US1498090A - Electric switch - Google Patents

Description

June 17, 1924; 1,498,090

B. E. GETCHELL l ELECTRIC SWITCH II FiledAprll 26 1920 2 Sheets-Sheet 1 June 17, 1924. 1,498,090 v B. E. GETCHELL ELECTRIC SWITCH Filed April 26 1920 2 SheetsfSheat -2 1b W l a m u I Qi 1 b ub `1 T A 3 Q g3 f n l l bg R* A u El( O o; f N N n 2g Inventor: .ece

' r Atty Patented une 17, 1924.

' UNITED STATES PATENT OFFICE.

BENJAMIN E. GETCHELL, F PLAIN'VILLE, CONNECTICUT, ASSIGNOR TO THE TRUM- BULL ELECTRIC MFG. COMPANY, OF PLAINVILLE, CONNECTICUT, A CORPORATION OF CONNECTICUT.

ELECTRIC SWITCH.

` Application led April 26, 1920. Serial No. 376,804.

cation.

My invention relates to a switch for starting and protecting a motor or the like.

My main object is to provide a simple,

rugged, and reliable construction which may be operated by a normal throw of a handle to either close or open the circuit and which will open with a quick break action either by hand or automatically in case of under voltage or overload condition even should the operator attempt to hold the handle.

In its referred form, the switch embodies ordinary well known knife blade type of switch contacts adapted to be operated by hand. A special link and spring connection between the handle and the switch blades enables the operator to close the circuit by a single throw of the handle. The switch is adapted to be opened by hand by the usual single throw of the handle, whereupon the link motion and spring will break the circuit with a snap action independently of the control of the operator. A no-voltage or under-voltage magnet is adapted to release the quick break mechanism upon occurrence of over-load or low voltage, even though the handle be held in the on position. This holds. true either at the time of starting or at any subsequent time while the motor is in operation.l The circuit throu h the no-voltage magnet can be controlle from a distance as well as through the conditions in the switch itself. An overload switch is also provided which is adapted to release the switch mechanism in case of excessive overload. This also is independent ofthe operator.

Fi 1 is a front view of a switch einbodying the improvements of my invention, the cover being omitted and parts shown in the closed circuit position.

Fig. 2 is a side view and partial vertical section of the same.

Fig. 3 is a similar View showing the switch in the open circuit position and omitting theoverload switch.

Fig. 4 is a diagrammatic View showing the circuits through the switch.

In its preferred form, all the parts with the exception of the handle are enclosed in a box or receptacle 6. The circuit terminals are carried by an insulating base 7.

Each of the three knife blades 8,18', and

8 is hinged to a post such as 9, 9', 9 and adapted to engage a stationar contact such as 10, 10', 10". The bla es are carried by an insulating cross bar 11. An operating shaft 12 has its ends 13 pivoted in the box, and is connected to the cross bar 11 by one or more links 14.

.The operating handle 15 has its hub 16 pivotally mounted in one wall of the box.

The handle crank 17 has one end connecti I ed to the hub 16 and the other pivoted in a bracket 18. This crank 17 is connected to the crank-shaft 12 by means of a folding or hinged rod made up of the two arts 19 and 2O hinged together at 21. A atch 22 is pivoted on the crank-shaft 12 :and provided with a shoulder 23 which normally engages the tip 24 on the up er end of the part 19. spring 25 has its ower end connect'ed to the box, and its upper end connected to 'the rod 20 between the shaft 12 and the hinge 21. When the parts are in a position shown in Fig. 2, this spring exerts a downward tension on the bar 20, the longitudinal component of which thrusts against the hinge 21 and tends `to push the bar 19 downwardly. As the crank 17 in this position is in rear of the center line connecting the bearing in the bracket 18 and the crankshaft 12, Ithe action of the spring is to forcibly hold the switch in the closed circuit position. The latch 22 is notched at 26 so as to allow a limited swinging motion of the latch with relation to the stud 27 at theupp'er end of the bar 20.

A releasing member` 28 hinged at 29 lis connected to or forms a part of the armature of the magnet having the coil 30. The magnet when energized holds up the releasing member 28 against the pressure of the spring 31. In case the current fails in the magnet, the armature is released and the spring 31 forces the member 28 downward into engagement with the tai-l of the latch 22. This releases the shoulder 23 from l cation, and dis osition of the weight of the parts is suc as to cause the shoulder 23 to automatically re-engage the tip 24 so that the parts are in vposition to be again set into closed circuit position without further attention or operation. A catch 28 may be provided for tripping the latch 22 when the switch is to be manually operated.

By providing one or more normally closed circuit switches such as 32 in the circuit of the magnet coil 30, I may control the switch from any-one or more remote places.

I also provide an overload switch having coils 33 andl 33 with movable cores 34C and 34 which are adapted to engage and lift the v armature 35 and open the switch 36 in case of an overload. The main line conductors' are connected at 37, 37 and 37 and the local circuit or load conductors are connect ed to the terminals 38, 38 and 38. The solenoid coil 33 is connected between the terminals 9 and 38 at one side and the coil 33 is connected between the terminals 9 and 38" on the other side. The no voltage or low voltage release coil 30 is connected in series with the switch 36 between the terminals 38 and 38. Iny case of an overload, the solenoids 33 and 33 lift the armature 35 and open the switch 36 through the shunt circuit which includes the release magnet coil 30, which being thus deenergized, releases the armature and member 28 so as to trip the latch22 and allow the spring 25 to break the circuit.

It will be noted that the closing movement of the switch is the usual type of single throw movement. The overload coils 33 and 33 will be so designed that the time limit of their action will take care of the starting current. Under voltage or excessive overload will vcause the switch to 4open instantly even though the operator may attempt to hold it by the handle. This holds true either at the time of starting the motor or at any other time while the motor is in op eration. On the other hand, the manual openin of the switch is effected by means of the andle. When once the switch starts to open, the circuit is interrupted with a quick break which cannot be controlled by the operator. No push button release is necessary unless it is desired to be able to open the switch from some remote point, in which case, the circuit of theunder voltage release magnet may be extended to a switch or push button 32 in any desired location.

Only a single main spring is required in this construction and serves to provide a quick'break both on the hand operation and on the automatic operation and also serves to automatically relatch themechanism. By pivoting the switch yoke above the switch pivot and close to the back of the box and locating the handle pivot below the switch should be understood that with an enclosed type of switch of this character a safety latch maybe used if desired. Reference may #1,310,163 for a type suitable to be used in be had to the Knudsen Patent this connection. By using a magnet type of under voltage release coil, I am able to usea much more ruggedl winding than is possible with a solenoid type, and the action is more positive and powerful. All the parts are so constructed that they may be made economically, and they are so arranged that they may be readily removed for repairs and replacements.

By this construction I eliminate the necessity for the use of fuses, and thus practically eliminate motor burnouts which are largely due to the breaking of one fuse and leaving the motor operating single phase. With this switch an overload on eitherphase will open the entire motor circuit.

I claim:

1. In an electric switch, `the combination of a movable contact, a swinging handle, quick break mechanism connecting said handle and said contact and including a spring and latch for normally holding said parts in their closed circuit position, means for releasing said latch when the handle is operated by hand and means for releasing said latch incase of an overload on the circuit, even when the handle is maintained i contact closing position.

2. In an electric switch, the combination of a movable contact, a swinging handle, quick break mechanism connecting said handle and said contact including a spring and latch for normally holding said rparts in their closed circuit position, means for releasing said latch when the handle is operated by hand, means for releasing said latch in case of an overload on the circuit, and means for releasing said latch in case of failure of voltage in the circuit of said switch, even when the handle is maintained in contact closing position.

3. In a switch, a switch casing, a switch blade, a pivoted operating shaft, a connection between said blade and shaft, a hinged member pivoted at one end in said casing' and at the other end to said operating shaft, a spring and a latch cooperating with said hinged member, means for moving said latch upon failure of voltage in the circuit whereby the switch will be opened by the spring with a snap action.

4. In a switch, a switch casing, a switch blade, a pivoted operating shaft, a connection between said blade and shaft, a hinged member pivoted at one end in said casing soz and at the other end to said operating shaft, a spring and a latch cooperating with said hinged member, means Jfor moving said latch in case of an overload on the circuit whereby the switch will be opened by the spring with a snap action.

5. In a switch, a switch blade, an operating crank, a normall rigid hinged member connecting said bla e and crank Whereb when the crank is manipulated the switch will be opened or closed, means for breaking the rigidity of said hinge member upon failure of current to the switch, means for breaking the rigidity of said hinge member when the opening movement of the switch is initiated by the crank, and a spring for opening the switch with a snap action as soon as the rigidity ofthe hinge member is broken.

6. In an electric switch, a movable switch member, a hand o erated crank, a swin ing member connecte to said switch mem er, a hinged member connecting said hand oper? ated crank to said swinging member, a latch pivotally mounted on said swinging member for holding the parts of said hinged member in a substantially straight line relation, means for engaging said latch to release it when said hand operated crank is moved by hand, and electro magnetically controlled means for releasing said latch, even when said hand operated crank is manually prevented from moving.

7. In an electric switch of the character described, a swinging member, a latch pivotally mounted thereon and having a` limited y motion with relation thereto, an operating crank, a member connecting said operating crank with said swinging member consisting of two parts hinged to each other, one part normally engaging said latch, means for releasing said latch from said part when said crank is operated by hand, and means for releasing said latch upon a change in electrical condition in the apparatus.

8. In an electric switch, a movable mem ber, a latch pivotally carried thereby, a hand operable crank, a bar connected to Said crank and normally engaging said latch, a second bar hinged to said vfirst mentioned bar and connected to said movable member, a trip member for engaging said latch when said crank is operated by hand, and an electrically controlled member for engaging said latch.

9. In an electric switch, a movable member, a latch relatively stationary trip for engaging one end of said latch, an electrically controlled member for engaging the opposite end of said latch, a hand operable crank, a bar 'connected to said crank and normally held by said latch, and a second bar hinged to said first bar and to said movable member.

10. In an electric switch, a movable member, a latch pivotally carried thereby, a relatively stationary trip for engaging one end of said latch, an electrically controlled member forenga ing the opposite end of said latch, a han operable crank, a bar connected to said crank and normally held by said latch, a second bar hinged to said first bar and to said movable member, and a .spring connected to said second bar for movin said movable member when said latch 1s re eased and returning said first bar to its normal engagement with said latch.

11. In an electric switch, a movable member, a latch pivoted thereto, a hand operable crank, a bar connected to said crank and normally engaging a shoulder of said latch, a second bar connected to said first bar and to said movable member, a spring connected to said second bar, means for engaging one end of said latch to release it when said crankis operated by hand, and electrically controlled means for engaging the op osite end of said latch to release it from sai first part.

BENJAMIN E. GETCHELL.

ivotally carried thereby, n

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