US2347528A - Switch - Google Patents

Description

April 25, 1944.

E. F. WEISER' SWITCH FiledMay 16, 1942 Fig.2.

Fig. 4.

Inventor: Earnest FWeiser; 25 1/ Attqrngs.

extension 29 on the arm l5 secured to the armature and the outer end of the support l9, suitable seats for the spring being provided in these parts. The spring is of the compression type and applies a force tending to move the sup port IS in a counterclockwise direction toward the stationary contact, as shown, about its pivot 20 and tending to move the link is in a counterclockwise direction about its pivot l8 to the limit of the small pivotal movement provided for the link. This normal position of the parts is shown in Fig. l, the coil l2 being deenergized and the armature ll being in its unattracted open circuit position. It will be observed that the contact engaging surface of the contact I1 is substantially in alignment with the pivots l8 and 20.

Another requirement of the spring 21 is that its line of force as applied to the support l9 must have a component as large as possible extending inward tending to hold the contacts together, but at the samev time its line of force must extend,'as seen in the drawing, above or outside of the initial point of contact between the movable contact ii and its stationary contact 30. As shown in the drawing, the line of force of the spring 21 is along the dotted line 3| of Fig. 1 which, it will be observed, passes slightly to the right of the upper end of the movable contact l1, and, therefore, clearly is above or outside of any initial point of contact between the contacts. In other words, the line of force passes on the side opposite said link of the initial point of contact. The purpose of this mounting of the spring i'iis to reverse the bias of the spring on the link i6 after the initial engagement of the contacts, the spring 21 then biasing the link it in a clockwise direction about the pivot l8. This is because after the contact I! engages the stationary contact 30, the spring 21 applies a force tending to turn the contact and the support l9 about this point of engagement as a pivot in a counterclockwise direction.

It should be noted that the device is workable if this line of force 3| extends below the initial point of contact between the contacts as long as it does not extend through or below the center line of the pin 20. However, when this line of force passes below the initial point of contact, the spring force and gradient necessary to supply tip pressure and to absorb the kinetic energy of the tip and support i9 make the spring impractical in' size.

It will now be assumed that. the coil I2 is energized and the armature is pulled to its attracted position by the coil. When the movable contact I l engages the stationary contact, it starts pivoting on the stationary contact and in a clockwise direction about the pivot 20 as the movement of the armature continues toward its attracted position. This produces the conventional rolling and wiping action between the contacts.

Also, upon engagement of the contacts, the spring 21 applies a force tending to turn the movable contact about the point of engagement between the contacts in a counterclockwise direction, as seen in Figs. 1 and i. This action reverses the bias of the spring 27 on the link l6 and moves the link about it's pivot i8 in a clockwise direction away from the stationary contact to its other extreme position against the opposite sides of the stops 23. The upper end of the link 16 and the pivot pin are under these condi tions yieldably movable in a counterclockwise direction back to their first positions to dissipate the kinetic energy stored in the contact I? and its support i9. This clockwise rotation of the contact I! and support l9 about the pivot 20 during the rolling and wiping action, while angularly small, is carried out at a very high speed and therefore stores a substantial amount of kinetic energy of rotation. in the contact I! and the support I9. This storedenergy is effective after the armature ll comes to rest in its fully attracted position, as shown in Fig. 4, to cause a slight continued movement of the contact I"! and support I9 on the stationary contact and about the pivot 20 in a clockwise direction. But the pivot 20 is now yieldably movable about the pivot l8 toward the left hand'and toward the stationary contact, as seen in Fig. 4, and the contact i1 and support IS in attempting to move about the pivot 20 actually cause this movement of the pivot 20 toward the left hand. In effect, therefore, this final movement is a pivotal movement of the movable contact on the stationary contact, this pivotal movement being about the final closed circuit point of engagement between them. It takes place without separation of the contacts and; consequently, arcing and welding are prevented.

When this slight energy dissipating movement has been completed, the spring 21 moves the contact ill and support is about the point of contact in a counterclockwise direction and the link i6 is moved clockwise about its pivot l8 to its other extreme position. The parts are then in the closed circuit positions shown in Fig. 4.

Another advantage of this anti-bounce and anti-weld construction is that the distance between the lower end of the movable contact and the pivot pin 20 can be decreased considerably as compared with conventional devices thereby obtaining a much larger angular wipe on the movable contact for the same rectilinear movement of the pin 20. This increased angular wipe has the advantage of giving greater wear allowance and thereby providing substantially longer life for the contacts. Without this antiweld construction, the distance between the movable contact and the pivot 20 must be great enough to decrease the arcing and welding to some permissible value. In this discussion of conventional construction, it will be understood that the pivot 20 is mounted directly on the end of the pivoted armature, the link it not being provided. I s

As shown in Fig. 4, the movable contact has a final line contact at its lower end with the stationary contact.

It will be understood that the pin it may be mounted, if desired, on the engl of a solenoid plunger or air cylinder piston rod so 'as to be given a rectilinear motion instead of an arcuate motion, as shown in thedrawing. In such case,

the link l6, support l9 and contact ll will extend laterally, substantially at right angles, to the direction of movement of the pin is as in the form shown in the drawing.

Also, if desired, an anti-bounce pivotal mounting embodying my invention may be applied to the stationary contact, the movable contact then being mounted rigidly on the armature or other operating member. In this case, it will be understood that the pivot support i8 and the spring support 29 are stationary while the contact corresponding to the contact 30 of Fig. 1 has itssupport mounted on the operating member so that this contact constitues the movable contact,

While it have shown a particular embodiment of my invention, it will be understood, of course, that I do not wish to belimited thereto since many modifications may be made, and I therefore contemplate by the appended claims to cover any such modifications as fall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States, is:

i. a. switch comprising a pair of cooperating switch contacts, a support for each of said con:

tacts, operating means for moving one or said supports between closed and open circuit positions, a link pivotally connected at one end to one of said supports, means iimiting the angular movement oi said linit on said one support a predetermined acute angle between two positions, a pivotal connection between one of said con tacts and the other end of said link, cooperating stop means on said link and said one contact, spring means biasing said link and said one contact about their pivots to predetermined first angular positions with respect to each other and with respect to said one support, the line of force of said spring passing outside of the point of contact between said contacts so that upon engagement of said contacts and continued movement of said operating means in a closing direction said spring applies a reversed bias to said link and moves said link on its support to the other of said positions, and when said operating means comes to rest, said link moves on its support toward said first angular position thereby to provide for a final energy dissipating pivotal movement between said one contact and said link without separation of said contacts.

2 A switch comprising an operating member, a stationary contact, a link pivotally connected at one end to said operating member, means limiting the angular movement of said link on said pivot to a predetermined acute angle between two positions, a. movable contact pivotally mounted on the other end of said link, cooperating stop means on said link and said movable contact, a spring having its ends bearing on said operating member and said movable contact thereby to bias said link and said movable contact about their pivots to predetermined first angular positions with respect to each other and with respect to said operating member, the line of force of said spring passing outside of the point of contact between said contacts so that upon engagement of said contacts and continued movement of said operating member in a closing direction said spring applies a reversed biasto said link and moves said link on said operating member to the other of said positions and when said operating member comes to rest said link moves on said operating member toward said first position thereby to provide for a final energy dissipating pivotal movement between said movable contact and said link without separation of said contacts,

3. A switch comprising a contact arm, means pivotally supporting said contact arm for movement or one end between ciosed and open circuit positions, a stationary contact, a link pivotally connected at one end to said one end of said arm, means limiting the angular movement of said link on said pivot to a predetermined acute angle be tween two positions, a movable contact pivotally mounted on the other end oi said link, cooperattog stop means on said link and said movable contact, a compression spring having one end secured to said am and its other end bearing on said movable contact thereby to bias said link and said movable contact about their pivots toward said stationary contact to predetermined first angular positions with respect to each. other and with respect to said arm, the line of force of said spring passing outside of the initial point of contact between said contacts so that upon engagement of said contacts and continued movement of said arm toward said closed circuit position said spring tends to pivot said movable contact about its point of engagement with said stationary contact and thereby applies a reversed bias to said link and moves said link on said arm to the other oi said positions after which said link and said arm move together in a predetermined relation With each other until said arm comes to rest in said closed circuit position when said link moves on said arm back to said first position thereby to provide for a final energy dissipating pivotal movement between said movable contact and said link without separation of said contacts.

i. it switch comprising a pair of cooperating switch contacts, a first support on which a first one of said cfintacts is mounted, an arm to one end of which the second of said contacts is secured, a second support, .a pivot member, a yieldable connection between said pivot member and said second support, a pivotal connection between the other end of said arm and said pivot member, spring means biasing said pivot member on said second support away from said first contact and biasing said arm about said pivot member toward said first Contact so that when one of said supports is moved to bring said contacts into engagement with each other said arm moves about said pivot to provide for wiping pivotal movement of said second contact on said first contact whereby kinetic energy is stored in said second contact and said arm, and said yieldable connection when sa d movable support has come to rest in its closed position providing movement of said pivot member toward said first contact and continued pivotal movement of said second contact on said first contact for the dissipation of said kinetic energy while maintaining engagement between said contacts during said energy dissipating pivotal movement.

5. A switch comprising a pair of cooperating switch contacts, a first support on which a first one of said contacts is mounted, an arm to one end of which the second of said contacts is secured, an intermediate-member, a second support, a first connection between said intermediate member and said second support providing for movement of said intermediate member toward said first contact, a pivotal connection between said intermediate member and the other end of said arm, a first stop means for limiting the movement of said intermediate member on salt! second support in a direction away from said first contact, a second stop means for limiting the pivotal movement of said arm on said pivot in a direction toward said first contact, spring means for biasing said intermediate member relative to said second support against said first stop means and for biasing said arm on said pivot against said second stop means so that when one of said supports is moved to a closed circuit position said arm turns on said pivot against the force of sa d spring means upon engagement of said contacts to provide for a wiping pivotal movement of said second contact on said first contact until said movable support is brought to rest, after which said spring means yields to provide for movement of said intermediate member on said second support toward said first contact to efiect a continuance of the pivotal movement of said second contact on said first contact for dissipation of the kinetic energy stored in said second contact and said arm during said wiping movement while maintaining engagement between said contacts during said energy dissipating pivotal movement.

6. A switch comprising an operating member mounted for movement between open and closed circuit positions, a stop against which said operating member comes to rest in said closed circuit position, a stationary contact, a movable contact, an arm to one end of which said movable contact is secured, a link, a first pivotal connection between one end of said link and said operating member, a second pivotal connection between the other end of said link and the other end of said arm, a first stop means for limiting the movement of said link on said first pivot in a direction away from said stationary contact, a second stop means for limiting the movement of said arm on said link in a direction toward said contact, spring means for biasing said link relative to said operating member against said first stop means and for biasing said arm relative to said link against said second stop means so that when said operating member is moved to said closed circuit position said arm turns on said second pivot against the force of said spring means to provide for a wiping pivotal movement of said movable contact on said stationary con-' tact until said operating member is brought to rest, after which said spring means yields to provide for pivotal movement of said link on said first pivot toward said stationary contact to efiect a continuance of the pivotal movement of said movable contact on said stationary contact for dissipation of the kinetic energy stored in said movable contact and said arm during said wiping movement while maintaining engagement between said contacts during said energy dissipating pivotal -novement.

7. A switch comprising an operating member, a stationary contact, a movable contact, an arm to.one end of which said movable contact is secured, a link, a first pivotal connection between one end of said link-and said operating member, a second pivotal connection between the other end of said link and the other end of said arm, stop means for limiting the movement of said link about said first pivot to an acute angle between two positions, stop means for limiting the movement of said, arm about said second pivot toward said stationary contact to a position in which said arm is insubstantial alignment with said link, and spring means normally biasing said arm and said link about their respective pivots toward said stationary contact to positions against said stop means but said .spring means upon engagement of said movable contact with said stationary contact reversing its bias on said link thereby to move said link about said first pivot to its other position and provide, after said operating member has come to rest in its closed position, for movement of said second pivot about said first pivot in a circuit closing direction for energy dissipating pivotal movement of said movable contact on said stationary contact.

8. A switch comprising a pair of cooperating accuses switch contacts, a first support on which a first one of said contacts is mounted, an arm to one end of which the second of said contacts is secured, a second support, a link, a first pivotal connection between one end of said link and said second support-a second pivotal connection between the other end of said link and the other end of said arm, cooperating stop means between said link and said second support for limiting the movement of said link about said first pivot .to an acute angle between two positions, stop means between said link and said arm limiting the movement of said arm about said second pivot toward said first contact to a position of substantial alignment with said link, a compression spring between said second support and said arm for biasing said arm and said link about said pivots toward said first contact so that when one of said supports is moved to bring said contacts into engagement said spring first yields to provide for movement of said link about said first pivot to its other position and thereafter upon further movement of the movable support said arm moves about said second pivot to provide for a wiping action between said contacts until said movable support is brought to rest whereupon the kinetic energy stored in said second contact and said arm causes movement of said link about said first pivot toward its other extreme position for dissipation of said kinetic energy while maintaining engagement between said contacts.

9. A switch comprising an operating arm having one end mounted on a stationary pivot, a stationary contact, a movable contact, a con tact arm to one end of which said movable contact is. secured, a. link, first and second pivotal connections between the ends of said link and the other ends of said operating arm and contact arm respectively, stop means for limiting the movement of said link about said first pivot to a predetermined acute angle between two positions and for maintaining said link in substantial alignment with said operating arm, stop means for limiting the movement of said contact arm about said second pivot toward said movable contact to a predetermined position in which the contact engaging surface of said movable contact is in substantial alignment with said two pivots, mans providing bearing seats on said operating arm and said contact arm, a compression spring between said bearing seats for biasing said contact arm and said link about their pivots toward said stationary contact, a stop against which said operating arm is brought to rest in a closed circuit position, and means for moving said operating arm at high speed to said closed circuit position, said stationary contact being positioned to be engaged by said movable contact energy stored in said contact arm during said wiping action.

' EARNEST F. WEISER.

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