US 3506883 A
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A ril 14, 1970 Filed Dec. 19, 1966 KAzu o SUGIYAMA ELECTRICAL LOOKING DEVICE 2 Sheets-Sheet z INVENTOR KAzuo SU WAMA ATTORNEYS United States Patent 3,506,883 ELECTRICAL LOCKING DEVICE Kazuo Sugiyama, Tokyo, Japan, assignor to Heiwa Denki Kabushiki Kaisha, Kawasaki-sill, Japan Filed Dec. 19, 1966, Ser. No. 602,811 Claimspriority, application Japan, Dec. 22, 1965, 40/ 78,616; June 6, 1966, ll/52,543 Int. Cl. H01f 7/10, 7/14; H01h 47/04 US. Cl. 317-154 3 Claims ABSTRACT OF THE DISCLOSURE This invention relates to an electrical locking device for doors or the like, which utilizes the coercive force of an electro-magnetic core.
Conventional electrical locking devices have an ability of controlling only two conditions, namely were closing and opening, since it utilizes in and out of the electricity for an electromagnet.
Therefore, an object of this invention is to provide a new electrical locking device utilizing the coercive force of an electromagnetic core other than the normal closing and opening control of an electromagnet circuit, thereby the locking operation is electrically remote-controlled automatically and mechanically, by de-magnetizing said coercive force of the core or giving a motion stronger than said coercive force to an attracted iron piece. Another object of this invention is to provide an electrical locking device as explained in the above, which can be operated by switching of direct and alternating currents from a common current source.
Further objects and merits of this invention will be made clear from the following explanation with preferred embodiments illustrated in the drawings.
FIG. 1 is a schematic section of an electrical locking device embodying this invention, with an outer power supply circuit;
FIG. 2 is a cross-section taken along line IIII in FIG. 1;
FIG. 3 is a diagram of a power supply circuit for another embodiment; and
FIG. 4 is a section of the locking device to be used in the second embodiment shown in FIG. 3.
In the first embodiment shown in FIGS. 1 and 2, the tip of a locking bolt 1, which is mounted in the swing side of a door panel and projected therefrom, is entrapped between jaws 3 and 4 of an operating cam 2 rotatably mounted on a shaft 6. A pushing pin 7 is slidably mounted between the operating cam 2 and an actuating arm 8 pivoted on a shaft 9. The actuating arm 8 is always urged to the clockwise direction, i.e. to the pushing pin side, by the action of a spring 12. However, the actuating arm 8 can be rotated in the counter-clockwise direction when the operating cam 2 is rotated clockwise and the pushing pin 7 is pushed rightwards by the crown of the cam 2. An arm portion 10 of the actuating arm 8 is normally in contact with a stopping rod portion of an L-shaped rod 13 pivoted by a shaft 14.-At the other end of the L-shaped rod 13, there is provided with an attractable iron piece 16 which is attracted in the counter-clockwise direction by.
the action of an electromagnet 19, while it is urged relaice.
tively weakly in the clockwise direction by a return spring 17. The characteristic feature of this invention is to make an iron core 20 of the electromagnet 19, a material having a large coercive force, such as SK-7. 21 and 22 show terminals of a switch 25 for supplying current to the electromagnet. By selecting the position of a set of movable contacts 25, the terminals 21 and 22 are respectively connected to power supply terminals 26, 26' or to power supply terminals 27, 27' having a series resistance 24.
Further, there are provided with a lever 11 on the actuating arm 8 and another lever 18 on the L-shaped rod 13. Either one of levers can be turned to a raised position by a suitable means, such as a click mechanism. In the embodiment shown in FIGS. 1 and 2, the lever 18 is the operable one.
Now, the functions and merits of the device shown in FIGS. 1 and 2 will be explained in detail.
By the movement of the locking bolt 1 according to the opening or closing of the door, the operating cam 2 is rotated around the shaft 6 since the locking bolt 1 is in engagement with the jaws 3 and 4 of the cam 2. The pin 7 is therefore pushed rightwards, resulting in the counterclockwise rotative force of the actuating arm portion 8, but such rotation does not take place, since the arm portion 10 is stopped by the stopping rod portion 15 of the L-shaped rod and could not be swung. Thus, the locking bolt 1 is in a locked condition.
When the bolt is to be unlocked, the movable contacts 25 are turned to the terminals 26, 26' for supplying the electricity to the electromagnet. By this operation, the electromagnet 19 attracts the attractable piece 16, and accordingly the L-shaped rod 13 is swung around the shaft 14 in the counter-clockwise direction, which results in the disengagement of the arm portion 10 from the stopping rod portion 15. Under the condition, the actuating arm 8 is movable in the counter-clockwise direction and then the operating cam 2 also movable in the clockwise direction in FIG. 2, allowing the escape of the locking bolt 1 from the jaws 3 and 4 of the operating cam 2. This is operable or unlocked condition of the door.
After this condition has been established or the switch has been once turned to the terminals 26, 26', the power source can be cut out. Even if the power source has been cut out, the iron piece 16, of the L-shaped rod will be held in the attracted or unlocked position by the coercive force of the electromagnet core 20, which force is Stronger than the force of the return spring 17.
When the locking operation is desired to function automatically andmechanically, the lever 18 of the L-shaped rod is raised. If the door is opened as shown by an arrow in FIG. 2 up to a predetermined angle by the entrance of a person, the crown 5 of the operating cam 2 will deeply push the pin 7 so that the actuating arm 8 Will be rotated to such an extent that the lever 11 pushes the lever 18. By the pressure applied to the lever 18, the L-shaped rod 13 will be swung in the clockwise direction against the coercive force. Thus, the piece 16 can be moved from the electromagnet 19.
Even if the door has been again closed or the pushing force applied to the lever 18 by the lever 11 is released, the attracting force applied to the piece 16 by the coercive force of the electromagnet will not overcome the force of the return spring 17, since the coercive force working on the spaced iron piece is very weak, and it remains in the position spaced apart from the electromagnet. Therefore, when the door has been completely closed as shown in FIG. 2, it is automatically locked by the re-engagement of the arm portion 10 with the stopping rod portion 15.
Finally, when the device is to be electrically locked from a remote position, the movable lever is previously brought down. In this condition, even if the door is opened widely in the direction shown by the arrow, the lever 11 will not contact with the lever 18, so that the L-shaped rod 13 remains in a position attracted by the coercive force of the core 20 and always in the unlocked condition. The contacts'25 are then turned to the terminals 27, 27 'which have opposite polarities in comparison with the terminals 26, 26'. The weak current is supplied from the terminals 27, 27 through a resistor 24 to an electro-magnetic core of the electromagnet, and de-magnetized the coercive force existing in the core. Therefore, the L-shaped rod is rotated in the clockwise direction by the action of the return spring 17 for closing the door as shown in FIG. 2, and the arm portion and stopping rod portion are engaged with each other for establishing the locking condition.
In the embodiment shown in FIGS. 3 and 4, an electromagnet 102 of an electrical locking device 10 1 has an iron core 103 made of a material having large coercive force, such as SK7. An L-shaped piece 104, which is to be attracted by the core 103, is rotatably pivoted on a casing 105 by a shaft 106, and urged to the direction opposite to the core 103 by the spring 107. The other end 108 of the L-shaped rod can be engaged with the curved bottom 1 11 of a locking bolt 110 which is urged to retract by a spring 109.
112 and 113 shows terminals for the electromagnet 102. The circuit to the electromagnet 102 includes a movable contact 114 and fixed contact 115, which contacts are actuated according to the opening and closing operation of the door. As shown in FIG. 3, the terminals 112 and 113 are connected to the operation board provided in the room, through wires 117 and 118.
An alternating current source 119 supplied electricity to a transformer 121 through a main switch 120. The secondary coil 122 of the transformer supplies a stepdown voltage directly to the terminals through a pilot lamp 123 of Wire 1155 and a de-magnetizing switch 124.
Further, a direct current source formed by a rectifier 125, and a condenser 126 is connected to the terminals in parallel with the above-mentioned alternating current supply through an energizing switch 127.
When the electrical locking device 101, which is in the locked condition, is to be unlocked, the energizing switch 27 for the direct current source composed of the secondary coil 122, the rectifier 125, and a condenser 126 is turned to in. Then, the direct current flows to the electromagnet 2 of the electrical locking device 101 and attracts the L-shaped piece 104. The piece 104 is rotated around the shaft 106 in the counter-clockwise direction, compressing the spring 7. By the movement of the piece 104, the other end 108 escapes from the curved bottom 111 and the locking bolt 110 is unlocked by the retracting force of the spring 109. When the electromagnet 102 has been once brought into the energized condition, the coercive force by the residual magnetism the condition, even if the energization of the electromagnet has been cut out by the switch 127. Namely, the piece 104 is maintained in its attracted condition, and the unlocked condition is continued.
In order to bring the locking device into the locked condition again, the de-magnetizing switch 124 of the secondary coil 122 is closed. Then, alternating current flows to the electromagnet 102 and it will not energize the magnet 102 but de-magnetize the residual magnetism remained in the core 103. Accordingly, the attracting force of the magnet 102 will completely disappear, and the L-shaped piece 104 attracted by the core will move by the stored mechanical force of the spring 107 in the clockwise direction. The other end 108 will push the curved bottom 111 of the locking bolt 110 so that the locking bolt 110 projects and is held not to retract. Thus, the locking is accomplished.
As explained in detail with the preferred embodiments, the characteristic feature of the present invention is the utilization of the coercive force of an electromagnet core. The coercive force in the attracted condition of the iron piece is made stronger than the retational force of the return spring, so that the unlocked condition is maintained and the electricity can be saved. The locking can be done either by separating the iron piece from the core or by de-magnetizing the coercive force of the core. Accordingly, automatic and mechanical locking and also electrical locking can be done.
Of course, this invention should not be construed as being limited by the above-mentioned specific forms of embodiment shown and described herein by Way of example. The device may be altered or modified within the spirit of the invention. For example, a suitable magnetic shield may be provided within order to prove the device from any unlocking by applying a strong outer magnetic field. The device may be designed to lock by the energization of the electromagnet and unlock by the demagnetizing of the same, just reversely in the embodiments explained in the above.
What I claim is:
1. An electrical locking device comprising an electromagnet having an iron core of large coercive force, a pivotally mounted operating cam having locking jaws, a pushing pin operatively engaging the cam, a pivotally mounted actuating arm engaging the pushing pin, and normally urging the cam through the pin to a locked condition, a pivotally mounted L-shaped 'rod mounted to effect limit to the rotation of the actuating arm, an attractable iron piece associated with the rod in cooperative relationship with the electromagnet, said iron piece mounted to take a first actuated position by the coercive force and a second retracted position by the action of a return spring on the L-shaped rod, the rotational force of said return spring being made Weaker than the attracting force of the energizing electromagnet and than the attracting force by the residual magnetism acting on said iron piece in the first position after power is cut therefrom, the rod retaining the actuating arm pushing pin and cam in locked position in the second retracted position, and releasably allowing pivotal action of the arm, and release of the cam in the first actuated position.
2. An electrical locking device as set forth in claim 1 which includes a lever on the actuating arm and another lever on the L-shaped rod, said levers positioned so as to cooperate with each other, means to adjust the relationship of the levers with respect to the arm and rod, and the operable position of the levers with respect to each other adjusted so that movement of the cam to release from its latched position causes the lever on the arm to engage the lever on the rod and mechanically force the iron piece away from the electromagnet.
3. A device according to claim 1 wherein said electromagnetic is connected to an alternating current source through a de-magnetizing switch, and also to a direct current supply delivered from said alternating current source, through an energizing switch.
References Cited UNITED STATES PATENTS 8/1939 Perry 335-254 X 8/1965 Ray 3l7156 X JAMES D. TRAMMELL, Primary Examiner UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent: No. 3, 883 Dated April 970 Inventor(s) Kazuo Sugiyama It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:
Change the title of the patent on both pages of the drawings from "Electrical Looking Device" to Electrical Locking Device Signed and sealed this 18th day of August 1970.
EDWARD M.FLETCHER,JR. WILLIAM E. SCHUYLER, JR. Attesting Officer Commissioner of Patents