US2454702A - Circuit controller - Google Patents

Description

Patented Nov. 23, 1948 CIRCUIT CONTROLLER Glen V. Jeflerson, Edgewood, Pa., assighor to The Union Switch & Signal Company, Swissvale, Pa., a corporation of Pennsylvania Application February 23, 1946, Serial No. 649,599

Claims.

My invention relates to circuit controllers, and particularly to circuit controllers for assembly on a control panel as one of a compact group of similar units for controlling railway switches and signals or other apparatus.

One object of my invention is to provide a circuit controller having three distinctive positions, and which includes means whereby a preliminary motion is required before the controller can be moved from any one of its positions to any other position.

Another object of my invention is to provide a circuit controller of the type described which is interchangeable with controller having only two operating positions.

The controller embodying m present invention is an improvement upon that described and claimed in Letters Patent of the United States No. 2,360,998 granted to R. A. Woods et al. on October 24, 1944.

According to my invention, the controller comprises an L-shaped supporting bracket the short leg of which is adapted to be secured to the rear side of a suitable control panel, and the long leg of which extends rearwardly from the panel and is provided at its rear end with a stack of contacts comprising cooperating fixed and movable contact fingers clamped between superposed blocks of insulating material. The contacts of the stack are disposed in units of four contacts each arranged in a horizontal row, and the units are so constructed that as many units as desired may be assembled one above the other. The contacts are divided into groups of two or more contacts each, and the contacts of each group are operated by a contact shifter comprising a flat spring clamped at one end in the contact stack, and provided at the other end with a return bend to increase the stifiness in the horizontal plane without interfering with the necessary flexing in the vertical plane. An insulating contact operating member provided with slots which receive with some clearance the free ends of the movable contact fingers of the associated group of contacts is clamped between a vertical surface formed by the return bend and a bracket which carries a forwardly projecting cam follower. Each cam follower extends into and cooperates with an associated cam slot formed in a circular rotatable cam plate secured to an operatin shaft predetermined sequence, but that axial movement of the shaft will not cause any movement of the contacts. The controller also includes a stationary cam plate which is secured to the long leg of the L-shaped bracket adjacent to the rotatable cam plate and which has substantially the same radius of curvature as the outer edge of the rotatable cam plate. The stationary cam plate is provided with an S-shaped cam slot which 00- operates with a projecting lug on the rotatable cam plate in such manner that the operating handle is locked in all three angular positions until the handle is pushed or pulled to cause the projecting lug on the movable cam to follow the configuration of the slot in the stationary cam plate.

Other objects and characteristic features of my invention will become apparent as the description proceeds.

I shall describe one form of circuit controller embodying m invention, and shall then point out the novel features thereof in claims.

In the accompanying drawings, Fig. 1 is a top plan view showing one form of circuit controller embodying my invention. Fig. 2 is a side View with some of the parts in cross section of the controller shown in Fig. 1. Figs. 3 and 4 are left and right-hand end views, respectively, of the controller shown in the preceding views. Fig, 5 is a sectional view taken substantially on the line VV of Fig. 2. Fig. 6 is a view in isometric projection of a stationary cam plate forming part of the circuit controller illustrated in the preceding views.

Similar reference characters refer to similar parts in each of the several views.

Referring to the drawings, the circuit controller here shown comprises an L-shaped supporting bracket I provided with a relatively short vertical leg la and a relatively long horizontal leg lb. The vertical leg I a is adapted to be secured to the rear face of a control panel indicated at 2 in the drawings, and for this purpose the relatively short leg la is provided with tapped holes 3 which receive screws 4 extending through holes 5 provided in the panel in alignment with the holes 3. A substantially U-shaped bearing bracket 6 is secured to the bracket I adjacent to the rear side of the vertical leg la, and this bracket is provided with aligned holes 6a and 6b which receive bearing bushings l and 8, respectively. The bearing bushing 1 also extends through a threaded opening 9 in the vertical leg la of the bracket I and an aligned opening [0 in the panel 2 and is provided with a screw-threaded shank portion. which is screwed into the openings 6a and and 9, and with an outer hexagonal flange portion Ia to facilitate screwing the bushing in place. The bushing 8 on the other hand is slidably supported in the opening 612 for a purpose which will be made clear presently. An operating shaft i l is mounted in the two bearing bushings l and 8 in such manner that this shaft is both rotatable and axially movable between intermediate and two extreme positions, and has attached to its outer end an operating knob E2 to facilitate moving it. The inner end of the shaft ii is provided with a squared portion Ha. which receives a circular cam plate it held in place by a nut 54 screwed onto the shaft. A washer l5 and a stop sleeve it are mounted on the shaft between the two arms of the bearing bracket 6, and

surrounding the stop sleeve it is a compressed coil spring ll one end of which abuts against the washer I5, and the other end of which abuts against an annular flange 30. formed on the end of the bearing bushing 3. It will be apparent that the spring ll constantly biases the washer E5 to the position in which it engages the adjacent leg of the bracket E3, and the parts are so proportioned that when the washer is engaging the bracket and the shaft H is in its intermediate axial position, the washer will also engage a shoulder ill) provided on the shaft H. The spring i! also biases the bearing bushing 8 to the position in which the flange 8a engages the adjacent leg of the bracket 6, and the parts are further so proportioned that when the bushing occupies this position and the shaft ii occupies its intermediate axial position, the right-hand end of the bushing 8 will engage the cam plate I3.

With the parts constructed in this manner, it will be obvious that upon pushing the operating member i2 inwardly, a force will be transmitted to the spring ll through the shoulder Nb and the washer it, which force will compress the spring il' beyond its initial compression, and that, as a result as soon as the operating member is released, the spring i"! will act to immediately return the operating shaft H to its intermediate axial extreme position. Likewise, upon pulling the operating member i2 outwardly, a force will then be transmitted to the spring I! through the cam plate [3, and the bushing 3, which force will also compress this spring i1 beyond its initial compression, with the result that as soon as the operating member is released, the spring will again act to immediately return the parts to the positions shown.

The contacts of the controller are arranged in a stack mounted on the rear end of the horizontal leg lb of the supporting bracket i, and are operated by the cam plate 13 in a manner which will now be made clear.

1 The contact stack as shown comprises eight contacts arranged in two rows of four contacts each, the contacts of the one row being disposed vertically above the corresponding contacts in the other row. As shown, each contact consists of a fixed contact finger 26 and an associated movable contact finger 2i clamped adjacent their rear ends against the opposite sides of an insulating block 22 by means of other insulating blocks 23 and 24. The insulating blocks are secured to the horizontal leg lb of the bracket 3 by means of screws 25 which pass through clearance holes in the blocks between the two outer pairs of fingers of each row and are screwed at their lower ends into threaded holes provided in the horizontal leg i b of the bracket I. Each block 22 is provided in its upper and lower edges with notches 22a and grooves 22b which receive tongues 23a formed on the blocks 23. The fixed and movable fingers are disposed in the notches or grooves as the case may be and are held in place by removable pins 26 in a manner which will be obvious from an inspection of Fig. 4.

The contact fingers may be assembled with the fixed fingers above or below the movable fingers depending upon the contact action desired. As illustrated, the contacts of the upper row are assembled with the fixed fingers above the movable fingers and the contacts of the lower row are assembled with the fixed fingers below the movable fingers. Associated with each fixed finger is a rigid stop member 21 which serves to position the finger when it is not in engagement with the associated movable finger.

The contacts are arranged in two groups of four contacts each, and the four contacts of the one group have associated therewith a contact shifter comprising a flat spring 30a, an insulating contact operating member 3m and a cam follower 32a, while the four contacts of the other group have associated therewith a contact shifter 3017, an insulating contact operating member Slb and a cam follower 32b. The fiat springs 30a and 38b are disposed between the upper and lower row of contacts of the associated group of contacts in parallel spaced relation, and are clamped at their rear ends between the lower insulating block 24 associated with the upper row of contacts and the upper insulating block 23 associated with the lower row of contacts. The forward ends of the springs are each formed with a return bend 380 which increases the stiffness of the spring in the horizontal plane without interfering with its ability to flex in the vertical plane. Each return bend is shaped to present a vertical surface 30d to which the associated contact operating member am or 3Ib is secured as by riveting. Formed in each of the contact operating members 31a and 3lb are slots Sic which receive the forward ends of the movable contact fingers of the associated group of contacts with clearance to thereby operatively connect the contact fingers with the contact operating members.

It should be pointed out that with the contact stack constructed in the manner just described, the screws 25 which clamp the various parts of the stack together are disposed as far from the fingers as possible and are adequately insulated from the fingers. This fact, together with the arrangement of notches, grooves and tongues which hold the fingers in alignment, enables the controller to be made as compact as possible and still be able to withstand a 3000 Volt breakdown test.

' The cam followers 32a and 32b are mounted on supports 33a and 33?) secured to the vertical surfaces 36d of the associated spring 30a or 3% at the outer side of the associated contact operating member am or 3"), and the two cam followers 32a 32b extend into and cooperate with cam slots [3a and i3?) formed in the previously referred to cam 53. The cam follower 33a. associated with the one group of contacts is turnedin the opposite direction from the one 33?) associated with the other group of contacts. That is to say, the one extends upwardly and the other downwardly, and the parts are so proportioned that with the supports disposed in this manner the cam followers are located on diametrically'opposite sides of the axis about which the cam rotates. The two cam slots 53a and i312 may have any desired shape to cause the contacts of the associated group to open or close in any desired sequence in response to rotation of the operating shaft II from its one extreme position to the other. As shown, the slot 13a is so shaped that when the operating shaft I I occupies its left-hand extreme position in which extreme position it is shown in the drawings, the contact operating member 3 la will be moved to its upper extreme position so that the contacts Zll-Zl of the upper row of the associated contact group will be closed and the contacts 20-2l of the lower row of the associated contact group will be open, and that as the shaft is rotated from this extreme position to its intermediate position, these contacts will remain in the positions just described until the shaft has been rotated approximately two-thirds of the way toward its opposite extreme position at Which time the cam follower 32a will be moved from its upper extreme position to its lower extreme position to thereby open the contacts 20- 2| of the upper row of the associated contact group and close contacts 20-2l of the lower row of the associated contact group. The slot 131) is so shaped that when the operating shaft I l occupies its left-hand extreme position in which it is shown in the drawing, the cam follower 3lb will be moved to its upper extreme position in which the contacts 20-2| in the upper row of the associated contact group will be closed and the contacts 202I in the lower row of the associated contact group will be open, but that when the operating shaft is moved from the extreme position shown toward its other extreme position, the cam follower 3lb will be moved from its upper extreme position to its lower extreme position to thereby open the contacts 20--2l in the upper row of the associated contact group and close the contacts 20-21 in the lower row of the associated contact group as soon as the shaft has been rotated through approximately one-third of its stroke from its one extreme position to the other, and that the cam follower will thereafter be retained in its lower extreme position during the balance of the stroke of the operating member from the extreme position shown to its opposite extreme position.

It follows from the foregoing that with the cam slots arranged in the manner just described when the operating shaft H occupies its left-hand extreme position in which it is shown in the drawing, all of the contacts 202| in the upper row of contacts will be closed and all of the contacts 20-2l in the lower row of contacts will be open. However, when the shaft occupies its intermediate extreme position, the two contacts 20-2l in the upper row of contacts operated by the contact operating member 3!?) will be open and the two contacts 20-2! in the lower row operated by the contact operating member 3lb will be closed, whereas the two contacts 20-2! in the upper row of the group operated by the contact member 3| a will be closed and the tWo contacts 20- 2I in the lower row of the group operated by the contact operating member 3 l a will be open. Furthermore, when the operating member II is moved to its right-hand extreme position, as viewed in Fig. 2, all of the contacts 202l in the upper row of contacts will be open and all of the contacts 202l in the lower row of contacts will be closed.

The circuit controller also includes means embodying my present invention for compelling the operator of the circuit controller to make a positive preliminary motion before he can operate the shaft 1 l away from any one of its three angular positions. comprise a stationary cam plate 35 secured to the long leg lb of the bracket l by means of screws 36 adjacent the lower edge of the ro- As here shown, these means tatable cam plate I3 which actuates the contacts. The stationary cam plate is bent into an arc having substantially the same radius of curvature as the radius of curvature of the outer edge of the cam plate l3, and is provided with an S-shapedcam slot 35a. (see Fig. 6) which receives and cooperates with a projecting lug 31 formed. on the edge of the rotatable cam plate l3. The S-shaped slot 35a is so shaped that when the operating knob occupies its left-hand extreme position in which it is shown in the drawing, the laterally projecting lug 31 will cooperate with a shoulder 35b to prevent the knob from being rotated away from this position unless the knob is first pushed inwardly from the intermediate extreme position to which it is biased to its inner extreme position. The slot 35a is also formed with a second shoulder 350 which cooperates with the laterally projecting lug 3'! on the rotatable cam plate [3 in such manner that when the operating shaft occupies its intermediate extreme position, it cannot be returned to the extreme position shown in the drawing unless the shaft is first pushed inwardly to its inner extreme position, and with a third shoulder 3501 which cooperates with the laterally projecting lug 3'! in such manner that when the operating shaft occupies its intermediate extreme position, it cannot be rotated from this position to its right-hand position as viewed in Fig. 2 unless the operating shaft is first pulled outwardly to its outer extreme position. The slot 35a is still further formed with a shoulder 35g which cooperates with the laterally projecting lug 31 on the cam plate I3 in such manner that the operating shaft cannot be moved away from its right-hand extreme position as viewed in Fig. 3 unless the operating shaft is first pulled outwardly to its outer extreme position. The cam slot 35a is still further formed with straight side portions 3% and 35] which cooperate with the laterally projecting lug 31 to limit the inner and outer extreme positions to which the operating shaft can be moved prior to rotating it from one position to another.

With the controller constructed in the manner just described it will be obvious that when the operating shaft occupies any one of its three positions it will automatically be moved to its intermediate position by the biasing spring l1, and that when the shaft occupies its intermediate extreme position, it will be positively locked against rotation in such position unless it is first pushed inwardly or pulled outwardly a sufficient amount to cause the operating memher to clear the shoulder 35b, 35c, 35d or 359 as the case may be. The fact that the operating knob must either be pushed inwardly or pulled outwardly before the position of the controller can be changed compels the operator to stop and think before operating the controller, and this provides an added degree of safety when the controller is used in certain applications for which it is particularly suitable. One such application is in railway signaling for clearing signals which permit train movements into territory which is not signaled for some distance after the train passes the signal controlled by the controller.

It should be noted particularly that in a controller embodying my invention the rotatable cam which operates the contacts also serves to cooperate with the stationary cam to provide the preliminary axial motion of the controller shaft required before the shaft can be moved from any radial position to any other radial position.

It should also be noted that the clearances between the cam followers 32a and 32b and the associated cam slots are such that the longitu dinal motion of the operating shaft necessary to unlock the shaft to permit its rotation will not cause operation of the contacts and that the cam followers are sufficiently long to permit this motion without any danger of disengaging the cam followers from the cam slots as a result of the motion.

Although I have herein shown and described only one form of circuit controller embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. A circuit controller comprising an operating shaft rotatable between an intermediate and two extreme positions and movable longitudinally between an intermediate and two extreme positions, means biasing said shaft to its intermediate longitudinal position, cam means including a cam plate secured to said shaft, contacts operated to different positions by said cam means in response to rotation of said shaft between its intermediate and two extreme positions, and other cam means formed in part on said cam plate for preventing rotation of said cam shaft between its intermediate and its one extreme angular position except when said shaft is moved to its one extreme longitudinal position and for preventing rotation of said cam shaft between its intermediate and other extreme angular position except when said shaft is moved to its other 1ongitudinal extreme position.

2. A circuit controller comprising an operating shaft rotatable between an intermediate and two extreme positions and movable longitudinally between an intermediate and two extreme positions, means biasing said shaft to its intermediate longitudinal position, a plurality of contacts, cam means operated by rotation of said shaft for selectively operating said contacts to different positions in the different angular positions of said shaft, a lug secured to said shaft, and a stationary cam plate provided with a cam slot coopcrating with said lug, said cam slot acting to position said shaft in all three of its angular positions and to prevent said shaft from being rotated between its intermediate and one extreme angular position except when said shaft is moved to its one longitudinal extreme position and to prevent said shaft from being rotated between its intermediate and other extreme angular position except when said shaft is moved to its other longitudinal extreme position.

3. A circuit controller comprising a supporting bracket, a stack of contacts secured to said bracket, each said contact comprising a fixed and a movable contact finger clamped at one end in parallel spaced relation between insulating blocks, a contact shifter comprising a flat spring mounted at one end in said stack and provided at the other end with an insulating contact operating member formed with slots which receive the free ends of the movable contact fingers to operatively connect the fingers with said contact shifter, an operating shaft mounted in said bracket in such manner that said shaft is both rotatable and longitudinally movable between an intermediate and two extreme positions, a circular cam plate secured to said shaft, a cam follower secured to said spring at the outer side of said contact operating member and extending into a cam slot provided in said cam plate to selectively operate said contacts in response to rotation of said shaft between its intermediate and two extreme positions without interfering with the longitudinal movement of said shaft, a projecting lug secured to said cam plate, and a stationary cam plate secured to said bracket adjacent said circular cam plate and provided with a cam slot which cooperates with said projecting lug in such manner that said shaft cannot be rotated between its intermediate and one extreme angular position unless said shaft is first moved to its one longitudinal extreme position and between its intermediate and other extreme angular position unless said shaft is first moved to its other longitudinal extreme position.

4. A circuit controller comprising a supporting bracket, a stack of contacts secured to said bracket, said contacts being divided into two groups, a contact shifter operatively associated with each group of contacts and each provided with a cam follower, an operating shaft mounted in said bracket in such manner that said shaft is both rotatable and longitudinally movable between an intermediate and two extreme positions, a circular cam plate secured to said shaft and provided with cam slots which receive said cam followers to selectively operate said contacts in response torotation of said shaft between its intermediate and two extreme angular positions, a cam lug secured to said circular cam plate, and a static-nary cam plate secured to said bracket and provided with a cam slot which cooperates with said lug to compel movement of said shaft to its one longitiudinal extreme position before said shaft can be rotated between its intermediate and one extreme angular position and to its other longitudinal extreme position before said shaft can be rotated between its intermediate and other extreme angular position.

- 5. A circuit controller comprising a supporting bracket, a stack of contacts secured to said bracket, an operating shaft mounted in said bracket in such manner that said shaft is both rotatable and longitudinally movable between an intermediate and two extreme positions, cam means including a circular cam plate secured to said shaft for selectively operating said contacts in response to rotation of said shaft between its intermediate and two extreme positions, a cam lug secured to said circular cam plate, and a stationary cam plate secured to said bracket and provided with a cam slot which cooperates with said lug to compel movement of said shaft to its one longitudinal extreme position before said shaft can be rotated between its intermediate and one extreme angular position and to its other longitudinal extreme position before said shaft can be rotated between its intermediate and other extreme angular position.

GLEN V. JEFFERSON.

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

UNITED STATES PATENTS Number Name Date 913,080 Weman Feb. 23, 1909 1,110,027 Aiken Sept. 8, 1914

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