US3593547A

US3593547A - Tamper-resistant locking latch for casement windows

Info

Publication number: US3593547A
Authority: US
Inventors: Harold V Taylor
Original assignee: Individual
Current assignee: Individual
Priority date: 1969-08-18
Filing date: 1969-08-18
Publication date: 1971-07-20
Anticipated expiration: 1988-07-20

Abstract

A locking latch assembly for a casement window has a handle block pivotally engaged on a base bracket which mounts on the jamb of the window. A cylinder lock is set in the block and can only be opened by a key. The bracket has slotted sidewalls which engage a cam at the inner end of the rotatable lock cylinder in the block. The cam and lock are enclosed and protected against tampering. The assembly has a replaceable handle.

Description

United States Patent 2,339,980 1/1944 Cloutier Harold V. Taylor 40 Parkway Circle, Scarsdale, N.Y. 10583 850,951

Aug. 18, 1969 July 20, 1971 Inventor Appl. No. Filed Patented TAMPER-RESIST ANT LGCKING LATCH FOR CASEMENT WINDOWS 7 Claims, 14 Drawing Figs.

[15. Cl 70/89, 70/137, 70/422, 292/108 Int. Cl. E051) 7/00, E05b 13/10, E050 3/04 Field of Search 70/89, 135,

References Cited UNITED STATES PATENTS 2,517,075 8/1950 Aquila 292/353 2,542,332 2/1951 Holmsten 292/351 UX 2,987,908 6/1961 Pelcin H 70/208 X 3,270,536 9/1966 Sprung 70/89 FOREIGN PATENTS 546,414 7/1956 Italy 70/215 Primary Examiner-Albert G. Craig, Jr. Attorney-Po|achek & Saulsbury E ACT: A locking latch assembly for a casement window has a handle block pivotally engaged on a base bracket which mounts on the jamb of the window. A cylinder lock is set in the block and can only be opened by a key. The bracket has slotted sidewalls which engage a cam at the inner end of the rotatable lock cylinder in the block. The cam and lock are enclosed and protected against tampering. The assembly has a replaceable handle.

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Harold 1/. Ta l r AHORNEYS TAMPER-RESISTANT LOCKING LATCH FOR CASEMENT WINDOWS This invention concerns a device for latching and locking casement windows against opening by unauthorized persons. The device is intended to replace a conventional nonlocking type of casement window latch.

Heretofore, whereconventional nonlocking types of casement window latchesare .used,'it.is easy for a burglar or other unauthorized person to break out a portion of the glass pane of the easement window, and by reaching through the hole in the window, release the latch. and crank or otherwise work the window open. I

It has been proposed heretofore to provide a casementwindow with locking means. Prior devices have been described in US. Pat. Nos. 2,2l4,884 and 3,270,536. In US. Pat. No. 2,214,884 a lock is provided for a crank mechanism ,by means of which a casement window is opened and closedA principal disadvantage of this arrangement is that the lock is placed in an exposed position where it can be broken off by a hammer blow. The latch itself isnot held by any lock. In U.S.'Pat. No. 3,170,536 a push-type cylinder lock is attached to the base bracket of a casement window latch. The lock extends horizontally as a horizontal appendage where it can easily be broken off to release the handle of the-latch. This s of course objectionable.

The present invention is directed at overcoming the difficulties and disadvantages of prior casement window protective devices by providing a locking type of casement window latch assembly which can easily be installed in place of a conventional nonlocking latcholn thepresent invention a rotating cylinder-type lock is installed inside the handle portion of the latch where the lock is not exposed to tampering or breaking off. The side of the latch facing toward the easement window occupies no more space than the nonlocking latch which it replaces. This avoids interference with inside'window screens. The device has a handle portion which is replaceable. This handle portion is made of softer metal than the hardened metal body of the device so that if tampering is attempted by prying or otherwise the handle portion will break off leaving the lock intact and the window almost impossible to open by the tamperer.

According to theinvention. the locking latch assembly includes a base bracket which is attached to the easement window jamb preferably by nonreversible screws. A handle block is pivotally attached to the bracket. A cylinder lock is disposed in the bodyof the block which has an integral latching finger and carries a replaceable handle. The handle block rotates on the axis-of its pivot pin and swings the latching finger to a position behind a fixed catch on the striker plate of the easement window to hold the window closed. Opening of the window on its hinges is accomplished by reverse rotation of handle block. Locking is accomplished by rotating the cylinder lock in the block by a suitable key. The lock cylinder has a cam at its inner end engaging slots in sides of the base bracket. Upon removal-of the key the block is left in locked condition to prevent rotation of the block and unauthorized opening of the window. The lock and locking earn are so encased in the handle block that they cannot be reached for imposing such damage as will'be effective to open'the latch. The device is arrangedf'so that the closed latch covers and conceals at least one of the screws holding the mounting bracket so that this bracket'cannot be pried loose. If prying of the locked assembly by use of a prying tool is attempted, the replaceable handle will break off first before any damage can be down to the locking parts.

The assembled device is flat on one side to permit installation of the device in place of a standard, conventional, flatsided nonlocking latch. The fiat side facing the window permits conventional interior window screens to be installed withoutinterference by the locking latch. -The device will be manufactured in left-hand and right-hand forms forinstallation on left-opening and right-opening casement windows.

For further comprehension reference may be had to the following detailed description taken in connection'with the accompanying drawing, in which FIG. 1 is a side view ofthe locking latch assembly embodying theinvention shown'installed on a casement window jamb. The jamb is shown in vertical section and the latch assembly is shown in open, unlocked position.

FIG. 2 is an edgewise bottom plan view taken on line 2-2 of FIG. 1, showing the open latch assembly, the" window jamb being omitted.

FIG. 3 is a front or inside elevational view of the latch assembly shown in closed position jamb of a casement window.

FIG. 4 is a vertical sectional view taken on line4-4 of FIG. 3 showing internal construction of the latch assembly, the windowjamb being omitted.

FIG. 5 and FIG. 6 are opposite side views of the latch as-,

' sembly taken on lines 5-5 and 6-6 respectively of FIG. 4, the I window jamb being shown in vertical section, with parts of the window catch being omitted from FIG. 6.

FIG. 7 is an edgewise elevational view of the latch assembly shown in closed position, taken on 7-7 of FIG. 6, the window jamb and base bracket being omitted.

FIG. 8 is an edgewise view of the handle block latch assembly.-

FIGS. 9 and 10 are opposite side views of the handle block taken on lines 9-9 and 10-10 respectively of FIG. 8.

FIGS. 11 and 12 are cross-sectional views taken on lines 11-11 and 12-12 respectively through the block as sown in FIG. 9. 1

FIG. 13 is a side view of the base bracket per se of the latch assembly.

FIG. 14 is a plan view taken on line 14-of FIG. 13.

Referring first to FIGS. 1-7, there is shown the locking 'latch assembly embodying the invention. The latch assembly includes a generally rectangular, massive block 20 made of steel, bronze or other very tough, strong metal. Block 20 is shown alone in FIGS. 8-12. The block is formed with an integral flat, arcuate finger 22 extending rearwardly of the block. A deep groove 24 with slanted bottom is formed in the per se of the 'block lengthwise thereof alongside of finger 22. Part of sidewall 26 of the block is cut away to define a recess 28 at the other ,side of finger 22. The finger 22 extends upwardly .beyond end 27 of the block. Near the other end 29 of the block is a lateral, enlargement 30 in which is a cylindrical bore 32. Opposite ends 33, 34of the bore are formed with annular enlargements. Groove 24 extends up to bore end 33; see'FIG.

8. Aligned

holes

35, 36 are formed in sidewall 38 and in inner wall 39 of which finger 22 is an extension.

The latch assembly further includes a cylinder. lock 40. This lock has a cylindrical casing 42 nonrotatably seated in bore 32 with annular flange 41-engaged at bore end 33; see "FIG. 4. Cylinder 44 of the lock has a keyhole 45 at its exposed flanged end-43. The cylinder extends axially through casing 42 and is rotatable therein. The cylinder terminates at the inner end of the casing inside bore end 34. An eccentric cam 50 is engaged on 'noncircular stub shaft 52 extending axially beyond the cylinder. On this shaft is engaged a screw 54 which holds the cam so that the cam rotates with the cylinder when a suitable key (notshown) is inserted in the keyhole and .rotated( The cam-has

adjacent edge portions

50a and 50b which are radially shorter than the remaining circular portion 500 of the cam; see FIGS. 2 and 7. A space 55 is defined between inner end 56 of wall 39 of the block and adjacent cutaway portion 58 of end 33 of the bore. The inner end 56 of wall 39 is cylindrically curved.

An L-shaped handle 57 is replaceably secured .by screws 59 to end 29 of the block. The handle is made of a material less strong than that of the block so that application of a prying tool to the handle in an attempt to open the latch will result in breaking off of the handle before the block or lock can be damaged.

The latch assembly also includes a base bracket 60 shown in FIGS. 1-6, 13 and 14. This bracket is an elongated member with flat, rectangular backwall '62 formed with holes 63 near opposite ends to receive screws 64. 65 for mounting the bracket "on amb 69. Two tapered flat sidewalls or

flanges

66, 68 extend perpendicularly to wall 62 at opposite edges thereof, Wall 66 has a short slot 70 formed In its narrow end edge. Wall 68 is slightly longer than wall 66 and has a shallow slot 74 formed in its inside face just beyond the edge of wall 66. A long rectangular opening 76 is formed in wall 62 through which curved finger 22 of the latch extends in the both open and closed positions of the latch. Finger 22 extends through the space between the walls 66. 68. Aligned holes 78 are formed in

walls

66, 68. A pivot pin 80 extends through holes 78 as well as

holes

35, 36 in the walls of the block. Open position is shown in FIG. 1 and the closed position is shown in FIGS.,36.

Finger 22 extends through hole 81 in jamb 69 and engages on catch 82 extending laterally of striker plate 84 mounted by screws 86 on casement window sash 88. Bracket 60 is mounted on the stationary jamb 69 of the casement window;

The plane of finger 22 is perpendicular to that of jamb 69. Window pane 92 is mounted in sash 88 which can swing outwardly away from the jamb as indicated by arrow A in FIG. 1, when the latch block is in open position with finger 22 disengaged from catch 82.

Installation of the latch assembly is easily accomplished by securing

screws

64, 65 in holes 94 in the jamb. In the closed position of the latch assembly lower screw 64 is covered byblock 20 as shown in FIGS. 5. 6. If an intruder attempts to remove the latch assembly by prying off bracket 60 he may break off the head of screw 65 but he cannot gain access to the covered and protected screw 64.

The window is shown closed in FIG. I, but the latch assembly is open and lock 40 is unlocked. To close the latch it is rotated on pin 80 as an axis until finger 22 engages catch 82 as shown in FIG. 5. To lock the latch assembly a key will be insertedin keyhole 45 and cylinder 44 will be turned. This will turn cam 50-t'rom the position where

edge portions

50a, 50b are clear of

slots

70 and 74 in

bracket walls

66, 68 to the position where-circular edge portion 50c engages in both

slots

70 and 74. For clarity this closed position of the cam is shown without the bracket in FIG. 7. It will be noted the circular edge portion 50c then extends laterally at the left into space 55 and also up to end edge 56 of wall 39. The cam 50 is sown in dotted lines of FIGS. and 6 engaged with the sidewalls of the bracket. The only way the latch assembly can properly be unlocked is by means of a suitable key inserted in lock 40.

The construction described is such that the locked latch assembly will effectively resist destructive prying and hammering in an unauthorized attempt to open it. The latch assembly readily replaces conventional nonlocking casement window latches. It provides maximum security in the following ways among others:

I. The lock and locking cam are enclosed and encased in v the massive handle block 22.

-2. One mounting screw of the base'bracket remains covered by the block in its closed lock so that the bracket cannot be pried 05.

3. The space 100 between the closed block and bracket as shown in FIGS. 5 and 6 is so narrow that no effective prying tool can be inserted. The lower edges of the block are also rounded to make more difficult any attempt at prying the block open.

4. The replaceable handle 57 which should be made of softer metal than block 20 will break off if a prying force is applied to it before any breakage or damage can occur to other parts of the assembly.

The device can be manufactured at relatively low cost. It will provide long, useful. trouble-free service. No special tools or special skills are required for installation.

Whatlclaim is: i

I. A locking latch assembly for a hinged casement window having a sash swinging open outwardly and closing against a stationary 'amb, said sash having a striker plate and catch mounted t ereon, said assembly comprising anelongated bracket having a flat backwall mountable on the jamb, said wall having a long opening therein, said bracket having a pair of spaced slotted sidewalls extending perpendicularly to said backwall; a generally rectangular, massive block pivotally mounted near one end thereof on said sidewalls; said block being rotatable between open and'closed positions with respect to said bracket, said block having an outwardly ex'- tending finger for engaging said catch, said finger extending between said sidewalls and through the opening in the backwall, said block further having a cylindrical bore formed therein near the other end thereof; a key-operated lock with rotatable cylinder engaged in said bore; and an eccentric cam at one end of the cylinder inside the bore arranged to engage in slots in said sidewalls of the bracket to lock the block against pivotal rotation and disengagement of said finger from said catch, said backwall of the bracket has holes near opposite ends for-receiving screws to mount the bracket on said jamb, said holes being so located that at least one of the screws is covered by the block when in closed position to prevent access by a tool to the covered screw, a handle mounted at said other end of the block for turning the block when the lock is opened to disengage said cam from the sidewalls of the bracket, said block is formed with a longitudinal groove an recess to receive said sidewalls respectively of the bracket to enable said cam to engage the slots in said sidewalls when the block is in closed position.

2. A locking latch assembly as defined in claim 1, wherein the handle is replaceably mounted.

3. A locking latch assembly as defined in claim 2 wherein said handle is made of a material less strong than that of the block to break before damage can be done to the lock and block by a prying force applied to the handle in an attempt to open the latch.

4. A locking latchassembly as defined in claim 1 wherein said bore extends between opposite faces of said block, and a pivot pin rotatably mounted the block to the bracket, said pin being located close to one face of the block so that said face is close to the backwall of the bracket in the closed position of the block to prevent insertion of a prying tool between the block and bracket.

5. A locking latch assembly as defined in claim 4 wherein the other end of the cylinder has a keyhole for receiving said key, said keyhole being exposed at the other face of the block.

6. A locking latch assembly as defined in claim 5, wherein said bore has end portions of larger diameter than an intermediate portion of the bore said lock comprising a cylindrical casing seated in the bore and having an end flange engaged in one of said end portions of the bore, said cam being rotatably disposed in the other end portion of the bore, said cylinder being rotatably disposed in said casing, whereby said flange and said cam retain the lock in the block.

7. A locking latch assembly as defined in claim 6, wherein said handle is replaceably mounted and is made of a material less strong than that of the block to break before damage can be done to the lock and block by a prying force applied to the handle in an attempt to open the latch.

Claims

1. A locking latch assembly for a hinged casement window having a sash swinging open outwardly and closing against a stationary jamb, said sash having a striker plate and catch mounted thereon, said assembly comprising an elongated bracket having a flat backwall mountable on the jamb, said wall having a long opening therein, said bracket having a pair of spaced slotted sidewalls extending perpendicularly to said backwall; a generally rectangular, massive block pivotally mounted near one end thereof on said sidewalls, said block being rotatable between open and closed positions with respect to said bracket, said block having an outwardly extending finger for engaging said catch, said finger extending between said sidewalls and through the opening in the backwall, said block further having a cylindrical bore formed therein near the other end thereof; a key-operated lock with rotatable cylinder engaged in said bore; and an eccentric cam at one end of the cylinder inside the bore arranged to engage in slots in said sidewalls of the bracket to lock the block against pivotal rotation and disengagement of said finger from said catch, said backwall of the bracket has holes near opposite ends for receiving screws to mount the bracket on said jamb, said holes being so located that at least one of the screws is covered by the block when in closed position to prevent access by a tool to the covered screw, a handle mounted at said other end of the block for turning the block when the lock is opened to disengage said cam from the sidewalls of the bracket, said block is formed with a longitudinal groove an recess to receive said sidewalls respectively of the bracket to enable said cam to engage the slots in said sidewalls when the block is in closed position.

4. A locking latch assembly as defined in claim 1 wherein said bore extends between opposite faces of said block, and a pivot pin rotatably mounted the block to the bracket, said pin being located close to one face of the block so that said face is close to the backwall of the bracket in the closed position of the block to prevent insertion of a prying tool between the block and bracket.