US1231992A - Electrical switch. - Google Patents

Description

0. R. BLUMBERG 6L 8. D. HORTON.

ELECTRICAL SWITCH.

APPLICATION FILED JUNE2, i914.

EOLIOE IIIII Patented July 3, 1917.

3 SHEETS-SHEET I.

O. R. BLUMBERG & B. D. HORTOF ELECTRICAL SWITCH.

APPLICATION FILED JUNE 2.19M

1,231,992. Patented July 3,1917.

- 3 SHEETS-SHEET 2 FIG. 5

0. R. BLUMBERG & B. D. HORTON.

ELECTRICAL SWITCH.

Patented July 3, 1917.

3 SHEETS-SHEET a 4 M 1 M. E N u 1 D E L H N o H A c U P P A a n J 1 W a p n a a k9? mm Du 4%: n i Y; [EL u H J 27 N n g T d m w E n a A Y 8 s 9 v o o F H 2 \N\\ J L 1 r n a Mam flu wua Mow UNITED STATES PATENT OFFICE.

OSCAR 13.. BLUMBERG AND BRYSOZN 1). HORTON, or person, vrrcnrenn, nssianons 'ro DETROIT FUSE & MFG. COMPANY, 0]? person, MICHIGAN, A CORPORATION or MICHIGAN.

ELECTRICAL $WITCH.

Specification of Letters Iatent.

"Patented July 3, 19 17.

To all-whom it may concern:

Be it known that we, OSCAR B. Bnu vrnnno and BRYSON D. Hon'ron, citizens of the United States, both residing at Detroit, in the county of Wayne and State of Michigan, have invented certain new and useful Improvements in Electrical Switches, of which the following, taken in connection with the accompanying sheet of drawings, is a full, clear, and concise description thereof.

This present invention relates to certain improvements in the type of electrical switches illustrated and described in United States Letters Patent No. 1,022,628 granted April 9th, 1912, to Bryson D. Horton. This type of switch is designed primarily for service as a three-phase motor starter, wherein the three lines or conductors are accommodated, their circuits being controlled by switching instrumentalities cooperatively arranged and controlled in such manner as to provide for the establishment and breaking of the circuit of the line con ductors.

Included among these instrumentalities, are two movable switch members arranged for vertical reciprocation, one a fuse carrying main switch member, which is designed for carrying the running load and the other the auxiliary switch member provided with a conductor for carrying the starting load. The operation of the main and auxiliary switch members may be manually accom' plished by means of a convenient operating crank, for the proper shifting or manipulation of the movable contacts relatively to the stationary contacts. For instance, when it is desired to start the motor, the main and auxiliary switch members (which we will term for sake of convenience running and starting switches, respectively) are simultaneously moved, effecting contact between the running switch and the stationary contacts of the line conductor, thus positioning the starting switch in the circuit. Automatic means are provided for disconnecting or releasing the starting switch, after the motor gets under way, from the running switch, the latter remaining in con nection with the stationary contacts of the line conductors. In order to interrupt or break the running load circuit, manual manipulation of the crank is required.

This is a brief description of the chief structural characteristics and mode of operation of the typeof switch referred to as described in the aforesaid Letters Patent. Our present improvements we have applied to this form of switch and have therefore, illustrated a structure which bears close analogy to the illustrated structure of Said patent, omitting certain features and adding others of improvement thereto.

Among these improved features, which are comprehended within our invention, is automatic means for releasing the running switch, to interrupt or break the motor circuit, in other words, Eto automatically throw the switch off. This means comprehends certain mechanical instruinentalities which are controlled by an alternating current magnet, comprising no-voltage or low-voltage resistance coils, which operate when the voltage is taken off from the'source or falls below a definite degree to actuate the intermediate instrumentalities which cooperate with the running switch, to release the same so that under spring tension, the running switch will automatically break the motor line circuit.

()ur invention furthermore comprehends certain modifications in this general scheme, wherein a series of auxiliary coils are ar ranged individually to control the breaking of the motor line circuit upon the blowing of any one of several fuses across the terminals of which the particular coil is connected.

Vith the above specific objects and advantages in view, we will proceed to describe one preferable embodiment of the structural characteristics of our invention, which we have illustrated by way of example only in the accompanying drawings, having it understood that we do not restrict ourselves in matters of details, as these may be changed or altered without departing from the invention as defined in the appended claims.

Figure 1 is a view in side elevation partly in vertical section of a switch embodying our invention.

Fig. 2 is an end View thereof showing the no voltage or low voltage magnetic release feature part ofthe housing being removed.

Fig. 3 is a view in vertical section taken on lines A-A of Fig. 1.

Fig. 4 is a detail showing the operating crank for manually releasing the running switch.

Fl 5 is a. plan view of Fig. 1 with the mova 1e switch mechanism removed and showing the wiring connections between the stationary contacts and the no voltage or low voltage magnet.

Fig. 6 is a diagrammatic illustration of a modification showing individual fuse controlled releasing coils which control the o eration of an armature, which opens t e circuit through the no voltage or low voltage release coils of the switch.

In detail the switch mechanism is arranged within a metallic housing 1, which is provided with a removable cover 2. Upon the base of the housing is mounted three porcelain blocks 3, upon which are mounted the stationary contacts 4 of the switch-jaw type. To these contacts are connected the three-phase circuit conductors, as is shown clearly in Fig. 5. cooperatively associated with the stationary contacts 4 are the movable parts of the switch mechanism, mounted upon and carried bythe underside of the cover 2 of the receptacle.

The movable switch mechanism comprises, as heretofore stated, a starting switch and a running switch, both including the necessary cooperating contacts, which provide for the establishment of the circuits. These switches are arranged to reciprocate along a pair of depending guide rods 5, fastened at oneend to the cover of the receptacle. The opposite ends of these guide rodsare connected together by a cross-bar (i which limits the downward movement of the reciprocating switches and also forms a support for springs, which provide the necessary power to throw the running" switch off when the same is automatically released by the no-voltage magnet. The running switch comprises a suitably formed cross-head 7 provided with bearings 8, which also are arranged to reciprocate along the guide' rods Ii. The cross-head 7 carries the switch knife blades J and fuse carriers 10. Between the cross-head 7 and cross-bar 6 is interposed expansion springs 11, held in position by the guide bins 12. The crosshead 7 also carries oppositely disposed to the blade contacts 9, knife blade contacts 13, which coooperate with the contacts of. the starting switch when the two switches are brought together.

The starting switch comprises a crosshead 14 also arranged for vertical reciprocation along the guide rods 5. The starting switch cross-head 14 is provided with jaw contacts 15 (three pairs in number) oppositely disposed to the knife-blade contacts 13 of the running switch. Each pair of jaw contacts 15 is connected by means of an electrical conductor 1.6 ofsuliicieut capacity to accon'nnodate the starting load or overload of the electrical apparatus with which the device is intended to cooperate.

At the ends of the cross-head 14 of the starting switch are depending arms 1.7, which are connected by means of expansion springs 18 to the underside of the cover of the housing. These springs normally tend to hold the starting switch in its off position. To provide for the throwing of the starting switch as well as the running switch into on position, an operating arm 19 is provided, this arm being journaled in the sides of the casin and is provided with'a handle 20 exterior t iereof, by means of which it is manipulated. The free end of this arm .19 rests upon an engaging surface 21. and by rocking the arm, both switches are caused to descend, the starting-switch descending against the tension or natural pull of the spring 18. It will be observed that as soon as manual power is removed from the opening handle 20, the spring 18 will immediately withdraw the starting switch to its ofl' position, which is done as soon as the motor has attained synchronism or its normal running speed leaving only in circuit the protective fuses of the running switch through which the circuit current flows.

Dependin centrally of the cross-head 7 is a hook mem er 22 arranged to cooperatively engage a complemental hook member 23, the latter being mounted upon a rock shaft 24. which is journaled in bearings 25, at one end of the casing and at 26 at the other end. The hook members 22 and 23 automatically couple themselves when the switches are thrown downwardly, the running switch being retained in this position while the motor is running. It will be noted that the compression springs 11 are under compressive tension ready to lift or throw off the running switch upon the release of the hook members 22 and 23. The movement of the rock shaft 24 controls the locking and releasing of the hook members 22 and 23.

Provision for both manually and automatically rocking the shaft 24 to release the running switch is provided. This feature of the invention. will now he described. Upon the side of the casing 1 is provided a housin 27. in which is positioned a no or low vditage alternating current magnet 2$. This magnet is made up of two-coils 29 in series and are made up with a plurality of laminated cores of single sheet metal stampings 30. The coils 29 are connected by leads or; wires 31 and 32 with jaw contacts 4; of two of the three-phase lines or leads to the motor as shown more clearly in Fig. Through these connections, the coils receive their energizing current and thereby attract and hold the armature 33 of the rock arm device 34, which is mounted fast upon our end of the rock shaft 24-, thereby retaining the rock shaft, and running switch in co operative running position so long as the coils 29 are energized. In order to eliminate all chattering between the points of contact with the magnet cores, the magnets are provided with what is known in the art as shading coils,- which produce a noiseless alternating current magnet, and serve to ettect a )ositive un t-vibrating connection or loosenmg connection between the hooks 22 and when the running switch mechanism is In on position.

The magnet is rendered inoperative as soon as it is deenergized by a bleak in the circuit, which may be caused by a blown fuse or upon a lowering of the voltage according to the character of the magnet used. In tl'ie'happening of such an event, the armature 33 is released of the required magnetic pull to hold it and the rock arm device 3-L is caused to rock or oscillate under the tension pull of the spring 35, connected to the hook member 36 rigidly connected to the side of the casin The movement of this rock arm device 3* causes the armature 33 to separate from the laminated cores of the magnet 28 and by reason of its rigid connection with the shaft 2% causes the latter to likewise throw the hook 23 out of engagement with the hook 22 of the running switch releasing the latter, which under the tension of the springs 11 is caused to quickly move upwardly breaking the connection between the knife blade contacts 9 and jaw contacts 4 and thus opening the circuit.

Should it be desired to throw the. running switch off while the current is llo\v ing and the magnets are energized, we. have provided an operating crank 37 )(Hlilluled in the magnet housing 27. lhe free interior end of this crank is provided with a finger 38 of cam formation, which upon being rotated is caused to engage end 39 of rock arm device 34., imparting to the latter a movement around its axis, thus causing a break between the magnet and its armature and likewise causing a rotation of the shaft l-t and a. release of the hooks 2:2 and 23. limiting stop 40 for limiting the extent of: movement of the rock arm device EH, is provided. and is mounted upon a fixed support 41 which includes a screw and lock nut 43, the end of the screw engaging a reduced portion or extension ll of the rock arm device 34.

in the modification shown in Fig. (3, we. employ three separate coils 47. (only one of which can be observed as they are intended to be in line with each other) each separately connected in parallel or shunt with one fuse of the three-phase motor starter illustrated. These fuses are mounted upon blocks 48, 49 and 50. It will be understood that this threephase motor starter is used in conjunction with the. no-voltage magnetic release switch. which has been heretofore described, the magnet of which is indicated at if a fuse is blown, the particular coil connected across its terminals is energized by a part of the current which normally passed through the fuse, and attracts the armature 51, which is of a bell crank forma tion pivoted at 52 and provided with a contact 53, which coopt-a'atcs with the contact 5-1 in the circuit across one phase, thus breaking the electrical connection l'ietween the contacts and 54, opening the no-voltage release circuit deiinergizing the no or low voltage release magnets 28, which in turn causes the rocking ot' the shaft 24: under the pull of the spring 35 and the release of the hooks 22 and 2 :5, so that the running switch may be thrown oti by the action ol the con'ipression springs ll. the various circuits being so clearly illustrz'ited. it is not thought necessary to spccil'ieallv de scribe them. I

Having thus described our invention, what we claim as new herein and desire to secure by Letters Patent, is

1. In a threephase motor starting switch, the combination of a starting switch and a running switch, means for simultaneously operating the starting and running switches to establish a closed circuit, automatic means for maintaining the running switch in closed circuit position after the starting switch has been thrown to its oil' position, and automatic means controlled by the volt age of the line circuit for releasing the running switch and throwing the same to its oll' position.

2. In a three-phase motor starting switch, the combination, of reciprocally-mounted starting and running switches, means common to both switches for moving them into circuit making position, automatic means for throwing the starting switch to its off position when the operating means is re leased, means for holding the running switch in on position after the starting switch has been thrown otf, means for releasing the running switch on a fall in the voltage of the line circuit, and means for :mtomaticallythrowing the running switch to its oil position.

A switch of the character described, comprising in combination, a starting switch, a running switch, means for simultaneously moving both starting and running switches into circuit-making position, a rocking member for holding the running switch in circuit making position, after the starting switch has been moved to its circuit-breaking position, said rocking member being controlled by an electro-magnet which receives its energizing current from the line circuit, means for manually operating the rocking member to release the running switch, and means for :tlltOllltttltiilll) throwing the running switch to its circuitbreaking position.

t. In a switch of the character described,

the combination of a starting switch and a running switch, means normally tending to hold the starting and running switches in their ofi or circuit-breaking position, marmally operated means for causing simultaneous movement of the starting and running switches to their circuit-making position, magnetically operated means for holding the running switch in the latter position, spring means for throwing the starting switch to its circuit-breaking position upon the release of the manually operated means, and means for releasing the holding means to permit the running switch to move to its circuit-breaking position.

5. A switch of the character described, comprising in combination, a starting switch, a running switch, means for simul taneously moving both starting and running switches into circuit-making position, a rocking member for holding the running switch in circuit-making position, after the starting switch has been moved to its cirwit-breaking position, means for either manually or automatically controlling the movement of said rocking member to effect the release of the running switch, and means for automatically throwing the running switch to its circuit-breaking position.

In witness whereof we have hereunto set our hands in the presence of two subscribing witnesses.

OSCAR R. BLUMBERG. BRYSON I). HORTON.

\Vitnesses ALBERT E. STU'rzNnn, JOHN B. PLATE.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents. Washington, D. C.

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