US1773164A - Electric switch - Google Patents

Description

'9, 1930. T. s. BINDSCHEDLER 1,773,164

ELECTRIC SWITCH Original Filed Oct. 1924 2 Sheets-Sheet l \9 I ENVENZZ U 5Y2 H 3 W RNEYFJ.

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Aug. 19, 1930. T. s BINDSCHEDLER ELECTRIC SWITCH Original Filed 001;. 4, 1924 2 Sheets-Sheet 2 WW6 Q INVEQETOQZ %TZORNEY5.

Patented Aug. 19, 1930 UNITED STATES PATENT OFFICE THEODORE S. BIND-SCHEDLER, OF DETROIT, MICHIGAN, ASSIGNOR TO BURROUGHS ADD- ING MACHINE COMPANY, OF DETROIT, MICHIGAN, A CORPORATION OF MICHIGAN ELECTRIC SWITCH Original application filed October 4, 1924, Serial No. 741,525, new Patent No. 1,658,086, dated February 7, 1928. Divided and this application filed September 18, 1926. Serial No. 135,752.

This invention relates to improvements in electric switches and the present a plication is a division of my application erial No. 741,525, filed October 4, 1924, now Patent No. 1,658.036 February 7, 1928.

The principal object of the invention is to provide an improved make and break switch adapted for controlling the circuit of an electric motor or for other purposes. A further object of the invention is to provide an improved quick acting and automatically controlled switch. A particular advantage of the improved switch lies in the provision of means for obtaining a positive contact and for effecting a relative movement of the contacting parts so that dirt and sediment are removed therefrom when the switch is operated. A further feature is the provision of an improved switch comprising means for effecting a quick or instantaneous action of the means by which the movable contacts are operated. Other objects of the invention relate to various features of construction and arrangement which will appear more fully hereinafter.

Although the present invention is capable of application to various uses, it has been illustrated in the accompanying drawings in connection with the clutch control mechanism of an adding machine which is more fully disclosed in Patent No. 1,658,036 above referred to.

The various objects and advantages of the invention will appear more fully from the following specification taken with the accompanying drawings in which one embodiment is illustrated. In the drawings, Fig. 1 shows an enlarged side elevation of the improved switch mounted on the clutch housing of an adding machine; Fig. 2 shows a' partial side elevation similar to that illustrated in Fig. 1, illustrating the positions of the parts of the switch at the moment of opening the switch and breaking the circuit of the motor or other device; Fig. 3 is a sectional view taken on the line 33 of Fig. 4, showing the means for controlling the operation of the clutch by which the electric motor is connected to the operating mechanism of the adding machine; Fig. 4 is an elevation of the driving mechanism of the adding machine together with a sectional view through the switch and clutch control mechanism on the line 4--4 of Fig. 1; Fig. 5 is a section taken on the line 5-5 of Fig. 1, showing the mounting of the control lever and the switch lever and related parts; and Fig. 6 is a perspective view showing variousparts which make up the yielding contact portion of the switch.

As illustrated in the drawings, the inven tion is adapted to an adding machine for the purpose of controlling the circuit of an electric motor employed in driving the adding machine mechanism. The armature of the motor is mounted on or connected to a shaft 12 which extends into and is journaled in the walls of the clutch housing 13, as shown particularly in Fig. 4. A worm 14: is fixed on the shaft 12 and meshes with a Worm wheel 15 rotatably mounted on a shaft 16 which is journaled in suitable bearings in the walls of the housing and which has fixed on the projecting end thereof a crank arm 17 pivotally connected by a pin 18 with a link or connecting rod 19. This rod 19 is in turn pivotally connected with a crank arm 20 fixed on the rock shaft 21 of the adding machine. The worm wheel 15 is adapted to be connected to the shaft 16 in order to effect the operation of the rock shaft 21 by the electric motor, through the operation of a clutch comprising an annulus 25 secured to the side of the worm wheel 15 concentrically with the shaft 16. The outer periphery of the annulus 25is provided with a series of semicylindrical recesses 26, any one of which may be engaged by a clutch pin 27, of semi-circular cross-section, which has the cylindrical end portion thereof rotatably mounted in a clutch disk 28 having an annular flange 29 surrounding the annulus 25. The disk 28 has its hub secured to the shaft 16 by means of a pin 30 and this hub also serves as a bearing for a clutch operating lever 31 which is secured on the hub by a plate 32 mounted on the end of the hub. The clutch pin 27 carries a segmental gear 35 on the outer end thereof and this gear meshes with another segmental gear 36 which'is formed on the hub of the operating lever 31 so that when this lever is rocked on its bearing the clutch pin 27 is rotated to bring it into or out of engagement with one of the clutch recesses 26 in the annulus 25. The clutch operating lever 31 is provided with arms 31 extending downwardly at each side of the segmental gear 35 to limit the move ment of the lever, and a plate 37, extending between these arms, serves to maintain the clutch pin 27 in its bearing in the clutch disk 28. The upper end of the operating lever 31 is normally moved toward the left as viewed in Fig. 3 by means of a coil spring which is connected at one end to the lever and at the other end to a pin attached to the clutch disk. lhe extremity 42 of the lever 31 is provided with a curved surface 43 adapted to enact with a detent 44 of se1ni-circular cross-section which is secured to one end of a pin or shaft 45 jourualed in the cover 13 of the clutch housing. hen the curved surface of the detent contacts with the curved surface 43 of the operating lever, the lever is held in the position illustrated in Fig. 3 against the tension of the spring 40 and the clutch pin 27 is then out of/cngagement with any of the notches 26, but when the shaft 45 is rotated to permit the end. of the lever 31 to pass beneath the fiat face of the detent 44, the lever 31 moves toward the left. as viewed in Fig. 3. under the influence of the spring 40, thereby rotating the clutch pin 27 and bringing it into engagement with one of the notches 26 in the annulus 25.

The shaft- 4-5 of the detent ll is actuated to control the clutch by certain mechanism comprising a segmental gear 46 secured to the shaft +15 and arranged to mesh with another segmcntal gear 47 mounted on a pin 48 secured to the cover 13 of the clutch housing. The segmental gear 4T is formed on or secured to the hub of an arm or lever 50, the outer end of which carries an eye-bolt 5i slidably engaged by a rod 52. the lower extremity of which is engaged by a nut 53 while a reduced portion thereof immediately above the part 51 surrounded by a coil spring 51 contacting at one end with the eye-bolt 51 and at the other end with a shoulder on the rod. The rod 52 is adapted to be elevated by the manual operation of certain mechanism connected thereto which is manipulated by the operator at the commencement of each operation of the adding machine. The manual operation which effects the lifting of the bar 52 serves to rock the arm through which the detent it is actuated and at the conclusion of an operation of the machine. means are provided for autouiatically returning the bar 52 to its lower normal position, thereby operating the lever 50 to effect a dis engagement of the clutch due to the action of the detent e l in obstructing the lever 31 and thereby causing an angular movement of the clutch pin, as hereinafter more fully described,

The movement of the rod 52, which controls the engagement-and disengagement of the clutch, serves also to control the closing of the switch by which the motor is connected to its supply circuit. This control is etlected e,

by a roller which is mounted on the lever 50 and adapted to coact with the head 71 of an inverted T-shaped switch control lever 71 pivotally mounted on a stud 72 secured in the cover 13 of the clutch housin The 75 lever 71 has two oppositely directed arms 71 and 71 at the lower end thereof and the head 71 is provided with a flat end face 71 and a curved cam-surface 71, these surfaces 71 and 71 being adapted to coact with the so movement being determined by a stationary pin or abutment 74: which is secured to the cover of the clutch casing. The outer end of the arm 71 of the lever also carries a stud 7 5 having pivotally mounted thereon a yokeshaped pawl 76 provided with a Vshaped head 76 having an upper inclined surface 76 and a lower inclined surface 76. pawl 76 is connected by a coil spring 77 with the body portion of the lever 71 so that the pawl is norn'ially moved toward the right, as ioo viewed in Figs. 1. 2 and 3, thereby tending to maintain one or the other of the inclined surfaces of the pawl in contact with a roller 78 mounted on a pin attached to the arm 79 of the switch lever 79 which is pivotally mounted on the stud 72 at one side of the switch control lever 71. The other arm 71 of the lever 71 is provided at its outer ends with a roller 80 which is adapted to coact with the periphery of a snail cam 81 secured m to the end of the clutch shaft 16 and adapted to control the opening of the electric switch, as hereinafter described. The upwardly extending arm 79* of the switch lever 79 carries the movable switch contacts 83 and 84 which are adapted to coact. with the stationary contacts 85 and 86. respectively, when the switch lever is operated to close the switch. The stationary contacts 85 and 86 are carried by L-shaped plates 87 and 88, re- 129 spectively, which are secured to an insulating plate 89 and connected with binding posts 91 and 92, respectively, secured in position in the insulating plate. An insulated cable 93. leading from a source of supply of electrical energy. carries a pair of line conductors. one conductor 9&- being connected to the binding post 92, while the other conductor 95 is connected to a binding post 96 connected A coil spring 3 is connected to the 35 The to and insulated from the casing 13 of the clutch housing. Another insulated cable 97,

n a wiping contact is obtained.

carries a pair of conductors leading to the motor, one of these ((')l1(lll(fli0lS 98 being connected to the binding post 91 while the other conductor 99 is connected to the binding post 96. It will be apparent that when the switch .is operated to bring contacts 83 and 84 into engagement with the contacts 85 and 86 the 'circuit is completed between the conductor 94. and the conductor 98 so that the circuit of the motor is then closed, the other side of the supply circuit being completed between the conductors and 99 through the com mon binding post 96.

The parts by which the movable contacts 83 and 84 of the switch are connected are preferably so constructed that the contacts have relative movement when they engage the stationar contacts 85 and 86, thereby removing carldon and other deposits from the surfaces of the contacts and insuring a perfect connection. For this purpose, the contact 83 is mounted on a transverse flange 100 of a plate 100 and the contact 84 is mounted on a transverse flange 101 of a plate 101, these plates being pivotally supported on an insulating bushing 102 which is secured on a pin 103 projecting laterally from the upper end of the switch lever 79, as shown particularly in Fig. 6. The bushing 102 engages the apertures 105 which are formed in the. plates 100 and 101 and the plates are maintained out of contact with the lever 79 by an insulating washer 106. The plates are secured in position against the washer and in contact with each other by means of a spring plate 107 which is secured to the switch lever 79 by a rivet 108 and which is provided at its upper end with an elongated slot 109 adapted to fit over the end of the bushing 102 in contact with another insulating washer 106. The projecting arms of the plates 100 and 101 which carry the flanges 100 and 101, respectively, are connected by a coil spring 110 which tends normally to move the contacts 83 and 84 toward each other, this movement being limited by the engagement of a trans versely extending lug 111 on the plate 101 with the notch 112 formed in the plate 100, the notch being slightly larger than the width of the lug 111 so that a limited relative angular movement of the plates is permitted. The connected plates 100 and. 101 also have a limited angular movement with respect to the lever 79, this movement being limited by the notch 113 formed in the lower end of the plate 101 and adapted to be loosely engaged by an insulating bushing 114 mounted on a pin 115 projecting laterally from the lever 79. \Vhen the switch contacts 83 and 8% are brought into engagement with the stationary contacts 85 and 86, respectively, the contacts 83 and 84 spread apart slightly against the tension of the spring 110 with the result that The movement of the switch lever 79 away from the stationary contacts 85 and 86 is limited by a lug 117 formed on the lever and adapted to engage the stop pin 74 by which the movement of the control lever 71 is limited.

In the operation of the mechanism, the elevation of the rod 52 produces an upward move ment of the crank or lever 50 from the normal position shown in Fig. 1, which throws the clutch detent 4 1 into such a position that the end of the clutch control lever 31 is permitted to pass beneath the flat face of the dctent under the influence of the spring 40. This movement of the clutch control lever 31 rotates the clutch pin 27 into engagement with one of the notches 26 in the annulus 25, thereby forming a driving connection bctwecn the motor driven worm wheel 15 and the shaft 16 by which the rockshaft 21 of the adding machine is operated. The initial upward movement of the lever 50 carries the roller 70 out of engagement with the flat end face 71 of the lever 71 and into engagement with the curved surface 71 of the lever so that the lever is then free to move toward the left, as viewed in Figs. 1 and 2. under the influence of the coil spring 73. This movement of the lever 71 insures a. complete upward movement of the lever 50 due to the engagement of the inclined cam surface 71 with the roller 70, and. it also brings about the closing of the switch simultaneously with the engagement of the clutch, the closing of the switch being caused by the downward movement of the arm 71 of the switch control lever which carries with it the pawl 76 until the apex of the head 7 6* of the pawl rides past the roller 78 and the roller 78 contacts with the upper inclined surface 70" of the pawl, as shown in Fig. 2, whereupon the in clined surface 76 forces the lever 79 upwardly and inwardly, under the influence oi the spring 77, until the switch contacts 83 and 8 1 engage and form a wiping contact with the stationary contacts 85 and 86. The switch remains closed during the forward stroke or first half of the cycle of operation of the adding machine, during which time the rock shaft 21 is operated by the power of the motor and energy is stored up in a.

coil spring, as explained in Patent No. 1,658,036, whereby the subsequei'itreturn stroke of the adding machine is effect d by the action of the spring. During the forward stroke, the snail cam 81, mounted on the shaft 16. rotates in a counterclockwise direc tion until at the end of the forward stroke. the projection of the cam forces the roller 80 on the control lever 71 downwardly to such an extent that the apex of the V-shaped head 70 of the pawl 76 is carried upwardly over the roller 78, whereupon the lower inclined surface76 of the pawl operates to force the switch lever 79 toward the left, as viewed in Figs. 1, 2 and 3, thereby snapping the switch into open position. This position of the parts of the switch is illustrated in Fig. 2 where the switch is shown in open position and the lever 50 is shown approaching the normal position illustrated in Fig. l. The return of the lever 50 to its normal position with the roller engaging the end face 71 of the lever 71, is brought about by certain mechanism of the adding machine which depresses the rod 52 and creates a compression in the spring 54 so that the lever 50 is in readiness to return to its normal position under the influence of the spring 5*. as soon as the head 71 of the switch control lever has moved toward the right, as viewed in Fig. 2, to a sutiicient extent by the snail cam 81 during the forward stroke of the adding machine. The parts are so constructed and arranged that the downward movement of the rod 52 returns the lever 50 to the normal position shown in Fig. 1 during the forward stroke, so that the detent 4% is turned into a position to obstruct the end of the clutch control lever 31 during the first half c vcle or forward strokcof the adding machine, and when the lever 31 completes its rotation at the end of the return stroke, the detent all engages the curved surface &3 on the end of the lever 31 and produces a movement of this lever on its bearing sufiicientto disengage the clutch pin 27 from its notch 26. Thus the electric power is cut off simultaneously with the ending of the forward stroke and the armature of the motor is permitted to idle and come to rest during the return stroke of the adding machine which is effected by spring mechanism, as explained in Patent No. 1,658.036. In this way the operation of the electric or other driving motor or other mechanism is rendered intermittent and the connection of the motor circuit is made bv the improved electric switch of the present invention in synchronism with the engagement of the clutch. The disconnection of the motor not only prevents it from acquiring undue speed under the noload condition. but also eii'ects a saving of the power required to operate the motor under load.

The invention not only serves to operate the electric switch simultaneously with the operation of the clutch, thereby preventing damage to the machine, but it also insures a complete operation of the clutch control mechanism even when the manually manipulated part of the adding machine is im erfectlv or incompletely manipulated. A slight depression of the manually manipulated member is suflicient to raise the roller 70 out of engagement with the end face 71 of the switch control lever and, thereafter, a complete upward movement of the lever 50 is brought about by the inclined surface 71 on the lever so that the detent 44 is moved to the proper extent to release the lever 31 and effect a proper engagement of the clutch pin bef re t e Part? a e set in motion y the driving motor. The construction produces a rapid operation of the switch mechanism and of the clutch control mechanism and the wiping contact of the switch contacts of relatively small area produces a more perfect circuit connection than can be obtained with switches of the type heretofore known.

Although one form of the improved electric switch has been shown and described in connection with a particular use thereof, it will be understood that the invention may be constructed in various other forms and adapted to various uses within the scope of the appended claims.

I claim:

1. In apparatus of the class described, a switch I operating lover, a pivot member mounted on said lever, an insulating bushing mounted on said pivot member, a plate pivotallv engaging said bushing, insulating washers on opposite sides of said plate, and a contact carried by said plate.

2. In apparatus of the class described, a switch operating lever, a )ivot member mounted on said lever, an insudating bushing mounted on said pivot member, a pair of plates pivotally engaging said bushing, insulating washers on opposite sides of said plates, and a spring clip connected to said lever and having a slot to receive the end of said bushing.

3. In apparatus of the class described, an operating lever, a switch lever, said levers being mounted on a common pivotal axis, contacts actuated by said switch lever, means carried by said operating lever for actuating said switch lever, and means for actuating said operating lever.

4. In apparatus of the class described, an operating lever, a switch lever mounted ad jacent said operating lever. a pawl mounted on said operating lever and having av pair of divergent cam faces adapted to coact with a part of said switch lever, a spring tending normall to move said operating lever in one direction, a manually releasable member acting normall v to restrain said operating lever from movement in said direction, switch contacts moved into circuit closing position by said switch lever, through the operation of one of said cam surfaces upon actuation of said manually releasable member, and means for eil'ecting a reverse movement of said operating lever to disconnect said contacts by the movement of said switch lever through the action thereon of the other of said cam faces.

5. In apparatus of the class described, an operating lever having a laterally projecting arm, a pawl pivotallv mounted on said arm and having a pair of divergent cam faces, a spring tending to move said pawl inwardly toward said lever, a switch lever having a part adapted to coact with said cam faces, means for effecting relative movement of said opera ing le er to bring one or the othe of said cam faces into engagement with said switch lever, a pair of switch contacts mounted on said switch lever and having a limited relative movement, and a pair of stationary contacts adapted to be engaged by said movable contacts.

6. In apparatus of the class described, a springactuated operating lever, manually controlled means normally holding said lever in a restrained position, a switch lever, switch contacts carried by said lever, and a springactuated detent pivotally mounted on said operating lever and engaging a part carried by said switch lever to effect the closing of said switch contacts when said operating lever is released by said manually operated means.

7. In apparatus of the class described, a spring-actuated operating lever having a pair of oppositely disposed arms, manually controlled means normally holding said operating lever in a restrained position, a cam arranged to actuate one of said arms for moving said lever against the action of its spring,

a detent carried by the other arm of said lever and having oppositely inclined faces, a switch lever, a roller carried by said switch lever to coact with the faces of said detent, and switch contacts carried by said switch lever.

8. In apparatus of the class described, a spring-actuated operating lever having a pair of oppositely disposed arms, manually controlltd means normally holding said operatin lever in a restrained posit-ion, a cam arranged to actuate one of said arms for movin said lever'against the action of its spring, a etent carried by the other arm of said lever and having oppositely inclined faces, a switch lever having an angularly disposed part pro- 40 vided with a roller to coact with said faces of said detent, relatively movable switch contacts carried by said switch lever, and'means for actuating said cam.

9. In apparatus of the class described, a

spring-actuated operating lever having a pair of op ositely disposed arms, manually controlled means normally holding said operating lever in a restrained position, a cam arranged to actuate one of said arms for movin said lever against the action of its spring, a etent carried by the other arm of said lever and having oppositely inclined faces, a switch lever mounted for pivotal movement about the axis of said operating lever and having a part to coact with the inclined faces of said detent, resilient means tending to maintain said detent in engagement with said part, and switch contacts carried by said switch lever.

In testimony whereof, I have subscribed my name.

THEODORE S. BINDSCHEDLER.

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