US 3901057 A
An electromagnetic padlock including a detent normally holding a padlock shackle in a locking position, a solenoid connected to said detent for disengaging the detent from the shackle when the solenoid is energized, and an energizing unit having a plug which may be detachably connected to a jack, carried by the padlock case, and which is electrically connected to the solenoid, for energizing the solenoid when an electric current is supplied thereto from a current source to which the energizing unit is connected. The solenoid is capable of being energized for disengaging the detent only when a voltage of a particular value is supplied thereto. The energizing unit includes a transformer for changing the voltage received from the current source to a voltage corresponding to that required to energize the solenoid.
Description (OCR text may contain errors)
United States Patent 1 1 1111 3,901,057 Coley, Sr. Aug. 26, 1975 PADLOCK Primary Examiner-Paul R. Gilliam Assistant ExaminerCarl F. Pietruszka 1 t Clff dL.Cl ,S.,Rt.2,B  nven or olgyhalia s 3 1 0x Attorney, Agent, or F1rmJohn N. Randolph  Filed: May 1, 1974 1211 Appl. No.: 465,888
[ 5 7 ABSTRACT An electromagnetic padlock including a detent normally holding a padlock shackle in a locking position, a solenoid connected to said detent for disengaging the detent from the shackle when the solenoid is energized, and an energizing unit having a plug which may be detachably connected to a jack, carried by the padlock case, and which is electrically connected to the solenoid, for energizing the solenoid when an electric current is supplied thereto from a current source to which the energizing unit is connected. The solenoid is capable of being energized for disengaging the detent only when a voltage of a particular value is supplied thereto. The energizing unit includes a transformer for changing the voltage received from the current source to a voltage corresponding to that required to energize the solenoid.
4 Claims, 3 Drawing Figures 1 PAnLocK BACKGROUND The prior art discloses the use of an electric plug for .SUMMARY It is a primary object of the present invention to provide an electrically actuated padlock which is especially adapted for use on freight cars and large freight carrying trailers and which utilizes an unlocking device for supplying an electric current to a solenoid of the padlock to effect release of a detent, and wherein the voltage of the current supplied to the solenoid differs from the voltage received from the current source, so that the solenoid cannot be energized to release the detent unless a prescribed voltage is applied thereto, so that unlocking of the padlock can only be accomplished with a particular unlocking device or energizer capable of stepping the voltage either up or down to a certain predetermined value.
Another object of the invention is to provide an energizer or unlocking device utilizing a transformer for changing the voltage from that supplied to the transformer to that transmitted therefrom.
Various other objects and advantages of the invention will hereinafter become more fully apparent from the following description of the drawing, illustrating a presently preferred embodiment thereof, and wherein:
BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a perspective view showing the padlock in a locked position;
FIG. 2 is a perspective view showing the padlock in an unlocked position and with the unlocking device or energizer connected thereto, and
FIG. 3 is a fragmentary plan view of the energizer or unlocking device.
DESCRIPTION OF THE PREFERRED EMBODIMENT Referring more specifically to the drawing, a padlock designated generally 5, of the electromagnetic type, is illustrated in FIGS. 1 and 2 and includes a case 6 having an end wall 7 provided with spaced openings 8 to slid ably receive the substantially parallel. legs 9 and 10 of a shackle Il. Sleeves l2 and 13 are secured to the inner side of the wall 7 and are disposed within the hollow interior of the case 6 in registration with the openings 8 to slidably guide and reinforce the shackel legs 9 and 10 respectively. The sleeve 12 which guides the longer leg 9 is longer than the sleeve 13; and said longer leg has an enlargement or flange 14 at its inner end to engage the inner end of the sleeve 12 to limit the extent that the shackle 11 can be moved to its projected, unlocked position of FIG. 2, under the biasing action of a compression spring 15 which is disposed against the inner side of the casing wall, located opposite the wall 7, and the adjacent side of the enlargement 14.
The shorter leg 10 which is out of engagement with the case 6 in the openposition of the padlock 5, as seen in FIG. 2, can be swung away from the case 6 about the leg as an axis, for engaging the shackle 11 with a hasp staple or chain links, not shown, as is conventional, or for disengaging the shackle therefrom. The shackle leg 10 has a notch 16 which faces away from the shackle leg 9 and which has an outwardly facing shoulder .17. A detent 18, in the form of a hook, is pivotally mounted within the case 6 by a pivot pin 19 which is supported by the case and which engages through an'intermediate portion of the shank of the hook. The hook 18 has a bill 20 to engage the notch 16 and abut the shoulder-17, when the shackle 1-1 is in its locked position of FIG.-1. -A .lightcompression spring 21 .which bears against a part of the interior of the case 6 and against the detent 18, opposite to the bill 20, urges the bill- 20 into engagement with the notch 16 .for lockingthe shackle leg 10 in the case 6. i
A solenoid 22 is secured in the case 6 and has anarmature 23 which is pivotally connected .to the detent 18, near the end thereof disposed remote'from the bill 20 and on the opposite side of the pivot 19 to said bill 20. The spring 21 normally holds the armature 23 in its extended position of FIG. 1 when the solenoid 22 is deenergized. In this position, the detent 18 abuts the stop 24 which limits the extent that said detent can be rocked on its pivot 19 under the biasing action of the spring 21.
A jack 25 is mounted in one wall of the case 6 and has three conductor sleeves 26 supported thereby and opening through said wall. Two of the sleeves 26 are connected by electrical conductors 27 to the solenoid 22 and the other sleeve 26 is grounded to the case 6 by a conductor 28.
An unlocking device or energizing unit, designated generally 29, includes a hollow handle 30 containing a transformer 31, which is connected at one end by a three conductor cable 32 to a three prong plug 33; and at its other end by a three conductor cable 34 to a three prong plug 35. A pushbutton switch 36 is also mounted in the handle 30 and is normally disposed in a circuit breaking position.
The transformer 31 is capable of changing the voltage of the electric current passing therethrough to a certain predetermined voltage which is the only voltage which will energize the solenoid 22. The plug 33 is adapted to be connected to a conventional electrical outlet, such as 1 10 volt outlet, or to a conventional bat tery pack, not shown. The plug 35 is connected to the jack 25. One prong of the plug 35 is only capable of engaging the sleeve 26 of the ground conductor 28. Thereafter, when the pushbutton switch 36 is depressed to close the circuit, voltage of a proper value will be supplied through the unit 29 to the solenoid 22 for energizing the solenoid to move the armature 23 thereof inwardly from its position of FIG. 1 to its position of FIG. 2, for rocking the detent 18 to its position of FIG. 2, for disengaging the bill 20 from the notch 16, so that the spring 15 can project the shackle leg 10 from the case 6 and into the unlocked position of the padlock 5, as seen in FIG. 2. Thereafter, and with the unit 29 disconnected from the padlock 5, said padlock can be returned to a locked position in a conventional manner.
While the lock has been illustrated and described as a padlock, it will be readily understood that the invention could be embodied in other types of locks and with the unit 29 being utilized for supplying electric current of a particular voltage to a solenoid to effect movement of a detent or its equivalent of the lock to accomplish the unlocking action.
Various other modifications and changes are contemplated and may be resorted to, without departing from the function or scope of the invention.
I claim as my invention:
1. A lock including a part movable between a locked an an unlocked position, a detent engaging and normally retaining said part in a locked position, a solenoid connected to said detent for moving the detent out of engagement with said part when the solenoid is energized, said solenoid being capable of being energized only by a voltage of a particular value, an electrical conductor connecting said solenoid to an electric current source, means interposed in said conductor for changing the voltage of the current to the particular voltage capable of energizing the solenoid, said conductor having connector means at each end constituting parts of an unlocking device which is normally detached from the lock, and said lock having means electrically connected to the solenoid to receive one of said connector means, said other connector means being adapted to be removably connected to the current Source.
2. A lock as in claim 1, said means comprising a transformer.
3. A lock as in claim 1, and a manually actuated normally open switch interposed in said conductor and adapted to be manually actuated for completing the circuit from the current source to the solenoid.
4. A lock as in claim 1, said lock comprising a padlock, said part comprising a slidably mounted shackle having one leg provided with a notch, said detent comprising a hook having a bill for engaging said notch, means pivotally mounting the hook in the padlock, and said solenoid having a slidably mounted armature connected to the hook for swinging the bill thereof out of engagement with said notch when the solenoid is energized to retract the armature.