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Publication numberUS3024640 A
Publication typeGrant
Publication dateMar 13, 1962
Filing dateMay 5, 1959
Priority dateMay 5, 1959
Publication numberUS 3024640 A, US 3024640A, US-A-3024640, US3024640 A, US3024640A
InventorsMiller Harry C
Original AssigneeMiller Harry C
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Chi-ray protective combination lock dial assembly
US 3024640 A
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Description  (OCR text may contain errors)

March 13, 1

6 V H. MILLER 3,024,640

X-RAY PROTECTIVE COMBINATION LOCK DIAL ASSEMBLY Filed May 5, 1959 IN VEN TOR 'ATTORNE'YS States The present invention relates in general to the art of combination locks, and more particularly to combination locks having a facility associated therewith for resisting compromise of security by X-ray or other radiation means.

It has been known for some time that the security of conventional combination locks in safes or other security closures may be compromised by radiography techniques as, for example, by making X-ray pictures by photographing high energy radiation which has passed through the lock mechanism. If the dial is manipulated in a special manner and the dial readings are recorded at the time the film is exposed to the radiation passing through the lock mechanism, the combination of the lock may be determined by observing the differences of photographic density resulting from the effects of the high density metallic tumblers and the voids at the location of the peripheral tumbler gatings.

In order to discourage this form of compromise of security, locks have been developed in which low density material, such as nylon, is used for the tumblers, and scattering material and shielding material is placed in the safe on all sides of the look. A radiograph of this look construction, when all of the lock elements are stationary does not reveal the location of the tumbler notches and hence can not be reliably used by unauthorized persons to detect the combination of the lock.

It has been discovered, however, that if an X-ray film magazine is placed in a special holder which may be removably attached to the dial of such a combination lock having low density tumbler material so that the X-ray film and dial rotate in unison, and if the dial and film holder are rotated at a uniform rate while an X-ray source placed at the rear of the safe directly behind the dial is emitting radiation, it is possible to detect the combination of the lock. By such a technique, the stationary parts of the lock including the scattering material tend to produce a uniform background on the radiograph or X-ray picture since they are in motion with respect to the film. However, those parts of the combination lock, including the three peripheral gatings on the tumbler wheels, which are in synchronous rotary motion with the film are clearly outlined and are visible in the radiograph. If suitable markers are provided on the film or the film mechanism the combination of the lock can be established as one of six possible sets of numbers. Thus the use of stationary scattering and shielding material and low density tumbler material does not, in itself, afford adequate protection against compromise of security of the safe by radiography.

It has been heretofore proposed in patent application Serial No. 770,390 filed by Oleg C. Enikeieif on October 29, 1958, now Patent No. 2,970,217, which patent application has been assigned to Grey B. Miller and me as the sole general partners of Harry C. Miller Company, to provide combination looks with a disk-like X-ray scattering element which is disposed between the tumbler and driving cam assembly and the front wall of the lock case, or between the front wall of the lock casing and the dial, and which is keyed to the dial spindle to rotate synchronously with the spindle, for the purpose of distorting a photographic image produced in the manner described in the preceding paragraph. This arrangement, however, contemplates the production of such an X-ray 3,024,640 Patented Mar. 13, 1962 scattering element as a separate member which must be assembled with the remainder of the lock components, and which either necessitates modification of the design of the lock casing and some of the components therein or the production of a special type of mounting plate for supporting the lock casing from the safe door or other supporting surface.

An object of the present invention, therefore, is the provision of novel means incorporated in the construction of a combination lock for resisting compromise of security of the look by radiation techniques.

Another object of the present invention is the provision of novel X-ray scattering means in the dial and dial ring assembly of a combination lock for distorting X-ray and like radiation energy patterns when the radiant energy is directed through the lock to prevent the production of radiographs which would reveal the combination of the lock or facilitate compromise of its security.

Another object of the present invention is the provision of a novel dial and dial ring assembly for combination locks having scattering material arranged in a stationary component of the assembly and scattering material arranged in a rotatable component of the assembly, both disposed in protective relation to the lock mechanism whereby the stationary and rotatable scattering material cooperate to prevent the production of radiographs of the X-ray energy directed through the lock mechanism which would reveal the locations of the tumbler wheel gatings.

Other objects, advantages and capabilities of the present invention will become apparent from the following detail description, taken in conjunction with the accompanying drawing illustrating one preferred embodiment of the invention.

In the drawings:

FIGURE 1 is a vertical section view taken through the medial plane of a combination lock dial and dial ring assembly embodying the present invention, the dial and dial ring being shown in exploded relation;

FIGURE 2 is a front elevation of the dial ring viewed from the plane 2-2 of FIGURE 1;

FIGURE 3 is a rear elevation of the dial member, taken along the plane 33 of FIGURE 1; and

FIGURE 4 is a vertical section view of the dial ring taken along the section plane spaced laterally from the center of the dial ring and indicated by the line 4-4 of FIGURE 2.

Referring to the drawings wherein like reference characters designate corresponding parts throughout the sev eral figures, the combination lock dial and dial ring assembly of the present invention, indicated generally by the reference character 10, comprises a dial 11 and a dial ring 12. The dial ring 12 is designed to be secured to the front surface of a supporting wall, such as a safe door, a file cabinet drawer front wall, or the like, to the rear surface of which the combination lock casing is secured. The dial 11 is provided with the usual spindle 13 which projects through the supporting door or wall and into the combination lock casing, and is designed to have the usual driving cam which is located within the casing keyed to the inner end of the spindle 13 to be driven thereby and effect adjustment of the tumbler wheels and movement of the bolt.

The dial and dial ring assembly 10 illustrated in the drawing is of the type designed to shield the dial graduations and indicia from observation by anyone other than the operator, and is of the general type disclosed in my prior Patent No. 2,836,052 issued May 27, 1958. To this end, the dial ring 12 is provided with the usual circular base 14 which is centrally apertured as indicated at 15 to permit the spindle 13 to pass therethrough, and

is provided with a forwardly projecting, interrupted annular shielding flange 16 disposed near the periphery of the dial ring. The shielding flange 16 terminates a selected, uniform distance to either side of the medial vertical plane through the dial ring in the upper portion of the dial ring, as indicated at 17 and 18, to define an upper sight opening 19 bounded by the ends 17, 18 of the shielding flange 16 and an arcuate surface 20 lying in the circular path of the annular flange 16. A fixed index mark 21 is located at the center of the sight opening 19. The base 14 of the dial ring 12 is provided with a plurality of openings 22 extending therethrough, which may be located on the vertical axis through the center of the dial ring 12 for accommodating the usual mounting bolts. The central region of the base 14 of the dial ring 12 is provided with a forwardly projecting boss 23 which surrounds the central spindle aperture and mounting bolt openings 22 and extends to the vertical plane of the arcuate surface of the sight opening 19.

The front surface of the base 14 is recessed between the boss 23 and shielding flange 16 to provide a cavity 24. The cavity 24 is bounded by an outer, cylindrical side wall 25 aligned with the inner surface of the shielding flange 16 and an inner side wall '26 which is also the side wall of the boss 23. This recessed cavity 24 is filled with a large number of X-ray scattering bodies 27, which may be, for example, X spherical lead balls potted or imbedded in a suitable carrier, indicated at 28. The carrier may be paraffin or a thermoplastic or thermosetting plastic composition of the type which may be poured into the cavity 24 when the X-ray scattering bodies have been placed therein to retain the bodies in position within the cavity. To further complicate the Xray scattering pattern, a plurality of additional X-ray scattering bodies 29, which may be of larger diameter than the bodies 27, may be provided in a circular zone about the center of the base 14 spaced from the center about the same distance as the mounting bolt openings 22, and to this end circular bores extending from the rear wall of the cavity 24 through the rear surface of the base 14 are provided into which these larger scattering bodies 29 project. It will be understood that the cavity 24 and the bores for the scattering bodies 29 are of sufficient depth and diameter in relation to the size of the scattering bodies 27 and 29 so that the outer surface of the mass of scattering bodies lies flush with or slightly behind the plane of the front surface of the boss 23.

The dial 11 may be cast from Zamac or other metallic or plastic casting material and is provided with a central boss formation 30, which in this embodiment is removably secured to the dial casting, having a socket 31 into which the front end of the spindle 13 is tightly fitted. The dial 11 comprises a circular or disk-like front wall 32 having a forwardly projecting knob 33 at the center thereof, the front wall 32 being inclined slightly forwardly from the edge of the knob 33 to the periphery of the wall. An annular flange 34 projects rearwardly from the periphery of the front wall 32 and forms a cylindrical surface 35 which bears the dial markings and indicia. The size of the flange 34 is such as to nest within the shielding flange 16 of the dial ring 12 so that the indicia bearing surface 35 lies immediately adjacent the inner surface of the shielding flange 16 and the indicia are shielded from view when out of registry with the sight opening 19.

This dial construction, as illustrated, provides an annular cavity 36 between the annular flange 34 and the central boss 30, which forms a convenient housing for a potted mass 37 of X-ray scattering bodies of a form similar to the mass of bodies 27 previously described. Thus, a plurality of lead balls or similar bodies, indicated at 38, may be disposed in the desired pattern within the cavity 36 and a suitable carrier 39 of paraffin or suitable plastic material may be poured over the mass of 4 lead balls 38 to retain the scattering bodies in position when the carrier composition sets.

It is desirable to protect the dial assembly against compromise of security by insertion of the X-ray film in and around the dial between the dial 11 and the dial ring 12. As one example of means for providing such protection, the annular rear wall 40 of the annular flange 34 of dial 11 is formed With a rearwardly opening annular groove 41 which is concentric with the axis of the dial 11 and the annular flange 34, and the dial ring 12 may be provided with an annular baffle member 42 seated in the cavity 24 of the dial ring 12. The baffle member 42 may be conveniently made in the form of a metallic ring having a thin, annular, outwardly projecting flange 43 adapted to project into and have a sliding fit with the annular groove 41 in the dial flange 34. The flange 43 projects from a very narrow base ring 44 which is adapted to butt against the rear wall of the cavity 24. The base ring 44 may be provided with a pair of diametrically positioned, inwardly projecting mounting ears 45 which extend into engagement with diametrically opposed portions of the boss 23 to hold the baffle 42 in position within the cavity 24. The baffle 42 may be retained in position by mere frictional engagement of the mounting cars 45 with the surfaces of the side wall of the boss 23, or by providing diametrically opposite the opening notches or grooves in the side wall of the boss 23 into which the inner edge portions of the mounting cars 45 are forced, or by other expedients which will be well known to persons skilled in the art. By extending the annular flange 43 into the annular groove 41 in the dial flange 34, the baffle member 42 shields the area between the dial 11 and dial ring 12 against the insertion of an X-ray film in the area surrounding the spindle 13 and thereby prevents circumvention of the protection afforded by the potted X-ray scattering bodies 38 carried by the dial 11. It will be apparent that other arrangements may be provided which will effectively shield the area between the dial and dial ring against introduction of X-ray film therebetween, the baffle member 42 being described as one example of a structure that would be effective for this purpose.

This construction provides an extremely convenient means of incorporating an effective X-ray scattering feature in a combination lock dial and dial ring assembly of more or less conventional form without necessitating any drastic modification of the dial and dial ring assembly construction. This drastically simplifies manufacture and cost of manufacture of combination locks hav ing this feature, and also permits the ready modification of existing combination lock installations to incorporate the X-ray scattering feature by the simple expedient of replacing the existing dial and dial ring assembly.

As explained earlier, it would be possible to compromise the security of conventional combination locks, even if they were provided with tumbler wheels or low density material by providing an X-ray film holder or jig which may be removably supported on the knob of the conventional dial, and disposing an X-ray source or other radiation source at the rear of the safe or security closure generally in alignment with the axis of the dial spindle so as to direct the radiation energy forwardly through the lock mechanism and on to the photosensitivll emulsion in the film holder. However, when the combination lock dial ring assembly hereinabove described is provided for the combination lock, the stationary mass of radiation scattering bodies 27 and 29 and the rotatable mass of radiation scattering bodies 38 are interposed in the path of the radiation energy between the radiation source and the film holder, and the mass of scattering bodies 38 rotates in synchronous angular relation with the dial 11, the mass of scattering bodies 38 remains stationary relative to the film in the film holder and so distorts the photographic image as to prevent reduction of the scattering pattern to background status and thus prevents recording of a visible outline of the lock parts including the tumbler wheels which remain stationary relative to the dial and the mass of scattering bodies 38 during manipulation of the dial. The scattering pattern is further complicated by the fact that relative movement occurs between the two masses 27 and 37 of scattering material. These features all cooperate to prevent recording of a visible outline of the lock parts and particularly the tumbler wheels which remain stationary relative to the dial and photo-sensitive emulsion in the film holder during manipulation of the dial. Actually, the mass of scattering bodies 38 in the dial cavity 36 would suifice, without the presence of the stationary mass of scattering bodies 27, to prevent recording of a visible outline of the tumbler wheels by which the lock security could be compromised, but the presence of the stationary mass affords additional protection against compromise of the lock combination by other radiation techniques. Thus, an effective counter measure technique is provided to prevent compromising of the lock security by the technique described above.

While but one specific embodiment of the present invention has been particularly shown and described, it is apparent that various modifications may be made in the invention without departing from the spirit and scope thereof, and it is desired, therefore, that only such limitations shall be placed thereon as are imposed by the appended claims.

I claim:

1. A dial for combination locks of the type having coaxially supported tumbler wheels and a rotatable dial spindle in coaxial relation to the tumbler wheels for adjusting the same, the dial comprising a generally circular body to be aflixed centrally to and rotated about the axis of the dial spindle and having a front face and a rearwardly opening cavity bounded by an outer peripheral wall, said cavity being disposed over an area to intercept radiation energy directed through the tumbler wheels of the associated lock along radiation axes lying within selected small angles of inclination relative to the axis of the spindle and dial, a layer of radiation scattering bodies disposed in a selected pattern throughout said cavity substantially filling said cavity over the entire area thereof forming a shielding radiation scattering mass to scatter the radiation energy intercepted thereby and distort the exit radiation pattern to prevent recording of a readable image of the tumblers which would reveal the angular position of the tumbler gatings, and a plastic retaining medium filling said cavity to at least the depth of said bodies in which said bodies are imbedded to retain the same in the selected pattern within said cavity and cause the layer of bodies to rotate as a unit with said dial.

2. A dial for combination locks of the type having coaxially supported tumbler wheels and a rotatable dial spindle in coaxial relation to the tumbler wheels for adjusting the same, the dial comprising a generally cylindrical dial body having a front wall including an integral knob projecting centrally therefrom and a cylindrical peripheral surface bearing dial markings and indicia, said dial body being adapted to 'be afiixed centrally to and rotated about the axis of the dial spindle and having a rearward-1y opening annular cavity in coaxial relation with the axis of the dial body disposed over an area to intercept radiation energy directed through the tumbler wheels 'of the associated lock along radiation axes lying within a range of selected small angles of inclination relative to the axis of the spindle and dial, a layer of radiation scattering bodies disposed in a selected pattern throughout said annular cavity to form a shielding radiation scattering mass to scatter the radiation energy intercepted thereby and distort the exit radiation pattern to prevent recording of a readable image of he tumblers which would reveal the angular position of the tumbler gatings, and a plastic retaining medium filling said cavity to at least the depth of said bodies in which said bodies are imbedded to retain the same in the selected pattern within said cavity and cause the layer of bodies to rotate as a unit with said dial.

3. A dial for combination locks of the type having coaxially supported, rotatable, peripherally gated tumbler wheels and a coaxially related rotatable dial spindle for adjusting the tumblers, comprising a dial body including a disk-like wall portion and a peripheral rearwardly projecting flange having a cylindrical outer surface carrying dial markings and indicia, a central boss projecting rear- Wardly from said disk-like wall to be aflixed to and rotated about the axis of the spindle, said boss terminating in a bearing surface adjacent the center of the disklike wall spaced rearwardly from said disk-like wall, said central boss and said peripheral flange defining a rearwardly opening cavity therebetween extending over an expense radially *of the center of the dial to a radius at least as great as the radius of the tumbler wheels to intercept radiation energy directed through the tumbler wheels of the associated lock along radiation axes lying within selected small angles of inclination relative to the axis of the spindle and dial, a layer of radiation scattering bodies of generally spherical configuration disposed closely adjacent to each other and extending throughout said cavity substantially to the depth of said boss to scatter the radiation energy intercepted thereby and distort the exit radiation pattern to prevent recording of a readable image of the tumblers which would reveal the angular position of the tumbler gatings, and means for retaining said radiation scattering bodies within said cavity and causing said bodies to rotate as a group with said dial.

4. A dial and dial ring assembly for combination locks of the type having coaxially supported tumbler Wheels and a rotatable dial spindle in coaxial relation to the tumbler wheels for adjusting the same, the dial comprising a generally circular body to be affixed centrally to and rotated about the axis of the dial spindle and having a front face and a rearwardly opening cavity bounded by an outer peripheral wall, said cavity being disposed over an area to intercept radiation energy directed through the tumbler wheels of the associated lock along radiation axes lying within selected small angles of inclination relative to the axis of the spindle and dial, a plurality of radiation scattering bodies substantially filling said cavity over the entire area thereof forming a shielding radiation scattering mass to scatter the radiation energy intercepted thereby and distort the exit radiation pattern to prevent recording of a readable image of the tumblers which would reveal the angular position of the tumbler gatings, means for retaining said radiation scattering bodies within said cavity, and said dial ring including a circular base to be disposed in coaxial relation with said dial having a central aperture for passage of the spindle therethrough, said dial ring having a forwardly opening cavity in the base thereof extending over an area corresponding generally to the area of said dial cavity, a plurality of radiation scattering bodies substantially filling said dial ring cavity, and means for retaining the lastmentioned radiation scattering bodies in said dial ring cavity.

5. A dial and dial ring assembly' for combination locks of the type having coaxially supported tumbler wheels and a rotatable dial spindle in coaxial relation to the tumbler wheels for adjusting the same, the dial comprising a generally cylindrical dial body having a front wall including an integral knob projecting centrally therefrom and a cylindrical peripheral surface bearing dial markings and indicia, said dial body being adapted to be aflixed centrally to and rotated about the axis of the dial spindle and having a rearwardly opening annular cavity in coaxial relation with the axis of the dial body disposed over an area to intercept radiation energy directed through the tumbler wheels of the associated lock along radiation axes lying within a range of selected small angles of inclination relative to the axis of the spindle and dial, a layer of radiation scattering bodies disposed in touching relation to each other extending throughout said annular cavity to form a shielding radiation scattering mass to scatter the radiation energy intercepted thereby and distort the exit radiation pattern to prevent recording of a readable image of the tumblers which would reveal the angular position of the tumbler gatings, a plastic retaining medium filling said cavity to at least the depth of said bodies in which said bodies are irnbedded to retain the same in a selected pattern within said cavity and cause the layer of bodies to rotate as a unit with said dial, said dial ring including a circular base to be fixed to a stationary supporting surface in coaxial, underlying relation with said dial having a central aperture for passage of the spindle therethrough, said dial ring having an interrupted, forwardly projecting flange adjacent the periphery of said base to surround the cylindrical periphery of said dial and a forwardly opening cavity disposed inwardly of said flange and extending over an area corresponding generally to the area of said dial cavity, a layer of radiation scattering bodies disposed in touching relation to each other extending throughout said dial ring cavity to form a shielding radiation scattering mass, and a plastic retaining medium within said dial ring cavity having said radation scattering bodies imbedded therein to retain the same in a selected pattern within said dial ring cavity.

6. A dial and dial ring assembly for combination locks of the type having coaxially supported, rotatable, peripherally gated tumbler wheels and a coaxially related rotatable dial spindle for adjusting the tumblers, comprising a dial body including a disk-like wall portion and a peripheral rearwardly projecting flange having a cylindrical outer surface carrying dial markings and indicia, a central boss projecting rearwardly from said disk-like wall to be aflixed to and rotated about the axis of the spindle, said boss terminating in a bearing surface adjacent the center of the disk-like wall spaced rearwardly from said disk-like wall, said central boss and said peripheral flange defining a rearwardly opening cavity therebetween extending over an expanse radially of the center of the dial to a radius at least as great as the radius of the tumbler Wheels to intercept radiation energy directed through the tumbler wheels of the associated lock along radiation axes lying within selected small angles of inclination relative to the axis of the spindle and dial, a layer of radiation scattering bodies of generally spherical configuration disposed closely adjacent to each other and extending throughout said cavity substantially to the depth of said boss to scatter the radiation energy intercepted thereby and distort the exit radiation pattern to prevent recording of a readable image of the tumblers which would reveal the angular position of the tumbler gatings, means for retaining said radiation scattering bodies Within said cavity and causing said bodies to rotate as a group with said dial, said dial ring including a circular base having an aperture for passage of the spindle therethrough and an interrupted forwardly projecting flange adjacent the periphery thereof to surround the peripheral flange of said dial, and a forwardly opening annular cavity surrounding said aperture, and a layer of radiation scattering spheres fixed in said dial ring cavity.

7. In a dial and dial ring assembly, the combination recited in claim 4 including baffle means supported on said dial ring and projecting forwardly thereof within said dial ring cavity into lapping relation with the rearward portion of the outer peripheral wall of said dial to shield the space between said dial and dial ring against insertion of radiation sensitive film therebetween.

8. In a dial and dial ring assembly, the combination recited in claim 5 including an annular baffle member having a base portion seated in the dial ring cavity and an uninterrupted annular flange projecting forwardly from said dial ring base, and said dial having a rearwardly opening, uninterrupted annular groove complementing a portion of said flange of said baflie member to receive the baflle member flange therein, said baflle member flange being disposed radially outwardly of the radiation scattering bodies disposed in said dial ring cavity to shield the space between said dial ring and said dial from insertion of radiation sensitive film therebetween.

References Cited in the file of this patent UNITED STATES PATENTS 1,781,060 Hill et al. Nov. 11, 1930 2,016,487 Doenges Oct. 8, 1935 2,675,485 Scag Apr. 13, 1954 2,916,906 Miller Dec. I5, 1959 2,938,374 Cirscuolo et al May 31, 1960 2,951,358 Miller Sept. 6, 1960

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US1781060 *Apr 4, 1928Nov 11, 1930Sargent & GreenleafSafety receptacle for small articles
US2016487 *Mar 15, 1934Oct 8, 1935Doenges William FTumbler for combination locks
US2675485 *Jan 2, 1951Apr 13, 1954Allis Chalmers Mfg CoLead pellet absorptive shield for betatrons
US2916906 *Oct 30, 1956Dec 15, 1959Harry C MillerCombination lock dial mechanism
US2938374 *Jun 24, 1957May 31, 1960Case Donald PProtection of combination locks against entry by radiography
US2951358 *Dec 27, 1957Sep 6, 1960Sargent & GreenleafDial and spindle assembly
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4197726 *Aug 15, 1977Apr 15, 1980La Gard, Inc.Combination locks
US4776190 *Jan 22, 1987Oct 11, 1988Sargent & Greenleaf, Inc.Radiological detection resistant key changeable combination lock
US4796446 *Jan 7, 1987Jan 10, 1989Miller Harry CRadiological detection resistant combination lock
US4803859 *Feb 5, 1988Feb 14, 1989Miller Harry CTumbler wheel structure for radiological detector resistant combination lock
US6904778Apr 28, 2003Jun 14, 2005Lockmasters, Inc.Mechanical combination lock
US7705335 *Mar 14, 2008Apr 27, 2010Parttec, Ltd.Security protection device and method
Classifications
U.S. Classification70/332, 70/442, 250/515.1
International ClassificationE05B37/00
Cooperative ClassificationE05B37/0027
European ClassificationE05B37/00B