US2248010A - Automatic circuit controller - Google Patents

Description

July 1, 1941. NELLES 2,248,010

AUTOMATIC CIRCUIT CONTROLLER I Filed March 9, 19:59

Patented July 1, 1941 AUTOMATIC CIRCUIT CONTROLLER Russell E. Nelles, South Orange, N. J assignor to The Union Manufacturing Company,

New

Britain, Conn., a corporation of Connecticut Application March -9, 1939, Serial No. 260,769

2 Claims.

My invention relates to the class of devices that are employed for controlling the conditions of electric circuits and an object of my invention among others is to produce an apparatus for such purpose that is simple in construction and particularly effective in operation to secure the results for which it is designed.

One form of an apparatus embodying my invention and in the construction and use of which the objects herein set out, as well as others, may be attained, is illustrated in the accompanying drawing in which- Figure 1 is a view in side elevationof my improved circuit controller.

Figure 2 is a view on enlarged scale in central vertical section of said controller.

Figure 3 is a view in cross section on a plane denoted by the dotted line 3-3 of Figure 2.

Figure 4 is a view in cross section on a plane denoted by the dotted line 4-4 of Fig. 2.

Figure 5 is an isometric perspective view of the controller supporting frame and parts mounted thereon.

In the drawing herein I have shown a portion only of a hoisting apparatus in connection with which my invention finds ready adaptation and have confined the illustration to so much only as is necessary for its full understanding, all of the parts comprising the invention, however, be-

ing shown. It will be understood, however, that the invention may be applied in various cases where the making and/or breaking of an electric circuit is required and its use is not therefore to be limited for any particular purpose. In the accompanying drawing the numerals 5 and 6 denote supports for a housing comprising part of a hoisting apparatus and which commonly encloses hoisting mechanism, which apparatus may be suspended underneath and carried by a trolley arrangement movable along a track depending from overhead, in a manner common to such structures and which will therefore be readily understood by those skilled in the art. A shaft 1 is rotatably mounted in the supports 5 and 6 and ball bearings 8 may be employed for this purpose if desired. A hoisting drum 9 is secured to the shaft 1 to be rotated thereby, and power may be applied to the shaft to rotate it by a motor of any desired form and common to structures of this type, this matter of driving being immaterial to my invention. However, for the purpose of the description, I have shown a gear In secured to the drum or shaft and affording a part of the driving connection between the motor and the shaft.

A hole II is bored into one end "of the shaft and is threaded to receive the threaded shank l2 of a switch actuating head l3 mounted for reciprocating movement in a switch supporting frame l4 secured to the support 6 in any suitable manner, screw bolts being shown herein for this purpose, the switch actuating head l3 which is of insulating material extending into said frame, as shown in Fig. 5. This frame is open from side to side and comprises ends |5-l6 with top and bottom bars 11 and I8 joined to and connecting said ends, as shown in Fig. 2. Contactor block guides in the form of guide'rods I9 are each secured at one end to and project from the frame end I5, the opposite ends of said guides being supported in the end l6. Contactor blocks 2-ll--2I are mounted for adjustable sliding movement on said guide rods, as shown in Fig. '5, these blocks being composed of any suitable insulating material. They are split as at 22 between the holes through which the guide rods extend, and clamp bolts 23 extend through each block and across said slot-s as a means for retaining the blocks in place after they have been adjusted in proper positions. These contactor blocks 20 and 2| have contacts 24 and 25, respectively, secured as by means of binding screws 26 each of which passes through the contactor block to which it is attached, the heads of-these screws serving for the attachment of a conducting wire to be hereinafter described. The contacts 24 and 25 are fixed and coact with spring contacts 21 and 28 secured, respectively, to the conductor blocks 20 and '21. These spring contacts are preferably of 'U -shape with their free ends positioned to touch the contacts '24 and 25, the opposite ends of the spring contacts being secured to the contactor blocks by means of screws as shown in Fig. 5, these screws, as 29, serving as binding screws for a wire to be hereinafter described.

The switch actuating head 13 has a guide pin 3B which travels in a guide groove 3! in the bar I8, as shown in Fig. 2, this to prevent the head from turning. Said head [3 also has a switch actuating pin 32 projecting from one side of the head to press against the spring contacts 21 28 for the purpose of breaking the circuit between the contacts 2 i25 and the spring contacts 2128.

The electrical circuits for operating the device may be arranged in various ways to suit fancy or convenience or any particular condition, such arrangement not being material to my invention. One arrangement which will satisfactorily answer the purpose is diagrammatically illustrated 2 of the drawing in which the light ,linesdenote the controlling circuit and the heavy of the cable (not shown) depending from the" carrier upon which this limit switch is mounted, the switch at the end of the cable being located in position for ready access by the operator in charge of the apparatus and in a manner well known to those skilled in the art. This switch 36 has a main contact 31 and two branch contacts, with a switch member 40' pivotally attached at the contact 31 and having swinging movement to engage either of the branch contacts 38 or 33. The switch member 40 may be operated in any well known manner as by either of the two push buttons, successive pressures upon each of which will cause said member to be engaged with and disengaged from one of the contacts 38 or 39.

Branch wires 4|42 extend from the branch contacts 33-49 to the binding screws 26 on the blocks and 2|, and return wires 4344 extend from the binding screws 29 to electrically operated switch actuating devices 4546, and from thence to the main line wire 34.

It will of course be understood that current passes from the wires 4| and 42, to the binding screws 26, to the contacts 24-25, and from thence to the spring'contacts 21--28, and from thence to the binding screws 29, and from thence to the return wires 43-44.

The actuating devices 45-46 may be of any well known type whereby when electrified by current passing through them, they will operate to throw switches now to be described for controlling the power circuit for operating the drum 9. It is not thought necessary to describe in detail these switch operating devices as they may be constructed in diiferent ways that will readily suggest themselves to electricians skilled in this art.

The power circuit for operating the drum 9 comprises two independent circuits each of which is connected with a power wire 41 or 48, the former extending from the main line wire 34 and the latter extending from the main line wire 33. For convenience of description the circuit on the left of Fig. 2 will be termed the up circuit as it will operate to rotate the motor 52 in a direction to turn the drum 9, to wind up the cable 49 on the drum and thereby raise the load suspended by said cable, and the, circuit on the right will be termed the down circuit as it will effect rotation of the drum 9 in a direction to unwind said 'cable and therefore lower the load suspended therefrom.

Each'of these circuits includes a three-pole switch, although other types of switches may be employed. These switches 50-5! when closed will effect rotation of the drum 9. For example, the push button, not shown but represented by the switch 36 and connected with the switch actuating device 45, being operated to excite said device, the up switch 50 will be closed and the electric current will be caused to pass through the armature of themotor 52 in one direction, thereby effecting rotation'of the drum 9 in a certain direction. Upon second operation of the push button just mentioned the switch actuating device 45 will cease to receive current and the switch will thereupon be opened in a manner well known, as by means of springs. Operation of the other push button hereinbefore mentioned will effect operation of the down switch 46 in,

is sufiicient for a clear understanding a brief description of one will answer for both. The wire 41 which is general to both the up and down circuits transmits current to the wire 53 connected with a contact of the switch blade on the left of the set 50 of blades and from thence the current passes along wire 54, field of motor 55, wire 56 to the center blade of said set 50, of blades, along said blade and wire 51 to the armature of the motor 52, through said motor and along wires 58 and 59 to the blade on the left of said set 50 and by said blade and along wire 48 to the main line 33, thus completing the air:- cuit.

The down circuit may be traced in substantially the same manner except that the current passes by wire 60 connected with the center blade of the set 5| of blades and also with wire 58 to the opposite side of the armature of the motor from that above described with reference to the up circuit, thereby operating said motor in a direction reverse to that before described and operating to rotate the drum to unwind the cable and lower its load. I

As a means for protecting the switch or make and break mechanism a housing 6| is secured to one of the supports 6 as shown in Figs. 1 and 2 of'the drawing. An important feature of the invention resides in a means for lubricating the threaded shank on the switch actuating head, this consisting of a duct or oil hole 52 extending axially within the shaft 1 of the drum and opening into the threaded hole I I, said duct extending from any oil opening conveniently located within the drum and shaft.

While the pin 32 is insulated by insertion in the insulated head 13 it is obvious that this result may be obtained by forming the head or pin, either or both, of insulating material.

In accordance with the provisions of the patent statutes I have described the principles of operation of my invention, together with the device which I now consider to represent the best embodiment thereof; but I desire to have it understood that the device shown is only illustrative and that the invention may be carried out by other means and applied to uses other than those above set out.

I claim: I

1. In a limit switch construction of the character described, a non-rotatable supporting member, a rotatable member having a threaded socket therein journaled in said supporting member, a shaft threaded in said socket with a switch actuating head on the projecting end thereof, a'mcmber rigidly mounted in said supporting member and wherein said rigidly mounted member includes a substantially rectangular frame with the switch actuating head located within said frame and wherein there are cooperative means including a pin carried by the switch actuating head extending into a slotted opening formed in one side of said rectangular frame.

2. In a limit switch construction of the character described, a non-rotatable supporting memher, a rotatable member having a threaded socket therein journaled in said supporting member, a shaft threaded in said socket with a switch actuating head on the projecting end thereof, a member rigidly mounted in said supporting member and wherein said rigidly mounted member includes a substantially rectangular frame with the switch actuating head located within said frame and wherein there are cooperative means including a pin carried by the switch actuating head extending into a slotted opening formed in one side of said rectangular frame, and means supported in opposite ends of said frame upon which said pairs of contacts are mounted.

RUSSELL E. NELLES.

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