Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.

Patents

  1. Advanced Patent Search
Publication numberUS3550410 A
Publication typeGrant
Publication dateDec 29, 1970
Filing dateApr 19, 1967
Priority dateApr 19, 1967
Publication numberUS 3550410 A, US 3550410A, US-A-3550410, US3550410 A, US3550410A
InventorsToepfer Edwin F
Original AssigneeToepfer Edwin F
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Indicating cylinder lock mechanism
US 3550410 A
Images(3)
Previous page
Next page
Description  (OCR text may contain errors)

Dec. 29, 1970 TOEPFER 3,550,410

INDICATING CYLINDER LOCK MECHANISM Filed April 19, 1967 3 Sheets-Sheet 1 FTQ C3F K% E- A H /5 fm amnff. 705v r Dec. 29, 1970 E, F TQEPFER 3,550,410

INDICATING CYLINDER LOCK MECHANISM Filed April 19, 1967 3 Sheets-Sheet z CU NT 4% Ida/122.7? T09 92' Dec. 29, 1970 E. F. TOEPFER INDICATING CYLINDER LOCK MECHANISM 5 Sheets-Sheet 3 Filed April 19, 1967 IdWmZ' 052? pr g Patented Dec. 29, 1970 3,550,410 INDICATING CYLINDER LOCK MECHANISM Edwin F. Toepfer, 1016A S. 16th St., Milwaukee, Wis. 53204 Filed Apr. 19, 1967, Ser. No. 632,034 Int. Cl. Eb 27/02, 39/04 US. Cl. 70364- 6 Claims ABSTRACT OF THE DISCLOSURE A microswitch is arranged to cooperate with each driver of a master keyed lock, to be actuated to a signaling position by actuation of the driver to an outer cylinder releasing position. Each switch actuator can comprise a leaf spring that also serves as a tumbler spring. In one embodiment the direction of cylinder rotation is controlled by bitting the key.

This invention pertains to indicating cylinder lock mechanisms and relates more particularly to a mechanism comprising a cylinder lock that can be actuated to and from its locked condition by any one of a plurality of keys, each having bitting that differs slightly from the hitting on the others, and electric switch means or other control means operatively associated with the lock to produce a distinctive signal or other output for each different key used in the lock.

A few examples of specific applications of lock mechanisms embodying the principles of the present invention will generally indicate the nature of the problem solved by the invention, the manner in which the invention solves that problem, and the principle objects of the invention.

First, consider the problem of securing an enclosed area that should be accessible at all times to a few persons having full authorization but should be accessible only at particular times to certain other persons having limited authorization. The area can be secured by a lock mechanism embodying the principles of the present invention and protected by an alarm system that is so connected with a timing device as to be operative at times when persons of limited authorization are denied access to the area. In this case the lock mechanism comprises a cylinder lock which cooperates with a normally closed electric switch connected in the alarm system circuit, and which is actuatable by either of two slightly different types of keys. One type of key is provided to fully authorized personnel; the other is given to persons having limited authority. When a fully authorized person unlocks the lock with his key, the normally closed switch is thereby actuated to its open position to disable the alarm system. When a person of limited authority uses his key in the lock the normally closed switch is not affected by it, and the alarm system therefore gives warning of his attempted entry if he unlocks the mechanism at a time when he is not authorized to do so.

A more complicated example is provided by a copying machine which is used by several different departments or employees in a plant or ofiice, Such machines are often used wastefully, either in the production of excessive numbers of copies or in personal work for employees. To eliminate such waste, the copying machine can be equipped with a number of automatic recording counters, one for each department or employee authorized to use the machine. Each counter is under the control of its own electric switch, and the several switches, in turn, are arranged in accordance with the principles of this invention to cooperate with a cylinder lock which secures the machine. Each employee or department authorized to use the machine is provided with a key which can actuate the lock but which differs slightly from the other keys.

When the lock is actuated by any one of these keys, the switch corresponding to that key is actuated, and in consequence the counter corresponding to the employee or department having that key is caused to record the number of copies made on the machine while that key is engaged in the lock. The records made automatically by the several counters can thus. point directly to the particular employee or department. responsible for uneconomical use of the machine.

As a third and still more complicated example of an application of a lock embodying the principles of this invention, consider a wholesale fuel oil depot arranged for self-service operation and to which oil retailers can come with their trucks at any time of the day or night. Assume that two kinds of fuel oil are available, designated A and B. Each retailer who patronizes the depot is given two keys, one for A fuel and one for B fuel. Each retailers keys are different from those of all other retailers, and the depot is provided with a number of automatically recording meters, one for each retailer for A fuel and one for each retailer for B fuel.

To draw oil at the depot, a retailer inserts into the cylinder of a lock mechanism of this invention either his A key or his B key, depending upon the fuel he desires. With the A key the lock cylinder turns only to the right from its unlocked position; with the B key it turns only to the left. Such rotation of the lock cylinder actuates one of a pair of switches that control the respective fuel supplies. At the same time, the distinctive hitting on the particular retailers key actuates other switch means associated with the lock and which controls that retailers meter for the kind of fuel being drawn, to provide an automatic record of his withdrawal.

From these examples it will be apparent that the general object of this invention is to provide a mechanism comprising a cylinder lock which is adapted to cooperate with any one of a plurality of slightly differing keys, and one or more switches or other control elements which so cooperate with the cylinder lock that a different one of the control elements is actuated in consequence of use of each different key in the lock.

Another general object of this invention is to provide a compact and inexpensive lock mechanism, adapted to be actuated by any one of a plurality of keys which differ slightly from one another, which lock mechanism can provide an indication of which one of the several keys has been used to actuate it and can incorporate a pin tumbler lock of substantially any conventional type.

.A further object of this invention is to provide mechanism comprising a control element having an actuator movable between normal and signal producing positions, and a pin tumbler cylinder lock operatively associated with the control element and adapted to be actuated by two or more slightly differing keys, wherein the particular key used in the cylinder lock determines whether or not the actuator of the control element is moved from one to the other of its positions, and wherein the control element is inaccessible to a picking tool or the like inserted into the key slot of the cylinder lock.

A more specific object of this invention is to provide a cylinder lock having pair of pin tumblers, each movable between a cylinder locking position and each of a pair of cylinder releasing positions, said tumblers being cooperable with one another and with means on the cylinder of the lock to permit rotation of the cylinder away from its locked position in only one direction when a key having one type of bitting is inserted into the cylinder, and to permit such cylinder rotation only in the opposite direction when a key having slightly different bitting is inserted into the cylinder.

A further specific object of this invention is to provide a mechanism comprising a control element having an actuator that is movable between normal and signal producing positions, and a cylinder lock of the pin tumbler type with which the control element is operatively associated, said cylinder lock having tumbler means comprising a pair of tumbler elements which can be disposed in either of two different cylinder releasing positions that are respectively establishable by insertion into the lock cylinder of a selected one of a plurality of keys that differ in their bitting, and wherein motion of the tumbler means to one only of said cylinder releasing positions moves the actuator of the control instrumentality from one to the other of its positions.

It is also a specific object of this invention to provide a lock of the character described having a cylinder rotatable in a casing, tumbler means slidable in the casing in directions radial to the cylinder axis, and leaf spring means whereby the tumbler means is biased inwardly with respect to the casing and whereby motion of the tumbler means is transmitted to an actuator of an electric switch or the like that is fixed to the casing.

The accompanying drawings illustrate several complete examples of physical embodiments of the invention constructed according to the best modes so far devised for the practical application of the principles thereof, and in which:

FIG. 1 is a view in longitudinal section of an indicating lock mechanism embodying the principles of this invention, illustrated in its locked, key-withdrawn condition;

FIG. 2 is a view similar to FIG. 1 but illustrating the mechanism with a key inserted into its cylinder and with the cylinder in its locked position of rotation;

FIG. 3 is a cross-sectional view taken on the plane of the line 3-3 in FIG. 1;

FIG. 4 is a cross-sectional view taken on the plane of the line 4-4 in FIG. 2;

FIG. 5 is a view corresponding to' FIG. 4 but showing the mechanism with its cylinder rotated to an unlocked position;

FIG. 6 is a cross-sectional view taken on the plane of the line 66 in FIG. 2;

FIG. 7 is a circuit diagram illustrating a simple indicating system in which the mechanism of this invention can be incorporated;

FIG. 8 is a view in longitudinal section of a modified form of mechanism embodying the principles of this invention;

FIG. 9 is a cross-sectional view taken on the plane of the line 99 in FIG. 8;

FIG. 10 is a cross-sectional view corresponding to FIG. 9 but showing the cylinder in one of its unlocked positions of rotation; and

FIG. 11 is a sectional view taken on the plane of the line 11-11 in FIG. 8 but with the cylinder shown in its unlocked position of rotation illustrated in FIG. 10.

Referring now to the accompanying drawings, the numeral 5 designates generally a mechanism embodying the principles of this invention and which comprises, in general, a fixed tubular sleeve or casing 6 having a bore 7 in which cylinder means 9 is rotatable, and tumbler means 10 cooperable with the casing 6 and the cylinder means 9 to releasably confine the latter in a locked position of rotation.

The cylinder means 9 can comprise a conventional plug or cylinder 11 having a lengthwise extending key slot '12 opening to the front thereof, and having a plurality of tumbler holes 14 which open radially to the key slot and to the circumferential exterior surface of the cylinder.

When the cylinder is in its locked position of rotation, each tumbler hole 14 registers with a driver hole 8 in the casing that opens radially inwardly to the bore 7. The holes 14 and 8 in the cylinder and casing accommodate the tumbler means 10.

The cylinder means of the lock mechanism of this invention can be rotated by means of any one of a plurality of different keys 15 inserted into its key slot, each of said keys having a bitting 16 on one edge thereof which differs slightly from the bitting on the other keys. This is possible because each of the tumbler means 10 can be key propelled to either of two cylinder releasing positions, and the particular cylinder releasing position to which each tumbler means is propelled is dependent upon the particular key that is inserted into the cylinder.

In the embodiment of the invention illustrated in FIGS. 1-6 each of the tumbler means 10 comprises a tumbler 13 slidable in a tumbler hole 1% in the cylinder, a driver 17, and an intermediate element 18 of the type sometimes referred to in the art as a master disc. The several drivers 17, which are of course slidable in the driver holes 8 in the casing, can be of uniform length. Each should be long enough to be capable of projecting from its driver hole partway into the tumbler hole 14 that registers therewith when the cylinder means is in its locked position of rotation, to thus confine the cylinder means against rotation, in the conventional manner of drivers in a pin tumbler lock.

The intermediate elements 18 although shown, for simplicity, as uniform in length are preferably of different lengths to frustrate decoding the lock by comparison of keys. The intermediate elements are preferably substantially shorter than the drivers since each must be wholly receivable in the tumbler hole 14 in which its cooperating driver is engageable, and must also be wholly receivable in the driver hole 8 in which its cooperating driver slides.

When there is no key in the key slot 12 (the condition illustrated in FIGS. 1 and 3), the tumbler means 10 are all so disposed that the tumbler 13 of each is at the inner end of its respective tumbler hole 14 in the cylinder and its intermediate element 18 is likewise wholly received in the tumbler hole, but its driver 17 projects partway into the casing and partway into the cylinder to prevent rotation of the cylinder means out of its locked position, as in conventional pin tumbler locks.

When a proper key 15 is inserted into the key slot, each of the tumbler means is established in one or the other of a pair of cylinder releasing positions that it can assume, the particular cylinder releasing position of each tumbler means being dependent upon how the bitting on the key is formed. Five of the six tumbler means 10 in the lock illustrated in FIG. 2 are established by the key 15 in an inner cylinder releasing position in which said tumbler means have their intermediate elements 18 disposed wholly within the cylinder. In the case of these five tumbler means, the outer ends of their intermediate elements and the adjacent inner ends of their drivers 17 are disposed substantially flush with the circumferential surface of the cylinder or plug 11, i.e., on the so-called shear line of the lock. However, the remaining tumbler means is in its outer cylinder releasing position, in which the outer end of its tumbler, which is designated 13', is at the shear line, and its intermediate element 18' is disposed wholly within the casing 6.

It will now be evident that the six-tumbler lock illustrated in FIGS. 16 can be actuated by no less than six different keys, each differing from the others with respect to its bitting at one of its tumbler engaging stations, and each adapted to dispose one of the several tumbler means in its outer cylinder releasing position and the remainder in their inner cylinder releasing positions. Furthermore, if it were desired to use different combinations and permutations of tumbler means disposed in their respective inner and outer cylinder releasing positions, as many as thirty-six different keys could be used with the lock. Similarly, if less than six different keys were needed, certain of the tumbler means could comprise conventional twopiece tumbler means, comprising only a tumbler and a driver cooperating in the usual manner. Those skilled in the art will recognize that an even larger variety of keys can be accommodated by providing two or more intermediate elements for each tumbler means in accordance with well known practice in master-keyed locks.

To produce a distinctive output signal for each of the several different keys that can be used to actuate the lock of this invention, the lock cooperates with a plurality of control elements 19 one for each driver that is associated with an intermediate element 18, each such control element 19 being arranged to be actuated by movement of its tumbler means from one to the other of its cylinder releasing positions. In this case the control elements 19 are illustrated as microswitches, each having a pushbutton actuator which is biased to a normal projected position and is depressable to a signal producing position. The several microswitches are mounted in any suitable manner in fixed relation to the casing 6, with their pushbutton actuators 20 generally adjacent to and facing the respective drivers with which they cooperate. For convenience the microswitches can be mounted on the casing in two axially extending rows, as shown, with the several switches in staggered relationship such that adjacent microswitches along the length of the casing are disposed near opposite sides thereof.

A plurality of leaf springs 21, one for each of the drivers, bias the tumbler means toward the cylinder axis and also provide motion transmitting connections between the tumbler means and the actuators of their respective microswitches. Each leaf spring is secured at one end to the casing, as by the mounting means 22 that attaches its associated microswitch to the casing. From its anchored end the leaf spring extends partway across the casing to have its free end 23 engaged with its associated driver under flexing bias. Note that each of the driver holes 8 opens to the exterior of the casing so that the leaf spring can enter it for engagement with the driver 17. Also note that each leaf spring is so curved that its free end portion 23 will at all times remain in biasing engagement with its assoicated driver.

When any one of the tumbler means 10 is in either its cylinder locking position or its inner cylinder releasing position (see FIGS. 3 and 6) the medial portion 24 of the leaf spring 21 associated with said tumbler means is spaced from the pushbutton actuator 20 of its associated microswitch, leaving the actuator in its normal projected position. But as the tumbler means is moved to its outer cylinder releasing position (see FIGS. 4 and 5) the medial portion of the leaf spring is thereby raised into actuating engagement with the pushbutton and depresses the same to its signal producing position.

As illustrated in FIG. 7, the control elements 19 can be connected with a plurality of indicating means 25, one for each control element and each connected in series with its microswitch. For purposes of illustration the in dicating mean are shown in FIG. 7 as individual signal lights, and the control elements are shown as normally-open switches. If the signal lights 25 are directly connected with the respective control elements 19, any attempt to pick the lock will be indicated by irregular flashing of individual signal lights over a period of time.

In some cases the detection of attempts to pick the lock may be unnecessary, and it might be undesirable to have brief spurious signals produced whenever a key is inserted into the key slot, as its hitting momentarily cams one or more of the tumbler means to their outer cylinder positions. In that event instead of the indicating means 25 being directly connected with a current source, the common terminals of the several indicating means can be connected with the current source through another control element 26, as shown in FIG. 7. The control element 26 can be another normally open microswitch, actuated in consequence of rotation of the cylinder out of its unlocked position. As illustrated, the microswitch 26 is mounted on the rear of the casing 6, at one side thereof, with its pushbutton actuator 20 engaging the circumferential surface of the cylinder. When the cylinder is in its locked position of rotation, a flat area 27 on its circumferential surface registers with the actuator of the switch 26 to permit the actuator to assume its normal projecting position, and as the cylinder is rotated away from its locked position it of course cams the actuator to its signal producing position. Hence in the FIG. 7 arrangement none of the signal lamps 25 is lighted until the switch 26 is closed in consequence of rotation of the cylinder out of its locked position, whereupon a predetermined one or more of the lamps are lighted in accordance with the particular key used in the lock.

In the embodiment of the invention illustrated in FIGS. 8-11 the direction in which the cylinder can be rotated out of its locked position is determined by the particular key used to actuate it, owing to the fact that the cylinder means 9 is so formed as to cooperate with two of the tumbler means, designated 10", to provide a pair of cylinder releasing positions for each of them.

Specifically, the lock of FIGS. 8-11 is illustrated as having cylinder means 9 comprising a plug or cylinder 11 with six tumblers 13. The four rear tumblers cooperate with three-element tumbler means 10, each of which comprises a tumbler 13, an intermediate element 18 and a driver 17, and each of which cooperates with a microswitch 19 that is fixed with respect to the casing 6, all as in the previously described embodiment of the invention. However the two front driver means, designated by 10", are of the conventional two-element tumbler-driver type that are biased radially toward the cylinder axis by means of small springs 28 reacting between their drivers and the casing. Note that the driver holes 8 for the two-element tumbler means 10" are conventional inwardly opening wells in the casing, and the springs 28 react against the bottoms of these wells in accordance with conventional pin tumbler lock construction.

The cylinder means 9 in this embodiment has in its circumferential plug surface a pair of radially outwardly opening grooves 29. Each of said grooves opens at one end to one of the tumbler holes 14 with which the tumbler means 10" cooperate, and extends circumferentially partway around the cylinder from said hole, with each groove extending in the circumferential direction opposite to the other. Thus, as viewed from the front of the lock, the groove 29 that opens to the front tumbler hole extends circumferentially to the left (counterclockwise) from said hole (see FIG. 9) while the groove 29 that opens to the second tumbler hole extends to the right (clockwise) from that hole (see FIG. 11).

Assume now that a key is selected which provides for right-hand (clockwise) rotation of the cylinder out of its locking position. When fully inserted into the key slot 12, that key will dispose the front tumbler and its associated driver in positions such that their adjacent end surfaces will be substantially flush with the bottom of the front groove 29 (see FIG. 10), and with said driver thus projecting into said groove the limits of cylinder rotation are defined by the engagement of the ends of the groove against the inner end portion of said driver. The same key will dispose the second tumbler and its associated driver in positions such that their adjacent end surfaces are substantially flush with the ungrooved circumferential surface of the cylinder (see FIG. 11), and at which they of course permit the desired clock wise cylinder rotation.

If counterclockwise rotation of the lock cylinder is desired, a key is used with which disposes the second tumbler from the front and its associated driver in positions at which their adjacent ends are flush with the bottom surface of the groove 29 that ext-ends from the second tumbler hole, and which disposes the front tumbler and its associated driver in positions in which their adjacent end surfaces are flush with the ungrooved circumferential surface of the cylinder.

A pair of microswitches 26 and 26 are fixed with respect to the casing at locations near the rear of the cylinder and at opposite sides thereof, to be actuated by a radially outwardly projecting tongue or cam lobe 31 on the rear of the cylinder. Upon rotation of the cylinder to the right, the pushbutton 20 of switch 26' is depressed to its actuated position, while rotation of the cylinder to the left actuates switch 26".

Each of the keys for clockwise and counterclockwise cylinder rotation of the mechanism illustrated in FIGS. 811 can also have its bitting so arranged as to selectively establish certain of the four rear tumbler means 10 in their outer cylinder releasing positions and the remainder in their inner cylinder releasing positions, for selective actuation of the microswitches 19 as in the previously described embodiment of the invention.

Using each of the switches 26 and 26 in combination with each of the four switches 19 that are actuated by the three-element tumbler means, eight different switchactuated arrangements are available with the mechanism illustrated in FIGS. 8-11, and more such arrangements can be had by utilizing various combinations and permutations of the switches 19 actuated by the three-element tumbler means.

From the foregoing description taken with the accompanying drawings it will be apparent that this invention provides a lock mechanism which comprises a cylinder lock adapted to be actuated by means of any one of a plurality of keys that differ from one another with respect to their bitting, and electrical switches or other control elements that cooperate with the lock to provide a distinctive signal or other output for each different key used therein.

What is claimed as my invention is:

1. A lock of the type having a casing with a bore therein, a cylinder rotatable in said bore and having a key slot opening to one end thereof and a pair of holes opening radially to the key slot and the circumferential surface of the cylinder, and a pair of key actuatable tumbler means, each comprising a driver slidable in the casing in directions transverse to the cylinder axis between a key withdrawn position in which the inner end portion of the driver projects into one of said holes to confine the cylinder in a locked position of rotation and a key established cylinder releasing position in which the inner end of the driver is substantially flush with the circumferential surface of the cylinder to free the cylinder for rotation in both directions, said lock being characterized by:

the cylinder having a pair of radially outwardly opening grooves in its circumferential surface, each communicating at one end with one of said holes in the cylinder and extending therefrom partway around the cylinder in the opposite circumferential direction from the other, each of said grooves being adapted to receive the inner end portion of a driver when the same is in an intermediate key established position of its sliding motion and to cooperate with said driver in confining the cylinder to rotation away from its locked position only in the direction opposite to that in which said groove extends, the direction in which the cylinder can be rotated away from its locked position being thus dependent upon the respective key established positions of said drivers and being determined by the bitting on a key inserted into the key aperture.

2. In a signal producing lock device, the combination (A) a casing;

(B) a cylinder in the casing that is key rotatable to and from a locked position;

(C) tumbler means normally locking the cylinder against rotation but key propellable to each of two ditferent unlocking positions to release the cylinder for rotation;

(D) a control element fixed with respect to the casing and having an actuator movable from a normal position to a signal producing position;

(E) cam means carried by the cylinder for key actuated movement therewith and engageable with the actuator to actuate the same in consequence of rotation of the cylinder in one direction from its locked position;

(F) means on the cylinder cooperable with the tumbler means to prevent rotation of the cylinder in one direction out of its locked position when the tumbler means is in one of its unlocking positions and to prevent rotation of the cylinder in the opposite direction out of its locking position when the tumbler means is in its other unlocking position;

(G) a first key receivable in the cylinder and having bitting by which the tumbler means is propelled to one of its unlocking positions; and

(H) a second key receivable in the cylinder and having different bitting by which the tumbler means is propelled to its other unlocking position.

3. The signal producing lock device of claim 2, further characterized by:

a second control element fixed with respect to the casing and having an actuator which is movable from a normal position to a signal producing position and which is operatively associated with the tumbler means to be actuated to its signal producing position by motion of the tumbler means to one of its unlocking positions.

4. The signal producing lock device of claim 2, further characterized by:

a second control element fixed with respect to the easing and having an actuator which is movable from a normal position to a signal producing position and which is engageable with the cam means to be actuated from one to the other of its said positions in consequence of rotation of the cylinder out of its locking position in the direction opposite to that in which actuation of the first mentioned actuator is effected.

5. A lock device of the type comprising a casing in which a cylinder is rotatable to and from a locked position by means of a proper key, and tumbler means received in holes in the cylinder and in the casing that are transverse to the axis of cylinder rotation and are aligned when the cylinder is in its locked position, said tumbler means being slidable in said holes to and from a normal locking position n whch the tumbler means cooperate with the casing and cylinder to prevent rotation of the cylinder out of its locked position, said lock device being characterized by:

(A) the tumbler means being arranged to be propelled out of the locking position (1) to one unlocking position by means of a key having one bitting, and (2) to be further propellable to a second unlocking position by means of another key having a different bitting and to release the cylinder for rotation at each of said unlocking positions;

(B) the cylinder having a radially outwardly opening groove in its circumferential surface, to one end of which the hole in the cylinder opens and which extends from said hole partway around the cylinder in a first circumferential direction, said groove, where said hole opens to it, defining a shoulder that faces in said first circumferential direction and cooperates with the tumbler means when the latter is in its first mentioned unlocking position to prevent cylinder rotation in said first circumferential direction out of its locking position, said groove then permitting cylinder rotation in the opposite circumferential direction, and said groove not interfering with cylinder rotation in said first circumferential direction when the tumbler means is in its second unlocking position;

(C) a cam member carried by the cylinder for key actuated movement therewith; and

(E) a pair of control elements fixed with respect to the casing, each having an actuator movable from a normal position to a signal producing position,

(1) one of said control elements having its actuator operatively associated with the tumbler means to be actuated to its signal producing position by motion of the tumbler means to its second unlocking position, and

(2) the other of said control elements having its actuator engageable by the cam member to be actuated thereby to its signal producing position in consequence of rotation of the cylinder in one direction from its locked position.

6. The device of claim 5, further characterized:

a third control element having an actuator movable from a normal position to a signal producing position and engageable by the cam member to be actuated thereby to its signal producing position in consequence of rotation of the cylinder in the other direction from its locked position.

References Cited UNITED STATES PATENTS MARVIN A. CHAMPION, Primary Examiner R. L. WOLFE, Assistant Examiner US. Cl. X.R.

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3705507 *May 14, 1971Dec 12, 1972Credit Keys LtdLock controlled electric switch mechanisms
US3912888 *Apr 12, 1974Oct 14, 1975Takigen Mfg CoSwitch lock assembly
US4198552 *Aug 2, 1978Apr 15, 1980Takigen Seizou Co., Ltd.Key operated switch lock assembly
US4262506 *Apr 24, 1978Apr 21, 1981Zeiss Ikon Ag GoerzwerkCylinder lock with warning of entry and drilling attempts
US4489359 *Jan 26, 1983Dec 18, 1984Kabushiki Kaisha Tokai Rika Denki SeisakushoCard key switch
US4924686 *Feb 2, 1988May 15, 1990R. Berchtold AgContact device for transmitting electrical signals between a lock and key in a cylinder lock
US5111007 *Aug 1, 1988May 5, 1992The Eastern CompanySwitch lock with lighted position indicator
US5229747 *Apr 13, 1992Jul 20, 1993Mantang ZhaoTamperproof lock
US7866195 *May 25, 2007Jan 11, 2011Levine Jonathan EDoor lock indicator
US8037725Jan 10, 2011Oct 18, 2011Levine Jonathan EDoor lock indicator
EP0278905A1 *Feb 2, 1988Aug 17, 1988R. Berchtold AgContact device for transmitting electrical signals between lock and key of a cylinder lock
WO1988005854A1 *Feb 2, 1988Aug 11, 1988Berchtold AgContact means for transmitting electric signals between a lock and key in a cylinder lock
Classifications
U.S. Classification70/493, 70/434, 340/542
International ClassificationE05B35/00
Cooperative ClassificationE05B35/001
European ClassificationE05B35/00B