US 3882702 A
An anti-pick device for a lock is described in which a housing is mounted over the key slot entrance in the lock and a key holder is mounted slidably in the housing for movement along a path aligned with the key slot. A recess is provided in the key holder extending transversely of the path of movement of the key holder for receiving a key and supporting the key in alignment with the key slot.
Description (OCR text may contain errors)
United States Patent Wiczer May 13, 1975  KEY FOR LOCK ANTI-PICK DEVICE 1,256,767 2/l9l8 Berg 70/447 1,768,040 6/1930 F h'ld... 70/408 X [761 Invent Max 9122 Kedvale- Skokle, 1,903,586 4/1933 Ai ri ld 70/408 X 60652 3,334,501 8/1967 Greenwald... 70/423  Filed: y 27, 1973 3,696,646 10/1972 Loscolzo 7()/l.5
[ PP N03 383,184 Primary Examiner-Robert L. Wolfe Related Application Data Attorney, Agent, or Firm-Fitch, Even, Tabin &  Division of Ser. No. 294,385. Oct. 2, 1973, Pat. No. Luedek  ABSTRACT  U.S. Cl 70/406; 70/408 An ami pick device for a lock is described in which a lift. i g i mounted Over the y slot entrance in the  Fleld 0f Search 70/406, 407, 408, 419, lock and a y holder i mounted i y i the hous 70/423 455 ing for movement along a path aligned with the key slot. A recess is provided in the key holder extending  References C'ted transversely of the path of movement of the key UNIT STATES PATENTS holder for receiving a key and supporting the key in 360,738 4/1887 Smith 70/407 x alignment with the key slot. 582,367 5/1897 OKeefe.. 70/408 X 2 Cl 9 D F, 888,478 5/1908 Drew 70 407 x rawmg PATENIEB MAY 1 3 I975 KEY FOR LOCK ANTI-PICK DEVICE This is a division of application Ser. No. 294,385 filed Oct. 2, 1973, and now U.S. Pat. No. 3,765,199.
This invention relates generally to locking devices and, more particularly, to an anti-pick device for a lock having a key slot.
A common locking device in general use comprises a front flange, an elongated threaded body extending behind the flange, and a cylinder extending from the flange, within the body. A key slot in the lock provides access to suitable internal devices which are operated by a key inserted in the slot. This enables one to turn the cylinder and operate a cam or other suitable device actuated by turning the cylinder. Typically, the flange portion of the lock is the only portion thereof which is mounted, externally of the panel in which the lock is mounted, and a retainer nut is utilized threaded on the threaded body of the lock to securethe lock in place in the panel. The panel is thereby clamped between the nut and the front flange of the lock.
Various techniques have been devised by nefarious individuals within society for opening such locks without the necessity of employing a key. Such techniques including picking, drilling, punching, and pulling the cylinder out of the lock.
In order to frustrate the activities of such persons employing the aforementioned techniques, various devices have been devised. Typically these prior art devices have not afforded as thorough protection against illegal tampering as might be desired. Moreover, such prior art devices have often been difficult to install, expensive to construct, and have sometimes required modification of the lock itself.
It is an object of the present invention to provide an improved anti-pick device for a lock having a key slot.
Another object of the invention is to provide an antipick device for a lock which prevents a direct line of sight access to the key slot.
Another object of the invention is to provide an antipick device for a lock which provides a means of protection for the lock against picking, drilling, punching, and cylinder pulling.
Various other objects of the invention in addition to those set forth above will become apparent to those skilled in the art from the following description, taken in connection with the accompanying drawings, wherein:
FIG. 1 is an exploded perspective view of a device constructed in accordance with the invention;
FIG. 2 is a full cross sectional view of the device of FIG. 1, shown installed with a lock in a panel;
FIG. 3 is a view similar to FIG. 2 illustrating the position of the device of the invention when a key is inserted in the lock;
FIG. 4 is a full cross sectional view of an alternative embodiment of the invention in the installed position;
FIG. 5 is a cross sectional view of a further alternative embodiment of the invention in the installed position;
FIG. 6 is a partial sectional view taken along lines 6--6 of FIG. 5 in the direction of the arrows;
FIG. 7 is an elevational view of a specially designed key which may be advantageously used in conjunction with the device of the invention;
FIG. 8 is an end view of an alternative key holder construction which may be employed in the device of the invention for use with the key of FIG. 7; and
FIG. 9 is a sectional view of the key holder taken along line 9-9 of FIG. 8 in the direction of the arrows.
Very generally, the anti-pick device of the invention comprises a security housing 11 adapted for mounting about the entrance to the slot 12 of a lock 13. A key holder 14 is mounted slidably in relation to the housing for linear movement along a path aligned with the key slot. The key holder has a recess 15 therein for receiving a key 16 and supporting the key in alignment with the key slot. The recess extends transversely of the path of movement of the key holder.
Referring now more particularly to FIGS. 1 and 2, the device of the invention in accordance with the illustrated embodiment may be more readily understood. The lock itself has a front flange 21 and a generally cylindrical body extending from behind the flange. Opposite sides of the body 23 are provided with flats 25 thereon to prevent the lock from turning in the hole in the panel in which the lock is mounted. The hole in the panel in which the lock is mounted is provided with a correspondingly out-of-round opening to mate with the flats and thus prevent rotation.
The lock 13 may be constructed internally of any suitable design, and in the illustrated embodiment, the lock 13 is provided with an internal cylinder, not shown, which, when turned, rotates a generally square stud 27 mounted at the back end of the lock. As shown in FIG. 2, the stud 27 may pass through a correspondingly shaped hole in a lock cam 29, and may be secured therein by means of a suitable bolt 31.
As is known in the art, the lock 13 is provided with a key slot 12 therein into which a key 16 may be inserted. When the key is of the proper configuration, the internal cylinder, not shown, in the lock may be rotated, to thus rotate the stud 27 and hence move the lock cam 29 appropriately. The lock cam 29 may bear against any suitable block, panel, or latch plate, to provide locking action, as is known in the art.
The housing or body 11 is generally cylindrical in shape, having outer and inner cylindrical surfaces. An annular recess 35 is provided at one end of the housing 11, thus providing an enlarging step in the internal diameter of the body 11. As may be seen in FIG. 2, the opposite end of the housing or body 1 1 is provided with an annular flange 37 which extends inwardly.
An outer retaining ring 41 is provided having an outer diameter matching the diameter of the recess 35 so that the outer retaining ring 41 will fit in the recess 35 as shown in FIG. 2. A pair of holes 43 are provided in the outer retaining ring 41 which are in alignment with a pair of threaded holes 45 in the housing 1 l at the bottom of the recess 35. In this matter, the outer retaining ring may be secured in the recess 35 by means of screws 47 (FIG. 2).
As may be seen in FIG. 2, the outer retaining ring 41 is provided with an annular recess 51 therein, the diameter of which is equal to the inner diameter of the housing 11. An inner retaining ring 53 is provided with an outwardly projecting flange 55 which fits within the annular recess 51 in the outer retaining ring 41.
The panel 57 in which the lock 13 is mounted may be any wall, door or similar structure. The inner diameter of the inner retaining ring 53 is made such as to be less than the outer diameter of the flange 21 on the lock 3 13. In this manner, the inner retaining ring 53 may be clamped against the panel 57 between the flange 21 and a lock retainer nut 59 threaded on the threaded body 23 of the lock 13. The flange 55 of the inner retaining ring retains the outer retaining ring 41 between it and the panel 57 and thereby secures the housing 11 over the key slot entrance 12 of the lock 13.
As previously mentioned, the key holder 14 is mounted slidably in the housing 11 for movement along a path aligned with the key slot 12. To this end, the key holder 14, which in the illustrated embodiment is generally cylindrical, is provided with an annular flange 61 which projects radially outward at one end of the key holder and which has an outer surface of a diameter equal to and mating with the inner surface of the housing 1 1. The outer diameter of the cylindrical key holder 14 is slightly less than the inner diameter of the inwardly projecting flange 37 on the housing 11. Thus,
the key holder 14 is mounted in and guided within the housing 11, but may not be pulled out of the housing.
The key holder 14 is provided with a recess 15 therein for receiving the key 33 for supporting same in alignment with the key slot. in the illustrated embodiment, this recess comprises a slot which extends along the axis of the cylindrical key holder to the end thereof disposed interiorly of the housing 11. The slot does not extend to the opposite end of the key holder 14, and thereby leaves a wall 65 which extends transversely to the path of movement of the key holder 14.
In the illustrated embodiment, a small hole 67 is provided at the base of the recess 15, and the key is provided with a stud 69 thereon which mates within the the key holder 14, the key holder is also rotated until the key llofindsand enters the keyway or slot 1 2 of the i lock 13. The key is then pushed into the lockby further slot 12 in the lock 13, and because the key holder 14 v fills up the opening in the housing 11, the only external access to the lock is through the recess 15. Since the recess 15 does not extend through the entire length of the key holder 14, but rather extends transversely of the path of movement of the key holder, 21 direct line of sight into the lock is prevented. Accordingly, a conventional lock picking tool cannot be used to pick the lock, and any picking attempt by the utilization of other tools must be blind. The external parts of the device of the invention are preferably hardened to resist cutting and drilling. By makingthe inner diameters of the outer retainer ring 41 larger than the outer diameters of the inner retainer ring 53, any torque applied to the housing merely rotatesthe housing about the lock- Accordingly, the lock cannot be removed by forcing it or unthreading it from the retainer nut 59.
An alternative embodiment of the invention is illustrated in FIG. 4. In FIG. 4, thoseelements of the device and associated structure which have function and dement of FIG. 4, the housing 111 is secured directly to the panel 157 by means of screws 147 which enter directlyinto the housing. This design eliminates the need hole to aid in retaining the key in position with respect to the key holder 14. Also in the illustrated embodiment the key 16 is provided with an L-shaped extension 71 thereon to facilitate inserting the key into and removing the key from the recess 15 in the key holder 14..
Since the key holder 14 is free to rotate with respect to the key slot 12 in the lock 13, and since the breadth of the recess 15 is selected to properly align the key 16 with the key slot entrance, the key holder may be I moved linearly to cause the key to enter the key slot, and may then be turned to cause the key to turn the internal cylinder within the lock 13 and open the lock.
FIG. 3 shows the key inserted in the lock with the key holder in its innermost position.
In assembling the device of the invention, the key holder is inserted into the body 11 so that the barrel of secured therein by the screws 47. The lock is then inserted into the hole in the panel 57 and secured therein by the retainer nut 59. The housing assembly is thus secured over the entrance to the slot 12.
In operating the device of the invention, the key holder 14 is pulled out from thehousing 11 as far as possible, i.e., the position shown in FIG. 2. The key is then inserted in the recess 15 with the stud 69 projecting downwardly into the hole 67 at the bottom of the slot. The key holder 14, with the key placed therein, is then pushed inwardly. While maintaining pressure on for the inner and outer retaining rings because the housingis secured to the panel independently of the lock.
Additionally, an optional blocking means 148 is schematically illustrated in FIG. 4%.for normally covering the key slot of lock 113, but beingmovable relative to the 7 key slot to permit access thereto for insertion of the key 1 16. This. provides an additional measure of security against blind picking of the lock through the use of perhaps a more sophisticated or specially designed picking .tool. Blocking means 148 may comprise any through the urging or contact with the inner end of the key as the key is axially moved toward the key slot. This position in response to the movement of the key holder i 114 relative to the key slot by anysuitable camming arrangement or linkage between the key holder and the shutter as indicated by broken line 150. In this embodiment, axial movement of the key holder to its closed or key engaged position (as shown, for example, in FIG. 3) is required to move the blocking means 148 to its open" or access position. Any mechanism of suitable size for translating the linear movement of the key holder to angular movement of the shutter may be :em-
Asa further alternative, the lock itself may be mounted to a panel, housing or bracket which is behind a second panel, serving asthe main panelor door. The 2 second panel may have a hole therein for accommodating and. guiding the key holder. Accordingly, in this situation the second panel comprises the security housing, and the need for a closed cylindrical type of security housing as has been hereinbefore described may be eliminated.
More particularly, reference is made to FIG. 5 which shows a further alternative embodiment, with those elements of the device and associated structure having function and design similar to the elements of the embodiment of FIGS. 1 to 3 given like reference numerals, preceded by a 2. As can be seen, the panel 257, together with the housing body 211, forms the security housing, since the panel 257 blocks access to the key slot of the lock 213 except through the opening 252 in the panel. The body 211 serves to support the lock 213 in fixed mounted relation to the panel and to the opening 252 therein. The body 211 may be fastened to the back or interior side of the panel 257 by means of screws 247 inserted through ears 254 formed integrally with the body. As shown, the key holder 214 has a flange 261 which nests within a counterbore at the back of the panel or door 257 when the key holder is in its open or extended position.
Blocking means 248 may be optionally included, and is shown to comprise a pair of separable metal vanes 258a and 258b (FIG. 6) which are respectively pivot mounted at 262a and 2621; for angular motion as shown by the arrows. Each point is located so that the center of mass of the vanes causes them to normally swing together in the closed position shown in FIG. 6 under the force of gravity. An inward bevel may be provided along the respective inner edges 264a and 264b of the vanes so that they will readily separate when contacted by the innerend of the key 216 as it is urged forwardly toward the key slot. The parting line of the vanes, being aligned with the key slot, will open and permit entry of the key when the key holder 214 has been rotated to the proper angular orientation.
Of course, other mechanisms, employing springs, etc., may be utilized for the blocking means of the embodiment of FIG. 5, as well as of the embodiment of FIG. 4. Also, any such means may be employed with the embodiment of FIGS. 1 to 3, if desired. It is understood that the key slot may be of a shape other than flat or straight such as circular or other special configurations.
FIG. 7 shows an alternative key design which may be used with the modified key holder construction of FIGS. 8 and 9. The key 16 has a straight tumbler engaging portion 302 along an axis 304 defined thereby for insertion into a key slot of a lock, as previously described. A tang or gripping portion 306 is joined to the straight key portion 302 by a stem 308 having a curved bearing surface 310 extending from one side of the axis 304 to the other.
The key holder 14' is similar to that hereinbefore described, except that the recess 63' has a key supporting wall 312 forming a curved surface extending from an external point 314 furthest from the key slot to an external point 316 on the face of the key holder closest to the key slot, and from one side of its longitudinal axis 318 to the other. The curvature of the supporting wall 312 mates with the complementary bearing surface 310 of the key 16, and the key nests securely within the recess 63' in proper alignment with the key slot for easy insertion and removal.
With the key placed within the key holder, the tang 306 hooks over the rearward end 320 of the key holder so that the straight surface 322 abuts flush against end 320. A hole 324 is provided within the tang 306 for key chain convenience. Of course, portions of the mating bearing and supporting surfaces may be straight or approximately straight in some circumstances, but generally less advantageously.
It may therefore be seen that the invention provides an improved anti-pick device for a lock having a key slot. The device provides a means of protection for the lock against picking, drilling, punching, cylinder pulling, and many other types of nefarious activities. The device of the invention is relatively simple of construction, is easily installed, and represents a significant improvement over the known prior art.
Various modifications of the invention in addition to those shown and described herein will become apparent to those skilled in the art, from the foregoing description and accompanying drawings. Such modifications are intended to fall within the scope of the appended claims.
What is claimed is:
1. A key for use with a lock of the type having a key holder disposed ahead of the key slot and a key receiving recess in the holder having a curved key supporting wall extending from an outer periphery of the holder to a location adjacent the key slot, said key having:
a. a straight tumbler engaging portion along a straight axis for insertion into the key slot of the lock, said tumbler engaging portion being disposed on at least one edge surface of said key, spaced from, but generally parallel to, said straight axis,
b. a gripping portion,
c. a stem joining the gripping portion to said tumbler engaging portion, said stem having a curved bearing surface generally complementary to the curved supporting wall of the holder to facilitate sliding insertion of the key into the key slot, and
d. an edge located generally between said gripping portion and said stem and extending generally transverse to said axis so as to contact an end surface of said key holder when the key is inserted therein.
2. A key as defined in claim 1 including a lateral portion located between said curved surface and said transverse edge, said lateral portion being adapted to contact a cooperatively shaped portion near the end surface of said key holder to prevent radially inward pivotal movement of said key relative to said key holder when said key is inserted in said key slot.
UNETEB STATES PATENT GFFICE CETIFEQATE 0F (IURERECTION PATENT-N6. 2 702 DATED May 13, 1975 iNVENTORk'S) Max Wiczer rr is certified that error appears in the ab0veidenhfred parent and that said Letters Patent are hereby co rected as shown below:
Title sheet, Item 62, the filing date of the parent application Column 3, line 56, place' should be -placed-.
En'gncd and Scaled this sixteenth Day of September 1975 [SEAL] Attesz:
C. MARSHALL DANN (mnmissr'nner uj'Parenls and Trademarks RUTH C. MASON Arresting Officer