US2332633A - Enclosed switch - Google Patents

Description

Oct. 26, 1943. F, s GREEN 2,332,633

ENCLOSED SWITCH Fi1ed Aug. 5, 1940 s sheets-,sheet 1 INVENTOR: Pz. @yD S. GREEN Oct. 26,' 1943.

F. s. GREEN ENCLOSED swITcH Filed Aug. 5, 1940 3 Sheets-Shel??I 2 INVENTOR: L om. S. GREEN Ot. 26, 1943. F. s. GREEN ENCLOSED SWITCH Filed Aug. 5, 1940 I5 Sheets-Sheet 5 INVENTOR: [s/*10m S. GREEN Patented Oct. 26, 1943 2,332,633 ENCLOSED SWITCH Floydv S." Green, St. Louis, Mo., assignor to Frank Adam Electric Company, St. Louis, Mo., a corporation of Missouri Application August 5, 1940, serial No. 351,522

(ci. zoo-o) 9 Claims.

This invention relates to improvements in enclosed switches. More particularly, the invention relates `to improvementsin safety devices used on enclosed switches. It is an object of the invention to provide lsimple but positive acting safety yvents the holding ofuarcs between the contacts when the circuit is lopened or closed. Arcing between the contacts causes burningthereof which materially decreases the eiciency of the electri- V cal connectionmadeby the switch. The burning also shortens thelife of the contacts and decreases the eifective life of the switch. The quick 'make and break mechanisms whichl have been used are of various types. A commonly used type of quick make and break operating mechanism for switches utilizes what is known as the overcenter spring. There are various arrangements Aof this ltype some employingthe spring' in tension andsome incompression. Such operating mechanisms usually have a dead center position when the spring is leither fully compressed or tensioned.v l'his makes a quick make or break in the circuit Vand savesjthe contacts from burning. An objection to the use Vof* the quick make and break mechanisms, which Ahave a dead center position, is thatthe switch sometimes gets set on dead center. In such cases the handle is not completely in the full "on" or ofi position, and

the operator cannot be sure Athat the switch is either "on or offL In vertically mounted switches it often happens that the lower position of the handle indicates that the switch is olf. If there is 4any play inthe' handle mechanism when the switch is in the dead center position the handle will fall to the off` position even though the switch maybe closed. j This is obviously a dangerous situation which can give rise tonumerous accidents. The applicant avoids such'fsitnations byproviding-,means to move the handle into the on positionwhen the switch is in the dead center positionl As a 'result of this improvement. the. operator will believe the switch is on Whenever it is on dead center. Since .the handle vindicates that the circuit .isr made, the operator will act as though it were and will be careful to avoid shocks. .l

In enclosed type switches,E the manufacturers try to avoid accidentsto laymen who work around the switches by locking the door to the switchbox whenever the circuit is made. This prevents contact with the electrified parts of the switches when the circuit is made. It is, however, sometimes desirable for the purpose of inspection, to open the door of the switch-box when the circuit is'made. lIt is, therefore, necessary to provide a locking arrangement which will prevent the open ing of the switch door at all ordinary times when the switch is on, but will letthe door be'opened for purposes of testing and inspection. Such a locking arrangement, to effectuate the object for which it is intended, should be so designed that a person could not open the door while the switch is "on unless he were shown how it can be done. By showing only lelectrical inspectors how to open the switch-box when the circuit is on, the man-l ufacturers would be assured that laymen would be very'unlikely to contact electried parts of the switch. Some of the switches now in use have provided means to do this, but these means are complicatedand require the inspector either to have a special tool to open the box, or to insert his hands in the box. Thisv is bothersome and dangerous, The applicant has provided a locking arrangement which precludes opening of the switch door by laymen when the circuit is on, which will, by an adjustment of the switch handle, permit the door to be opened for inspection even when the circuit is made. This prevents any accidental shocking of layme'n, since the box cannot be opened without knowledge of its operation.

In enclosed type switches which have a switch handle extending` from the iront of the box, it is difficult to ship them Aeiiiciently since the handle projects out from the front of the box. This will not permit the boxes to be piled closely together for shipment, and a pile of switches with handles already`installed takes much more room than one in' which the switches are shipped withoutthe handles being installed. The applicant avoids this objection by providing a handle which may be shipped with the Abox and assembled merely by inserting it in the front of the box. This `permits the box to be shipped economically and yet avoids expensive assembly charges for the .drawings and accompanying description do not limit the invention and that the invention will be defined by the accompanying claims.

,ber 22 rotates. locking projection 28 thereon which cooperates with the door-locking catch 20 .to prevent the .opening of the door.

, rotation of the'locking member 22. .tion 40 on the locking member 22 rotates with Fig. is a view of a broken section of the en- A closed switch-box and shows the arrangement and position of the locking means when the h'andle is in the off position.

Fig. 6 is a view of a broken section of the enclosed switch-box andr shows Ythe arrangement and position of the locking means when the parts of the switch cooperate to permit opening of the door while the switch is on.

Fig. 7 is a View of a broken section of the enclosed switch-box and shows the arrangement and position ofv the locking means .when the handle is in the on position.

Fig. 8 is a perspective view of an optional form of handle and rotatablemember assembly to be used with an enclosed type switch.

Fig. 9 is a partial cross sectional view of the handle and rotatable member sh'own in Fig. 8, andV Figs. 10 and 10A are side and end views of a. spring used to secure the handle to the rotatable member.

Referring to the drawings in detail, the switch-box is denoted by the numeral I4 and has ardoor which is denoted by the numeral I6. 'I'h'e switch door I6 has a hasp I8 attached to it which ypermits the operator to open the door manually. Also attached to th'e door I6 is a locking catch which engages the locking member 22. The

locking member 22 has a hole 24, through Which a pin 26 extends, and around which' the mem- The locking member` 22 has a A projection 30 extends from the side of locking member 22 and engages the rotatable member 32 connected to the handle 34. VA curved opening 36 in the locking member 22 Ycooperates with a pin 38 to permit limited A projecthe locking member 22 and serves to clear or to vobstruct the opening 42 in the cover oi.A the.y

. switch-box.

In the quick-make and break operating mechanism 44A is va pivoted oscillating member. A switch' operating bar or lever 46 is struck by i turned out portions '48' onthe pivoted oscillating member 44. The pivoted oscillatingmember is actuated by bar which extends from the y'operating handle and is rotatably secured to the pivoted oscillating member. A spring 54 is carried on a guide rod 52. When the rod 52 is aligned with the pivot of the oscillating member and its point of connection with the oscillating 'member the spring is compressed to its maximum and the oscillating member is in a deadcenter position. Slight movement from this positioncauses the spring to bias the oscillating member away from this position. The lever 50 has a slot 56 with which the lower end of the handle 34 cooperates. The switch mechanism is provided with a number of springs. A spring 58 connects the locking member 22 with the pin 38 and tends to cause the rotation of the locking member into the off position. A spring 60 is connected to the switch-box and to the lever 50 and tends to urge the switch into the on position. Another spring 62 connected to the lever 50 and the end of handle 32 tends to hold the handle in the on position.

AAn optional form o! handle design is shown, by use of which the handle may be shipped separate from the switch-box, and may be inserted nin the box when the box is to be used. A spring switch' door 64 is set in the rotatable member 32 and holds the optional form of handle 35 so that it cannot slip out. i By use of this device, the switches can be shipped economically without wasting space and assembled without inconvenience to the purchaser.

- When the box is shipped to the consumer, he need only insert the handle into the rotatable member to put the box in operating condition. When the handle is moved into the on position, the member 32 moves the bar or lever 50 `which rotates the oscillating member 44 to com'- press spring 54. When the oscillating member is carried beyond the dead-center position, the

'spring 54 is released and quicklyrotates theoscillating member 44.` Slots 56 in bar 50 allow movement of vthe oscillating member independently of th'e handle, so that the projections 48 strike the switch operating bar 46 to snap the switch into the "on" position. This provides a means to quickly make thecircuit and avoid the many objections to slow circuit-making. The rotation of the rotatable member 32 into the on position moves it into the path' of projection 30 on the locking member 22. This, prevents the opening of the switch door I6 since, to open the door I6, the locking member 22 must rotate and release the door catch 20. Since the I6 cannot be opened when the switch isV in this position, the operator is protected against shocks of an accidental nature.

It sometimes is desirable to open the door` of the' enclosed switch-box when the switch is in the on position, for the purposes of testing or inspection. In many of the boxes now'in use, the door can be opened while the switch is in the "on position, but the operator is requiredeither to insert a tool or his fingers into the box. The insertion of a tool or a finger into the switchbox renders the operator subject to shock, and this makes the job of testing and inspecting switch-boxes a dangerous one. The invention provides a Way of opening the switch-box door by proper manipulation of the handle and does not require the operator to insert anything into the box. This provides a very safe way of opening the door for the purposes of inspection. The operator only needs to grip the hasp on the box with one hand and to rotate the handle with the other. The rotation of the handle causes the ro- Atatingmember 32 to move a short distance toward the 01T position and open'a path for the projection 30 on the locking member 22. The projection 30 can move into the opening 33 in the vrotatable member 32, and such movement of prodoor cannot be opened. In. order to open the door, the `operator must overcome the pull of the spring SZandhold the lharidle stationary in the proper position;V In addition, tlieopening $3 in the rotatable member 32-ls made small and conforms to4 theshape ofprojection 30 on the locking membex'v22'. Thislpermits the. door to be `opened at only oneposition'of the handle when the switch is on, andlprevents the opening of the door at all other positions except the oi position. When thehandle is in the on position', the rotatable member 32 is ln the position shown in Fig..5. Theprojection 40 on the locking member 22 is free to move across the opening I2' in theswitch-box cover under the influence of the spring: 58.- SWhile .the projection 40 is across the opening 42, the handle cannot be rotated into the on" 'po'sltiomsince rotatl'on'of the rotatable member 32 is prevented by the projection 40. 'I'his is an'additional safety feature since the operator cannot turn on the switch while the switch door is open. The operator, therefore, cannot electrify the parts of the switch while he is working on the box and is protected from accidental shocks. When the locking member 22 is in the off position, the projection 28 is rotated so that it does not obstruct the door catch 20. This permits the door I6 to be opened and closed freely. By use of this type of locking member, a switch-box is provided which cannot be opened when the switch is in the full "on position, which can be opened by proper manipulation of the handle when the switch is in the on position, and which can be freely opened and closed when the switch is in the oi position.

Another feature of the invention is the means which keeps the handle in the on position whenever the oscillating member is in the dead center position. In circuit breaker boxes now in use which employ a dead center snap-acting mechanism, the handle can drop down near the olf position when the oscillating member is in the dead center position. This is dangerous since it indicates that the switch is off even though it may be on. Because the handle indicates that the switch is off, the operator may work on sub-panels and distribution boxes and be shocked. This is very dangerous and has been objected to by Various organizations. licant has devised a means to move the handle into the on position whenever the switch is on dead center. This warns the operator and prevents his believing that the switch is oil when the circuit is made. The means is simple l and consists of a spring 62 that is connected to 50 and the handle 34 and urges the handle into the on position.

Whereas I have described a preferred embodiment of my invention, it is obvious to those skilled in the art that various changes and alterations may be made in the form of the invention without altering its scope.

It can be seen from the above, that by use of the present invention, a switch-box is provided which safeguards the operator from shocks and electrical accidents.

What I claim is:

1. In an enclosed type switch, a switch-box having an opening therethrough, a switch-operating mechanism located in the switch-box ccmprising a bail having a handlel receptacle attached thereto, a spring in the handle receptacle, and a handle, said handle being adapted to be inserted through the opening in the switch-box The apinto the handle receptacleland tightly held by a spring mounted therein, said spring and said handle receptacle being arranged to lock the handle in engagement with the handle receptacle and prevent the disengagement of thehandle and the handle receptacle under most conditions.

2. In a switch-operating mechanism, the combination of a switch-box, a bail having a handle receptacle attached thereto, a handle adapted to be installed in the switch-operating mechanism by insertion in the handlereceptacle, and means to automatically hold the handle upon its insertion in the handle receptacle, and prevent the disengagement of the handle and the handle receptacle under most conditions.

3. In a quick make and break operating mechanism for switches, a pivoted oscillating member adapted to bring about actuation of an electric switch, an over-center spring biasing said oscillating member to both on andfoff" positions, said spring causing a dead-center position of the oscillating member when it is under maximum stress, a handle effective to rotate the oscillating member and a means biasing the handle to on position when the oscillating member is in dead-center position.

4. In an enclosed type switch a quick make and break operating mechanism comprising a switch operating bar, a pivoted oscillating member arranged to actuate said bar, means to operate said oscillating memberrinto on and oil position, an over-center spring biasing said oscillating member into both off and on position, said spring causing the oscillating member to assume a dead-center position when it is under maximum stress and means to indicate that the switch is on when the oscillating member is in the dead-center position.

5. A switch operating mechanism comprising a switch operating bar, a pivoted oscillating member arranged to actuate said bar, an operating handle, a lost-motion connection between the handle and the oscillating member, an over-center spring biasing the oscillating member to both on and oi position and means biasing the handle to the on position.

6. In an enclosed type switch, an enclosing box, an electric switch in said box, a door in the box, a catch on the door, a locking member pivotally supported from the box, one end of said locking member engaging the catch, means biasing the locking member to rotate said end against the catch, a handle pivotally supported from the box and movable to an off and on position and eiective to actuate the electric switch, a disc rotatable with the handle, a projection on the other end of the locking member adapted to move under the disc to prevent its rotation when opening of the door moves the catch out of the path of the irst named end of the locking member, a projection on the catch adapted to cause movement of the locking member whenever the door is opened or closed, a projection on the locking member engaging the side of the disc and arranged to prevent movement of the locking member, a recess in the disc adapted to allow entrance of the projection on the locking member and thus allow movement of the locking member when the switch handle and rotatable disc are in a predetermined position.

'7. In an enclosed type switch, an enclosing box, an electric switch therein, a door in said box, a catch on the door, a locking member pivotally supported from the box, one end of said locking member engaging the catch, means biasing the rlocking meinberto rotate said endagainst the catch, a handle pivotally supported from the box and movable to an' on and oif position and eiective toV actuate the electric switch, a semi-circular disc rotatable with the handle in a plane perpendicular to the face of the box, a projectionon the other end of the locking member adapted to m'ove under the disc and prevent movement of the handle to the on position when the door is opened and the catch is moved out of the path of the iirst named end of the locking member, a projection on the door catch adapted to cause movement of the locking member whenever the door is opened or closed, a projection on the locking member engaging the side of the disc and arranged to prevent movement of the locking member and thus opening of the door.

8. In an enclosed type switch, a switch box, a switch, an operating bail for said switch, a pivoted oscillating member provided with projections thereon to strike opposite sides of the operating bail, a bar having one end rotatably secured to said oscillating member and having the other end slotted, a handle, a connection between the handle and the slotted portion of the bar allowing lost motion therebetween, an over-center spring biasing the oscillating member in both ofi and on positions and means biasing the handle in the on position.y

9. In an enclosed type switch, an enclosing box, an electric switch therein, a switch operating mechanism located in the switch box comprising a bail and a handle receptacle attached thereto, a spring in the handle receptacle, and a handle adapted to have one end inserted into the handle receptacle, said spring and said handle receptacle being arranged to lock the. handle in the receptacle and prevent the removal oi.' the handle under most conditions.

FLOYD S. GREEN.

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