US920032A - Electric switch. - Google Patents

Description

W. DENNY.

ELECTRIC. SWITCH.

APPLICATION FILED AUG. s, 1908.

Patented Apr. 27, 1909.

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} UNITED STAT FATE/1h T OFKGE.

CHARLES W. DENNY OF MIDDLETOWN, OHIO, ASSIGNOR TO THE BARKELEW ELECTRIC MANUFACTURING COMPANY, A CORPORATION OF OHIO.

ELECTRIC SWITOH.

Specification of Letters Patent.

Patented April 27, 1909.

Application filed August 3, 1908. Serial No. 448,527.

in one position for starting motors and in another position for the running position.

Although particularly adapted for alternating current motors, my improved switch may be used with other forms of motors and may be used to control other forms of translating devices.

One object of my invention is to secure a form of controlling switch simple in construction, durable, compact and easily ac- ,cessible to all its parts.

Another object is to provide a form of switch in which the circuit or circuits will be protected by protective devices in one position and not so rotected in another position. For example, in operating motors it is desirable to insert protective overload devices in the circuit in running position which will open the circuit upon the occurrence of a predetermined overload current, whereas in .the starting position such a current is permissible for a short length of time and if the protective devices were in circuit during starting they would interrupt the circuit unnecessarily. My improved switch is therefore adapted to insert suitable overload protective devices in thenormal operating position but avoids suchinsertion in another position, such as the starting position.

Other objects and advantages of my construction will be understood from the following description and accompanying drawlngs.

Figure 1 is a plan view of one form of switch embodying my invention; Fig. 2 is a side View thereof, and Fig. 3 is an end view.

My improved switch in the form shown in the drawings is of the double throw type with the parts mounted upon a base 1 and comprises fixed contacts 2 for connection in circuit during normal position, also fixed contacts 3 for connection in circuit in the abnormal position,'such as the starting position for a motor, and also a series of fixed contacts 4 to which the supply mains are connected and which are located between the other two series of fixed contacts. The iixed contacts 2 and 3 areprovided with spring clips 5 adapted to receive the switch blades of the movable element.

Themovable part of the switch is pivotally mounted upon. extensions 6, from the fixed contacts 1 by means of switch blades 7 pivotally connected to the extensions 6 by screws 8. The switch blades 7 are adapted to connect the fixed contacts 4 to fixed contacts 3 respectively when the switch is thrown to starting position, at which time the switch blades 7 engage the extensions 5 ofathe fixed contacts 3. The movable ele ment is provided with an operating handle 9 connected to crossbar 10 of insulating material. Fixed to the cross bar 10 by screws 11 are cross pieces 12 also of insulating material, and at the two ends of the cross bar are fixed by screws 11 extensions 13. The cross pieces 12 are slotted at opposite ends for the reception of the switch blades 7 on one side and the switch blades 14 on the other side of the cross bar. The switch blades 7 and 14 are fixed to the cross pieces .12 by screws 15.

The movable element of the switch, supports fuse clips 16 on opposite sides of the cross bar which are stamped and formed from sheet metal and have lower extensions 17 embracing both sides of the switch blades 7 and 14 in the slotted portions of the cross pieces 12, and the screws 15 which serve to fix the switch blades in position also serve to clamp the extensions ofthe fuse clips firmly to the switch blades thus securing good electrical connection with the switch blades and also firmly supporting the fuse clips in place. The fuse clips iixcd to each of the cross pieces 12 are so related to each other that they are adapted to receive the ends of an inclosed or other form of fuse 18, the fuse being shown in place at the left of Figs. 1 and 2 and not being shown in position in the other fuse clips in order to add clearness to the drawings. Each fuse clip is provided with projections 19 bent over at right angles in order to embrace the ends of the fuse 18 as shown in Figs. 1 and 2, and thus prevent the fuses from being improperly placed in position.

Between the projections 13 and the base plate are located coil springs 20, one end of the wire of each s ring being inserted in a perforation in eac extension 18 and the 'wardly extending extensions other end of each spring being inserted in a perforation in the base plate. Thus, when the switch is thrown to the right, referring to Fig. 3, the s prings 20 will be compressed and revent the switch from remaining in this position anlcss held by the operator, and when released by the operator will cause the movable element to be forced quickly from such position over to the running position when the blades 14 will engage the fixed contacts 2, the lower ends of the springs 20 freely working in the perforations in the base plate in order to avoid any tension on the movable element of the switch when placed in running position. The switch will therefore remain in running position, but is prevented from remaining in starting position unless held oy the operator.

I provide at the fixed contacts where circuit connections are to be made, washers 21, having downwhich embrace the sides of the fixed contacts. The ends of the circuit wires to be connected are placed under these washers around the screws and the projections 22 will prevent th'ewashers from turning with the screws 'cuit connections will and'al'so pr vent the ends of the wires from being displaced While the screws are tightened.

The form of switch shown is adapted for startin an alternating currentjmotor of the three-p hase type and the leads'from the sup- 1y wires are connected respectively to the Excel intermediate contacts 4, and the leads .to the motor windings are connected to the fixed contacts 2 respectively. The contacts 3 are connected electrically to corresponding contacts 2, and in this particular formof switch these connections are made at theback of the base 1, the connecting wires 23 for this purpose being located in troughs cut in the back of the base plate and connected to screws 24 engaging the fixed contacts 2 and 3. The troughs and openings in the base at the screws 24 are afterward filled with sulfur or wax in order to insure permanent connection and protection.

It operating the switch, it will first be thrown bythe operator so that the switch blades 7 engage theclips 5 of the fixed contacts' 3, the operator holding the switch in this position against the pressure of the s rin' s 20. The circuit connections will t en e from the supply circuits to the fixed contacts 4, and extensions 6 and switcl'i blades 7 to the-clips 5 of the fixed contacts 3 and then by the. connections 23 to the fixed contacts 2, and thence to the motorcircuits. It will thus be seen that the. fuses 18 are not connected in circuit during this starting position. When the switch is thrown to the running position the blades 14 will engage the clips 5 of the fixed contacts 2 and the cirbe from the supply mains to the fixed contacts 4, then through the extensions 6, through the switch blades 7 and clips to to the fuses 18, thence to the switci'r blades H and through the clips. 5 of the lixed contac ts 2 and thence to the motor circuits, the switch blades' H being connected to the switch blades 7 only by means ofthe fuses.- it will thus be seen that in running position, the circuits are protected by the overload fuses 18 and that these fuses are in circuit only when the. switch is in normal runningposition.

It will be understood that my invention may be embodied in other forms than the articular form shown without departing rom the scope of my invention.

Having thus described my invention,-I declare that what I claim as new and desire to secure by Letters Patent, is, i

1. In an electric switch, the combination .of a double-throw movable element, comprising a plurality of switch blades, a set of flxed contacts to which at least one of said switch blades is Jermanently connected, a second set of fixer contacts, and a protective device carried by said movable element and .electtrically connected in series with at least one of said switch blades.

In an electric switch, the combination of a double-throw movable element com rising a plurality of switch blades, a set of ed contacts to which at least one of said switch blades is permanently connected, a second set of fixed contacts, and an overload protective device carried by said movable element and electrically connected in series with at least one of said switch blades.

3. In an electric switch, the combination of fixed contacts, a movable element for making circuit connections in a plurality of different positions, and an overload protective device carried by said element, and

means for cormecting said device in circuit in one ofsaid positions but not in another of said positions.

4. An electric switch comprising in combination a double-throw movable element in: cluding at least two switch. blades, a fixed contact to which one of said switch blades is permanently connected, a second fixed contact adapted to beengaged by one of said switch blades in one position of said movable element. a third fixed contact adapted to be engaged by another of said switch blades in another position of said movable element, and a protective device mounted on said movable element in series with at least one of said switch blades.

5. In an electric switch, the combination of fixed contacts, a double throw movable clement, an overload protective device carried by said element, and\ means whereby said device is connected in circuit in one position of said element but not intheother position of said element.

6. in an electric switch, the combination tion of said element, a second switch ilade of a double throw movable element, a switch blade carried by said element pivotally connected to a fixed contact, a second fixed eon: tact engaged by said switch blade in. one posicarried by said element, a third fixed contact engaged by said second switch blade in another position of said element, and an overload protective device electrically connectin said two blades.

7. In an electric switch, the combination of a movable element, a switch blade perina-v nently connected to a fixed contact, a second fixed contact engaged by said blade in one position of said element, a second switch blade carried by said element, a third fixed contact engaged by said second switch blade I in another position of said element, and an I overload protective device connecting said two switch blades.

8. In an electric switch, the combination of fixed contacts, a movable element for v I l l i v l l l y l i i l l I l l l l E r making circuit connections in a plurality of '1 different positions, and a protective device v carried by said element, and means for eornecting said device in circuit in one of said positions but not in another of said positions.

9. In an electric switch, the combination of fixed contacts, a double throw movable element, a protective devicecarried by said. element and means whereby said device is 1 1 connected in circuit in one position of said element, but not in the other position of said 3 element.

position of said element, a second switch blade carried by said element, a third fixed contact engaged by said second switch blade in another position of said element, and a protective device connecting said two switch blades.

11. In an electric switch, the combination of sets of fixed contacts, a double-throw element including a plurality of sets of switch blades and nonconducting elements main-- I taining the switch blades of said set in a de- F sired relation, one set of said switch blades 1 being permanently connected to one set of the said fixed contacts, and a protective device carried by said donble-throw element and electrically connecting said sets of switch i blades in series.

in testimony whereof I alfix my signature, in presence of two witnesses.

CHAS. W. DENNY.

Witnesses H. D. DELL, B. l. HARWIT

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