting with a lug on the bolt to limit rotation of the bolt and with the back plate being reversibly mountable in assembly to change the orientation of said arcuate slot.

Additionally, a plurality of the security locks are mounted within the frame of a window and constructed and positioned whereby at least two persons are required to fully unlock the window.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of the security lock shown in association with a window;

FIG. 2 is a sectional view, taken generally along the line 2--2 in FIG. 1;

FIG. 3 is a sectional view, taken generally along the line 3--3 in FIG. 1;

FIG. 4 is an elevational view of the housing and associated structure of the security lock, looking toward the rear thereof;

FIG. 5 is a sectional view, similar to FIG. 3, showing the latch structure and the tool associated therewith in use as a handle;

FIG. 6 is an elevational view of a window or panel embodying a modification of the invention;

FIG. 7 is a plan section, on an enlarged scale, taken generally along the line 7--7 in FIG. 6;

FIG. 8 is a vertical section, taken generally along the line 8--8 in FIG. 7; and

FIG. 9 is a section, taken generally along the line 9--9 in FIG. 8.

DESCRIPTION OF THE EMBODIMENTS

The security lock is shown in association with a window in FIG. 3 and is primarily intended for use in the metal window field and for use with vertical pivot windows, casement windows, and project-in windows. The security lock is intended to require a special tool for locking and unlocking of the window and to also have provision for use as a handle to pull or push the window. The security lock includes a keeper, indicated generally at 15, and a latch 16 engageable with the keeper. The keeper 15 is mounted on a stationary part 20 of the window and has a base 21 with suitable attachment means 22 for securing the keeper to the stationary part 20 of the window. A curved flange 25 extends upwardly from the base 21 to coact with the latch 16.

A housing 30 is secured to a movable part 31 of the window by attachment means 32 extending through openings in the housing and threaded into a movable part 31 of the window. The housing 30 carries a rotatable bolt 35 which extends outwardly from the rear thereof for extension through an opening 36 in the movable part 31 of the window and which has the latch 16 extending normal thereto. The housing has an internal chamber between a front wall 40 thereof and a back plate 41 to receive a shaped end 45 of the bolt 35 and a flange 46 on the bolt. The shaped end 45 has a hexagonal shape, such as may coact with a similarly shaped opening in a tool.

A bearing plate 50 is also positioned within the chamber of the housing and is slidable on and rotatably locked to the shaped end 45 of the bolt. The bearing plate 50 is urged against the inner face of the front wall 40 by a spring 51 positioned in the chamber and surrounding the shaped end 45 of the bolt. This spring engages between the bearing plate 50 and the flange 46 on the bolt. The bearing plate 50 and housing 30 have coacting means for holding bolt 35 in either of two rotative positions. This coacting means includes a pair of inwardly-extending lugs 55 and 56 on the interior of the housing with two pairs of notches 57 and 58 on the periphery of the bearing plate 50. With the security lock in locked position, as shown in FIGS. 1-3, the pair of notches 57 coact with the lugs 55 and 56 to lock the bolt 35 against rotation. When the bearing plate 50 is moved against the action of the spring 51 and toward the right as viewed in FIG. 3, the notches of the bearing plate are moved out of coacting relation with the lugs 55 and 56 to permit rotation of the bearing plate 50 and bolt 35. The periphery of the bearing plate provides a guide bearing during rotation of the bolt. After the bolt has been rotated to its alternate position, the bearing plate can be freed for movement to the left, as viewed in FIG. 3, with the alternate pair of notches 58 then in alignment with the lugs 55 and 56 to lock the bolt 35 in adjusted position.

The limits of rotation of the bolt 35 are provided by coacting structure on the back plate 41 and the bolt 35. As shown particularly in FIG. 4, the back plate 41 has a pair of arcuate slots 60 and 61 having an arcuate length of approximately 90.degree.. These slots coact with a pair of lugs 62 and 63 extending rearwardly from a face of the flange 46 on the bolt 35. As shown in FIG. 4, the structure has limited the rotative position of the bolt 35 and the latch 16 to the locked position, with the keeper 15. The bolt 35 may rotate approximately 90.degree. in a counterclockwise direction to a position wherein the latch 16 is free of the keeper 15. The back plate 41 is constructed separately from the remainder of the housing 30 whereby, upon initial assembly, the back plate 41 may be mounted in the position shown in FIG. 4 or reversed therefrom in order to enable use of the security lock as either a right-hand or left-hand assembly. The back plate 41 has a pair of openings 65 and 66 to fit upon a pair of protrusions 67 on the housing which have their ends flattened to secure the back plate 41 to the housing.

Access to the shaped end 45 of the bolt 35 is obtained through a front opening 70 in the front wall 40 of the housing. The opening 70 is of a size to receive an end 71 of a tool, indicated generally at T in FIG. 5. The end 71 has a hexagonal opening 72 to fit upon the shaped end 45 of the bolt, whereby rotation of the tool T rotates the bolt and the latch 16 between either the locked position, shown in FIG. 3, or an unlocked position. Initial insertion of the tool end 71 causes inward movement of the bearing plate 50 to free the coacting lock structure, whereby the tool T may then be rotated to rotate the bolt 35. The tool T is shown in FIG. 5 with an opposite end 73 thereof in association with the security lock structure and with the tool in use as a handle. The tool end 73 has an internal opening 74 provided with a hexagonal shape to engage on the shaped end 45 of the bolt. As shown, insertion of the tool end 73 depresses the bearing plate 50 to compress the spring 51 and release the coacting lock structure on the housing and the bearing plate 50. This frees the bolt 35 for rotation. The tool end 73 differs from tool end 71 in having a pair of oppositely extending ears 75 and 76 which may pass through a pair of radial slots 77 and 78 extending outwardly from the front wall opening 70 to permit initial entry of the tool end 73. The bearing plate 50 is then depressed sufficiently to provide a space between the bearing plate and the inner face of the housing front wall 40 to receive the ears 75 and 76. The tool T is then rotated to rotate the bolt 35 and the latch 16 and the rotation of the tool places the ears 75 and 76 behind the front wall 40 of the housing, whereby the tool T is retained with the security lock to function as a handle. The tool T is retained with the security lock structure until the tool is rotated back to a position wherein the ears 75 and 76 align with the radial slots 77 and 78 whereby the tool T may be withdrawn from the housing 30. When the end 73 of the tool T is initially inserted, the window is locked and after rotation of the tool the window is unlocked and the tool is then used as a handle.

The withdrawal of the tool in either rotative position will permit the bearing plate 50 to move, under the urging of the spring 51, to reengage one of the pair of notches on the perimeter of the bearing plate with the lugs 55 and 56 on the interior face of the housing front wall 40 to retain the security lock in either of its adjusted positions.

In the embodiment shown in FIGS. 6 to 9, a window or other type of panel, indicated generally at 100, is removably mounted in a surrounding frame, indicated generally at 101. In instances where the window or panel is in institutional use, it is particularly desirable to make certain that an inmate cannot remove the window or panel. For this purpose, a plurality of the security locks are positioned, as at 102, 103, 104, and 105 and in sufficient number whereby one person cannot manipulate all of the security locks at the same time. Additionally, the security lock in the embodiment in FIGS. 6 to 9 differs from the first embodiment in having an internal mounting and with spring means acting to increase the torque on the lock during unlocking and which tends to return the lock to locked position.

The security lock is shown particularly in FIGS. 7 to 9 wherein a keeper 110 is mounted to a section 111 of the surrounding stationary frame 101 and coacts with a latch 115 carried on a rotatable bolt 116.

The window or panel has a sash or frame, shown in cross section in FIG. 7 at 120, which, when in closed position, defines an interior chamber with the surrounding frame section 111 which houses the security lock structure.

The security lock is of generally the same construction as in the embodiment of FIGS. 1-5, including a housing 130 secured to the sash 120 by attachment means 132. The housing 130 has an internal chamber between a front wall 140 thereof and a back plate 141 to receive a shaped end 145 of the bolt 116 and a flange 146 on the bolt.

A bearing plate 150 is positioned within the chamber of the housing and is slidable on and rotatably locked to the shaped end 145 of the bolt. The bearing plate 150 is urged against the inner face of the front wall 140 by a spring 151. The bearing plate 150 and housing 130 have coacting means for holding the bolt 116 in either of two rotative positions, with this structure being the same as in the embodiment of FIGS. 1-5. This structure includes a pair of inwardly extending lugs on the interior of the housing 130, with one shown at 155, which coact with either of two pairs of notches on the periphery of the bearing plate 150. One pair of notches 158 is shown in FIG. 7.

The limits of rotation of the bolt 116 are provided by a coacting structure on the back plate 141 and the bolt 116. The back plate 141 is of generally the same construction as the back plate 41 shown in FIG. 4 and has a pair of arcuate slots 160 and 161, with these slots coacting with a pair of lugs, one of which is shown at 163, extending rearwardly from a a face of the flange 146 and movable within the associated arcuate slot.

The back plate 141 is associated with an apertured bearing plate 168 and both are held in assembly relation with the housing 130 by a pair of fastening devices 169, which extend through the parts, as shown in FIG. 9.

Access to the shaped end 145 of the bolt 116 is through a front opening 170 in the housing 130 having the same shape as the front opening 70 in the embodiment of FIGS. 1-5. Additionally, the sash 120 has an opening 171 of the same contour as the opening 170 to receive either of the ends of the tool T.

A torsion spring 180 is wrapped about a part of the bolt 116 and has a first end 181 engaging the latch 115 and the other end 182 engaged against the housing 130. The spring 180 functions to increase the torque on the lock when a person is trying to open the lock by raising the latch 115 upwardly in the direction of arrow 185 in FIG. 8. Additionally, the spring always urges the lock to the locked position, shown in FIG. 8, whereby it is necessary for an operator to positively hold the lock in an unlocked position. This increases the security feature in that two people would be required to simultaneously operate the four security locks, 102-105.

The security lock structure has the inherent capability to be latched into unlocked position, as described in the embodiment of FIGS. 1-5; however, this action does not readily occur in the embodiment of FIGS. 6-9 because of the action of the torsion spring 180. If an operator attempts to remove the tool T when the lock is in unlocked condition, the torsion spring 180 tends to rotate the bolt 116 back toward locked position prior to the time the bearing plate 150 moves forwardly to have a pair of notches on the periphery of the bearing plate 150 engage the lugs on the housing 130.

Claims

We claim:

1. A security lock for a window having a frame including a keeper and a latch engageable with the keeper, means for operating said latch relative to the keeper including a housing positioned within said frame with an internal chamber and a front wall, a bolt rotatably mounted in said housing and extending therefrom and carrying said latch and having a shaped end within said chamber, a bearing plate slidably mounted on said shaped end of the bolt and rotatable therewith, coacting notch and lug means on said front wall and bearing plate for locking said bearing plate against rotation, spring means urging said bearing plate against said front wall to maintain said coaction, and an opening in said front wall and window frame for entry of a tool to move said bearing plate against said spring means to release said slot and lug means and to engage said shaped end of the bolt for rotation of the bolt and latch.

2. A security lock as defined in claim 1 wherein said front wall opening includes at least one radial slot, said tool having opposite ends each with a shaped recess to lock on said shaped end of the bolt and one of said tool ends having at least one ear to pass through said radial slot and engage behind said front wall upon rotation of the tool for retention in the housing to function as a handle.

3. A security lock as defined in claim 1 wherein said housing includes a body and a separate back plate through which said bolt extends, an arcuate slot in said back plate, a lug on said bolt engageable in said arcuate slot to limit rotation of said bolt, and means for attaching said back plate to the housing body in either of two positions whereby the security lock may be either a left-hand or right-hand assembly.

4. A security lock as defined in claim 1 wherein said coacting notch and lug means includes a pair of lugs on said front wall and two pairs of notches on said bearing plates with one pair of notches engaging said pair of lugs to hold the latch in locked position and the other pair of notches engaging said pair of lugs to hold the latch in unlocked position.

5. A security lock as defined in claim 1 and including a second spring means operatively connected to said bolt for rotatably urging said bolt and latch into locked relation with the keeper.

6. A structure as defined in claim 5 where a plurality of said security locks are positioned in the window frame at a distance from each other and require holding of the bolts of both security locks against the action of said second spring means to maintain the latches disengaged from the keepers for release of the window.

7. A security lock including a keeper and a latch selectively engageable with the keeper, a housing with an internal chamber, a front wall and a back plate, a bolt rotatably mounted in said housing and extending through said back plate, said bolt carrying said latch and having a shaped end within said chamber, a bearing plate in said chamber and slidably mounted on said shaped end of the bolt and rotatable therewith, a flange on said bolt in abutting relation with said back plate, a spring positioned between said flange and bearing plate urging the bearing plate against said front wall and the flange against said back plate, coacting lock means on said bearing plate and front wall to lock said bolt against rotation and releasable by movement of the bearing plate away from said front wall, and an opening in said front wall for entry of a tool to move said bearing plate away from said front wall and against the action of the spring to release said coacting lock means and permit rotation of the bolt and latch by the tool.

8. A security lock as defined in claim 7 wherein said front wall opening includes at least one radial slot, said tool having opposite ends each with a shaped recess to lock on said shaped end of the bolt and one of said tool ends having at least one ear to pass through said radial slot and engage behind said front wall upon rotation of the tool for retention in the housing to function as a handle.

9. A security lock as defined in claim 7 wherein said back plate has an arcuate slot and lug on said flange engageable in said arcuate slot to limit rotation of said bolt, and means for attaching said back plate to the housing in either of two positions whereby the security lock may be arranged for either right-hand or left-hand assembly.

10. A security lock as defined in claim 7 wherein said coacting lock means includes a pair of lugs on said front wall and two pairs of notches on said bearing plate with one pair of notches engaging said pair of lugs to hold the bearing plate and latch in locked position and the other pair of notches engaging said pair of lugs to hold the bearing plate and latch in unlocked position.

11. A security lock as defined in claim 6 and including a second spring means operatively connected to said bolt for rotatably urging said bolt and latch into locked relation with the keeper.