US2144665A

US2144665A - Push button operated master switch

Info

Publication number: US2144665A
Application number: US58459A
Authority: US
Inventors: Christian A Rasmussen
Original assignee: Individual
Current assignee: Individual
Priority date: 1936-01-10
Filing date: 1936-01-10
Publication date: 1939-01-24
Anticipated expiration: 1956-01-24

Description

Jan. 24, 1939. c. A. RASMUSSEN 2,144,665

PUSH BUTTON OPERATED MASTER SWITCH Filed Jan. 1Q, '1936 E Sheets-Sheet l F'IE- 2.

N E 5 S U M n R a... N m M ATTORN EY Jan; 24, 1939. c. A. RAsMUssEN 2,144,565

PUSH BUTTON OFERATED MASTER SWITCH n Filed Jan. lO, 1956 2 Sheets-Sheet 2 PIE VIR/6 T'IHN H HSHUSS E N INVENTOR ATTORNEY Patented Jan. 24, 1939 UNITED STATES PATENT OFFICE PUSH BUTTON OPERATED MASTER SWITCH 3 Claims.

This invention relates to master switches adapted to control the current supply to electric motors by the medium of magnetic contactors, and more particularly to push button operated master switches.

Presently known master switches of the push button type embody a plurality of individual, independent push button switches, each of which controls an individual circuit. It is well known, that the operation of these individual push button switches complicates the control of the master switch and also necessitates a special cut-out switch, to permit of the current being cut off, when one or the other of theY push button switches sticks or should get out of order.

The primary object of the present invention is the provision of a simplified push button operated master switch, having only two coupled push buttons, each of which is adapted to control a plurality of circuits, the push buttons being coupled with each other to prevent their independent operation.

Another object of the invention is the provision of a push button operated master switch with two coupled push buttons, each of which is adapted to control a plurality of circuits, and with means for automatically and simultaneously returning the push buttons to their neutral position, when the buttons are released by the operator.

A further object of the invention is the provision of a simplified push button operated master switch with two coupled push buttons actuating a multi-contact switch, which switch is adapted to control a plurality of circuits for multi speed forward and reverse rotation of a motor.

Still another object of the invention is the provision of a simplified push button operated master switch with two push buttons actuating upon a rotary switch drum adapted to control a plurality of circuits for multi speed forward and reverse rotation of a motor.

A still further object of the invention is the provision of a simplified push button operated master switch with two push buttons, coupled with each other and with a rotary switch drum adapted to selectively open and close a plurality of circuits ior multi-speed forward and reverse rotation of a motor, the switch drum being provided with means for automatically rotating same and the push buttons coupled therewith to neutral position.

In addition the invention has certain other marked superiorities, which radically distinguish it from presently known structures. These improvements or superior characteristics embodying certainnovelfeatures of construction arevset forth in the appended claims, and a preferred form of embodiment of the invention is hereinafter shown with reference to the accompanying drawings forming part of the specification.

In these drawings:

Figure 1 is a front elevation of a push button operated. drum master switch according to the invention.

Figure 2 is a cross sectional view through the push button operated drum master switch shown in Figure i, the section being taken on line 2 2 of Figure 1.

Figure 3 is a longitudinal sectional view through the push button operated drum master switch shown in Figure 1, the section being taken on line 3 3 of Figure l.

Figure 4 is a front elevation of the drum or cylinder of the push button operated master switch.

Figure 5 is a cross sectional view through Figure 4, the section being takenvon line 5 5.

Figure 6 is a longitudinal sectional view through Figure 4, the section being taken on line 6 6.

Figure 7 is a cross sectional view through Figure 6, the section being taken on line 1 1.

Figure 8 is a wiring diagram for a magnetic reversing panel with five speed points and with a five position push button operated master switch, as shown in Figures 1-7, for the control of a slip ring motor.

Referring more particularly to the drawings, the push button master switch embodies a housing having a base 2, a middle portion 3 and a cover 4, the base, the middle portion and the cover being rigidly connected to each other by means of screws 5 and 6 respectively. The box-shaped base mounts a bakelite or fiber plate l, which plate is rigidly secured to the base by means of screws 8, and this iiber plate carries two rows of spaced contact members 9, which members are attached to said plate by means of screws I0. The contact members 9 are electrically connected by means of leads I I with the net I2 and with the contacts I3 of a magnetic reversing panel I4', which panel is provided with iive speed points, see Figure 8. The Contact members 9 cooperate with a rotatable switch drum I4, which drum is mounted to rotate around a xed shaft I5, having its lower end I6 guided in a bore I1 in the middle portion 3 and its upper end I8 pinned to a bracket I9 by means of a pin 20. The bracket I9, which is rigidly secured to the wall 2| of the middle portion 3 by means of screws 22 suspends the shaft I5 and prevents its rotation, so that the drum I4 is properly guided during switchingV operations.

freely rotate around the shaft I5 and the hub 'I'he drum I4, which is made of bakelite or other suitable insulating material, embodies a hollow cylinder 23, having its open top and bottom portions closed by

ber discs

24, 25 respectively. The top disc 24 is provided with a cylindrical extension' 24', supporting a gear 26, which gear is rigidly attached to said extension by means of screws 2'I, so that the cylinder 23, its top disc 24 and the gear 26 rotate jointly around the shaft I5, when the gear 26 is actuated upon by mechanism hereinafter to be described. The outer surface of the cylinder 23 of the drum I4 carries two, substantially oppositely arranged contact segments 28, which segments are secured to the cylinder 23 by'means of screws 29. These contact segments 28 cooperate with the contact members 9, when the drum I4 is rotated and thus permit of a plurality of circuits being opened and closed by rtation of the drum i4.

The drum i4 can be rotated in either direction against the torsional force of a spring 30, which spring tends to automatically rotate said drum to ar neutral position, in which the segments 28 and the Contact Ymembers 9 are separated from each other and no current flows through the switch. This spring is sleeved upon Vthe elongated hub 3i of a disc 32 having its hub lholds the spring 30 in proper position upon the hub 3|. The disc 32 carries close to its peripheral edge an upwardly extending post 35, which post ,is engagedat opposite sides by the laterally extended free ends 36 and 3l of the spring 3i), when said spring is under torsional tension, see Figure '7. The ends 36 and 3l of the spring 30 furthermore engage a post 38, extending downwardly from the gear 23. This post 38 is extendedthrough the top disc 24 of the drum i4 and so related to the post 35, that post 38 can 3i connected therewith without interfering with the upwardly extending post 35. The post 38, which terminates just above the disc 32, effects the rotation of the drum I4 against the torsional force of the spring 30, when the gear 26 is rotated in either direction by the mechanism now to be described, and thus insures automatic resetting of the drum to its neutral position at will of the operator. y

The operating mechanism for the gear 2S and therewith for the drum I4 embodies two push buttons 39 and 4U, the push `button 39 effecting a left-handed rotation of the drum and the push button lil effecting a right-handed rotation. of said drum. rI'hus the two push buttons carry at their lower ends rack bars 4I, 42 respectively, which bars are symmetrically arranged with respectV to the gear 26 for cooperation therewith. lThe rack bars 4I, 42 are guided in brackets 43, which brackets arev secured byv means of screws 44 to the middle portion 3 of the housing. The

push buttons

39 and 43 extend through openings 45 in the cover 4 to permit of these buttons being readily actuated upon by the operator. It should be noted that these push buttons are coupled with each other by the gear 26 and that therefore the operator, when actuating one button,.simultaneously shifts the other button, as a downward movement of one button effects an upward movement of the other button and viceversa. k

`The shape of the contact segments 28, which cooperate with the contact members 9 permitsA of five consecutive positions of the master switch for forward and for reverse operation of a motor, as will readily be seen from an inspection of Figure 8. This figure shows diagrammatically the electric coupling of the five position push button Voperated master switch with a reversing magnetic panel having five speed points, the panel being connected with a slip ring motor 46. Such magnetic reversing panels being old in the art and rnot subject to this invention, a tracing of the circuits for the diierent'speeds of the motor is thought to be superfluous and. therefore omitted, the diagram being merely shown to indicate an application of the master switch.

Multi-position push button operated master switches of the typeV described are particularly adapted for manual control of motors in machine tools, hoisting apparatus and so forth. When used'for hoisting apparatus these switches may be used with the so called stiff arm control of the carriage, as these switches can readily be attached to and suspended from the carriage by means of a stiff arm lever extended from theV carriage. For pendent control, a wire cable, not

on the middle portion 3 of the housing, so as to release strain on the iiexible conduit tothe switch. A handle bar 48, arranged on .the cover 4 just below the

push buttons

39 and 40 permits of convenient operation of the switch.

Having thus describedmy invention, ,what I claim is: Y

1. A master switch for a stiff arm control hoist comprising a housing, a handle bar extended from said housing parallel to the longitudinal axis thereof, reversible rotary switch mechanism insaid housing substantially in alignment with its longitudinal axis,rspring means holding said Vswitch mechanism yieldingly in neutral position,

and two push button means arranged side by side in rectangular relation with respect to said spring means. Y

2. A master switch comprising a housing having a handle bar extended from its upper front portion parallel to the longitudinal axis of the housing, a shaft having one end rigidly secured to said housing in substantial alignment with the longitudinal axis thereof, a control drum mounted to freely rotate around said shaft, contact members secured to said housing and cooperating with said drum during switching operations, two push button means rectangularly related to said shaft extended through said housing adjacent to each other just above and symmetrically arranged to said handle bar, coupling meansconnecting said push buttons with veach other and said control drum adapted to shift said drum to forward and reverse positions, and yieldingV means coupled with said shaft and said drum for automatically and simultaneously shifting said drum and push button means to neutral position. Y 'Y 3.A A master'switch comprising a housing having a chambered extension at its upper front portion, a handle bar extendeddownwardly fromfl said chambered extension, a stationary shaft extending through said housing parallel to said handle bar having one end rigidly secured to said housing, a control drum mounted to freely rotate around said shaft, contact members secured to said housing and cooperating with said drum during switching operations, two push button means extended through said chambered extension adjacent to each other and symmetrically arranged to said handle bar, rack bars at the inner ends of said push button means, a gear engaging said rack bars rigidly secured to the top of said control drum for rotation therewith,

and yielding means Within said drum connecting said drum and shaft and permitting rotary movements in opposite directions of said drum with respect to said shaft, said coupling means holding said drum yieldingly in neutral position and returning same automatically to its neutral position after each rotary movement of said drum by said push button means.

CHRISTIAN A. RASMUSSEN.