US3520161A - Key controlled lock having built-in switch actuator operated by insertion and removal of key - Google Patents

Description

y 1970 E. N. JACOB! 3,520,161

KEY CONTROL LO H NG B T-IN SWITCH ACTUATOR OFERA D BY E ON A REMOVAL OF KEY Tl S1.

Filed July 17, 1968 cots-SW01 IamvmiA/fhmbz y 1970 E. N. JACOB] 3,529,161

KEY CONTROLLED LOCK HAVING BUILT-IN SWITCH ACTUATOR OPERATED BY INSERTION AND REMOVAL OF KEY Filed July 17,, 1968 :3 Sheets-$heet United States Patent 3,520,161 KEY C(PNTROLLED LOCK HAVING BUlLT-IN SWITCH ACTUATOR OPERATED BY INSER- TIGN AND REMUVAL OF KEY Edward N. Jacobi, Milwaukee, Wis., assignor to Briggs & Stratton Corporation, Milwaukee, Wis., a corporation of Delaware Filed July 17, 1968, Ser. No. 745,639 Int. Cl. E051!) 35/14 US. Cl. 70-387 Claims ABSTRACT OF THE DISCLOSURE A key controlled tumbler lock with a cylinder rotatable in a bored lock casing, has a switch actuating lever pivotally mounted in a longitudinally extending slot in the wall of the lock case. The free end of the lever is projected beyond the cylindrical boundary surface of the lock case by the engagement of the straight back edge of the key with a finger on the lever as the key is inserted into the keyway of the cylinder, and is retracted by a spring when the key is withdrawn, at which time the finger on the lever enters the keyway.

This invention relates to locks and refers more particularly to ignition switch locks for automobiles.

SUMMARY The invention is concerned with the problem of reducing automobile thefts resulting from the drivers failure to remove the igntion key from the ignition switch lock. It deals with the problem by effecting closure of a buzzer energizing circuit by the opening of the door on the drivers side of the automobile in the event the the ignition key is left in the keyway of the lock. Ignition switch locks having this capability are presently standard equipment in the cars of at least one large automobile manufacturer, but in those cars, the warning buzzer circuit can be disabled by simply withdrawing the key a slight amount-not more than about one-eighth of an inch either before or after the door is opened. Needless, to say, this can lead to a habit which defeats the entire purpose of the Warning system.

With this invention, the lock controlled switch in the warning buzzer circuit is closed as long the key remains in the lock far enough to keep from falling out. Only upon complete removal of the key does the lock controlled switch open.

The invention achieves its objective by providing the lock with a switch actuator located in an aperture in the side of the lock case, and yieldingly biased to a retracted position in which a finger on the actuator projects into the keyway of the cylinder when the cylinder is in its locked position of rotation and no key is present therein. In this retracted position, no part of the actuator protrudes beyond the cylindrical boundary surface of the lock case. But, upon insertion of the key, the finger on the actuator is expelled from the keyway and another part thereof is projected beyond the side of the lock case. The movement of the actuator between its retracted and projected positions is utilized to open and close a switch in the warning buzzer circuit.

The purpose and object of the invention, thus is to "ice provide an improved key controlled lock having a builtin switch actuator which is movable between a retracted position in which no part thereof protrudes beyond the side of the lock case and a projected position in which a switch actuated part thereof does protrude beyond the side of the lock case; and wherein the actuator occupies its projected position whenever a key is in the lock and until the key is fully removed.

The only prior art known that comes close to disclosing a lock having the aforesaid capabilities is the Fitzgerald Pat. No. 2,105,350.

With these observations and objects in mind, the manner in which the invention achieves its purpose will be appreciated from the following description and the accompanying drawings. This disclosure is intended merely to exemplify the invention.

The drawings illustrate one complete example of the physical embodiments of the invention constructed according to the best mode so far devised for the practical application of the principles thereof, and in which:

FIG. 1 is essentially a longitudinal sectional view through a key controlled lock embodying this invention, said view illustrating the situation which obtains when no key is present in the lock;

FIG. 2 is a view similar to FIG. 1, but with a key in the keyway;

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

FIG. 4 is a cross sectional view through FIG. 2 on the plane of the line 44; and

FIG. 5 is an exploded perspective view of the parts of the lock primarily involved with this invention.

Referring to the drawings, the numeral 6 designates generally a key controlled pin tumbler lock of the type commonly used to control automobile ignition switches. As is customary, the lock comprises a casing 7 having a bore 8 in which a lock cylinder 9 is rotatably received. The cylinder is secured against rotation by a group of pin tumblers and drivers, collectively designated by the numeral 10, until insertion of a proper key 11 into the keyway 12 of the lock cylinder. Insertion of the key frees the cylinder for rotation and enables switch actuating motion to be imparted to the contactor of the ignition switch (not shown) through a driver 13 which projects from the rear or inner end of the cylinder.

Since the purpose of the invention is to control an electric circuit asfor instancethe energizing circuit of a warning buzzer by the presence or absence of the key in the lock, the lock case 7 has a switch actuator 14 mounted therein for movement between a retracted position shown in FIG. 1 and a projected position shown in FIG. 1 and a projected position shown in FIG. 2. Movement of the actuator 14 from one to the other of these positions, is utilized to actuate a micro-switch 15 mounted in juxaposition to the lock. In a customary installation, the switch 15 and adoor controlled switch in series circuit therewith (not shown) controls energization of a warning buzzer, the sounding of which indicates that the key has not been removed from the lock.

The actuator 14 is a fiat sided lever-preferably stamped from sheet metal. It is received in a longitudinally extending slot 17 which is open throughout its length to the cylindrical boundary surface of the lock case and communicates with the bore 8 through a hole 18. The actuator lever is pivotally assembled with the lock case by the insertion of an embossure 19 protruding from one side of the lever into a recess or cavity 20 in the adjacent side of the slot 17 The recess or cavity 20 opens to the front end of the lock case, and the embossure is retained in the recess 20 by the attachment of an escutcheon cap 21 to the front end of the lock.

Preferably, a hardened steel apertured disc 22 is interposed between the front end of the lock case and the escutcheon cap to provide protection against drilling into the lock. The inner surface of this hardened steel disc closes the open mouth of the recess 20 and thus confines the actuator lever 14 in position.

A finger 23 on the actuator lever projects through the hole 18 and into the keyway 12 of the lock cylinder when the cylinder is in its locked position of rotation, and no key is present in the keyway. This relationship of the parts (illustrated in FIGS. 1 and 3) is yieldingly maintained by a spring 24 confined between the finger 23 and the opposite wall 25 of a recess 26 formed in the lock case and opening to said slot 17 and also the hole 18.

The spring produced rocking movement of the actuator lever 14 is limited by the engagement of its free end with a surface 27 which constitutes the bottom of the adjacent portion of the slot 17. In this spring retracted position of the actuating lever, no part thereof projects out of the mouth of the slot 17 or protrudes beyond the cylindrical surface boundary of the lock case.

Upon insertion of the key, however, the finger 23 is expelled from the keyway and, as a result, the actuator lever 14 is rocked about its pivot 19 to project the outer free end of the lever beyond the cylindrical boundary surface of the lock case and, in so doing, depress the driver or contact controlling member of the microswitch 15, as shown in FIG. 2.

Since the keyway 12 opens to the cylindrical boundary surface of the cylinder, at least along that portion of the length of the keyway which encompasses the group of pin tumblers and drivers, and since the back edge 30 of the key is flush with the cylindrical boundary of the lock cylinder, it follows that the actuator undergoes no change in position from that shown in FIG. 2 when the cylinder is turned by means of the key. Also, since the finger 23 is located close to the pivot 19 for the actuator lever, and opposite the front end of the group of pin tumblers and drivers, it follows that the actuator lever 14 will occupy its projected position as long as the key remains far enough in the keyway to prevent its falling out. This will be evident from the dotted line illustration DL of the nose of the key in FIG. 2.

It will be noted that the outer edge of the actuator lever 14 is so shaped that, even in its projected position, substantially only its free end portion 31 protrudes beyond the cylindrical boundary surface of the lock case. This relationship enables the lock to be mounted in the conventional way, which requires that a substantial part of the length of the lock case be received in a relatively close fitting round hole in the supporting structure in which the lock is mounted.

From the foregoing description taken in connection with the accompanying drawings, it will be apparent to those skilled in this art that this invention provides a significantly improved ignition lock for automobiles in which the presence of absence of the key is utilized to control the energizing circuit of a warning buzzer.

Those skilled in the art will also appreciate that the invention can be embodied in forms other than as herein disclosed for purposes of illustration.

The invention is defined by the following claims.

I claim:

1. In a key controlled lock wherein a cylinder having a keyway is rotatably mounted in a bore of a lock case and secured against rotation from a locked position by key controlled tumblers until insertion of a proper key into the keyway of the cylinder, the keyway having an open edge debouching to the cylindrical boundary surface of the cylinder from a point closely adjacent to the mouth of the keyway, said open edge being closed by the back edge of a proper key in the keyway and said back edge of the key when so posi tioned being fiush with and forming substantially a continuation of the cylindrical boundary surface of the cylinder, insertion and removal of the key requiring the cylinder to be in a predetermined position of rotation, said lock being characterized by:

(A) the lock case having a longitudinally extending slot opening to its exterior boundary surface and communicating with the bore through a hole near the mouth of the bore and hence near the mouth of the keyway,

said hole being so located that the open edge of the keyway aligns therewith when the cylinder is in said predetermined position of rotation;

(B) a switch actuating lever in said slot,

said lever having a front end in that portion of the slot that is adjacent to the mouth of the keyway and having a rear end remote therefrom;

(C) pivot means pivotally connecting the front end portion of the switch actuating lever with the lock case and mounting the lever for movement between a defined retracted position in which no part thereof protrudes from the slot, and a projected position in which the rear end portion of the lever protrudes from the slot and projects beyond the exterior boundary surface of the lock case;

(D) a finger on the switch actuating lever adjacent to but rearwardly of its pivoted front end, said finger being received in said hole and projecting therethrough into the keyway when the switch actuating lever is in its retracted position, to be expelled from the keyway by a proper key inserted into the keyway, whereby the switch actuating lever is held in its projected position by the key,

the location of the hole and said finger adjacent to the mouth of the keyway assuring that the switch actuating lever will be held in its projected position until the key is withdrawn far enough to preclude its remaining in the keyway when released; and

(E) a spring reacting between the switch actuating lever and the lock case, yieldingly urging the lever to its defined retracted position.

2. The lock of claim 1, wherein the switch actuating lever is substantially a bellcrank having a long arm and a short arm, and

wherein the pivot means is located near the junction of Said arms, the long arm extending lengthwise of the slot and lying wholly within the slot when the switch actuating lever is in its retracted position, but having its free end portion protruding therefrom in the projected position of the lever, and the short arm providing said finger which projects through said hole and into the keyway in the retracted position of the lever.

3. The lock of claim 2, wherein the spring is seated in a pocket in the lock case in juxtaposition to the junction of the slot and the hole,

said pocket having a surface facing the short arm of the lever, and the spring being confined between said surface and the short arm.

4. The lock of claim 2, wherein the pivot means comprises an embossure on the lever seated in a recess in the adjacent side of the slot and opening to the front end of the lock case; and

further characterized by an escutcheon cap secured to the front end of the lock case and closing the open front end of the recess.

5. The lock of claim 2, wherein the long arm of the 5 lever is shaped to provide an outwardly projecting finger on its free end to minimize the portion of the lever that protrudes from the slot in the projected position of the actuator.

References Cited UNITED STATES PATENTS 2,063,088 12/1936 Fitzgerald 70-252 2,105,350 1/1938 Fitzgerald 70-264 2,261,868 11/1941 Arriaza 2006l.66 2,613,258 10/1952 McKeon 34052 Jacobsen 34052 Kiwi 200153 Rink et a1. 70-237 5 RICHARD E. MOORE, Primary Examiner R. L. WOLFE, Assistant Examiner US. Cl. X.R.

Azano 34052 10 70 372, 441; 200-61.66; 340--64

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