US2479266A - Quick make and break switch - Google Patents

Description

R. N. ROWE QUICK MAKE AND BREAK SWITCH l' l L il HHK Filed Aug. 13, 1947 Aug. 16, 1949.

1g INVEN TOR.

RAYMoNn N. Rowe A RNEY Illllmlm' l f IIIIHI'T EXAMINER R. N. RowE Filed Aug. 13, 1947 QUICK MAKE AND BREAK SWITCH 3 Sheets-Sheet 2 f l /19 f i' I T- v50 Z6 21 a 15 INVENTOR. RAYMONDNROWE AT oRNEY EXAMNER i g 16, 1949 R. N. Rows 2,479,266

QUICK MAKE AND BREAK SWITCH Filed Aug. 13, 1947 3 Sheets-Sheet 3 INVEN TOR. RAYMOND N Rowe By y Patented Aug. 16, 1949 2,

.UNITED sTATEs PATENT OFFICE QUICK MAKE AND BREAK SWITCH Raymond N. Rowe, Plainville, Conn., assignor to The Trumbull Electric Manufacturing Company, Plainville, Conn., a corporation of Connecticut Application August 13, 1947, Serial No. 768,399

(Cl. 20G-67) 2 Fig. 2 is an end view of the mechanism of Fig. 1.

Fig. 3 is a side view of the same but with the parts in the "off position.

in my application Serial Number 713,194, led 5 Fig. 4 is a side view showing the power apply- November 30, 1946. It is designed to give easier ing parts in the position they occupy at the mooperation of the switch handle, to minimize hazment when the switch is to snap from the on ards from sticking contacts and otherwise imto the on position of the switch.

prove the electrical performance of the switch, Fig. 5 is a side view showing the power applyand to prolong the mechanical life of the coning parts in the on position of the switch contact-operating mechanism. tacts.

These objects, and others, are obtained by a Fig. 6 is a similar view showing the parts as new arrangement in the mechanical linkage bethey have started to move from the on toward tween the switch operating handle and the bar or the oi position. yoke which moves the movable switch contacts. l5 Fig. 7 shows the mid position of the parts in An improved over-center spring action is used for passing from the on to the oi position of the the usual quick-make and quick-break motion. switch contacts.

This is supplemented by an assembly which Fig. 8 is a rear view showing the snap action varies the mechanical advantage of the power of throwing mechanism in the off or open circuit the throwing spring during different portions of position of the switch.

the switch contact movement. Figs. 9, 10 and 11 are detail views of parts of the It is especially important to have high mesnap action mechanism. chanical advantage when the mechanism is The base I5 of the construction may be of any breaking the contacts during contact opening. suitable form adapted to support one or more This ensures added mechanical power applied switch units I6 with stationary and movable conto the contacts to prevent their sticking or weldtacts which may be of any suitable form such, ing during the natural arcing which results from for instance, as shown in my patent No. 2,468,235, the interruption` of heavy power circuits. How- April 26, 1949. ever. the throwing distance of neither the switch For the operation of the movable switch memcontact nor the operating handle should be great. ber I provide a cross bar I'I which has a shaft I3 otherwise the space occupied by the parts and and is carried by a yoke pivoted at I9 and havmechanism would be enlarged over those at presing side arms 20. The arm 2I is hinged at I3 ent known. and provided with means for engaging a plate My improved mechanism will increase the me- 22 which has a reciprocating movement at one chanical advantage from the handle and throwside of the base of the mechanism. Plate 22 has ing spring to the switch contact during opening three shoulders 23, 2l and 25 adapted to coact movement by shifting the point of application of with the projections 26 and 21 which extend subforce during this movement. During closing stantially parallel with the pivot axis and with movement of the contacts, when the mechanical the shaft I8 of the cross bar I1 as will be later advantage is of less importance, the point of apunderstood. plication of force is shifted so that the advantage The plate 22 is formed as a part of a projection is constant. This relieves the parts of the forward from the operating lever 30 hinged at mechanism from unnecessary stresses and 3| in the back of the base of the mechanism. strains during this part of the cycle of operation This lever is adapted to swing or reciprocate with of the switch. plate 22 in the base between open and closed These and other objects and advantages, toposition of the switch and abuts against the gether with the details of preferred mechanisms shoulder 32 when the switch is in the oi posifor reaching them will be clearer with reference tion and against the shoulder 33 when the switch to the following detailed specification and the is in the on position. The operating lever accompanying drawings in which: member moves in a path extending substantially Fig. 1 is a front View of switch actuating mechat right angles with the axis of the arm and at anism embodying one form of my invention the an acute angle with the arm when the arm is in parts being in the position they occupy when the closed circuit position. the electric current is closed and showing the The actuating shaft 34 is pivoted to the base throwing mechanism in dotted lines. on the axis 35 and is connected to the cam 3Q which is oscillatable within an opening in the lever 30. This cam 36 has a slotted extension 31 by which it is connected to the swing plate 40 hingedat 4I to the base. This plate 40 has a pin at 42 which extends into the slotted extension 31 so that the plate 40 is tilted by the turn of the cam member 36. The throwing or snap action mechanism includes a tilting piece 43 which has two pins 44, 44 which operate in slots 45, 45 in the offset lug 46 of the plate 40. The throwing rod 41 has a bearing 48 at one end pivoted in the lug 49 which extends rearwardly at one edge of the lever 3U. The other end 5U is pivoted at 5I to the tilting piece 43 and a compression spring 52 is mounted on the rod 41 between the head of the rod 50 and the bearing 48.

In the position shown in Fig. 8 it will be seen that the pressure of the spring 52 pushes the lever 30 in a counterclockwise direction so that the plate 22 is held in the lower position shown in Fig. 3 at which time the cross bar I1 is in the off or open circuit position of the switch.

To close the circuit the actuating shaft 34 is turned in a clockwise direction as viewed from the front or counterclockwise direction as viewed from the rear, as shown in Fig. 8. The rotation of the cam member 36, by reason of the slotted connection with the pin 42, tilts the plate 40 from the position shown in Fig. 8 to that shown in Fig. 1 and thus compresses the spring 52 and throws over the lever 30 from the 01T to the on position. In this action the movement of the plate 22 causes the shoulder 25 to engage the shaft I8 of the cross bar and thus applies a rotative force to the cross bar about the axis of the pivots I9.

To open the circuit, the shaft 34 is rotated in a counterclockwise direction as viewed from the front which reverses the action of the snap action mechanism during which action the lever 30 is turned in a clockwise direction as viewed from the front and moves the plate 22 from the position of Figs. 1 and 5 toward the position of Fig. 3. At the beginning of this movement the shoulder 23 of the plate 22 engages the projection 26 on the arm 2l and thus applies a maximum leverage to the arm 2| for the purpose of moving the switch actuating cross bar l1. As the plate 22 moves downward the shoulder 24 on the plate engages the projection 21 on the arm 2l which being much closer to the axis of the pivot I9 applies less power to the switch actuating yoke and cross bar at which time less force is required.

It will thus be seen that the mechanical advantage is varied during the movement of the mechanism corresponding to the opening of the circuit of the switch. It is important to have high mechanical advantage when breaking the circuit but also desirable to have a short throwing distance in order that the mechanism may be as compact as possible. By shifting the point of application of force as above mentioned this is accomplished.

By the construction of the snap action mechanism herein shown and described I am enabled to obtain a quick-make and quick-break by the use of a single spring.

In case of a broken spring the movement to open the circuit is elected as the cam shoulder 60 engages the shoulder 6I on the lever 3B and thus moves the lever toward the off position of Fig. 3 after the cam tilts plate 40.

In moving from off to on the cam shoulder 62 engages shoulder 63 on the lever 30 and presses it toward the position of Fig. 1.

The construction and operation of the tilting piece 43 with respect to the plate 40 are such that it is practically impossible for the parts to get stuck on a dead center.

The quick make and break mechanism herein shown is more fully set forth and claimed in Patent No. 2,368,463, April 26, 1949.

I claim:

1. In a quick make and break switch, a hinged actuator, manually operable snap action mechanism including a plate having stepped shoulders, said actuator including a hinged arm having a number of projections at dilferent distances from the hinge of said actuator coacting sequentially with said shoulders in moving said actuator from on to off position.

2. In a quick make switch, a hinged arm, a switch actuator shaft carried by said arm, said arm having an outer projection further than said snaft from said hinge and another inner projection between said shaft and said hinge and a throwing plate having shoulders coacting sequentially with said outer and inner projection in moving from an "on to an off position of said switch.

3. In a quick make switch, a hinged arm, a switch actuator shaft carried by said arm, said arm having an outer projection further than said shaft from said hinge and another inner projection between said shaft and said hinge and a throwing plate having shoulders coacting sequentially with said outer and inner projection in moving from an on to an off position of said switch and a third shoulder coacting with said shaft in moving from an "o to an on position.

4. An electric switch comprising a hinged arm having an operative member for reciprocating a switch member, manually actuated means for throwing said arm, including a member having a stepped plate, said arm havingr a projection near its outer end and another projection nearer its hinged end adapted to be engaged sequentially by said plate when moving said switch member from its off to its on position.

5. In an electric switch, a frame for moving a switch member, said frame having a hinged side arm with two projections at different distances from the axis of said hinge, manually actuated snap action mechanism having a plate with shoulders adapted rst to engage the projection at the greatest distance from the axis of the hinge of said frame at the first part of the movement of the snap action mechanism and then to engage a projection nearer the axis of the hinge as the mechanism is moved to open the circuit through said switch member.

6. In an electric switch a base for supporting contact mechanism, a movable switch member, means for actuating said member, including a hinged arm having projections at two different distances from its axisy a hinged lever carried by the baseand having a projection with stepped shoulders for sequentially engaging said projections, a rotatable cam having means for engaging said lever for actuating the same, a plate hinged to said base and having a sliding connection with said cam and a throwing arm having a tilting connection with said plate and a rocking connection with said lever.

7. An electric switch comprising cooperating switch contacts, one of which is movable, a. pivotally mounted arm, means connecting said arm to said movable contact for movement thereof by said arm between open and closed circuit positions, inner and outer projections on said arm. said inner projection being between the pivot axis of said arm and said outer projection, an operating member for said arm mounted for reciprocating movement transversely of said pivot axis, and shoulder portions on said operating member extending substantially at right angles with said pivot axis and positioned first to engage said outer projection for maximum leverage to initiate opening movement of said arm and thereafter engage said inner projection for decreased leverage during the completion of the movement of said arm to said open position.

8. An electric switch comprising cooperating switch contacts, one of which is movable, a pivotally mounted arm. means connecting said arm to said movable contact for movement thereof by said arm between open and closed circuit po- LHVH Miti extending substantially at right angles with said pivot axis and at an acute angle with said arm when said arm is in said closed position, and shoulder portions on said operating member extending substantially at right angles with said pivot axis and said path and positioned first to engage said outer projection for maximum leverage to initiate opening movement of said arm and thereafter engage said inner projection for decreased leverage during the completion of the movement of said arm to said open position.

RAYMOND N. ROWE.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS sitions, inner and outer projections on said arm Number Name Date extending in a direction substantially parallel 20 1,564,330 Meyers Man 27, 19231.09 fr with the pivot axis of said arm, said inner por- 1,736,727 Adam Dea 30, 1930 U,- f tion being between said pivot axis and said outer 1,799,099 Johnson MaI- 31, 1931 L., o f projection, an operating member for said arm 1,314,777 Wurdack July 14, 1931 mounted for reciprocating movement in a. path

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