US2036628A - Electric switch - Google Patents

Description

April 7, 1935' GQ B. GRosvENoR 2,036,628

ELECTRIC SWITCH Filed Feb. 16, 1923 2 Sheets-Sheet 2 Patented Apr. 7, 1936 UNITED STATES PATENT OFFICE ELECTRIC swircn Application February 16, 1923, Serial No. 619,426

11 Claims.

My invention relates'to electric switches and more particularly to switches which are operated by the magnetic pull bet'ween acore having a winding that may be energized and a cooperating iron armature.

In many cases, for example in the operation oi electric elevators, it is desirable to have a switch mounted on the elevator in such a way that it will open or close at a denite point in the hatch- Way to control the movements of the elevator.

One object of my invention is to provide an electrical switch which will be certain to operate, noiseless in operation, little affected by wear and cheap to construct.

I accomplish this object by mounting a solenoid coil in a xed position on one of two bodies adapted for relative movement and providing the coil with a cylindrical core which can rotate about the axis of the coil. At either end of the coil, I provide arms extending away from the axis and secured to the core. At some point and attached to the core or arms, switch contacts are provided to be operated by the movement of the arms. A coacting armature that spans the two arms is mounted on the other of the two relatively movable bodies so that when it is opposite the extremities of the two arms the magnetic pull across the air-gap will move the arms to rotate them about the axis of the coil and thereby operate the switch contacts, provided the coil is energized.

In order that my invention may be fully understood, it will be described in connection with the accompanying drawings, in which:-

Figure 1 is an end view of a preferred form of my switch.

Figure 2 is a bottom plan view of the switch of Figure l.

Figure 3 illustrates my switch, in connection with an elevator, to operate certain control circuits.

Figure 4 shows an end view of a modification useful, for example, in railroad work.

Figure 5 illustrates still another modification.

Referring to Figures 1 and 2, a coil I is secured by straps 2 to supporting plate 3, which is of nonmagnetic material such as brass, by bolts 4. Coil I is provided with a non-magnetic bushing 5, for example, a brass bushing. Rotatably mounted in bushing 5 ls a cylindrical iron core 6, the 0 ends of which project beyond the ends of coil I. Attached to these projections and extending downwardly are` arms 1, also of iron. Arms 'I are secured to core 6 as by halving the projections of core 6 on its horizontal diameter and fastening the two together by screws 8. The lower ends of arms 'I are bent at right angles to the vertical and extend horizontally beyond one edge of coil I. The horizontal extremities of arms 'I are flattened in a vertical direction and extend toward each other, so that the magnetic circuit of the coil I is, in effect, a horse-shoe.

On the upper side of each projection of core 6 is mounted a switch arm 9, which extends horizontally in the opposite direction to the horizontal extensions of arms l. A contact piece I0 is attached to each arm 9 through the insulating block II by bolts I2. Contact pieces I0 are normally in contact with contacts I3 which are mounted on base plate 3 through insulating block I4 by screws I5. An iron armature I6 or any suitable length in a vertical direction and of sufficient width to span the tips of the arms I is mounted on any desired object which has vertical movement relative to the coil and its support. The distance I'I between the armature I6 and the tips I8 of arms I is such that when the armature is opposite the tips I8 (as shown) and the coil is energized through wires I9 and 20, there will be suiiicient magnetic attraction to rotate arms l, core 6, and switch arms 9 about the axis of the coil to open contacts I3 and I0. An adjustable stop 2I is provided in plate 3 to arrest the motion of the core and arms after contacts I3 and I4 have opened and to prevent pole tips I8 from touching armature I6. that the contacts I3 and I4 are closed by the action of gravity, due to the center of gravity of the rotatable parts of the magnetic circuit being on the opposite side of the axis of the core from contacts I3 and I4, when the coil is deenergized.

It will also be noted that, when armature I6 is not opposite pole tips I8, contacts I3 and I4 will remain closed, whether the coil I is energized or not.

In Figure 3, a switch according to Figures 1 and 2 is shown in connection with an elevator. It is attached to the elevator car ZI through plate 3 and the armature I6 is mounted stationary at It Will be noted a point in the hatchway in such a way that the tips of arms I will pass by it as the elevator is raised or lowered. Assuming coil I energized Y. through wires I9 and 20, and the elevator approaching the position shown in the drawings, the magnetic attraction between arms 'l and armature I6 will cause contacts I3 and I4 to open by rotating the core and arms. Contacts I3 and I4 may be in a control circuit (not shown) for stopping the elevator. I have found that the gap I1 may be made about one-half inch with contacts I3 and I4 closed and also that oneeighth inch motion of tips I8 is sumcient to give excellent operating results.

'I'he modication shown in Figure 4 may be used for horizontal or vertical movements. The arms 22 may hang vertically and the plate 3 be .in a vertical position also. As there are no horizontal extensions to arms 1, gravity will not affect a switch of this construction. The contacts are held closed by spring 23 acting between arm 22 and plate 3. An adjustable stop prevents an excessive movenent of arm 22. If armature 25 is opposite arm 22 and coil I be energized, arm 22 will be attracted and the arm and core will rotate about the axis o! coil l, opening the contacts against the tension of spring 23 and they will be held open as long as the coil is energized and armature 25 is opposite arm 22.

This construction is useful for many purposes. As an example, the plate with the coil, arm and contacts mounted on it may be placed along a railroad in such a position that the armature 25 when mounted on a moving train will pass by the switch parallel to the axis of the core. The coil may be continuously energized so that the train in passing will open contacts 26 and 21, which may control, for example, a block signal.

Under certain conditions, it is necessary to have but one arm 22 on one end only of the core 6, as it will be attracted, but to a lesser degree than two arms, by an armature brought near it.

In Figure, a modified form useful for purposes similar to that shown in Figure 3, is shown. The construction, in general, is like the switch of Figures 1 and 2, but the arm 1 is balanced by a horizontal extension 28 so that gravity ds not enter into nor atl'ect its operation. Extension 28 also serves as a mounting for contact 29. The companion contact 30 is secured to the plate 3| which is mounted vertically. A spring 32 is provided to close contacts 29 and 30 at such times as the magnetic pull between arm 1 and armature 33 does not exist. Contacts 29 and 30 may be used to control circuits, as desired.

In the operation of my switch, there are no pivots or joints in the magnetic circuit, where friction due to the attraction of one part for another can develop. Furthermore, the movable part of the magnetic circuit rotates as a unit about the axis oi the winding, which is the neutrai point of any radial forces due to the ilux. Another advantage is that the movement of the core in the sleeve 5 is very slight as its radius is small compared to the radius on which the tip of arm 1 moves. The above considerations combine to make my switch reliable, positive, and not apt to get out of order.

The principles embodied in this switch are obviously applicable to uses other than specically described, and the invention is not limited to the location of one of the elements on a travelling member such as the elevator car, with the other on`a stationary part such as the elevator hatchway.

I claim:-

1. In combination, an electromagnet, a switch, an armature, and means for causing movement of said electromagnet and switch as a unit with respect to said armature, to cause the movement of a part of said electromagnet with respect to the remainder of its unit due to magnetic attraction between said armature and said part when the electromagnet is energized, and thereby actuate said switch.

2. A switch having normally closed contactors actuated by magnetizing and magnetzable elements brought into and out of attractive relation by car movement.

3. A switch having back-contactors actuated by a magnetizing and magnetizable element brought into and out of attractive relation by movement of the car.

4. In an inductor relay, a coil, a core for said coil, an armature comprising two legs, means for mounting said core and said legs for unitary movement relative to said coil, means for energizing said coil to magnetize said armature with a diierent polarity for each leg, a magnetizable plate, movable relative to said armature for causing the magnetic force in said legs to produce a relative movement of said armature and said coil, and circuit-controlling means operable by movement of said armature.

5. In'combination, an electromagnet having a winding and a core movable with respect to the winding, a switch operable by said core during its movement, an armature, and means for causing n relative movement of said switch and electromagnet with its core as a unit with respect to said armature, the armature causing the movement of said core to operate said switch during said relative movement with the electromagnet energized.

6. In combination, a winding, a core for said winding and movable with respect thereto, a switch, said switch comprising a blade mounted for movement with said core and a cooperating contact for said blade, an armature, and means for causing relative movement of said armature with respect to the unit comprising said winding, core and switch, said armature causing the operation ot said core to operate said switch during said relative movement with the winding energized.

7. In an elevator system comprising an elevator car and a hatchway, the combination oi' a coil, a support for said coil, said support being secured to said car, a rotatable core for said coil, said core being extended to form pole pieces, a switch blade secured to said core, a cooperating contact, said contact and switch blade being normally in engagement, an armature mounted in the hatchway so as to cause said pole pieces, as they come opposite said armature during movement o! the car and when said coil is energized, to rotate said core to separate said switch blade and contact.

8. In combination, a coil mounted on one oi' two relatively movable bodies, a core of magnetic material adapted to rotate in said coil and having an arm of magnetic material extending to some distance from its axis, a switch operable by said core during its rotative movement, and an armature mounted on the other of said two relatively movable bodies for cooperation with said arm as it comes opposite said armature during the relative movement of said movable bodies to cause the rotative movement of said core to operate said switch.

9. A magnetic switch comprising in combination, a coil mounted on one of two relatively movable bodies, an iron core adapted to rotate in said coil and having an iron arm extending to some distance from its axis and a switch blade mounted for movement with said core, a cooperating contact mounted on the support for said coil, said switch blade and contact being normally in engagement, and an armature mounted on the other of said two relatively movable bodies so that said armature comes opposite said arm as the relative motion occurs between said bodies and when said coil is energized, rotates the core, arm and switch blade as a unit to separate said blade and contact.

10. A magnetic switch comprising in combination, a coil mounted on one of two relatively movable bodies, an iron core adapted to rotate in said coil and having an iron arm extending transversely from its axis, and a switch blade mounted for movement with said core, a oooperating contact mounted on the support for said coil, said switch blade and contact being normally in engagement, and an armature mounted on the other of said two relatively movable bodies so that said armature comes opposite said arm as the relative motion takes place and when said coil is energized, rotates the core, arm and switch blade as a unit to separate said blade and contact and when the armature has passed said arm, or said coil has been deenergized, allows the core, arm and switch blade to return to normal position to cause the engagement of said blade and contact.

11. A magnetically operated switch, comprising in combination, a coil having a suitable support, an iron core through said coil along its axis, downwardly extending iron arms rigidly fixed on the ends of said core, horizontal iron extensions rigidly projecting from the lower ends o! said arms each in the ysame direction beyond the side of said coil, said core and arms constituting a movable system adapted to pivot as a unit about the axis of said coil, a contact mounted on the movable system, a second contact mounted on the support for the coil, said contacts being normally held closed by the action of gravity on the unbalanced weight of the movable system, and an iron armature adapted when opposite the horizontal extension of the movable system to cause the opening of said contacts by the magnetic attraction between said armature and said horizontal extensions when the coil is energized.

GRAHAM B. GROSVENOR.

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