US3013426A

US3013426A - Protective apparatus for combination locks

Info

Publication number: US3013426A
Application number: US584965A
Authority: US
Inventors: James L Taylor
Original assignee: Individual
Current assignee: Individual
Priority date: 1956-05-15
Filing date: 1956-05-15
Publication date: 1961-12-19
Anticipated expiration: 1978-12-19

Description

Dec. 19, 1961 J. L. TAYLOR 3,013,426 PROTECTIVE APPARATUS FOR COMBINATION LOCKS Filed May 15, 1956 2 Sheets-Sheet 1 'llm INVENTOR L/w/ms' l. Ivy/01' ATTORNEYS Dec. 19, 1961 J. L. TAYLOR 3,013,426

PROTECTIVE APPARATUS FOR COMBINATION LOCKS Filed May 15, 1956 2 Sheets-Sheet 2 IIIIIlIlI////// 1N VENTOR lam/091. h

ATTORNEYS United States Patent Ofifice 3,013,426 Patented Dec. I9, 1961 3,013,426 PROTECTIVE APPARATUS F OR COMBINATION 6 Claims. (CI. 70-15) The present invention relates in general to security devices, and more particularly to protective means for use with combination locks and the like for relocking the enclosure secured by the lock when tampering by unauthorized personnel occurs or to present readily noticeable evidence that such tampering has taken place.

In order to achieve maximum security in the protection of valuable information or articles, particularly in preserving the integrity of enclosures for security-sensitive Government documents and the like, it is imperative that means be associated with conventional high security combination locks to dog or otherwise lock the enclosure in closed condition independently of the combination lock if unauthorized efforts are made to gain access to the lock housing by drilling or other means of penetration. Heretofore, so-called relocking devices have been associated with combination locks in such a manner as to be tripped when the spindle is driven inwardly of the lock casing or otherwise actuated to force the rear cover plate of the lock casing rearwardly. These devices are not arranged, however, to be triggered upon attempted entry to the lock casing other than by driving the dial spindle inwardly.

Of even greater importance is the necessity of affording some indication that the lock casing has been penetrated or the lock otherwise tampered with to the extent that unauthorized personnel may have secured knowledge of the combination of the lock. One of the frequent techniques for gaining unauthorized access to security file cabinet-s and the like is by drilling through the dial into the lock casing, detecting the combination for which the lock is set, and replacing the drilled dial by a new dial, so that the unauthorized personnel can return from time to time and manipulate the lock to repeatedly gain access to the classified or otherwise restricted contents of the ecurity file. If no indication of such a situation is made evident, the security personnel are not advised that unauthorized personnel are in possession of the combination and would not be prompted to change the combination or take other security precautions.

An object of the present invention, therefore, is the provision of novel means for association with comb-ination locks in security closures and the like for positively indicating unauthorized penetration of the lock mechanism or eiforts to that end.

Another object of the present invention is the provision of novel means arranged in shielding relation to a combination lock casing to be altered in condition upon attempted unauthorized penetration of the lock casing and render such alteration in condition evident upon visual inspection.

Another object of the present invention is the provision of novel relocking means in association with comb-ination locks in security closures to be triggered upon attempted penetration of the lock casing from outside of the closure and independently lock the closure in closed condition.

Another object of the present invention is the provision of novel means associated with a combination lock in a. security file cabinet or the like in shielding relation to the combination lock housing to be visibly altered in appearance upon attempted unauthorized penetration of the lock housing and to release independent file cabinet locking means to independently lock the file cabinet in closed condition upon such attempted unauthorized penetration.

Other objects, advantages and capabilities of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings illustrating two preferred embodiments of the invention.

In the drawings:

FIGURE 1 is a fragmentary perspective view of a security file cabinet and combination lock protective mechanism constructed in accordance with a preferred embodiment of the present invention.

FIGURE 2 is a transverse horizontal section view taken along the line 2-2 of FIGURE 1.

FIGURE 3 is a vertical section view taken along the line 33 of FIGURE 2.

FIGURE 4 is a horizontal transverse section view of a security file cabinet, combination lock and protective mechanism constructed in accordance with a modified embodiment of the present invention.

FIGURE 5 is a vertical section view taken along the line 55 of FIGURE 4, and

FIGURE 6 is a perspective view of the protective shield housing member of the modified embodiment illustrated in FIGURE 4.

Referring to the drawings, wherein like reference characters designate corresponding parts throughout the several figures, and more particularly to FIGURES l, 2 and 3, there is illustrated a file cabinet, generally indicated by the reference character 19, of more or less conventional design having the usual tier of sliding drawers, of which only the top drawer 11 is illustrated. The present invention is designed to be applied to the drawer front 12 in protective association with a combination lock 13 mounted on the drawer front 12. The combination lock may be of any conventional form but is preferably a high security combination lock, for example, of the type illustrated in U.S.'Patent No. 2,575,674 issued to Harry C. Miller on November 20, 1951, and comprises the usual combination lock dial 14 affixed to a spindle 15 which projects through the drawer front 12 and into a combination lock casing 15 to adjust tumblers or the like within the lock casing 16 and eifect retraction or projection of a conventional reciprocating bolt 17 relative to a keeper 18. The keeper 18 in the preferred embodiment herein illustrated is formed of an apertured plate integral with and projecting toward the front of the file cabinet from a mounting panel 19 which is affixed to the top wall 20 of the file cabinet 10 in any desired manner, such as by a securing flange 21 welded or otherwise rigidly fixed to the top 20.

interposed between the lock casing 16 and the drawer A front 12 is a glass shield 22 having a front wall 23 adapted to lie against the interior surface of the drawer front "12' and being apertured to permit the dial spindle 15 to project therethrough. Projecting rearwardly from the marginal edges of the front panel 23 of the glass shield 22 and formed integrally with the front panel 23 are lateral flanges 24 and 25 and upper and

lower flanges

26 and 2 7 which are connected together at their ends and project rearwardly to an extent greater than the depth of the lock casing 16 to extend in protective encasing relation to all surfaces of the lock casing except for the inwardly facing rear cover plate thereof.

The glass shield 22 is formed of glass material which will shatter or pulverize throughout the entire extent of the glass shield when drilled or punched at any portion thereof and preferably will pulverize or shatter when sub-- stantial heat is applied to any point along the glass body. Preferably, it is formed of commercially available tempered glass, which is prestressed during formation to place the surface of the glass body under compression and the interior under tension. It is known that such tempered glass bodies, while they have great mechanical strength, will pulverize or shatter if any portion of the glass body is drilled, punched, scratched, or subjected to substantial heat. Thus, drilling of a hole through the dial 14 and the drawer front 12 to gain access to the interior of the lock casing 16 or application of heat to one spot on the glass shield 22 to gain entry to the lock casing will result in shattering or pulverizing of the entire glass shield 22.

Mounting bracket 28 is provided to support the glass shield 22 and lock casing 16 on the drawer front 12 and includes lateral flanges 29 at the opposite ends thereof to be secured by welding or other conventional securing means to the interior surface of the drawer front 12, a medial panel portion 30 and rearwardly projecting U- shaped formations 31 for partially enveloping the lateral flanges 24, 25 of the glass shield 22. Relocking bolts 32 are supported by the Ushaped formations 31 of the mounting bracket 28 to be projected laterally in opposite directions from the lock casing 16. The relocking bolts 32 comprise smaller cross section cylindrical portions 33 extending through complementary apertures in the outermost legs 34 of the U-shaped formations 31 and enlarged heads 35 of any desired cross sectional form extending through complementary apertures in the innermost legs 36 of the brackets 31. Coil springs 37 surround the smaller cross section portions 33 of the relocking bolts 32 and are normally maintained under a state of compression between stop shoulders 38 on the smaller cross section portions 33 and the outer surfaces of the outermost legs 34 of mounting brackets 28. The smaller cross section cylindrical portions 33 of the bolts 32 extend through complementary apertures 39 preformed in the flanges 24, 25 of the glass shield 22 and are resiliently biased to project laterally outwardly from the lock casing 16 by the coil springs 37 but are restrained against full projecting movement by engagement of the enlarged heads 35 with the portions of the glass shield flanges 24, 25 bounding the apertures 39.

Apertured relocking keeper plates 40 project forwardly from the mounting panel 19 at positions to be spaced slightly outwardly from the ends of the relocking bolts 32 when the same are restrained by engagement of their enlarged heads 35 with the lateral flanges 24, 25 of the glass shield 22. They are so positioned, however, that the smaller cross section portions 33 of the relocking bolts 32 will be projected into the apertures of the relocking keepers 40 by their coil springs 37 when the glass shield 22 is pulverized or shattered in any manner described above which destroys the restraining action of the glass shield flanges 24, 25 on the enlarged heads 35 of the relocking bolts.

It will thus be apparent that upon attempted unauthorized entry into the interior of the lock casing 16 when the file drawer 11 is in closed position within the file cabinet, which attempted entry results in drilling, punching or severe scratching of any spot or portion on the glass shield 22, or excessive heating of such spot or portion, the glass shield 22 will be pulverized or shattered throughout due to the inherent nature of tempered glass. This will result in destruction of the restraining flanges 24, 25 thereof which normally retain the relocking bolts 32 in inwardly withdrawn condition with their associated coil springs 37 under compression and release the relocking bolts 32 to be projected outwardly into the apertures of their associated keepers 40 under the influence of their coil springs 37.

p In the embodiment illustrated in FIGURES 4, and 6, the relocking features are dispensed with and the glass shield 45, in the form of a flat tempered glass plate, is inserted between the dial 14 and lock casing 16. The flat tempered glass shield 45 is, in this embodiment, mounted in a housing 46 formed of sheet metal, which is adapted to be secured to a drawer front 47 which is of less height than the drawer opening to extend between the top of the drawer front and the top of the drawer opening. The housing 46 comprises a rectangular front panel 48 bounded by upper and lower marginal flanges 49 and 50 respectively, and

lateral flanges

51, 52. A backing plate 53 is, over the larger portion thereof, spaced rearwardly from the front panel 48 of the housing 46 a distance equal to the thickness of the tempered glass shield 45 which is to be positioned therebetween and is bent forwardly at its lateral edges, as indicated at 54, to meet and be secured to the front housing panel 48. The upper flange 49 of the housing member 46 is provided with a plurality of inspection openings or slots 55 arranged over the tempered glass shield 45 so as to permit visual inspection of the condition of the tempered glass shield 45. Any suitable apertured keeper may be fixed on the file cabinet 10 to receive the bolt 17, which may, for example, be in the form of a keeper plate 56 supported in depending relation on the top wall of the file cabinet.

It will be apparent that with this modification, any attempt to gain unauthorized access to the lock casing 16 by drilling or otherwise producing an opening through the dial 14 and the front wall of the lock casing 16 will pulverize or shatter the tempered glass shield 45. Thus, the fact that access may have been gained to the interior of the lock casing 16 and knowledge of the combination of the lock surreptitiously obtained is afforded by the pulverized or shattered condition of the tempered glass shield 45 which is evident upon visual inspection through the apertures 55.

It will be obvious to those skilled in the art that the areas or directions of entry protected by the tempered glass shield 45 may be extended by providing rearwardly projecting flanges to produce a cup-shaped plate similar in form to the glass shield 22 disclosed in FIGURES l, 2 and 3, or that the glass shield may be produced in other desired forms and shapes to more completely envelope the lock casing 16.

While the present invention has been described in association with one drawer of a conventional file cabinet, it will also be apparent that it is equally applicable to safes and other types of security closures and that the relocking bolts as disclosed in FIGURES 1-3 may be associated with keepers or locking mechanisms of various types for locking either one or a plurality of security drawers or closures in closed condition, the keeper structure illustrated herein being merely illustrative of arrangements which may be used in cooperation with the present invention.

I claim:

1. In combination with a file cabinet having a movable front wall portion affording access to said file cabinet upon movement thereof and a combination lock supported on said front wall portion including a dial on the exterior surface of said wall portion and a lock mechanism enclosing casing controlled thereby on an interior surface of said wall portion, protective apparatus for said combination lock comprising a cup-shaped tempered glass shielding member including a panel poition entirely overlying a wall of said casing between said casing and said front wall portion and dial and integral marginal flange portions extending perpendicularly inwardly of said front wall portion in surrounding relation with said lock casing, apertured keeper plates projecting from a fixed wall of said file cabinet, relocking bolts supported for reciprocable movement into and out of locking engagement with said keeper plates, said relocking bolts having enlarged heads, resilient means continuously biasing said relocking bolts into locking engagement with said fixed keeper plates, and said inwardly projecting flanges of said shielding member having apertures therein accommodating said relocking bolts for sliding movement therethrough, said flange apertures being of smaller cross section than said enlarged heads of said relocking bolts, said relocking bolts being disposed in said shielding member flange apertures with said relocking bolts restrained in a position withdrawn from said fixed keeper plates by interengagement of said flanges with said enlarged heads, and said shielding member being shatterable substantially uniformly throughout its extent in response to drilling, punching or heating of any portion thereof to release the restraining action of said flanges on said enlarged heads of said relocking bolts and free said relocking bolts to be projected under the influence of said resilient biasing means into locking engagement with said fixed keeper plates.

2. Protective apparatus for use with combination locks in security closures and the like wherein the combination lock includes a lock mechanism enclosing casing located internally of the security closure, comprising relocking means supported within said securityclosure for movement from a closure locking position to a closure unlocking position including resilient means continuously biasing said relocking means to lock said closure in closed condition, and a control member for said relocking means formed of tempered glass and located in shielding relation to said lock casing to intercept tools projected from selected regions externally of said security closure in the direction of said lock casing, said control member having the property of shattering into small fragments substantially uniformly throughout its entire extent in response to drilling, punching or heating thereof at any location along said control member, and said control member having integral marginal portions disposed in restraining engagement with said relocking means to normally hold the relocking means in unlocking position when said control member is intact and to release said relocking means to respond to the biasing means and shift to closure locking position upon shattering of said control member.

3. Protective apparatus for use with a combination lock supported on the drawer of a file cabinet and the like, said combination lock including a dial supported on said drawer in exposed condition and a lock mechanism enclosing casing positioned to be concealed in the file cabinet when said drawer is closed, the protective apparatus comprising relocking bolts independent of said combination lock supported for axial movement along axes projecting oppositely from the combination lock for projection into and withdrawal from fixed keeper members, resilient means continuously biasing said relocking bolts to project the same into locking engagement with said keeper members, and an integral tempered glass control member for said relocking bolts including a panel portion extending in coplanar relation with said dial between said dial and said lock casing in a position to intercept attempted entry into said lock casing from externally of the file cabinet and integral flanges projecting inwardly of the file cabinet from said panel portion in at least partially surrounding relation with said lock casing, said tempered glass control member having the property of shattering into small fragments substantially uniformly throughout its entire extent in response to drilling, punching or heating thereof at any location along said control member, and said integral flanges of said control member havin integral portions in restraining engagement with said relocking bolts to normally hold said bolts under resilient tension in withdrawn condition relative to said keeper members when said control member is intact and to release said bolts to project into the keeper members upon shattering of the control member.

4. 'In combination with a security closure having a movable front wall portion affording access to said security closure upon movement thereof and a combination lock supported on said front wall portion including a dial on the exterior surface of said wall portion and a lock mechanism enclosing casing controlled thereby on an interior surface of said wall portion, protective apparatus for said combination lock comprising apertured keeper members fixed in said security closure, reciprocable relocking bolt members movably supported on said front wall member for projection into locking relation with and withdrawal from said fixed keepermembers,

having the property of shattering into small fragments substantially uniformly throughout its entire extent in response to drilling, punching or heating upon attempted entry into said lock casing from externally of said security closure to release the control member from relockingbolt-restraining condition and free said relocking bolts to be projected by their resilient biasing means into locking relation with their associated keeper means.

5. Protective apparatus for use with a combination lock supported on the drawer of a file cabinet and the like, said combination lock including a dial supported on I said drawer in exposed condition and a lock mechanism enclosing casing positioned to be concealed in the file cabinet when said drawer is closed, the protective apparatus comprising relocking members independent of said combination lock supported within said file cabinet,

for movement between an unlocking position wherein the drawer is released from movement relative to the file cabinet and a locking position wherein the drawer is locked in closed condition and including resilient means continnously biasing said relocking members to lock said drawer in closed condition, an integral tempered glass control member for said relocking members extending in coplanar relation with said dial between said dial and said lock casing in shielding relation wtih the lock casing to intercept attempted entry into said lock casing from externally of the file cabinet, said control member including integral marginal portions having apertures therein through which said relocking members project and portionsbounding said apertures in restraining engagement with said relocking members to hold said relocking members in unlocking condition against the biasing action of said resilient means, and said control member having the property of shattering into small fragments substantially uniformly throughout its entire extent in response to drilling, punching or heating upon attempted entry into said lock casing from externally of said file cabinet to destroy the restraining relation imposed by said control member on said relocking members and free the latter to be projected under the influence of said resilient means into drawer locking condition. I

6. Protective apparatus for use with a combination lock in a security closure or the like wherein the combination lock includes a lock mechanism enclosing casing located internally of the security closure, comprising relocking means supported within said security closure for movement from a closure lockingposition to a closure unlocking position including resilient means continuously biasing said relocking means to lock said closure in closed condition, and a control member for said relocking means formed of tempered glass and located in shielding relation to said lock casing to intercept tools projected from selected regions externally of said security closure in the direction of said lock casing, said control member having the property of shattering into small fragments substantially uniformly throughout its entire extent in response to drilling, punching, or heating thereof at any location along said control member, and said control member having portions disposed in restraining engagement with said relocking means tov normally'hold the relocking means in unlocking position when said control member is intact and to release said relocking means to respond to the 8 biasing means and shift to closure locking position upon 666,185 Damon Jan. 15, 1901 shattering of said control member. 718,359 Koerber Ian. 13, 1903 1,093,662 Tyden Apr. 21, 1914 References Cited in the file of this patent 1,452,567 Miller et a1 Apr. 24, 1923 UNITED STATES PATENTS 5 1,5 Dill n A g- 1 2 1,568,740 Kinnear Jan. 5, 1926 1 7 2 R h r n n- 27, 1 74 2,726,625 Evans Dem 13, 1955 596,294 Curtis Dec. 28, 1897