US2807684A - Reversing switch - Google Patents

Description

Sept. 24, 1957 E. H. AYERS REVERSING SWITCH Filed Sept. 7, 1955 3 Sheets-Sheet 1 FIG. I

-INVENTOR. EDGAR H. AYERS BY ATTY.

E. H. AYERS REVERSING SWITCH 54 wQw 4 Y I' "In 100 I] Li li III,

Sept. 24, 1957 Filed Sept. 7, 1955 ATTY.

Sept. 24, 1957 E. H. AYERS 2,807,684

REVERSING SWITCH Filed Sept. 7/1955 3 Sheets-Sheet s INVENTOR. EDGAR H. AYERS ATTY.

United States Patent REVERSING SWITCH Edgar H. Ayers, Niles, Mich., assignor to Clark Equipment Company, a corporation of Michigan Application September 7, 1955, Serial No. 532,816

13 Claims. (Cl. 20067) This invention relates to electrical switches, and has to do with a reversing switch for use in starting, stopping and reversing the direction of drive of direct current electric motors.

My invention is directed to a reversing switch which is of simple construction and operation and may be produced at comparatively low cost and assures definite pressure contact between the contact elements while avoiding arcing therebetween. The switch of my invention has a snap action and assures quick opening and closing of the contact elements regardless of the speed of movement of the operating lever.

In brief, the switch of my invention comprises a pair of toggle actuated switch mechanisms which are spring biased to either open or closed switch positions, substantially according to conventional practice. A common actuator means is disposed and associated with such toggle mechanisms to alternately operate the same. Ar-v rangement between the common actuator and each toggle mechanism includes means whereby the actuator is afforded a neutral operating zone, in which neither toggle mechanism is actuated thereby. Arrangement is further made so that movement of the actuator beyond either limit of its neutral operating zone causes positive actuation of one of the toggle mechanisms. By interconnecting the two toggle switch mechanisms with a suitable electrical connector means, I am able, by the above described arrangement, to provide a toggle actuated switch mechanism which has a positive neutral switching position. Such a switch is ideal for a motor reversing function; since to reverse the switch, it is necessary to first move the actuator through its neutral zone in which the switch and motor are deenergized. Thus, a motor coupled to a switch of this character is fully protected for reverse operation.

Further provision is made in the mechanism of the switch to provide positive separation of welded contact members, independently of the toggle mechanisms, by manipulation of the actuator means. This latter feature assures against jamming of the switch due to welded contacts and thus promotes safety of operation.

The main object of my invention is to provide a new and improved switching device in which toggle actuated switch blades which do not have a stable, neutral switch position are associated in combination with a common actuator means in a manner to provide a toggle actuated switch mechanism having a defined neutral operating position.

Another object of my present invention is to provide a new and improved toggle actuated switch mechanism having a stable neutral operating zone.

A still further object of my invention is to provide a new and improved reversing switch employing toggle actuated switch blades associated with a common actuator by means whereby a switch assembly producing alternate operation of switch blades after movement of the actuator through limits of its neutral operating zone is provided.

Still another object of my invention is to provide a new and improved switch mechanism embodying tog- 2,807,684 Patented Sept. 24, 1957 gle actuated switch blades in which means are provided to produce a stable, neutral operating condition for the switch assembly.

A still additional object of my invention is to provide a meant for disassociating welded contacts in a switch as aforesaid.

The above and further objects, features, and advantages of this invention will appear to those familiar with the art from the following detailed description and with reference to the accompanying drawings.

In the drawings:

Figure l is a plan view of a switch embodying my invention with the parts in the positions which they occupy when the switch is open;

Figure 2 is a side view of the switch of Figure 1;

Figure 3 is a view similar to Figure 1 but with the switch operating lever turned to a position in which certain of the contact elements are closed;

Figure 4 is a sectional view taken substantially on line 4-4 of Figure 2 but with the parts in the positions shown in Figure 3; and

Figures 5, 6 and 7 are diagrammatic views showing the positions of the parts respectively corresponding to the several different positions to which the operating lever may be moved.

The switch comprises a rectangular base plate 10 of suitable material and conductor strips 11 and 12, formed of copper and of substantial thickness, secured on the upper face of base plate 10 along each side thereof. The strips 11 and 12 are of elongated U-shape providing, at the ends of strip 11, upwardly extending arms 13 and at the ends of strip 12 upwardly extending arms 14. Contact elements or buttons 15 are mounted on the inner faces of arms 13 of strip 11 and similar but-,

tons 16 are mounted on the inner faces of arms 14 of strip 12.

Switch blades 17 and 18, preferably formed of strips of copper of substantial thickness, are pivotally mounted adjacent each end of base plate 10 on pivot rods 19secured through base plate 10 and passing through a steel reinforcing strip 20 at the under face of base plate 10, rods 19 being electrically insulated from strip 20 in a suitable known manner. Each of the blades 17 and 18 has secured thereto, at its midlength, a substantially U- shaped stirrup 21 extending outwardly beyond the associated switch blade and receiving the rod 19 for pivoting the switch blade thereon. The lower arm of stirrup 21 seats upon the upper end of a sleeve 22 seating at its lower end on base plate 10 and spacing the switch blade an appropriate distance above the base plate. Each of the stirrups 21 is provided with an inward extension or finger 23 for a purpose to be described presently. A binding post 24 is secured through base plate 10 adjacent each end thereof and is connected, by a braided flexible lead 25 to the adjacent Switchblade 17 or 18. Each of the switch blades 17 and 18 is provided, at each end thereof, with a contact button, blade 17 carrying buttons 26 and 27 which cooperate with contact buttons 16 and 15, respectively, adjacent thereto, and blade 18 carrying buttons 28 and 29 which cooperate with buttons 16 and 15, respectively, adjacent thereto.

A switch operating lever 32 formed of suitable electrical insulating material, is pivotally mounted on a pivot rod 33 secured through reinforcing strip 20 and base plate 10 centrally thereof, rod 33 preferably being at the midlength of lever 32. The lever 32 is of generally H-shape in side view and comprises an upper handle 34 with a downwardly extending neck 35 from the lower end of which extend two arms 36 disposed in underlying parallel relation to handle 34 sides of neck 35.

and at opposite L Each of the switch blades 17 and 18 has secured to its midportion a toggle arm 39 extending inwardly toward neck 35 of lever 32 and provided at its inner end with a notch 40 of substantial width. The notch 40 receives the bight portion 41 of a U-shaped toggle member 42 the upper arm of which overlies toggle arm 39 in proximity thereto. The arms of toggle member 42 .are provided at their outer ends with upwardly and downwardly directed fingers '43 and 44, respectively, finger 43 being pivoted in handle 34 of operating lever 32 and finger 44 being pivoted 'in the corresponding arm 36 of lever 32. A tension spring 45 is anchored at its inner end to a suitably recessed element-of bight 41 of toggle member 42, and is anchored at its outerend'to finger 23 of stirrup 21-on the adjacent switch blade. Adjustable stops '46 are secured to conductor strip 12 and are disposed to be-contacted by arm's 36'of switch =lever 32 for limiting turning thereof in either direction, as will be explained more fully later. An elongated-stud 47 is secured to the switch'blade 17 adjacent'contac't button 26 thereof and a similar stud 48 is secured to switch blade 18 adjacent the contact button 28 thereof, the studs "47 and '48 extending .inwardly'from the switch blades. A pressure applying block 49 is 'secured to one side of :switch operating lever 32 centrally thereof and projects toward the studs '47 and 48 for cooperation therewith in a manner and for alpurpose to be described later.

A binding post 52 is secured through base plate and conductor strip 11 and is provided with an annular flange 53 seating on theupper face of strip 11. Asimilar .binding post 54 is secured through base plate 10 and conductor strip 12 and is provided with an annular flange 55 seating on the upper face-of conductor strip 12. In the use of the.switch,'one pole of a suitable source of direct current electrical energy is connected to the hind ingpo'st 52 and theother pole of such source, which may conveniently be a storage battery, is connected to one side of the armature of the motor to be controlled. Theother side of the motor armature is connected to the binding post 54 and the terminals of the field winding of the motor are connected to the binding posts 24. When the switch-operating lever 32 is in its neutralor switch opening position shown in Figure 1, bothof the tension springs 45 are in over center position and have swiing'the'toggle members 42 toward" the conductor strip 12 thereby turning the switch blades 17 and 18 counterclockwise and'clockwise, respectively, so as to move .the contact buttons 26 and 28 thereof into contact with the 'buttons16 with a snap action. With the parts in the positions shown in Figure 1, the bight portions 41 of the toggle membe'rs 42 are held in pressure contact with the arms 39 at the upper sidesof'the slots or notches 40 thereof,'and the tension springs 45 maintain pressure contactbe-tween the buttons 26 and 28 and the buttons 16. The'buttons 27 and 29 are then in open circuit position spaced away from the buttons of the conductor strip 11,- this opening the power circuit and stopping the motor.

"When the switch operating lever 32 is turned clockwise from its position shown in'Figure 1 to its position shown in Figure 3,'the outer end of the toggle member 42 associated with switch blade 17 passes over'center relative to the corresponding tension spring 45, which is thus stretched and then contracts so as to swing the toggle member 42 in clockwise direction and bring the bight 41 thereof into contact with the toggle arm 39 at the other side of the notch 40 thereof. Thatswings'the switch blade 17 in clockwise direction with asnap action so-as to open the contact buttons 16 and 26-'an'd closethe contact buttons 27 and 15. During that operation the switch blade 18 remains in its position shown in- Figure 1, due to the fact that the outer endof the'corre'sponding toggle member 42 is moved away from the-associated tension spring 45 in the clockwise turning of ope'ra'ting lever 32. With the switch blades in the positions shown in Figure'3 and'in Figure 6 currentfiows from one side of the power source in one direction through the field winding of the motor and, by way of switch blade 18, contact buttons 28 and 16 and the conductor strip 12 to one side of the motor armature and from the other side of the motor armature back to the opposite side of the power source, thus driving the motor in one direction. By turning the switch operating lever 32 counterclockwise from its position of Figure 3 to its position of Figure l, the switch blade 17 is returned to its position shown in Figure 1 thus opening the circuit and stopping the motor. If the switch operating lever 32 is turned in counterclockwise direction beyond its neutral position shown in Figure 1, switch blade 18 is turned counterclockwise with a snap action, in the same manner in which the switch blade 17 was turned clockwise, opening the contact buttons 28 and 16 and closing the contact buttons 29 and 15. The switch blade 17 then remains in its position shown in Figures 1 and 5 and the switch blade 18 is in its position shown in Figure 5. Thecurrent then flows from one side of the power source through conductor strip 11, contact buttons 29 and 15, switch blade 18 and through the field winding of the motor and then through blade 17, contact buttons 26 and .16 and conductor strip 12 to one side of the motor armature, and from the other side of the motor armature to the other side of the power source. That reverses the direction of flow of current through the motor field winding and the motor is then driven in the opposite direction to that which it wasdriven when the contact buttons 27 and 15 were closed. 'By turning the switch operating lever 32 counterclockwise to its neutral position, the switch is opened and-the motor is stopped in the same manner as before.

Referring to Figure 3, it will be noted that when the switch blade 17 is in position closing the contact buttons 27 and 15, the stud 47 carried by that switch blade is disposed with its inner end spaced but a short distance from'the'block 49. In the event the buttons 27 and 15 are stuck together, due to arcing caused by dirt or foreign matter thereon, the switch operating lever 32 may be turned counterclockwise until the block 49 contacts the inner end ofstud 47, after which by exerting turning force counterclockwise on lever 32 pressure may be applied to the stud 47 and thereby to the blade '17 sufiicient for breaking the buttons 15 and .27 apart, after which the blade 17 will be moved,by a snap action, to its position shown in Figures 1, Sand 7. Likewise, when the switch blade 18-is in its position shown in Figure 5, if the contact buttons .29 and .15 become stuck together, by turning the switch operating lever 32 clockwise adequate pres sure may be exerted against the inner endof stud-43 carried by blade '18 for breaking loose the contact buttons 29 and 15, after which blade 18 will be returned to its position shown in Figures 1, 6 and7 with asnap action.

It will be understood from what has been said that the switch operating lever 32 may be turned in either direction, to an extent limited by the stops 46 in cooperation with arms 36, to an operating position. When lever 32 is turned in one direction from one operating position to its other operating position, the switch blades 17 and 18 are rocked successively in one direction and in opposite relation and when lever 32 is turned in the opposite direction to its other operating position, switch blades 17 and 18 are successively rocked in the other direction and in opposite relation. With the switch blades'17 and 18 in their positions shown in Figures 1 and 7, the power contact buttons 27 and 29 carried by the blades 17 and 18 are in open position, spaced away from the power contact buttons 15. The switch operating lever 32 is then in its neutral position of Figure 1 and the switch is open so that no current can flow to the motor. Turning lever 32 clockwise from its position of Figure l to its position of Figure 3, closes the power, contact buttons 27 and 15 and opens the motor contact buttonsioand l6,

l the power contact buttons 29 and 15 remaining open and thevmotor contact butons 28 and 16 remaining closed as shown in Figures 3 and 6. 7 Current then flows in one direction through the motor field winding and to the motor armature for driving the motor in one direction, as above explained. Turning lever 32 counterclockwise to its other operating position .returnstblade 17 to its position shown in Figures 1 and 5, thereby opening the power contact buttons 27 and 15, and then rocks blade 18 to its position of Figure 5. Current then flowsthrough the motor field winding and to the motor armature for driving the motor in the opposite direction. It is to be noted that in turning the lever 32 from either of its operating positions to its other operating position it passes through its neutral position and the power circuit is opened preliminary to reve'rsal of the motor connections. That is of importance in assuring that all flow of current to the motor is shut off before reversal of the field winding connections to the motor.

It will be understood that changes in detail may be resorted to without departing from the field and scope of my invention, and I intend to include all such varia tions, as fall within the scope of the appended claims, in this application in which the preferred form only of my invention has been disclosed.

I claim:

1. In a motor reversing switch, two sets of contact elements, each set comprising a first pair of elements and a cooperating second pair of elements movable alternately into and out of contact with said first elements respectively, a switch operating member having a neutral switch opening position and movable in opposite directions therefrom to a first operating position and a second operating position, and operating connections between said operating member and said second pairs of elements respectively comprising snap action means effective for successively actuating said second pairs of movable elements respectively in opposite relation responsive to movement of said operating member from its first operating position to its second operating position, said operating connections being so constructed that the second pair of elements of one set of contact elements remains in a first contact engaging position while the second pair of elements of the other set of contact elements moves from a corresponding first contact engaging position to a second such position and vice versa.

2. In a motor reversing switch, two sets of contact elements, each set comprising a first pair of elements and a cooperating second pair of elements movable alternately into and out of contact with said first elements respectively, a switch operating member having a neutral switch operating position and movable therefrom to a first switch operating position and a second switch operating position, and operating connections between said operating member and each of said second pairs of movable elements respectively comprising snap action means effective for successively actuating said second pairs of movable elements respectively in opposite relation responsive to movement of said operating member from its first operating position to its second operating position and for selectively actuating said second pair of movable elements of either set of contact elements independently of the other pair thereof to achieve said neutral position and either of said operating positions for the switch, as selected.

3. In a motor reversing switch, two sets of contact elements, each set comprising a pair of stationary elements and a cooperating pair of elements movable alternately into and out of contact with said stationary elements, a switch operating member having a neutral switch operating zone and movable therefrom in one direction to a first operating position and in an opposite direction to a second operating position, and connection means between said operating member and each pair of said movable elements comprising snap action means for actuating 6 either of said pairs of movable elements, one at a time, in response to movement of said operating member from one of its said operating positions into its neutral operating zone.

4. In a motor reversing switch, two sets of contact elements, each set comprising a pair of stationary elements and a cooperating pair of elements movable alternately into and out of contact with said stationary elements respectively, a switch operating member having a neutral switch operating zone and movable therefrom in one direction to a first operating position and in the opposite direction to a second operating position, and operating connections between said operating member and said pairs of movable elements respectively comprising over center snap action spring toggle means for actuating each of said pairs of movable elements as selected in response to movement of said operating member from one operating position to its neutral operating zone, movement of said operating lever between the limits of its neutral zone actuating said operating connection without actuating the pairs of movable elements.

5. In a motor reversing switch, two pairs of fixed contact elements, a switch blade rockably mounted adjacent each pair of contact elements, two contact elements carried by said switch blade alternately movable into and out of contact with said fixed contact elements by rocking of said blade in opposite directions, a switch operating member having a neutral switch operating zone and movable therefrom in one direction to a first operating position and in the opposite direction to a second operating position, and operating connections between said operating member and each of said blades comprising snap action means efiective for rocking said blades successively in alternately opposite relation responsive to alternate movement of said operating member from its said neutral zone into either its said first and second operating positions and vice versa, the said switch blades being held in a contact engaging position with positive pressure throughout the movement of said operating member, in its said neutral zone.

6. In a motor reversing switch, two pairs of fixed contact elements, a switch blade rockably mounted adjacent each pair of contact elements, two contact elements carried by each switch blade alternately movable into and out of contact with corresponding members of an associated pair of said fixed contact elements by rocking of said blade in opposite directions, a switch operating member having a neutral switch operating zone and movable therefrom in one direction to a first operating position and in the opposite direction to a second operating position, and operating connections between said operating member and said blades respectively comprising snap action means including spring means effective for rocking said blades to bring said contacts thereon into engagement with alternate fixed contact elements in response to movement of said operating member from its neutral operating zone into either of its operating positions, the said operating connections requiring the movement of said operating member into one of its operating positions before responsive actuation of a related switch blade, whereby said spring means serves to hold the engaged contact elements of said related switch blade in positive engagement with a corresponding fixed contact element during movement of said operating member in its said neutral operating zone.

7. In a motor reversing switch, two pairs of fixed contact elements, a switch blade rockably mounted adjacent each pair-of contact elements, two contact elements carried by said'switch blade alternately movable into and out of contact with said fixed contact elements by rocking of said blade in opposite directions, a switch operating lever pivoted between said blades for turning movement in opposite directions to two operating positions and an intermediate neutral switch opening position, snap action toggle connections between said lever and said blades efiective for rocking said blades successively in alternately opposite relation responsive to turning of said lever from one operating position to its other operating position and vice versa, and means actuated by said operating lever for exerting positive pressure on either of said switch blades for disengaging either of said contact elements thereon from one of said fixed contact elements.

8. In a motor reversing switch, two pairs of fixed contact elements, a switch blade rockably mounted adjacent each pair of contact elements, two contact elements carried by said switch blade alternately movable into and out of contact with said fixed contact elements by rocking of said blade in opposite directions, a switch operating lever pivoted between said blades for limited turning movement in opposite directions to two operating positions and through a neutral switch opening position, toggle arms secured to the midportions of said blades and extending therefrom inwardly toward said lever, said arms having openings of substantial width in their inner ends, toggle members pivoted at their outer ends on said lever with their inner ends extending through said openings and of small cross area relative thereto, and over center tension springs anchored to said blades and to the inner ends of said toggle members for turning the latter in opposite directions with a snap action when the outer ends of said toggle members pass over center relative to said springs in the turning of said lever to either of its operating positions from its said neutral position.

9. In a motor reversing switch, two pairs of fixed power contact elements, a switch blade rockably mounted adjacent each pair of fixed contact elements, two contact elements carried by said switch blade alternately movable into and out of contact with said fixed contact elements by rocking of said blade in opposite directions, a switch operating lever pivoted between said blades for limited turning movement in opposite directions through a neutral operating position to two operating positions, toggle arms secured to the midportions of said blades and extending therefrom inwardly toward said lever, said arms having openings of substantial width in their inner ends, toggle members pivoted at their outer ends on said lever with their inner ends extending through said openings and of small cross area relative thereto, over center tension springs anchored to said blades and to the inner ends of said toggle members for turning the latter in opposite directions with a snap action when the outer ends of said toggle members pass over center relative to said springs in the turning ofsaid lever to either of its operating positions, saidlever having a projection at one side thereof, and studs secured to said blades and extending inwardly toward saidprojection at opposite sides thereof, said studs being respectively disposed to be contacted by said projection when the corresponding blade is in position with one contact element thereof in contact with the corresponding fixed power contact element whereby pressure may be exerted on said stud for moving the blade toward its other position by turning said lever in the corresponding direction.

10. In a motor reversing switch, two pairs of fixed contact elements, a switch bladerockably mountedadjacent each pair of contact elements, two contact elements carried by said switch blade alternately movable into and out of contact with said fixed contact elements by rocking of said blade in opposite directions, a switch operating member having a neutral switch opening position and pivotally movable therefrom in one direction to a first operatingposition and in the opposite direction to a second operating position means limiting pivotal movement of said operating memberin .said first and second directions, operating connections between said operating member and said blades respectively comprising snap action meansefiective for rocking said blades successively in alternately opposite directions responsive to movement of said operating'member from one operating position to its other operating position and vice versa,

and means actuated by said operating member for exerting positive pressure upon either of said blades for moving it from its position in which one of its Contact elements is in contact with the corresponding fixed contact element.

'11. In a motor reversing switch, first and second pairs of spaced stationary contacts, first and second pairs of spaced movable contacts, two switch blades pivotally mounted one adjacent and extending between the mem bers of each pair of stationary contacts, each of said blades carrying a pair of said movable contacts, pivotal movement ,of each switch blade toward either member of thepair of stationary contacts adjacent thereto serving to bring one movable contact into engagement with such member, a pair of spring biased means operable to pivotally actuate each switch blade independently with snap action toward alternate members of the adjacent pair of stationary contacts as selected, rotatable operating means for actuating said spring biased means to effect sequential pivotal movement of said two switch blades in like rotational directions in response to rotation of said operating means, and connection means providing lost motion association between said .operating means and each of said two spring biased means whereby said operating means is rotatable through a non-operating zone intermediate its zones for operating said spring biased means.

12. The combination as set forth in claim 3 including electrical connection means between corresponding members of said first and second pairs of stationary contacts whereby the movement of said operating means through its non-operating zone serves to place said corresponding members in circuit with one another thus to provide neutral operating position for the switch with the switch being placed in such neutral operating position each time saidoperating means passes through its said neutral zone.

13. In a motor reversing switch, two sets of contact elements each set comprising a first pair of elements and a cooperating second pairof elements movable alternately into and out of contact with said first elements respectively, aswitch operating member having a neutral switch opening position and movable in opposite directions therefrom to a first operating position and a second operating position, operating connection means between said operating member and each of said second pairs of elements comprising snap action means effective for successively actuating said second pairs of movable elements in opposite relation responsive to movement of said operating member from its first operating position to its second operating position, said connection means being so constructed that the second pair of elements of each setof contact elements remains in a first position while the second pair of elements of the other set of contact elements moves from a corresponding first position to a second position and vice versa, and means actuated by said operating member for exerting positive pressure upon either pair ,of movable elements to move the same independently of said connection means from a position wherein one of said movable elements is engaged with one of saidfirst elements.

References Cited in the file of this patent UNITED STATES PATENTS 365,585 Davis June 28, 1887 707,843 Heany Aug. 26, 1902 1,293,532 Peck Feb. 4, 1919 1,474,013 Benjamin Nov. 13, 1923 1,753,975 Welsh Apr. 8, 1930 2,289,882 Myers July 14, 1942 2,448,444 Kricger Aug. 31, 1948 2,483,122 Bower Sept. 27, 1949 2,641,663 Krieger June 9, 1953 FOREIGN PATENTS 551,221 Great Britain Feb. 12, 1943

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