US2319810A - Alternating switch - Google Patents

Description

May 25, R -r JR" ETAL' A'LTERNATING SWITCH Original Filed Jan. 24, 1940 Jag @ T fi Invenio r5 5 PAUL T. (SALT JR. HAROLD ESCHLEICHER Patented May 25, 1943 ALTERNATING SVITCH Paul T. Galt, Jr., Hartford, and Harold E. Schleicher, West Hartford, Conn, assignors to The Arrow-Hart & Hegeman Electric 00., Hartford, 001111., a corporation of Connecticut Original application January 24, 1940, Serial No. 315,428. Divided and this application October 8, 19 -10, Serial No. 360,330

8 Claims.

This inventionrelates to an alternating switch device to accomplish the alternate use of one or another of two motors or other pieces of electrical apparatus. More particularly, the invention relates to a switch for alternating the use of electrically-driven pumps.

It is an object of our invention to provide a simplified switch for use in a circuit for alternating the use of two pieces of electrical apparatus in certain conditions, or conjointly using them in certain other conditions. Another object of our invention is to provide a switch of the above type having a minimum number of contactors and having means to enclose the mechanism. Other objects and advantages of our invention will become apparent as it is described in connection with the accompanying drawing.

In the drawing- Fig. 1 is a side elevation view of an alternator switch mechanism embodying the principles of our invention;

Fig. 2 is an end elevation, partly broken away, of the switch mechanism shown in Fig. 1;

Fig. 3 is a transverse section view taken along line 33 of Fig. 1;

Fig. 4 is a diagram showing the circuit arrangement of the switch shown in Figs. 1, 2 and 3, when used for accomplishing alternate or joint operation of two electric motors; and

Figs. 5 and 6 are detail views of two of the cam discs of the switching device.

This application is a division of our prior application,-Ser. No. 315,428, filed January 24, 1940, now Patent No. 2,266,020, granted December 16 1941.

Referring to the drawing, Fig. 1 shows a switch mechanism which is mounted upon a base I 0, which may be stamped from sheet metal. Upon the base on opposite ends are mounted standards l2 and I4, which may be stamped from sheet metal to provide flanges, for example (2a, [2b, at their top and bottom. Upon the upper flanges a block of insulating material l6 rests and carrie the fixed and movable contacts of the switch mechanism.

The fixed contacts may comprise contact buttons, such as [8a, which are mounted upon the inner surface of one leg of a U-shaped member ISI). This member is stamped from a strip of sheet metal and secured to the under surface of the insulating block 16 by a bolt 20 passing through the block from the top surface. The bolt 20 may also serve to secure a wire terminal plate 22 in position on top of the block, and the terminal plate may have a binding screw 24 for the purpose of securing lead wires thereto.

Also mounted upon the under surface of the insulating block Iii are resilient movable contact members comprising contact buttons such as 26a which are adapted to cooperate with the contact buttons I811. The buttons 25a may be mounted upon the end of a U-bent strip of resilient sheet metal, such as 26b. One leg of this U- bent metal strip may be secured to the under surface of the insulating block l6 by a bolt 28, passing through the block from the top, which at the same time secures a terminal plate 30 in position on top of the block. Although only one set of fixed and movable contacts have been described, there are four sets of these mounted side by side on the underside of the block l6. These sets are operated by four cam discs 34, 36, 38, 40, as will hereinafter be more clearly described. Each of the movable contact members has a hump 26c struck out of its resilient U-member 26b in position to be engaged by the surface of the cam members.

Contact operating cam discs 34 and 36 are mounted upon an axle 42 which is journalled in the standards [2 and I4. These cam discs 34 and 36 are spaced apart by an insulating sleeve 44 and are secured permanently to the axle 42 so as to move as a unit therewith. The cam discs 38 and 49 are fixedly mounted upon a sleeve 46 which is, in turn, loosely mounted upon the axle 42. The discs 40 and 38 are spaced apart from each other by an insulator sleeve 48 and, by a sleeve 50, from a ratchet wheel 52. The ratchet wheel 52 is mounted fixedly upon the end of sleeve 46 so as to move as a unit with the sleeve and cam members 38 and 40. A pawl 54 mounted upon a fixed axis 56 in the standard M has a laterally-extending pin 58 engaging with the teeth on the periphery of the ratchet wheel 52 and held against the teeth by a spring 60, whose upper end is attached to the pin 58, while its lower end is attached to a pin 62 in the bottom portion of the standard l4. This pawl engages with the teeth on the ratchet wheel 52 to limit clockwise (Fig. 2) rotation of the cam discs 38 and 40.

For the purpose of oscillating the shaft 42 and for rotating the ratchet wheel 52, there is provided an operating lever 64 which has a yokeshaped end embracing the standards l2 and 14. The arms 64a and 64b of the yoke are pivotally mounted upon the standards l2 and M by pins, such as 56, which are co-axial and whose axis is spaced from, but parallel to, the axis of the axle 42. Operated by the movements of the member 64 is an arm 68 which is rigidly mounted upon, and extends radially from, the axle 42 between the standard l4 and ratchet wheel 52. To connect the yoke portion of member 64 with the arm 68, a pin 61 is rigidly mounted upon, and extends laterally from, the mid-portion of the arm 68 through a slot 69 in the standard I4 and into an elongated aperture in the portion 64b of the operating member 64. In this manner, movement of the member 64 will be partaken by the lever 68 and axle 42 so that cams 34 and 36 and the lever 68 will oscillate as a unit with operating member 64.

By spacing the pin 6'! from the pivot 55 of the operating arm and on the opposite side of the axle 42 from the pivot 66, there is accomplished a multiplied eiiect of movement of the operating arm over what would be had if the axes of pivot 65 and axle 42 were coincident. This construction also makes possible other uses of the invention, besides that specifically mentioned herein, where the amount of movement of the element which controls the operating, arm is sub stantially different than a float. The spacing of the pivots may be varied, within the scope of the invention, to accommodate the apparatus to various fields of use.

In order to cause rotation of the cams 38 and 40, a pawl device I2 is pivotally mounted by a pin "I4 upon the end of the arm 68 and is urged by a spring I5 which is connected with the pawl 72 and with the lever 68 so as to hold a laterallyextending pin 78 in the end of the pawl member I2 in engagement with the periphery and teeth I of the ratchet wheel 52. Thus, as the operating member 64 moves up, it thereby causes movement of thev arm 5.8. Thus, the pawl I2 and its pin engage with one or another of the teeth of the ratchet wheel to cause movement of the ratchet wheel and corresponding movement of the sleeve 46 and cams 38 and 40.

In the example shown, there are four high points, such as 40a and 38a, on each of the cam discs 38 and 40, and between each high. point is a low point of slightly greater extent. The. high portions 38 and 40. are staggered with relation to each other, so that. when a high point, for example 40a, engages with the portion 260 of the movable contact 2617, to elevate it, a low point on the cam 38 will permit the movable contact controlled by that cam to remain in closed circuit position. Thus, when the switch controlled by the cam 40 is opened, the switch controlled by V the cam 38 will be closed, and vice versa.

In Fig. 2, the operating member 64 is shown in its lowermost position. In Fig. 3, it is shown in its uppermost position. The lowest position is the oif position of the whole switch mechanism, and the uppermost position is the. abnormal or flood condition position. In between the high and the low, is a normal operating position. In this normal position, as will hereinafter be more fully described, one or another of the two motors for operating electrically-driven pumps, are encircuited. In the uppermost position, both pump motors will be encircuited for the reason that both of the switches controlled by the cams 38 and 40 will be in closed circuit position, as shown in Fig. 3. In order. to accomplish the simultaneous closing of both switches, the high points on the cams 38 and 40 are short enough so that the high point of one cam, for instance 38a, will pass on, to permit closing of the switch it controls, before the high point 40a of the cam 40 moves far enough to cause opening of the switch which it controls (see Fig. 3).

At the same time, the parts of the device are proportioned so that this simultaneous closing occurs when the operating arm is in its uppermost position, so that further movement of the arm with concomitant opening of either one of the alternator switches I04 and I06 is precluded.

The form of the teeth on ratchet wheel 52 and the strength of the spring 16 are such as to create suflicient friction to cause clockwise rotation of the ratchet 52 and earns 38 and 40 back to normal position (Fig. 2) wherein pawl 54 holds the ratchet wheel 52 against further clockwise movement. It will be understood that the parts must be proportioned so that the movement of the operating arm 64 to uppermost position will not be sufiicient to permit the pawl 54 to catch a succeeding tooth.

In the diagram of Fig. 4, the switch controlled by the cam 34 is illustrated as switch I00, whose contacts are connected with the neutral line N of a three-wire power supply and with the solenoids SI and S2 of electromagnetically-operated switches, MI and M2. This switch may be called a stop switch. It functions to cause opening of the circuit when the operating lever 04 comes into its lowermost position.

The switches controlled by cams 38 and 4 may be called alternator switches. They are shown as I04 and I 06. One contact of each of these alternator switches I04 and I05 is con nected to the solenoids SI and S2 respectively, while the other contacts are connected to one contact of a starting" switch I02 which is con.- trolled by the cam disc 36'. The other contact of switch I02 is connected to the power line LI. Normally the starting switch is the last to close and first to open of all the switches which are operated by the cams 34, 36, 38 and 40. The alternator switches normally operate before switch I02 closes. Thus, when the operating lever moves from the position shown in Fig. 2, it will first cause closing of the switch I00. Then further movement will cause opening of one of the alternator switches and closing of the other. Upon still further movement to the mid or normal operating position, the switch I02 will close, whereupon one or another of the solenoids SI, S2 will be energized. However, before switch I02 is closed by cam 36, the ratchet 52 will have rotated sufiiciently to have the pawl 54 catch a new tooth. Otherwise, one of the motors might be started without the alternation of motors on the next cycle being assuredby prevention of reverse (clockwise) movement of the ratchet and cams 38 and 40.

If, as switch I02 closes, the solenoid SI be energized as shown in Fig. 4, the electromagnetic switch MI will be closed, causing the motor PI to be connected to the power lines LI, L2 and N. At the same time, an auxiliary switch AI is closed by the closing movement of the electromagnetic switch MI. This switch has one contact connected to the power line LI, while the other is connected to the side of the solenoid SI, which is opposite to that which is connected to the Neutral line N through the switch I00. In 'a'similar manner, an auxiliary switch A2 is closed as the electromagnetic switch M2 operates. Switches AI and A2 shunt around starting switch. I112 and alternator switches I04 and I06. It may, therefore, be seen that the energization of the solenoid SI will continue so long as the switch I00 is closed. Since this switch is the first to close and the last to open, it will only open when the operating lever 64 comes into its lowermost position, or, in other words, if the lever 64 be operated by a float, the switch I will only open when the water lever has reached a predetermined minimum.

In case of unusually heavy inflow of water, the

float-operated lever 64 will move through midposition (where either I04 or I05 will close, as the case may be), to uppermost position, as shown in Fig. 3, causing both switches I04, I06 to close. This will cause both electromagnetic switches Mi, M2 to close and remain closed until the water has reached a predetermined minimum and the arm 64 is in its lowermost position. At that time, the switch I00 will open and cause both electromagnetic switches to open.

It is important to note that the operation of both pump motors simultaneously does not interfere with the normal alternation of the apparatus. Thus, the high water condition simply causes another pump to function in the event that the float continues to rise above inormal. Nothwithstanding that, that pump will be the one which operates next, in the normal sequence. This principle will apply even though more than two pumps are incorporated in the system and operate normally in sequence, or all together, during flood conditions.

From the foregoing, it will be observed that we have provided an electric alternator switch mechanism which has but four sets of fixed and movable contacts comprising four individual switch means that are controlled by a single operating lever in a predetermined order. Our alternator only requires the same number of sets of contacts or switching means as there are motors to be sequentially operated, plus an opening switching means and a closing switching means. Furthermore, we have provided an arrangement of our alternator in a circuit which requires a minimum number of connections but which accomplishes the maximum desired functions in a system for controlling the operation of one or another, or all of the motors of several electrically-driven pumps. The alternator switch can be operated by a float or in response to the movement of any part whose action is governed by the conditions to be controlled or work to be done by the motors.

The operating parts on the base It] may be totally enclosed by side plates 10 of insulating material. Tongues or extensions 19a on the top and bottom edges of said plates may project through or into complementary apertures or recesses in the base Ill and block l6, whereby the plates are interlocked, in proper permanent position, with the block i6 and base I0. Within the scope of our invention, is the provision of another block, like block IS, with its accompanying parts, to be mounted on the bottom of the device in place of base NJ. The switching devices of this bottom block may be operated by the cams 34, 36, 38 and 40 or by similar cams mounted beside cams 34, 36, 38 and 49 and moving as units with them respectively. In this manner, additional motors, or the like could be sequentially selected for operation by earns 38 and 40 and controlled by cams 34, 3B or their counterparts. By changing the shape of the cams 34 and and varying the circuit connections. this alternator invention can be adapted to direct control of the motors or other devices, eliminating the need for the supplementary electro-magnetic switches or equivalent devices to close and open the motor circuits, thatopening and closing being accomplished by the alternator invention itself.

Many modifications within the scope of our invention will occur to those skilled in the art. Therefore, we do not limit the invention to the specific embodiment shown.

We claim:

1. A switching device for controlling alternate and joint operation of electric units, comprising an operating member, a. plurality of cam means, individual contact means operable by each cam means, certain of said cam means being operable as a unit with said member, means to cause certain other of said cam means to move only when said member moves in one direction, said certain other cam means being constructed and arrangedto alternate the engagement of the several contact means controlled thereby each time said operating member comes into one position and to cause engagement of all the contact means controlled by said certain other cam means when said operating member moves said certain other cam means beyond the position of normal alternation.

2. In a device for controlling the stopping, starting and sequential or joint operation of several electric units, an insulating lock having contact means thereon for making and breaking a circuit and a single set of contacts for each unit, means operable in one direction only to sequentially operate said single sets as said means moves into consecutive positions, means oscillatable to operate said making and breaking means, a base and end formations cooperating with said block to support the moving parts of the device, and side plates having portions interlocking with said block and base and held in place thereby to totally enclose the operating parts, and a single operating member mounted exteriorly of and connected with said oscillatable and said unidirectional means to operate the same.

3. In a device for controlling the stopping, starting and sequential or joint operation of several units, supporting means including a base, end formations and an insulating block, said block having contact means thereon for making and breaking a circuit, and a single set of contacts for each unit, means operable in one direction only to sequentially operate said single sets as said means moves into consecutive positions, means oscillatable to operate said making and breaking means, andside plates interlocking with opposite parts of said supporting means and held in place thereby to totally enclose the operating parts of the device, and a single operating member mounted exteriorly of and connected with said oscillatable and said uni-directional means to operate the same.

4. In a device for controlling the stopping, starting and sequential or joint operation of several electric units, comprising an insulating body having thereon circuit making and breaking means, and a single selector contact means for each of the several units, in combination with a single operating means for all of said contact means, a central axis about which said operating means moves, means causing said making and breaking means to oscillate with said operating means. means for causing continuous movement of said selector means in one direction only as said operating means moves in said direction, a pivotally mounted arm having a connection for moving said operating means, means constructed and arranged to transmit the motion of said arm to said operating means with multiplied efiect.

5. In a device for controlling the stopping, starting and sequential or joint operation of several electric units, comprising an insulating body having thereon circuit making and breaking means, and a single selector contact means for each of the several units, in combination with a single operating means for all of said contact means, a central axis about which said operating means moves, means causing said making and breaking means to oscillate with said operating means, means for causing continuous movement of said selector means in one direction only as said operating means moves in said direction, a pivotally mounted arm having a connection for moving said operating means, the pivot of said arm being spaced from said central axis of the operating means on the opposite side of said axis from said connection, whereby to multiply the effect of the motion of said arm on said operating means.

6. A device for controlling alternate or joint operation of electrical devices comprising an operating member moving responsive to the conditions to be controlled, a plurality of cam means, individual contact means operable by each cam means, certain of said cam means being operable as a unit with said member, means to cause certain other of said cam means to move only when said member moves in one direction, said certain other cam means being constructed and arranged to operate as a unit and to alternate the engagement of the several contact means controlled thereby each time said member moves into one position and to cause engagement of all of the contact means controlled by said certain other cam means when said certain other cam means is moved beyond the position for normal alternation.

'7. A device for controlling alternate or joint operation of electric devices comprising a rotary shaft, an operating member for oscillating said shaft, a plurality of cam means revoluble about the axis of said shaft, individual contact means operable by each cam means, certain of said cam means being operable as a unit with said shaft, means to cause certain other of said cam means to move only When said operating member moves in one direction, said certain other cam means being constructed and arranged to operate as a unit and to alternate the engagement of the several contact means controlled thereby each time said member moves into one position and to cause engagement of all the contact means controlled by said certain other cam means when said certain other cam means is moved beyond the position for normal alternation.

8. A device for controlling alternate or joint operation of electric devices comprising a rotary shaft, an operating member for oscillating said shaft, a plurality of cam means revoluble about the axis of said shaft, individual contact means operable by each cam means, certain of said cam means being operable as a unit with said shaft, a sleeve rotatable on said shaft to which certain other of said cam means are afiixed, means to cause said certain other cam means and sleeve to move only when said operating member moves in one direction, said certain other cam means being constructed and arranged to alternate the engagement of the several contact means controlled thereby each time said member moves into one position and to cause engagement of all the contact means controlled by said certain other cam means when said certain other cam means ismoved beyond the position of normal alternation.

PAUL T. GALT, JR. HAROLD E. SCHLEICHER.

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