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Publication numberUS3714804 A
Publication typeGrant
Publication dateFeb 6, 1973
Filing dateNov 4, 1971
Priority dateNov 4, 1971
Also published asCA961297A1
Publication numberUS 3714804 A, US 3714804A, US-A-3714804, US3714804 A, US3714804A
InventorsFrench W
Original AssigneeCameron R
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Shutter structure
US 3714804 A
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Description  (OCR text may contain errors)

Feb. 6, 1973 w. K. FRENCH SHUTTER STRUCTURE Filed Nov. 4, 1971 2 Sheets-Sheet 2 Sheets-Sheet 2 Filed Nov. 4, 1971 IIHHII.

United States Patent 3,714,804 SHUTTER STRUCTURE Walter K. French, Montrose, N.Y., assignor to Richard William Cameron, New York, N.Y. Filed Nov. 4, 1971, Ser. No. 195,606 Int. Cl. E05b 17/14, 19/00 US. Cl. 70--419 9 Claims ABSTRACT OF THE DISCLOSURE Apparatus for increasing the security of existing door lock installations by rendering the same impervious to picking. The apparatus includes an armored cover plate and shutter mechanism adapted to prevent the effect ve application of picking torques to the lock plug, and includes novel key means and an operator thereon, and an auxiliary locking provision which bars operation of the lock even by persons having a properly fitting key.

BACKGROUND OF THE INVENTION Field of the invention The present invention is in the field of security devices and particularly in the field of an auxiliary apparatus adapted to be attached to an existing lock mechanism effectively to increase the security of the lock mechanism.

The prior art There i a present trend toward increased losses by way of theft, both in private residences and in commercial establishments. As a result of this trend, multiple inventions by way of improved locking mechanisms having high resistance to picking have been developed and are in use. These apparatuses are calculated to increase the difficulty of compromising a lock by picking. The apparatuses involve a variety of different principles, including the use of magnetic type lock operating mechanisms, highly complex modified disk and pin tumbler locks, electrically coded lock release systems and the like.

While such devices are effective in frustrating picking to varying degrees, they are characteristically expensive and require substitution for the existing lock mechanisms. As a result of this high cost factor, the use of the improved locking devices has been limited to persons able to afford the same, with the result that the owners of residences and apartments in low income, high crime incidence areas have been unable to avail themselves thereof.

It has heretofore been proposed to employ means integrally incorporated in a lock for increasing security against picking, which means may comprise secondary apparatus for preventing even slight relative rotation of the plug and cylinder whereby the conventional lock picking techniques of applying a torque to the plug and hanging the locking pins or disks is neutralized. Such secondary mechanisms may include a means for blocking access to the keyway except when the secondary alignment means is in position. Pick resistant locks employing this concept have, as noted above, required replacement of existing locks, have been expensive, and have lost their effectiveness after protracted use due to the fact that locks of this sort depend upon providing closer tolerances between the interfit of the secondary locking means than the primary locking means. Any significant wear on the secondary locking means results in play between the parts which, when such play becomes suflicient, enables a torque to be transmitted to the primary locking means, thereby enabling the latter to be picked by conventional methods.

SUMMARY OF THE INVENTION The present invention relates to an auxiliary apparatus which is to be combined with an existing lock mechanism, which may be of conventional design, to render the latter pickproof.

In accordance with the invention, a cover member is secured to the face of the door over the existing lock, the cover incorporating an aperature in registry with the lock and a shutter plate slidably mounted on the cover and movable selectively between blocking or covering position of the lock and unblocking or exposing position of the lock.

A gate mechanism is affixed to the lock plug, the shutter plate being likewise slidably mounted within the gate mechanism whereby, when the shutter is prevented from rotation relative to the cover, the shutter acts to prevent angular movement of the gate and, hence, of the plug with respect to the lock cylinder.

By reason of the relatively large displacement of the shutter from the axis of rotation of the plug, it will be appreciated that with the same degree of tolerances between the shutter and its associated slide mechanisms as is provided between the locking pins and the pin chambers, the angular movement of the plug relative to the cylinder will be insufficient to permit the locking pins to bind or hang on the shear line between the plug and cylinder.

The lock is operated by a key mechanism including a portion for operating the lock tumbler pins in a con ventional manner, the key mechanism preferably differing from the normal key in that it projects only a small distance from the face of the plug. The key may include a retriever slot in the projecting portion.

There is provided a key retriever having a cam actuatable connection with the slot of the key mechanism, the connection between the key and the retriever being effected by an axial movement of the parts. In the engaged position, the retriever is coupled to the key for axial, conjoint movement, yet by reason of the nature of the connection, torque forces applied to the retriever will not be transmitted, to any significant extent, to the plug. Instead, such torque forces will operate to release the key from the retriever.

The lock is operated by inserting the key through the use of the retriever, separating the key and retriever, shifting the shutter to the plug blocking position and rotating the shutter.

The apparatus is preferably provided with means for locking the shutter in its non-rotatable position by means of an additional padlock or the like, whereby even one in possession of a proper key for the existing lock will be unable to release the lock unless possessing a key to the padlock.

Accordingly, it is an object of the invention to provide an attachment for existing locks whereby the latter are rendered pick resistant.

A further object of the invention is the provision of a device of the type described which also protects existing lock mechanisms from being compromised by methods other than picking, such as jimmying, etc.

A further object of the invention is the provision of a device of the type described wherein a secondary padlock maybe readily applied to prevent operation of the existing lock mechanism even by one having a key therefor.

Still a further object of the invention is the provision of adevice of the type described including a novel key retriever mechanism which may be readily engaged with and disengaged from a specially formed key to expedite operation of the lock and positioning and retrieval of the key.

It is still a further object of the present invention to provide an apparatus for pickproofing a lock wherein high security is attained without the necessity of machining the apparatus to unusually close tolerances.

To attain these objects and such further objects as may appear herein or be hereinafter pointed out, reference is made to the accompanying drawings, forming a part hereof, in which:

FIG. 1 is an exploded perspective view of the pickproofing apparatus, and a door and lock to which the same is to be applied;

FIG. 2 is an enlarged front elevational view of the apparatus in the locked position thereof;

FIG. 3 is a view similar to FIG. 2 showing the parts in the unlocked position;

FIG. 4 is a vertical section taken on the line 44 of FIG. 2;

FIG. 5 is a section taken on the line 55 of FIG. 4, depicting the details of the key and key retriever;

FIG. 6 is a section taken on the line 6-6 of FIG. 5;

FIG. 7 is a view similar to FIG. 6, showing the manner in which the retriever is detached from the key.

Referring now to the drawings, 10 is a door or the like to which a conventional lock cylinder 11 is applied. 12 is the rotatable lock plug having a keyway 13. In the usual manner, a proper key inserted into the keyway 13 is effective to release the plug to enable its rotation within the cylinder, whereby a conventional connecting mechanism can withdraw the usual latch bolt (not shown).

While the present lock apparatus is depicted as employing a series of pins 14 driven by springs 15 normally to cross the shear line 16 defined between the plug 12 and cylinder 11, whereby the junction between the upper and lower pins is at the shear line only where a proper key is employed, it will be recognized that the present attachment is adapted for use with any lock mechanism, whether or not employing the pin tumbler principle.

In accordance with the invention and as best appreciated from FIG. 1, the pickproof attachment includes a cover assembly 17, a shutter 18 and a gate member 19. The gate member 19 is comprised of a basically circular metal plate having arcuate polar sections 20, 21. Struck up from the body of the gate 19 are a pair of parallel lugs 22, 23', the lugs being cut away to define cars 24, 25, 26, 27.

The cars 24 and 26 are aligned, as are the cars 25, 27, in such manner as to provide a guide surface slidingly engaging the side marginal edges 28, 29 of the shutter plate 18, so that when the plate is disposed within the noted cars, it is constrained to reciprocate in a linear direction only.

The gate 19 includes a rectangular aperture 30 which is aligned with the keyway 13 in the lock plug, the gate being fixed to the plug by pins 31 passing through apertures 32 in the plate and into the bores 33 drilled into the plug in the course of applying the pickproofing device.

The pins '31 are so-called drive lock wedging pins which are formed of hardened steel and are of tapered configuration, it being understood that after the pins have been driven into position within the bores 33, they cannot be released from the bores. A variety of pins suitable for such purpose are known.

The shutter 18 is provided with an outwardly projecting operator portion 34, bent at right angles to an attachment leg 35 atlixed, as by welding to the shutter plate 18. A circular aperture 36, approximating the size of or slightly smaller than the diameter of the plug, is formed through the shutter.

The shutter and the gate plate are protected beneath a housing assembly 37 comprising a face portion 38 adapted to lie against the outer face of the door and a cover plate portion 39 overlying and spaced from the lock.

The cover portion 39 is defined by a generally cylindrical side wall portion 40, there being a downwardly projecting lobe portion 41 forming a continuation of the side walls.

There is formed in the cover plate, an access aperture 42 comprising elongated parallel side walls 43, 44- and having a rounded upper end portion 45. The cover plate is mounted to the door by means of inwardly directed, internally threaded bosses 46 at the corners, which bosses are adapted to receive bolts 47 extending outwardly from the inside of the door into threaded engagement with the bosses. It will be appreciated that since the heads of the bolts are exposed only on the internal face of the door, the assembly may be demounted only from the inside.

Preferably the housing 17, shutter 18 and gate 19 are formed from hardened armored steel so as to resist any attempt to compromise the same by drilling or the like.

The cover plate 39 of the housing is preferably provided, adjacent the aperture 42, with a hasp 48. The operator portion 34 of the shutter 18 is provided with an aperture 49, the hasp and aperture 48 and 49, respectively, together providing a means for securing the parts in a locked condition by the use of an external padlock, as will be explained more fully hereinafter.

As best seen in FIG. 4, it will be appreciated that when the parts are assembled against the face of the door, the gate member 19 is permanently keyed to rotate with the plug, the housing 17 is fixed to the face of the door and the shutter 18 is free to slide or reciprocate in a vertical direction.

In FIG. 2 the shutter member 18 is shown in its downwardmost position, wherein it will be noted that the lowermost edge 18 of the shutter lies adjacent the bottom wall 41 of the lobe 41 of the housing. In this position it will be seen that the side edges 28, 29 of the shutter lie closely adjacent the inner parallel edges 50, 51 of the lobe portion 41, preventing any angular (rotary) movement of the shutter with respect to the housing 17. Since the shutter 18 is slidably mounted to the gate member 19 by being disposed between the cars 24, 25, 26, 27, it will be further appreciated that no angular movement of the shutter with respect to the gate 19 is possible. Since the shutter cannot be angularly moved relative to the gate and, in the downward position cannot be angularly moved relative to the housing, it will be clear that the shutter has etfectively locked the gate and, hence, the plug against any angular movement within the cylinder.

As is clear from an inspection particularly of FIG; 4, the aperture 36 formed in the shutter is, in said downwardly disposed position of the shutter, aligned with the keyway portion of the lock plug, the keyway of the plug thus being visible from the exterior of the door-see 'FIG. 2.

Through the use of the operator portion 34 which projects outwardly through the aperture 42 in the cover plate 39 of the housing, it is possible to slide the shutter 18 from the downward limiting position shown in FIG. 2 to an upward limiting position. The total length of the shutter from its uppermost edge 18" to its lowermost edge 18' is such that in the upper limiting position the corners of the shutter will be positioned intimately adjacent but clearing the inner surface of the cylindrical side wall portions of the housingsee FIG. 3. In this lifted position, no portion of the shutter lies within the slideway defined between the walls 50, 51 in the lobe 41 of the housing, and, hence, if the lock plug were otherwise free to rotate, the shutter would not provide any obstacle to such rotation.

It will furthermore be noted that in such raised position of the shutter, the aperture 36 will have been shifted out of registry with the lock plug whereby access to the lock plug will be blocked by solid portions of the shutter. Hence, by reason of the blocking position of the shutter, there is no possibility of picking the lock in the one position of the shutter in which the plug is released for rotation.

Where the plug is accessible, as for the insertion of picking tools or the like, i.e. in the lowered or partially lowered position of the shutter, angular movement or torque exerted on the operator portion of the shutter will not be effective to shift the plug angularly with relation to the cylinder (which shifting movement is essential to picking) due to the engagement of the lower portions of the shutter in the slideway defined between the walls 50, 51. Due to the considerable spacing of the lower portions of the shutter from the axis of rotation of the lock plug, substantial angular rotation of the plug relative to the cylinder cannot be achieved even with significant clearances between the shutter and slide-way.

In order to open the lock, there is provided a novel key and key retriever assembly, shown particularly in FIGS. 1 and 5 to 7.

In accordance with the invention, the key member K includes the usual bitted portion 52 adapted, when inserted into the lock plug, as shown in FIG. 4, to align the tumblers with the shear line 16. Instead of the usual enlarged bow or keyhead, the key K includes a foreshortened head portion 53 having a transversely extending slot 54 formed therethrough.

The key retriever 55 includes a gripping portion 56 and a key engaging portion 57. The key engaging portion comprises a blade member 58 of stiffened construction and a spring retriever finger 59. The retriever finger 59 is secured to lie parallel to the blade portion 58, as by an eyelet 60, which also stresses or biases the spring finger yieldingly against the blade.

The spring finger includes at its outer terminal end a retriever hook 61, including a cam surface 62 inwardly inclined toward the blade 58.

Optionally and preferably, the outermost end of the key K is provided with an angled follower portion or portions 63 adjacent the aperture 54.

OPERATION The operation of the apparatus will be evident from the foregoing description.

Assuming the door to be in the locked condition and the shutter 18 in its lowered position as shown in FIG. 2, the key is inserted into the keyway either manually or through the use of the retriever 53. Assuming the tumblers to be accurately aligned, as shown in FIG. 4, the shutter 18 is shifted to its upward limiting position, blocking access to the lock plug and clearing any portion of the shutter from the slideway defined between walls 50, 51 of the lobe 41. In this position, and assuming the pin tumblers to be accurately aligned, the operator handle or portion 34 may be rotated, with the result that the lock plug is rotated, to retract the latch bolt. The entirety of the key K is shielded between the shutter 18 and the lock plug.

In order to lock the assembly, it is merely necessary to shift the bolt to its downward position, shown in FIG. 2, at which position the aperture 36 in the shutter is once again aligned with the lock plug, providing access to the end portion of the key K. The key is withdrawn from the lock plug by first inserting the retriever 55 axially in the direction of the plug.

As will be best appreciated from FIG. 5, the hook portion will, in the course of said axial movement, be cammed by the interengagement of the cam surface 62 on the spring finger and the follower portion 63 on the end of the key away from the blade 58, the spring snapping back through the transverse aperture 54 in the key head, permitting the key to be withdrawn by an outward axial force exerted on the retriever.

The connection between the retriever and the key is readily released by exerting a torsional force against the retriever. Thus, if a key is inserted through the use of a retriever, release of the retriever from the key is effected by merely rotating the retriever, whereupon the finger 59 will be caused to shift outwardly from the blade 58, which movement is best appreciated by comparing FIGS. 6 and 7.

After partial rotation of the retriever, the latter is simply pulled outwardly, leaving the short key section in the lock. It will be understood that the torsional force exerted in the course of such removal cannot operate the lock plug since the plug is isolated from such torque by the presence of the shutter within the slide of the housing.

In many instances, a tenant Who may have given a key to his apartment to acquaintances or to apartment managers, superintendents, etc., may be away from the premises for a protracted period of time, during which period it is desired that no one gain access to the premises. This function may be readily accomplished by passing the shackle of a padlock P through the hasp 4 8 and through the aperture 49 formed in the operator handle 34 of the shutter 18.

As is clear from FIG. 2, the padlock, which may be key or combination operated, will prevent lifting the shutter to an extent necessary to permit the latter to clear the slideway formed in the lobe 41 of the housing. Thus, only one in possession of the combination or the key to the padlock will be able to release the shutter for lifting movement to the degree necessary to permit rotation of the shutter within the cylindrical portion 40 of the housmg.

It will be evident that there is disclosed herein an attachment for installed conventional locks of various types which will render the same highly resistant to picking. The cost of the device is nominal as contrasted with the cost of replacing an existing lock with one of the high security type units currently available, and is easily and inexpensively installed. In addition to providing a safeguard against picking, the armored housing protects the lock against compromise by such alternate methods of breaking and entering as jimmying the lock and applying a wrench to the exposed bezel of the lock.

The present invention additionally provides simplified means of inserting and removing a special key which is desirably employed in conjunction with the lock. It will, however, be readily recognized that by differently shaping the housing so as to provide greater spacing between the cover plate portion of the housing and the plug, it is possible to employ a conventional key including the usual projecting key bow. For purposes of making a neater installation which does not project a substantial distance from the face of the door, the use of a key having a foreshortened bow is preferred.

Having thus described the invention and illustrated its use, what is claimed as new and is desired to be secured by letters Patent is:

1. Apparatus for pickproofing an existing lock installed on a door or the like having a plug rotatable in a cylinder, comprising an enclosure member having a cover and side wall portions extending inwardly from said cover and terminating in a planar, open mouth portion, attachment means for fastening said enclosure member to said door with said mouth portion surrounding said lock, an enlarged aperture in said cover in registry with said lock, a slideway formed on said cover, a shutter member slidably mounted in said cover and shiftable between first and second limiting positions, said shutter, in said first limiting position, closing said aperture and being cleared from said slideway, said shutter, in said second limiting position, opening said aperture to provide access to said lock, said shutter, in said second position and in positions intermediate said first and second positions, being engaged in said slideway to key said shutter against angular movements relative to said cover, a gate member fixed to and extending from said plug of said lock, said gate member including a receiver groove slidingly and nonrotatably receiving said shutter in all positions of said shutter, whereby said shutter keys said gate member against rotation in all but said first limiting position of said shutter.

2. The device of claim 1 and including key means insertible into said plug for releasing said lock for rotation, the portions of said key means extending from said plug in said first limiting position being disposed beneath said shutter.

3. The device of claim 2 wherein said shutter includes an operator projection means accessible through said aperture in said cover for manually transmitting torque to said shutter.

4. The device of claim 2 and including a key retriever having at least one spring jaw, cam means on said jaw,

a jaw receiver recess formed on said projecting portion of said key, follower means on said key spaced outwardly from said recess, said cam and follower means being adapted to deflect said jaw and yieldingly engage the latter in said recess responsive to axial movement of said retriever thereby to connect said key and retriever for conjoint axial retractile movements of said key from said plug.

5. The device of claim 4 wherein said key and said retriever are decoupled responsive to rotation of said retriever relative to said key.

6. The device of claim 2 and including a key retriever, complemental cam and follower means on said key retriever and said projecting portions of said key, said cam and follower means connecting said retriever and key for conjoint axial movement responsive to inward movement of said retriever toward said plug, said cam and follower means being disconnected responsive to rotation of said retriever relative to said key.

7. The device of claim 2 wherein said shutter includes a projection member extending outwardly therefrom and projecting above the plane of said cover, a second pro.- jection member formed on said cover in spaced relation to said first projection member, registering apertures formed in said projection members, said apertures being adapted to receive the shackle of a padlock or the like whereby to connect said projections and, hence, said shutter and cover against relative movement.

8. The device of claim 7 wherein said projections in the padlock-applied position secure said shutter in said second limiting position.

9. Apparatus in accordance with claim 1-wherein said side Wall portions of said housing are generally cylindrical and said shutter is generally rectangular inv vertical section, the corners of said shutter being disposed Within said cylindrical wall portions in said first limiting position.

References Cited UNITED STATES PATENTS 2,179,947 11/1939 Miller 3s4 A 2,491,337 12/1949 Segal 70 419 2,883,849 4 1959 Lorenzo 70 427 3,267,707 8/1966. Adams 70-419 3,680,337 8/1972 Krakauer 70'419 ROBERT L. WOLFE, Primary Examiner U.S. c1. X.R.

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3882703 *Jan 29, 1974May 13, 1975Hermann RobertPick-proof lock mechanism
US3959997 *Apr 21, 1975Jun 1, 1976James E. WilliamsPick-proof lock system and method for locking a door, window, or other closure
US4070882 *Sep 20, 1976Jan 31, 1978Roberto RuizLock shielding assembly
US4107967 *Dec 12, 1977Aug 22, 1978Grabb William CAccess-limiting apparatus
US4350032 *Aug 25, 1980Sep 21, 1982Kochackis Donald GVending machine lock security cover
US4584855 *Jun 29, 1983Apr 29, 1986Glen BurlingamePick-proof locking system
US4686840 *Dec 24, 1986Aug 18, 1987Mccarroll ClarkLock guard
US4875352 *May 11, 1987Oct 24, 1989Schlage Lock CompanyConstruction keying
US4884424 *May 4, 1989Dec 5, 1989Meyer David RMortise cylinder lock guard
US6408661 *Sep 14, 1999Jun 25, 2002Waterson ChenPadlock assembly with a two-part U-shaped lock casing
US6453706May 23, 2000Sep 24, 2002Waterson ChenPadlock with a U-shaped lock casing
US6574999Dec 3, 2001Jun 10, 2003Waterson ChenPadlock with a U-shaped lock casing
US6782723 *Apr 19, 2002Aug 31, 2004Waterson ChenFlexible shackle lock with a replaceable shackle and a replaceable lock core
US7866194 *Sep 24, 2009Jan 11, 2011Shih-Te LiuUnlocking device for concealing keyhole of lock
US8022299 *Nov 19, 2008Sep 20, 2011Zhejiang Kedu Electric Mfg. Co. LtdRotatory emergency stop cover with plug-in unit
US8347679 *Sep 24, 2009Jan 8, 2013Shih-Te LiuUnlocking device for concealing keyhole of lock
US20100077815 *Sep 24, 2009Apr 1, 2010Shih-Te LiuUnlocking Device for Concealing Keyhole of Lock
US20120144886 *Sep 20, 2011Jun 14, 2012Eric Wolfgang MelchiorAnti-theft lock assembly for universal key switches and locks
US20130139562 *Nov 27, 2012Jun 6, 2013Shih-Te LiuAnti-picking Device for Lock and Key Thereof
EP2458117A2 *Nov 21, 2011May 30, 2012Drumm GmbHProtective fitting for windows
U.S. Classification70/419, 70/423, 70/395, 70/455
International ClassificationE05B17/14, E05B17/00
Cooperative ClassificationE05B17/142
European ClassificationE05B17/14B