Electrically Actuated Lock Mechanism

Abstract

A locking mechanism includes a tubular sleeve adapted to receive a shouldered projection extending from the closure member, a spring biased plunger normally projecting into the projection seat to engage the projection. A solenoid is associated with the plunger for retracting the plunger from the tubular sleeve to release the projection when it is required to unlock the closure member.

Parent Case Text

This is a Continuation-In-Part Application of application Ser. No. 837,643 filed June 30, 1969.

Description

BACKGROUND OF INVENTION

1. Field of Invention

The present invention relates to an electrically operated locking mechanism and more particularly to a lock for the hood or doors of an automobile to protect the automobile from pilferage.

2. Description of Prior Art

Heretofore, developments have been made relating to locks, particularly for the hood of an automobile. These locks can be classified between two groups. The first group is of the mechanical articulated type such as shown in U.S. Pat. No. 2,723,552 -- Dlugatch -- 1955, wherein a key-operated rotary lock is articulated to the latch-locking device of a hood. The other type of locking device as represented in U.S. Pat. No. 2,940,292 -- Heath -- 1960 operates on the basis of an electrically influenced solenoid which is combined with the latch-locking mechanism of the hood.

Both types of locking devices for hoods mentioned above utilize relatively complicated lever devices which result in a more expensive hood-locking device and one which is more subject to tampering or breakdown, in view of the many lever elements involved.

SUMMARY OF INVENTION

It is the purpose of the present invention to provide an electrically operated locking device which has a minimum of moving parts and which presents a high degree of security from tampering.

A construction in accordance with the present invention for use in a body defining an opening and movable closure member associated with said body to normally close the opening, the construction comprising a projection secured to one of said closure members and said body, means on the other of said body and said closure member, defining a seat adapted to receive said projection, said projection adapted to move to and from the seat along a predetermined path, means defining a plunger path in said seat substantially normal to the path of said projection, a plunger member movable in said plunger path and adapted to engage said projection in said seat in a first position, means normally biasing said plunger member towards said first position, electromagnetic means, when activated, adapted to retract said plunger member, overcoming said biasing means from a first position out of engagement with said projection; whereby the closure is locked when said projection is in said seat and said plunger engages said projection in the first position; and said closure member is unlocked when said electromagnetic means is activated to retract said plunger member from said seat and out of engagement with said projection.

BRIEF DESCRIPTION OF DRAWINGS

Having thus generally described the nature of the present invention, particular reference will be made to the accompanying drawings, illustrating a preferred embodiment of the invention and in which:

FIG. 1 is a perspective view of the electrical locking mechanism as it would appear in an embodiment associated with the hood of an automobile;

FIG. 2 is a perspective view of the locking mechanism and a schematic of the electrical circuit associated therewith;

FIG. 3 is an enlarged fragmentary axial cross section taken through the locking mechanism shown in FIG. 2 with the plunger means in a first position; the retracted position of the plunger shown in dotted lines;

FIG. 4 is an enlarged fragmentary cross-sectional view of a detail shown schematically in FIG. 2;

FIG. 5 is an enlarged cross-sectional view similar to FIG. 4 showing a different embodiment of the invention;

FIG. 6 is a cross-sectional view similar to FIG. 5 with the elements in a different operative position.

Referring now to FIG. 1, the embodiment shown is directed towards a lock for locking the hood of an automobile. In FIG. 1 an automobile body is referred to by the numeral 10 with a hood 12 hinged to the body 10 covering the engine recess 13. Mounted to the frame member 15 in the body 10 near the radiator 17 is the seat and plunger housing 14. Mating with the seat housing 14 and mounted on the hood 12 to a bracket 24, is the projection 16. A push-button switch 18 is shown located in a grill 19 of the automobile body 10 with leads passing from the housing 14 to a fuse panel 20 located at the instrument panel of the automobile. The numeral 22 refers to an ignition switch.

Referring now to FIGS. 2 and 3, the projection 16 is shown as being mounted to bracket 24, and the bracket 24 is mounted to a cross member 25 of hood 12 by means of screws 26. In one embodiment, the projection is threaded throughout its length at 28 and cooperates with the threaded aperture in the bracket 24. Near the end of the projection 16 is an enlarged head having shoulders 30 and a conical tip 32. The projection 16 is threaded at 28 so as to be adjustable in length for different types of automobiles in which the lock can be mounted.

The seat and plunger housing 14 as shown in FIG. 3 includes a tubular sleeve 34 defining a bore 36 with the opening to the bore being beveled at 38. A threaded aperture 40 extends through the wall of the sleeve 34 and communicates with the bore 36 at right angles thereto. A threaded bushing 42 is engaged in the threaded aperture 40. A plunger sleeve 44 which has a threaded inner surface is engaged to the free portion of the bushing 42. The plunger sleeve 44 defines a plunger bore 46 while a plunger member 48 is adapted to slide in the bore 46. The plunger 48 has a neck portion 50 of smaller diameter which is adapted to pass through the bushing 42 and into the bore 36 of the tubular sleeve 34.

A cap 52 is screwed to the other end of the plunger sleeve 44 and mounts a spring 54 which urges against the end of the plunger 48 and normally presses the plunger 48 and plunger neck 50 into the position shown in full lines in FIG. 3 with the neck 50 extending into the bore 36 of sleeve 34. A casing 56 is mounted about the sleeve 44 and provides an annular space therebetween. A solenoid coil 58 is provided at the rear portion of the sleeve 44 and an annular insulated spacer sleeve 60 is provided between the annular coil 58 and the tubular sleeve 34. An insulated annular ring 62 is also provided in the space between the casing 56 and sleeve 44 against the face of the tubular sleeve 34.

A pair of leads extends from the solenoid coil 58 and are connected to terminals 64 and 66 on the insulated spacer 60. A wire communicates the terminal 64 with a terminal 65 on the push-button switch 18 which is in turn mounted to a bracket 68 in the grill 19 of the automobile as shown in FIG. 4. A lead extends from the push-button switch 18 to a ground connection. A wire connects the terminal 64 through the firewall of the automobile to the instrument panel and is connected to the accessories terminal on the fuse panel 20 (FIG. 1). Of course, as is conventional, the accessories terminal on the fuse panel 20 is connected directly with the accessories terminal of the ignition switch.

In operation, if the bond is pivoted to a closed position, the projection 16 including the conical tip 32 will travel along an arcuate path passing into the bore 36 of the tubular sleeve 34. The plunger 48 is normally urged into a first position by a spring 54 so that the neck 50 projects into the bore 36. As the projection 16 passes through the bore 36, the control surface 32 forces neck 50 and plunger 48 to move inwardly against the urging of the spring 54. Once the shoulder 30 of the projection 16 is past the axis of the plunger 48, the spring 54 again pushes the plunger 48 and neck 50 into its first position so that the neck extends within the bore to a position blocking the upward passage of the projection by means of its abutment with the shoulder 30.

Since the axis of the plunger 48 is at right angles or is normal to the axis of the bore 36, the force applied when someone attempts to open the hood is not communicated to the spring 54 but is applied radially of the neck 50 and therefore it is almost impossible to force the plunger 48 back to allow the plunger to retract. When the operator of the automobile wishes to open the hood, he must first insert the key into the ignition switch 22 and turn the key to the accessories or ignition position. This will communicate the power source to the circuit of the locking device. However, the push-button 18 which is normally in open position and until the push-button is pressed to close the switch, the circuit will remain broken. Once the operator has turned the key in the ignition switch 22 to the accessories or ignition position, he must then pass to the front of the automobile and press the push-button 18 to complete the circuit to the solenoid coil 58 and activate the solenoid 58 thus retracting the plunger 48. This causes the neck 50 to free the bore 36 and upon raising the hood 12, the projection will be removed from the bore 36 along its predetermined path.

Of course, the switch 18 could be located in the cab of the automobile.

In the embodiment shown in FIGS. 5 and 6, all of the reference numerals have been raised by 100 in relation to similar parts shown in the embodiments of FIG. 3. The projection 116 extends from bracket 124 which is fastened to a suitable mounting by means of screws 126. The projection 116 has a conical-head 132 with enlarged shoulders 130 and is adapted to pass in the bore 136 of the seat and plunger housing 114. Similarly, the bore 136 terminates in a beveled portion 138 near the ends thereof.

The seat and plunger housing 114 is of one-piece construction as shown and defines a plunger bore 146 and a bore 142 of smaller diameter breaking into the bore 136. The plunger 148 having a neck 150 of smaller diameter slides in the bore 146 and 142. The end of the housing is closed by a cap 152 and is fastened to the housing 114 by means of screws 153. Solenoid coil 158 is also provided about a projection of the bore 146. A spring 154 is mounted to the cap 152 and urges the plunger 148 towards the bore 156.

AT right angles to the bore 146 is transverse bore 159 in which a locking pin 160 is adapted to slide. When the hood is closed and the projection 116 is in the bore 136, the pin 160 is normally retracted as shown in FIG. 5 and the neck 150 of the plunger 148 is in a position locking the projection 116. However, when the solenoid is activated, the plunger 148 is forced rearwardly against the urging of the spring 154. Also, in the course of the plunger moving rearwardly, the magnetic effect of the solenoid 158 is also induced in the plunger 148 protracting the sliding pin 160. Since, in its terminal position the plunger 148 has cleared the bore 159, the sliding pin 160 will be caused to move magnetically to the neck 150 thereby locking the plunger clear of the bore 136.

When it is required to again close the hood and place it so that it is locked by the plunger 148, the locking pin 160 is simply retracted manually allowing the plunger 148 to return to its forward position as shown in FIG. 5 under the urging of spring 154.

The position of the locking pin 160 obviates the necessity of a separate push-button switch 18, since when it is not required to lock the plunger 116 by means of the plunger 148, the plunger is simply locked in its rearward position by the locking pin 160.

Claims

I claim:

1. A locking apparatus for use in a body defining an opening and a movable closure member associated with said body to normally close the opening, the locking apparatus comprising a projection secured to one of said closure member and said body, a housing on the other of said body and said closure member defining a first bore adapted to receive said projection, said projection adapted to move to and from the housing along a predetermined path coextensive with said first bore, said projection including an enlarged head defining an abutment shoulder, an aperture provided in a side wall of a portion of the housing normal to the axis of the bore, a second bore defined in the housing communicating with said aperture and coaxial with the axis of said aperture, a plunger member comprising a continuous piece of magnetizable material having a rear portion and a neckportion of smaller cross section than the rear portion and forming a shoulder therebetween mounted for sliding movement in said second and through said aperture bore and normal to the axis of said first bore, spring means in the end of said second bore normally urging the plunger towards said first bore, a single solenoid coil provided about a portion of the second bore opposite the first bore for retracting said plunger from a first position to a second position out of engagement with the abutment shoulder of said projection; the closure being locked when said projection is in said first bore and said plunger is in said first position engaging the abutment shoulder of said projection, and said closure member being unlocked when said solenoid coil is activated to retract said plunger member to said second position, and a third bore substantially at right angles to the second bore, a manually-displaceable, freely-slidable locking pin of a magnetizable material in said third bore subject to the influence of induced magnetism in said plunger by said single solenoid coil for sliding movement therein between a retracted position clear of said second bore and an engaging position projecting within said second bore and engaging said plunger whereby the plunger is retained thereby against said spring means in said second position until manually retracted in said third bore.

2. An apparatus as defined in claim 1, wherein a mounting bracket is secured to one of the closure member and said body and the projection extends from the mounting bracket.

3. An apparatus as defined in claim 2, wherein the mounting bracket and the projection are secured to the closure member while the housing is mounted to the body.

4. A magnetically-operated locking mechanism for use on a body defining an opening, a closure member associated with said body for closing said opening, the locking mechanism comprising a projection and a housing operatively connected between said body and said closure member, said housing having a bore disposed in a path of movement of said projection and removably receiving the same therein, said projection including an abutment shoulder portion positionable in said bore, said housing including a second bore normal to said first-mentioned bore and communicating therewith through a reduced cross-sectional aperture, a magnetically-attractive plunger reciprocatably supported in said second bore and including an axial projection extendable through said aperture for engaging said abutment shoulder and locking the projection in said first-mentioned bore, said axial projection forming an intermediate shoulder on said plunger, a single electrically-energizable coil in said housing for creating a magnetic field about said plunger for withdrawing said plunger away from said projection abutment shoulder and permiting said projection to be withdrawn from said first-mentioned bore, spring means in said housing operatively engaging said plunger and normally urging it toward said first-mentioned bore when said coil is de-energized, a third bore in said housing intersecting said second bore, and a magnetically-attractive lock pin supported for free sliding movement in said third bore and subject to the magnetic field created in said plunger by said single coil, said lock pin being engageable automatically with the intermediate shoulder of said plunger for retaining the projection in an unlocked condition in opposition to said spring means and being manually displacable out of engagement with said shoulder for "unlocking" said plunger to permit said plunger to be urged into "locking" relation with the projection abutment under the influence of said spring means.