US1280076A - Multiple-switch starter. - Google Patents

Description

A. H. OLMSTED & L. BOOTHMAN.

MULTIPLE SWITCH STARTER.

APPLICATION FILED DECA. 1913.

Patented Sept. 24, 1918.

2 SHEETSSHEET 1.

ATTORNEY WITNESSES:

A. H. ()LMSTED & L. BOOTHMAN.

MULTIPLE SWITCH STARTER.

APPLICATION man DEC. 4. 191a.

Patented Sept. 24, .1918.

2 SHEETSSHEET 2.

WITNESSES INVENTOR UNITED STATES rA'rE OFFICE.

ALEXANDEE'H. oLms'rEn, E BOWDEN, AND LAWRENCE 300THMAN,' 0E scmn'rronn',

ENGLAND, ASSIGNORS T0 wE's'rxNcnonsE ELECTRIC AND MANUFACTURING com- :eANY, a CORI'OBATION or PENNSYLVANIA.

MULTIPLE-SWITCH STARTER.

subject of the King of. Great Britain, and a resident of Stretford, in the county of Lane caster, England, have invented a new and useful Im rovement in .Multiple-Switch Starters, 0 which the following is a specification. .Our invention relates tostarting and regulating devices for electric motors in which a number of hand-operated switches are employed, and it has for its object to provide an improved device of this description.

According to our invention, the. switches employed are of the so-called loose handle. circuit breaker type which cannot be held closed either when the voltage fails or when there is an overload on the circuit. Each switch is mechanicallyinterlocked with the next in such a manner that the switches cannot be closed except in a predetermined sequence and will open only in the inverse order to that in which they were closed.

In one form of our invention, catches are employed for each switch so that the device may be utilized for regulating as well as for starting a motor, but, owing to the fact that the switches are of the loose handle type, the motor will still be protected by the overload and no-volt release devices. i

In order that our invention may be clearly understood, a practical form of the same will now be described, by way of example, with reference to the accom anying drawings, in which Figure 1 is a ront view of a multiple switch rheostat constructedin accordance with our invention, all of the switches being in the closed position; Fig. 2'.

is a sectional view of therheostat shown in Fig. 1, illustrating the means employed for preventing the separate switches from being closed except in the predetermined sequence and under the desired electrical conditions of the circuit, and Fig. 3 is a view, similar to Fig. 2, showing one of the switches in Specification of Letters Patent.

I 12, as mentioned above.

Patented Sept. 24, 1918.

Application filed December 4, 1913. Serial No. 804,641.

the open position and the means employed for closing the first switch of the series.

I Fig. 4 is an enlarged view illustratin the interlocking mechanism for two 0 the switches.

Referring particularly to 1 of thedrawings, the multiple switch starting rheostat 1 constituting this invention is shown as comprising four separate switches 2, 3, 4 and 5 mounted u on an insulating baseplate 6, which, if desired, may form a panel of a switchboard, the switches being connected in the motor circuit so as to control the usual regulating resistor. An electromagnet '7, which is arranged on the baselate 6, or on an other suitable support in the vicinity of t e rheostat, comprises an armature 8 in the form of a crank. that is secured upona shaft 9. The shaft 9 is supported in bearings 10 and 11 and carries levers adapted to act upon suitable toggle mechanism for closing the switches and retaining them closed, as will be more particularlydescribed hereinafter. This shaft is rotated by means of a handle 12, to bring the armature 8 into engagement with the pole pieces 13, 14 of the electromagnet 7 prior to closing the first switch 2 of the rheostat. The electromagnet 7 is connected in the motor circuit and, if there is no failure of voltage, it is energized u on this circuit being closed and then he ds its-armature 8 against the pole pieces 13 and 14, assuming that the armature has first been moved into that postion by hand by means of the handle In case of a failure of voltage on the motor circuit, the electromagnet 7 fails to hold its armature against the pole pieces 13 and 14 and, in consequence, when the handle 12 isreleased by the operator, the shaft 9 is rotated through a considerable angle and carries the arma- 14 of the electromagnet '7, the arrangement being such that, under the action of gravity, assisted, if desired, by a spring or the like acting upon the handle 12- and armature 8, the shaft 9 has a tendency to rotate in a direction to move the armature 8 away from the said pole pieces. This rotative movement is commonly employed for the protec-- tion of electrical apparatus against overloads and it is, therefore, unnecessary-to.

complicate the drawing by showing any devices for dealing specially with overloads.

Referring now to Figs. 2 and 3 of the drawings, each separate switch of the rheostat 1 is constructed and operated after the manner of the well .known loose handle type of circuit breaker. Only the first switch 2 is shown in these figures and will be described in detail, as the remaining switches 3, 4 and 5 are, or may be, similar to switch 2, with the exception of those additional details which are peculiar to the first and last switches of the series and which will be pointed out hereinafter. Each of the switches 2, 3, 4 and 5 cpnsists of a switch arm 15 pivoted at a fixed point 16 and carrying a movable laminated brush contact piece 17 adapted to engage and connect together the fixed contact members 18 and 19. A carbon block 20, which is connected to the contact member 19, coacts with a sparking tip 21 that is provided at the upper end of the switch member 15 to make rubbing contact therewith when the switch is closed and opened, in a manner well understood. A link 22 is pivoted at one end 23 to the switch arm 15 and, at the other end, is connected by a pin 24 toone end of a link 25, the other end of which is piv oted to any suitable fixed point 26. A third depending link 27, which is also connected, at one end, tothe pin 24, carries, at its lower end, a roller 28 to be engaged by the switchoperating lever 29, which is actuated by means of a handle 30. The links 22, 25 and 27 and roller 28 constitute a toggle mechanism that is adapted to force the switch arm 15 from the open into the closed position when the roller 28 is raised. When the switch arm 15 is open, the toggle links 22, 25 and 27 are in the collapsed position shown in Fig. 3. If the operating lever 29 is raised into engagement with the toggle roller 28, when the toggle mechanism is in this collapsed position, the link 27 only tends to turn on the pivot pin 24 to cause the roller 28 to slide to the right, as-seen in Fig. 3, along the upper edge of the operating lever 29. Consequently, the switches may be closed only by means of the corresponding operating levers 29 by providing .ing arm 38 that is adapted a device to restrain each roller 28 from sliding along the operating lever, in the manner stated above. In order to thus restrain the toggle roller'28 of each of the switches2, 3, 4 and 5 from slidin along its operating lever, when engaged t ereby, a hook 31 is pivoted upon a lug 32 on each switch arm 15 with the exception of the last switch of the rheostat. The hooks 31 are formed with lateral extensions 35, as clearly seen in Fig. 1, to enable the hook attached to one switch arm, when this has been closed, to come into engagement with the toggle roller 28 of the next switch of the series. Each hook 31 is also provided with a dependin arm 33 that is adapted to be engaged by a le the shaft 9 when the latter has been rotated by the handle-12 into the position shownin Fig. 2. In this position, the armature 8, carried by the shaft 9, is in en agement with the pole pieces 13 and 14 o the .novoltage electromagnet 7, as described above, the arms 33 of the hooks 31 being so formed that a hook of one switch arm will fail to engage the toggle roller 28 of the next swltch arm to be closed if the shaft 9 is not in the said position. 7

To enable the first switch 2 of the rheostat to be closed, this switch is provided with a special hook 36 (Fi'g. 3) which is pivoted upon a fixed point 37, preferably arranged so as to be in alinement with the ivots of the hooks 31 corresponding to the ollowing SWIt ChBS 3, 4 and 5 when these are successlvely closed. The hook 36 has a dependto be enga ed by the corresponding lever 34 on the sha t 9.

In order that the closure of each succ eeding switch of the rheostat may be utillzed to retain the operating lever 29 of the preceding switch in its closed position, in the preferred form, a projection 39 is provlded upon the arm of each of the switches 3, 4 and 5 that is adapted, in the closed positionof the corresponding switch, to engage beneath and support a projection 40 on-the operatmg lever 29 of the preceding switch, while the operating lever of the last switch 5 of the series is held in its closedposition by any suitable mechanical catch 41 (Fig. 1).

The operation of the rheostat, for the purpose of tarting one or more electric motors, is as follows :The' operator first raises the armature 8 into engagement with the pole pieces 13 and 14 of the no-voltage electromagnet 7 by raising, with one hand, the handle 12 and thus rotating the shaft 9 into the position shown in Fig. 2 in which a lever 34 thereon enga s the depending arm 38 of the special hook-36. The hook 36 is thusbrought into a position to restrain the toggle roller 28 of thefirst switch 2 of the rheostat from sliding along the corresponding operating lever 29. Each of the remainver 34 upon.

sesame ing levers 34 on the shaft 9 engages the dependin arm 33 of the hook 31 of the correspon ing switch 2, 3 or 4, respectively,

' described above. With the other hand, the

' rheostat.

operator now raises. the handle 30 of the operating lever 29 of the first switch 2 of the As the toggle roller 28 of this witch is restrained by the hook 36 (Fig. 3)

from. sliding along the operating handle, the raising of the latter raises the toggle roller 28, thus causing the end 23 of the link 22 that i pivoted to the switch arm 15 to be forced away from the fixed point 26 and the switch arm 15 is thus brought into the closed position shown in Fig. 2. Current then flows through the motor circuit and 'through the no-voltage electromagnet 7 and the latter, in consequence, attracts its armature 8 and thereby holds the shaft 9 and levers 34 in the operative position shown in Fig. 2. The operator then releases the handle 12 and, if there is neither failure of voltage nor an overload upon the motor circuit, he proceeds to close the remaining switches 3, 4 and 5 of the rheostat in succession by means of the corresponding operating levers 29 and handles 30, holding switch 2 closed with one hand until, with the other hand, he has closed switch 3, then releasing the handle of switch 2 to close switch 4, and so on. As switch 2 is closed, the hook 31 attached thereto is brought into engagement with the toggle roller 28 of switch 3, the closure of which again brings the corresponding hook 31 into engagement with the toggle roller 28 of switch 4, and so on; it being impossible to close any switch of the series except in the predetermined sequence provided for. As switch 3 is brought into the closed position in the manner just de scribed, the projection 39 thereon engages beneath the projection 40 on the operating lever 29 of switch2, holding this in the closed position and enabling the operator to release the handle of switch 2 in order to close the next switch of the series, each succeeding switch arm, on being brought into the closed position, supporting the operating lever 29 of the preceding switch in a similar manner. On the last switch 5 of the rheostat being closed, the mechanical catch 41 is brought into position to support the corresponding operating lever 29. All resistance being now out out of the circuit, the

' motors will receive their maximum acceleration, and the rheostat may be relinquished by the operator.

Invcase a failure of voltage or an overload should occur on the motor circuit, the no-voltage electromagnet 7 will release its armature 8, and the shaft 9 will be rotated by gravity acting on the handle 12 and armature 8, in the manner described above to bring the levers 34 into the position shown in Fig. 3. The hook 31 and 36 are thus allowed to rotate into their inoperative position, and the toggle rollers 28, being left unsupported, slide along the operating levers 29, thus allowing the toggle mechanism to collapse and the switch arms 15 to come into the openfiposition. As each operating lever 29 is supported by the arm 15 of the next succeeding switch, the opening of the switches by reason of a failure of voltage .or of an overload will cause'the operatinglevers 29 also to come'into the open position shown in Fig. 3, with the exceptionof the operating lever of switch 5, which is retained in its raised positionby the catch 41 until released by the operator. In order that all of the switches may not open simultaneously, projections 42' are provided on the left hand side of the arms 15 of switches 5, 4 and 3 (see Fig. l) to respectively overlap projections 43 on the right hand side of the'arms of switches 4, 3 and 2, in such a manner that switch 5 must open first, switch 4 second, switch 3 third, and lastly switch 2. By reason of this arrangement, the switches can only open in the inverse order to that in which they were closed. 1

In order to open the switches at will, the operator may withdraw the catch 41'which supports the operating lever 29 of the last switch 5 in its closed position, when this lever will fall into the position shown in Fig. 3, thus allowing the corresponding toggle links to collapse and the switch 5 to open, while the opening of switch 5 permits tions shown in Fig.- 3. As an alternative to the above procedure, the operator may simply open the circuit of the n'o-voltage elec' tromagnet 7 by means of a special switch (not shown) provided for this purpose. The electro-magnet, being thus denergized, releases its armature 8, thus allowing the shaft 9 to 'rotateand move the levers 34 out of.

engagement with the hooks 31 and 36 which, consequently, fall into their inoperative positions. The toggle roller 28 of switch 5, being now no longer restrained, slides along its operating lever 29 and allows the toggle links of switch 5 to collapse and. the switch to open. As all the-toggle rollers 28 of the remainin switches 4, 3 and 2 are now unrestrained y the corresponding hooks 31 and 36, these switches also open in the order stated after the opening of switch 5. The opening of switch 5 permits the operating lever 29 of switch 4 to fall into its open position, and the operating levers of switches 3 and '2 are similarly released by theopening of switches 4 and 3, respectively, the operating lever of switch 5 being finally released by withdrawing the catch 41.

From the above description, it will be seen that the switches 2, 3, at and 5, constituting the rheostat 1, can only be closed in the sequence stated and can not be closed at all if there is any failure of voltage or an overload on the motor circuit, the said sequence being so arranged that the regulating resistance units are successively cut out of the motor circuit by the closing of the switches, and the motors are thereby accelerated up to their maximum working speed.

In some cases, it may be desirable to use the multiple switch rheostat constituting this invention for the purpose of regulating the voltage or other electrical characteristic of an electric circuit. To enable the rheostat to be employed in this manner, accordin to this invention, a mechanical catch similar to the catch 41 (Fig. 1) may be provided for each switch or any selected switches of the rheostat, and,. on any such switch being closed, it may be left in the closed position by applying the catch to the switch-operating handle 29 and without the necessity of closing the next succeeding switch of the rheostat. The circuit to be regulatedby the rheostat in thismanner will still be protected against failures of voltage or overloads, owing to the fact that each switch is of the loose handle circuit breaker type and can only remain closed as long as the no-voltage electromagnet 7 is energized and, by means of its armature 8, holds the shaft 9 and levers 34 in the position shown in Fig. 2, in which the hooks 31 and 36 are held in operative engagement with the corresponding toggle rollers 28, as has been described above. 7

We claim as our invention:

1. In a motor starter, the combination with a plurality of switches, actuating members therefor, and means for loosely connecting said members to said switches, of means for controlling said connecting means to insure the closing of said switches in .a predetermined sequence.

2. In a motor starter, the combination with a plurality of switches, actuating members therefor, and 'means for loosely connecting said members to said switches, of means for controlling said connecting means to insure the opening of said switches in a predetermined sequence.

3. In a motor starter, the combination with a plurality of switches having actuating levers that are independently movable relatively thereto, of means for operatively connecting said levers to said switches and means for insuring the closing of said switches and the actuation of said levers in a predetermined sequence and the opening of said switches in a sequence inverse to that in which they were closed.

4. In a motor starter, the combination with a plurality of switches, actuating members for said switches, and toggle mechanism for connecting said members to said switches, of means controlled by one of said switches for controlling the operativeness of the toggle mechanism of a second switch.

In a motor starter, the combination with a plurality of switches, and means for operating said switches, said means comprising members independently movable relatively to said switches, of means for interlocking said switches, and means for interlocking said members.

6. The combination with a movable switch member, a lever, and means for connecting the lever to the switch member,said means comprising a rotatable member for engaging said lover, of means for manually and automatically controlling the movement of said rotatable member relatively to said lever.

7. The combination with a movable switch member, a lever, means for connecting said lever to said member, said means comprising a toggle mechanism and a rotatable member connected to said toggle mechanism for engaging said levcr, of means for controlling the movement of said rotatable member relatively to said lever.

8. The combination with a movable switch member, a lever, and means for connecting the lever to the switch member, said means comprising a member movable relatively to said lever, a lever for controlling the movement of said movable member relatively to the first lever, and automatic means for controlling the second lever.

9. The combination with a plurality of switch members, actuating levers therefor, and means for operatively connecting each of said levers to a correspondin switch, of means controlled by one of said switch members for controlling the operativeness of the connecting means between another of said switch members and its corresponding lever.

10. The combination with a-plurality of switch members and actuating levers therefor independently movable thereto, of means controlled by one of said switch members, according to its position, for controlling the operative connection of one of said levers to another of said switch members.

11. Ina motor starter, the combination with a plurality of switch members and actuatinghandles therefor independently movable with reference thereto except under predetermined conditions, of means for operatively connecting said handles to the corresponding switch members, and means for rendering the connecting means for one of said switches operative only when another of said switches occupies a closed position.

12. In a motor starter, the combination with a plurality ofswitch members and actuating handles therefor independently movable with reference thereto except under predetermined conditions, of means for operatively connecting said handles to the corre sponding switch members, the connecting means for one of said switches comprising a pivotally mounted member for engaging one of the parts to be connected but which is movable thereon about its point of pivotal support when another of said switches is open, and a member controlled by said other 20 switch for preventing the pivotal movements of said member when said other switch is closed.

In testimony whereof, we have hereunto v subscribed our names this. 6th day of No- 35 vember, v1913.

ALEXANDER H. OLMSTEIl. LAWRENCE BOOTHMAN.

Witnesses:

J. S. PECK, K. FAYE HANSEN.

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