US2680971A - Positioning mechanism for movable switch members or the like - Google Patents

Description

June 15, 1954 A. J. KREINER 2,680,971 POSITIONING MECHANISM FOR MOVABLE I SWITCH MEMBERS OR THE LIKE Filed Dec. 31, 1949 2 Sheets-Sheet l INVENTOR.

June 15, 1954 KRE|NER 2,680,971

POSITIONING MECHANISM FOR MOVABLE SWITCH MEMBERS OR THE LIKE Filed Dec. 31. 1949 2 Sheets-Sheet 2 vlllllllllllllrlllllllll1111,1111:

INVENTOR. 14/YZ7/6WY JAfiE/NER M, W W fiW Patented June 15, 1954 POSITIONING MECHANISM FOR MOVABLE SWITCH MEMBER Anthony J.

Designers a corporation of Ohio Kreiner, Wickliife, Ohio,

For Industry,

S OR THE LIKE assignor to Inc., Cleveland, Ohio,

Application December 31, 1949, Serial No. 136,376

4 Claims. (Cl. 74-527) This invention relates to electric switch mechanisms and, more particularly, to an improved positioning mechanism for positioning a movable member such as the movable contact member of an electric switch of the coaxial type.

In the operation of a coaxial switch it is very important that when the movable contact means is moved to an engaged switch position it assume an accurately aligned relation with respect to the stationary contact means engaged thereby. The present invention is especially concerned with an actuating means for the movable switch member or rotor of such a coaxial switch and provides novel positioning means by which such an accurately aligned relation will be automatically obtained during each movement of the movable contact means to its engaged switch position.

In a coaxial switch mechanism of the type in which the movable contact means, or the rotor carrying the same, is actuated by a power means such as an electromagnetic device, the need for such a positioning means is even more imperative because the momentum of the moving parts and the irregularities or variations inherent in the functioning of the power device prevent the movable contact means from regularly assuming an accurately aligned position relative to the stationary contact means engaged thereby.

The present invention accordingly provides novel positioning means which is efiective for locating a movable switch member or the like during the shifting thereof to an engaged switch position, such that the movable contact means will always assume an accurately aligned relation with respect to the stationary contact means engaged thereby.

As another object thereof this invention provides novel positioning mechanism for a movable switch member or the like in which a holding member cooperating with a toothed member is a pivoted lever and an eccentric adjusting means is efiective on such lever for adjusting or setting the positioning means so that it will cause the desired accurate alignment of the movable and stationary contact means.

The invention can be further briefly summarized as consisting in certain novel combinations and arrangements of parts hereinafter described and particularly set out in the claims hereof.

In the accompanying sheets of drawings,

Fig. 1 is a longitudinal section taken through a coaxial switch mechanism embodying the present invention;

' indicated by section line Fig. 2 is an outside end view of the mechanism looking toward the coaxial switch;

Fig. 3 is a transverse section taken through the mechanism adjacent the outer end of the electromagnetic power device as indicated by section line, 3-3 of Fig. 1;

Fig. 4 is a transverse section taken at a point between the power device and the coaxial switch as indicated by section line 44 of Fig. 1;

Fig. 5 is a fragmentary sectional view taken longitudinally through one of the pivoted levers of the positioning means substantially as indicated by section line 5-5 of Fig. 4;

Fig. 6 is another fragmentary sectional view taken through the eccentric adjusting means of the pivot levers substantially as indicated by section line 6-6 of Fig. 5;

Fig. 7 is a transverse section taken through the power device adjacent the ratchet mechanism thereof, as indicated by section line 'I'I of Fig. 1;

Fig. 8 is a partial transverse section taken through the power device substantially at the location of the ratchet mechanism thereof, as

88 of Fig. 1;

Fig. 9 is a partial transverse section taken through the power device adjacent the indexing switch means thereof, as indicated by section line 9-9 of Fig. 1;

Fig. 10 is a fragmentary sectional view of the coaxial switch corresponding with a portion of the longitudinal section of Fig. 1, but showing a sighting device substituted for one of the stationary contact carriers;

Fig. 11 is another fragmentary sectional view taken through the coaxial switch substantially as indicated by section line II-II of Fig. 10 and further illustrating the sighting device; and

Fig. 12 is a perspective View showing a shaft coupling member in detached relation.

As shown in the drawings, the improved coaxial switch mechanism IO comprises, in general, a coaxial switch I I and a switch actuating mechanism I2 operably connected with such coaxial switch. The coaxial switch II is more fully disclosed in related copending application Serial No. 780,059, filed October 15, 194.7 now Patent 2,565,643, granted August 28, 1951.

The coaxial switch I I is of the type comprising a switch housing I3 formed of connected sections defining a switch chamber I4, and a rotor I5 substantially filling said chamber and operable therein. This coaxial switch also includes a plurality of arcuately spaced stationary switch contacts I6, in this instance three such stationary contacts, which extend into the switch chamber and engage a circumferential flange ll carried by the rotor i5. Each of th stationary contacts i6 is mounted in coaxial relation in a carrier 18 by a body of electrically insulating plastic material It contained therein. The carrier is is mounted on the housing 13 so as to have a snug fitting engagement in a socket opening 2c of the latter and locates the contact It in proper position for running engagement with the rotor flange ll.

The rotor I of the coaxial switch ll carries a movable contact 21 which is formed by the end of a conductor 22 and is located in an interruption or gap 23 of the rotor flange ll. The conductor 22 is coaxially mounted in a passage 24 of the rotor by a body of plastic insulating material 25 contained in such passage. The conductor 22 extends into the rotor radially and axially thereof from the contact 2! and its outer end projects from the rotor as a reduced pin 23 which is rotatable in a stationary contact member 2.? mounted in a carrier 23.

The contact 23 is of the sam thickness as the rotor flange i? and forms a smooth, flush continuation of this flange. The portions of the gap 23 are closed on opposite sides of the contact 2i by portions 29 of the insulating body 25 so that these insulating portions also form smooth, flush continuations of the rotor flange. The stationary contact 21 forms a receiving terminal to which electrical signals are delivered and the stationary contacts H5 form delivery terminals. By movement of the rotor Hi the contact 26 can be shifted to an engaged switch position in engagement with any desired one of the stationary contacts H3. The rotor i5 is provided with a shaft extension 3% which projects from the housing l and to which actuating torque can be applied for driving the rotor. When the rotor contact 21 has been engaged with a desired one of the stationary contacts l6 it is necessary for the proper functioning of the coaxial switch il, as mentioned above, that the rotor contact be accurately aligned or oppositely positioned. with respect to the stationary contact so engaged. The present invention provides novel positioning means for obtaining this accurate alignment and which positioning means will be described in detail hereinafter.

The switch actuating mechanism l2 includes an outer housing 3% formed by complemental cup-shaped housing sections 3m and 3H). The housing section 3 la is connected with the switch housing it by a pair of posts 32 having threaded ends 32a which are screwed into the switch housing for clamping the housing member 3 la thereagainst with a gasket 33 interposed therebetween. The housing section 3m forms the base of the outer housing and the housing section 3H) forms a cover which is held in assembled relation to the base by a group of ti rods 34. As shown in Fig. 1, the adjacent ends of the housing sections 31a and 3H) engage in oppositely extending grooves of a sealing ring 35.

Also included in the switch actuating mechanism I2 is an electromagnetic power device 38 having an intermittently rotatable power output shaft 39. This electromagnetic power device is a so-called rotary solenoid of the kind forminga part of the mechanism disclosed in U. S. Patent No. 2,430,9 10, granted November 18, 1947. The power device 33 also includes a magnet coil Ail located in a casing 4H and an axially movable armature 12 connected with a rotary shaft 43 which is axially aligned with the power output shaft 39. The armature 42 is movable toward and away from a core 44 which is also located in the casing 4| and is adapted to be magnetized by the coil 40.

At its outer end the armature 42 is connected with a plate 45 which is disposed in spaced relation to the end wall 46 of the casing ll. The adjacent faces of the plate 45 and the nd wall 46 are provided, respectively, with shallow arcuate recesses 41 and 48 located in overlapping relation to each other and forming a pocket in which an antifriction ball 49 is confined. Three groups of the paired arcuate recesses 4'? and 48 are provided and, as shown in Fig. 3, these paired recesses are disposed in circumferentially spaced relation around the axis of the rotary shaft 43. A spiral spring 50 disposed around the shaft 43 and having one of its ends anchored thereon transmits thrust through the shaft to the armature 42 normally urging the same toward the left, as seen in Fig. 1, or, in other words, away from the core M.

When the coil Lit is electrically energized, the magnetic pull on the armature l2 stresses and overcomes the spring 50 and moves the armature toward the core, that is, toward the right as seen in Fig. 1. During this movement of the armature 52, the plate 65 travels in an axial direction from its dotted line position to its full line position and the thrust applied to the balls 69 by this axial movement causes the plate torotate through the limited arcuate movement represented by the permissible travel of the balls in the paired arcuate recesses 41 and 48. This combined rotary and axial movement of the plate 45 causes a corresponding combined rotary and axial movement of the shaft 43.

The adjacent ends of the shafts G3 and 39 are operably connected by a ratchet mechanism formed by a pair of cooperating plate members 5! and 52 mounted on these shafts. These plate members carry groups of circumferentially spaced inclined fingers 53 and 54 which are de- 'f flected toward each other out of th planes of the respective plate members. During the combined rotary and axial movement of the shaft 43 a similar combined rotary and axial movement is imparted to the plate member 55, causing one of the fingers 53 thereof to engage one of the fingers 5c of the plate member 52 and impart rotary movement to the latter plate member and to the shaft 39 connected therewith. Thus, during each such combined rotary and axial power stroke of the shaft 43, one of the fingers 53 of the plate member 5| engages and drives one of the fingers 54 of the plate member 52 and successive power strokes of the shaft 43 impart a step-by-step rotary movement to the shaft 39. During the retracting movement imparted to the shaft 43 in the opposite direction by the spiral spring 53, the plate member 5| is rotated in the reverse direction thereby disengaging the finger 53 from the finger 54 and causing the plate member 5| to have a rotary ratchet movement with respect to the plate member 52.

The power device 38 also includes two switch devices 56 and 51 for intermittently energizing and deenergizing the magnet winding 40 and which switch devices are in a series relation in the energizing circuit for this winding. The switch device 58 comprises a pair of normally closed contacts 58, one of which is a movable contact carried by a spring arm 56a. The contacts 58 are adapted to be opened by an actuating finger 59 of a plate member 60 which is formed of insulating material and is rotatable about the shaft 39. The switch actuating member 60 is adapted to be oscillated by movement transmitted thereto from the plate member For this purpose, the plate member 5| carries an axially extending finger 6| which extends between the finger 59 of the plate member 60 and an adjacent finger 62.

When rotary movement in the clockwise direction indicated in Fig. 8 is imparted to the plate member 60 by the above-mentioned axial finger 6| of the plate member 51, the radial finger 59 will engage the portion 56b of the spring arm 56a and will deflect this spring arm to cause opening of the contacts 58. Since these contacts are in the circuit of the magnetic coil 40, the opening thereof will temporarily deenergize the magnet and permit the spiral spring 59 to retract the armature 42. reverse rotary movement is imparted to the plate member 5! by the spiral spring 50 during the retraction of the armature 42 and, by means of the axial finger 6|, this causes the switch actuating member 69 to be shifted in the opposite direction, that is in a counter-clockwise direction as seen in Fig. 8, to disengage the radial finger 53 from the spring arm 56a and permit reclosing of the contacts 58 by this spring arm for reenergizing the magnet coil 40. The closing and opening of the switch 58 causes the magnet 46 to be repeatedly energized to operate the ratchet drive formed by the cooperating plate members 5| and 52 to thereby impart a step-by-step clockwise rotation to the output shaft 39.

The energizing circuit for the magnet coil 40 is also controlled by the switch device 51 which comprises a fiat ring 63 of conducting material connected with the shaft 39 so as to be driven thereby through an insulating disk 64. The switch device 51 also includes a number of contact 65 mounted on an insulating support 66 and having sliding engagement with the contact ring 63. As shown in Fig. 9, the contact ring 63 has a gap or interrupting recess 61 therein which passes under the contacts 65 in succession during the rotation of this contact ring by the shaft 39.

The energizing current for the magnet 40 passes through the contact ring 63 and a selected one of the contacts 65. So long as the energizetion of the magnet coil 40 is interrupted only by the self-closing switch device 56, the power device 38 will operate to drive the rotor output shaft 39 with a step-by-step angular movement. When the gap 61 of the contact ring 63 arrives at the contact which is then included in the magnet energizing circuit, such as the contact 65a, the circuit will be broken and the magnet will remain deenergized regardless of the reclosing of the contacts 58 of the switch device 56.

The outer end of the power output shaft'39 of the power device 38 is connected with the shaft extension of the rotor l5 of the coaxial switch I I and the operation of the power device imparts a similar step-by-step rotary movement to the rotor. In the coaxial switch ll here shown the stationary contacts l6 are spaced apart an angular distance of one hundred and twenty degrees, and in the construction here shown for the power device 38 each energization of the magnet causes the shaft 39 to be rotated through an angular distance of thirty degrees which. bears a modular relation to the one hundred and twenty degrees spacing of the stationary contacts [6 of the coaxial switch. The magnet 40 of the power;

As mentioned above, a I

Cir

device 38 is energized through a selected one of the contacts 65 of the switch device 51, such as the contact 65a, which will result in operation of the power device continuously until the rotor contact 2| reaches the stationary contact [6 desired to be engaged for the signal circuit to be completed, whereupon the gap 61 of the contact ring 63 will arrive at a position under the selected contact 65a to deenergize the circuit of the magnet coil 46, thereby leaving the rotor contact 2| in engagement with the desired stationary contact [6.

As has already been indicated above, it is-important in the operation of the coaxial switch II that the rotor contact 21 be accurately aligned with the stationary contact I6 which is engaged thereby. To this end the present invention provides a positioning means 10 which is effective for locating the rotor contact 2| in such accurately aligned relation with respect to the stationary contact l6 engaged thereby. The positioning means 10 comprises a wheel 1| having a hub 12 and such wheel being mounted on the shaft extension 36 of the rotor l5 by means of the transverse pin 13. The wheel "H has a circumferential series of spaced teeth 14 thereon and each pair of adjacent teeth provide therebetween a locating recess 15. The positioning means 10 also includes a pair of levers 16 located on opposite sides of the wheel 1! and each of which carrie an antifriction roller 11.

The rollers 11 of the levers 16are engageable in a pair of recesses of the wheel 1| at substantially diametrically opposite points thereof and the rollers are urged into the recess of the wheel by tension springs 18 acting on the arms. The levers 16 are preferably of a hollow construction, as shown in Fig. 5, and the antifriction roller 11 comprises a ball bearing located in the hollow lever and mounted on a shaft formed by a pin 19 extending through the spaced arms of the lever. inwardly deflected portions of the arms of the lever extend around the pin 19 and engage the inner race 8! for positioning the ball bearing substantially midway between the spaced arms. The outer race 82 of the ball bearing is thus held out of rubbing contact with the arms of the lever and forms the rim portion of the antifriction roller 11 which engages in one of the recesses 15 of the toothed wheel 1 I.

A pair of posts 83 having threaded ends connected with the switch housing l3 extend in substantially parallel relation to the posts 32 and to the axis of the shaft extension 39 and provide a mounting means for pivotally mounting the levers 16. This mounting means will be presently described in greater detail.

From the construction of the positioning means 13 as thus far described, it will be seen that the wheel 15 constitutes a reaction member which is connected with the rotor l5 and each of the levers 16 constitutes a holding member which cooperates with this reaction member. The wheel 1! is provided with twelve of the recesses 15 and, hence, these recesses are spaced apart an angular distance of thirty degreesb which bears the same modular relation to the spacing of the stationary contacts i6 of the coaxial switch H as the increments of angular movement imparted to the power output shaft 39 by the power device 38. When the rotor 15 is driven by the power device 38, the wheel 1| is rotated and the antifriction rollers 11 of the levers16 ride over the tops of the teeth 14, there- 7 by passing from one to another of the recesses '15 of this wheel.

When the rotor contact 2| arrives at the selected stationary contact l6 and the magnet 40 of the power device 38 is deenergized by the switch device 57 to leave the rotor contact in engagement with such stationary contact, the iantifriction rollers of the levers 15 will then be engaged in a pair of diametrically opposit recesses of the wheel II. This engagement accomiplishes an important purpose in that as the rollers are urged into the recesses by the tension springs 18, the wheel H functions as a reaction member and the engaged recesses thereof center themselves with. respect to the antifriction rollers engaging therein. This self-centering of the recesses 15 of the wheel 1| with respect to the rollers 11 reacts through the wheel and the shaft extension 30 to position the rotor IS with the rotor contact 2| in accurately aligned relation to the stationary contact It engaged thereby.

Because of the antifriction characteristic of the rollers ll, they will be very effective under the influence of the springs 18 in producing a powerful self-centering action of the wheel I In this connection it is also important to note that the size and shape of the teeth 14 with respect to the size and shape of the roller H is such that the recess 15 will have a shape and depth causing the rim of the roller to engage the pair of adjacent teeth at points near the tops thereof. These points of engagement are thus located at the maximum distance from the axis of rotation and this contributes to the application of a selfcentering force of maximum magnitude on the wheel 1|. Since the shape thus provided for the recess 15 is such as to prevent the roller T from engaging the bottom of the recess, it will also be seen that this desired engagement of the roller with the pair of teeth adjacent the ends thereof will always be maintained and will enable the levers L6 to serve as a holding means for maintaining the rotor contact 2| in the aligned relation with respect to the stationary contact l6 engaged thereby.

Another important feature of this novel positioning mechanism is the provision of an adjusting means which is embodied in and effective on the positioning means 10. This adjusting means is incorporated in the pivotal mountings for the levers 1B. As shown in Figs. and 6, the reduced end portion 84 of each of the posts 83 provides a pivot shaft for the lever associated therewith. The lever is not pivoted directly on the shaft 34 but is connected therewith through an adjusting means in the form of an eccentric bushing 85 interposed between the shaft and the sleeve portion 8 6 of the lever. A spacing washer 81 also disposed around the shaft 34 holds the lever 16' in spaced relation to the bottom wall 88 of the housingsection 3 la.

The eccentric bushing 135 is provided at one end thereof with a head 8d of a non-circular shape, preferably hexagonal, as here shown, and by which this bushing can be rotatably adjusted on the pivot shaft 84 by means of a suitable iwrench. A shoulder 90 provided on the post 83 adjacent the pivot shaft portion 84 thereof cooperates with the head of the eccentric bushing for applying a clamping force to the bushing and the spacing washer 81. The sleeve portion of the bushing is somewhat longer than the sleeve por-- tion 88 of the lever 15 so that when the bushing is clamped in the desired position of angular movement just described above.

adjustment, the lever 16 will still be free to swing pivotally on the eccentric bushing.

The adjusting means provided by the eccentric bushing affords a means by which the rotor contact 2| can be shifted to the extent necessary to align the same accurately with the stationary contact l6 after the rotor contact has been moved into engagement with such stationary contact. In making this adjustment the post 83 is unscrewed relative to the switch housing |3 to release the clamping engagement of the shoulder r on the head 89 of the bushing 85 and then by a wrench applied to the head 88 the eccentric bushing 85 is rotated on the pivot shaft 84, causing lever 18 to be shifted longitudinally thereof. This longitudinal movement of the lever moves the roller 11 toward or away from the pivot shaft 84, depending upon the direction in which the eccentric bushing has been rotated, and this shifting of the roller imparts a corresponding rotary movement to the wheel 1| and to the switch rotor l5. When this adjusting operation has resulted in the rotor contact 2! being accurately aligned with the stationary switch contact I6, the post 83 is rotated in a direction to tighten its screw-thread connection with the switch housing |3 to thereby clamp the eccentric bushing 85 between the shoulder 90 and the spacing washers ill and lock the bushing in its adjusted setting.

To facilitate the accomplishment of this adjusting operation, the invention provides a sighting device 92 shown in Figs. 10 and 11 and which is used a reference means with respect to which the rotor contact 2| is shifted by the adjusting This sighting device comprises a cup-shaped member or bushing which is interchangeable with any one of the stationary contact carriers l3 of the switch housing l3. When the stationary contact carrier I8 has been detached from the switch housing i3, the sighting device 82 will be snugly received in the housing opening 20 and in Figs. 10 and 11 the sighting device is shown in its operative position engaged in such housing opening.

The sighting device 32 has a transverse wall 93 at its inner end and is also provided with a main axial opening or recess 9% extending thereinto and which includes a convergently tapered portion 94a at such end wall. On the axis of the recess 94 a circular sighting opening or orifice .95 is provided and extends through the end wall .93. The sighting orifice 95% has a diameter or plan dimension which is exactly equal to the diameter of the conductor 22 and hence is exactly equal to the plan dimension of the conductor 2| extending in the direction of the curvature of the switch rotor 15.

While the adjustment of the eccentric bushing 85 is being made, as explained above, the operator looks into the recess 524 of the sighting device 92 and observes the end of the rotor contact 2| through the sighting orifice E35 and thus uses the orifice as a reference means for determining when the rotor contact has been adjusted to a position which will provide an accurate alignment of this contact with the stationary contact Hi. When this accurate alignment has been obtained and the adjusting bushing 85 has been reclamped in its locked position, the sighting device 92 is removed and the contact carrier H3 is replaced in the housing opening 20.

This invention also provides novel mounting means for the electromagnetic power device 38 by which this device can be firmly connected with the switch housing I3. This mounting means comprises a plate member 96 which is connected with the casing 4| of the power device and projects laterally therefrom so as to provide mounting portions 96a lying in a transverse plane disposed in substantially normal relation to the axis of the power output shaft 39. The mounting portions 96 a are here shown as being the corner portions of asubstantially square shape for the plate member 96 and are provided with openings 95?) which receive the reduced and threaded upper ends of the posts 32 and 83. When the power device 38 has been inserted into the outer housing 3i" of the switch mechanism and the ends of the post engaged in the openings 19Gb of the mounting plate 96, the power device will be located with its power output shaft 39 in properly aligned relation withrespect to the shaft extension 30 of the switch rotor 15. The posts 32 and 83 have shoulders 9! thereon against Which the mounting portions 96a of the plate are clamped by the nuts 9% applied to the threaded ends of these posts.

With respect to the driving connection between the power output shaft 39 of the power device 38 and the shaft extension 30 of the switch rotor I 5, this invention also provides a novel construction. As shown in Fig. 1, the power output shaft 39 is of a length such that it will project into the hollow hub 12 of the toothed wheel II when the power device 33 has been assembled in its proper position on the mounting posts 32 and 83, as explained above. The outer end of the power output shaft 39 preferably does not engage the shaft extension 30 directly but is connected therewith by a flexible coupling means which is substantially universally flexible. This coupling means is shown in this instance as comprising a coupling member 99 (see Figs. 1, l, and 12) having a tongue portion me on the inner end thereof which engages in a corresponding transverse slot provided in the end of the shaft extension 30 and at its other end the coupling member is provided with a pair of spaced axial arms HH which embrace the outer end of the power output shaft 39 and define a transverse slot H12 in which a flattened end portion of the power output shaft is received. Since the coupling member 99 is partially housed in the opening of the hub 12 it will always be maintained in assembled relation with respect to the ends of the shafts 30 and 39 connected thereby. The opening of the hub 12 is of a size to provide a small clearance around the coupling member 99 so that this member will be capable of limited shifting in two directions for correcting small misalignments of the shafts so and 39.

As shown in Fig. 1, one of the mounting posts 33 is provided at its outer end with an extension post member I03 instead of one of the clamping nuts 88, and this extension post member provides a mount on which a condenser Hi4 can be mounted by means of a clamping bracket I05. The section Bib of the outer housing 3| is shown in ig. 1 as being provided with an electric coupling member fill; with which the various electrical conductors serving the power device 38 can be connected and which provides a terminal means for electrically connecting the switch actuating mechanism with external circuit conductors.

From the foregoing description and the accompanying drawings it will now be readily understood that this invention provides novel positioning mechanism for use in indexing or locating a movable member in predetermined desired positions or settings, such as the movable switch member of a coaxial switch, or the like. Additionally, it will be seen that this invention provides eccentric adjusting means in such a posi tioning mechanism for calibrating the location of the pivot axis of the holding lever means with respect to the predetermined positions to which the movable member is shiftable.

Although the novel positioning mechanism has been illustrated and described herein to a detailed extent, it will be understood, of course, that the invention is not to be regarded as being limited correspondingly in scope but includes all changes and modifications coming within the terms of the claims hereof.

Having thus described my invention, I claim:

1. In a positioning mechanism for an electric switch or the like, a housing structure, drive shaft means rotatable in said housing structure, a member in said hou ing structure and. con nected with said shaft means to be moved by the latter to predetermined positions, a wheel connected with said shaft means for rotation therewith and having thereon an annular series of teeth with intervening spaces between pairs of adjacent teeth, a lever having roller means engageable in any one of said spaces for holding cooperation with said wheel, spring means acting on said lever to urge said roller means into one of said spaces, pivot means mounting said lever for swinging movement, and eccentric adjusting means effective on said lever through said pivot means for calibrating the location of the effective axis of said pivot means with respect to said predetermined positions.

2. In a positioning mechanism for an electric switch or the like, a housing structure, drive shaft means rotatable in said housing structure, a member in said housing structure and connected with said shaft means to be moved by the latter to predetermined positions, a wheel connected with said shaft means for rotation therewith and having thereon an annular series of teeth with intervening spaces between pairs of adjacent teeth, a lever having roller means engageable in any one of said spaces for holding cooperation with said wheel, spring means acting on said lever to urge said roller means into one of said spaces, said lever having an opening therein at a point spaced from said roller means, a pivot shaft, and eccentric means carried by said pivot shaft and engaging in said lever opening for calibrating the location of the effective fulcrum axis of said lever with respect to said predetermined positions.

3. In a positioning mechanism for an electric switch or the like, a housing structure, drive shaft means rotatable in said housing structure, a member in said housing structure and connected with said shaft means to be moved by the latter to predetermined positions, a wheel connected with said shaft means for rotation therewith and having thereon an annular series of teeth with intervening spaces between pairs of adjacent teeth, a lever having roller means engageable in any one of said spaces for holding cooperation with said wheel, spring means acting on said leverto urge said roller means into one of said spaces, said lever having an opening therein at a point spaced from said roller means, a pivot shaft extending into the lever opening, and eccentric bushing means mounted on said pivot shaft and rotatable in said lever opening for calibrating the location of the effective pivot axis of said lever with respect to said predetermined positions.

4. In a positioning mechanism for an electric switch or the like, a housing, a rotary power device, shaft means rotatable relative to said housing and connected with said power device to be driven thereby, a member in said housing and connected with said shaft means to be moved by the latter to predetermined positions, a plurality of posts having reduced end portions connected with said housing, said posts extending in the direction of the axis of said shaft means and forming a mount for said power device, a Wheel connected with said shaft means to be driven thereby and having an annular series of teeth with intervening spaces between pairs of adjacent teeth, a pair of levers located on opposite sides of said wheel and each having a roller thereon and an opening therein at a point spaced from the roller, said levers, being disposed with said reduced end portions extending through the lever openings as pivot pins and said rollers being engageable in said spaces for holding cooperation with said wheel, spring means acting on said levers for urging said rollers into said spaces, and eccentric adjusting bushings mounted on said pivot pins and engaging in the openings of said levers for calibrating the location of the effective fulcrum axes of said levers with respect to said predetermined positions.

References Cited in the file of this patent UNITED STATES PATENTS Number Number Name Date Kinkead Mar. 9, 1915 Beauchamp May 30, 1916 Holmgren Dec. 11, 1917 Gent Aug. 12, 1924 Perry Feb. 7, 1933 Fjellstedt et al Nov. 2'7, 1934 Getty Dec. 31, 1935 Kimball May 2'7, 1941 Glogau May 18, 1943 Mares Aug. 8, 1944 Bentley May 7, 1946 Michael June 25, 1946 Leonard Sept. 17, 1946 Newkirk Feb. 17, 1948 Sansbury Sept. 14, 1948 Bird June 21, 1949 Klein May 30, 1950 Klay June 13, 1950 Charles June 12, 1951 Baddour Aug. 28, 1951 Kreiner Nov. 27, 1951 FOREIGN PATENTS Country Date Great Britain Nov. 30, 1939

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