US2276674A - Controller - Google Patents

Description

March 17, I942. v 2. s. SCHROVEDER 2,276,674

CONTROLLER Filed March 26, 1938 5 Sheets-Sheet 1 wwb ATTORNEY Mzirch 17, 1942. s. SCHRQEDER 2,276,674

CONTROLLER Filed March 26, 1958 5 Sheets-Sheet 2 Q3 m y. w

ATTORNEY March 17, 1942. c. s. SCHROEDER CONTROLLER 5 Sheets-Sheet 3 Filed March 26, 1938 ATTORNEY March 17, 1942. c. s. SCHROEDER CONTROLLER Filed March 26, 1958 5 Sheets-Sheet 4 C/sweus 5 507M505? ATTO R N EY March 17, 1942- c. s. scHRoEDER CONTROLLER Filed March 26, 1938 5 Sheets-Sheet 5 whv RY Patented Mar. 17, 1942 CONTROLLER Charles S. Schroeder, Philadelphia, Pa., asslgnor to The Yale & Towne Manufacturing Company, Stamford, Conn., a corporation of Connecticut Application March 26, 1938, Serial No. 198,206

Claims.

This invention relates to an electric controller of the type used in electric industrial trucks. More particularly, this invention is an improvement over the controller set forth in my Patent No. 2,094,851, issued October 5, 1937.

As a matter of fact, in many respects the controller of the present application is practically a duplicate of that shown in my earlier patent. As will hereinafter be more specifically shown, the means for moving the speed controller shaft into its several speeds are the same in this application as in my patent. Similarly, the cushioning mechanism of the controller shown in my patent is practically identical with the cushioning means of this application. Further, the direction controller to be described in this application is identical with that of my earlier patent, except as to minor respects.

Having now set forth those points of similarity between the controller of this application and the controller of my patent, I should like to point out generally the means which constitute the advance in the art which I desire to cover in this application.

In my patent, the speed controller comprises a drum mounted for rotation relatively to a series of contacts for closing various speed circuits. In my application, I eliminate the drum of my patent, and substitute therefor a series of movable contacts adapted to move in predetermined order into circuit closing position relatively to a series of stationary segments.

Those skilled in the art will readily appreciate that the contacts could be moved into circuit closing position by contactor relays, and against spring pressure. In such a construction, the opening of the circuits through the contactor relays will permit the springs to move the contacts away from the segments so as to open the various speed circuits. I have found, however, that such conventional electromagnetic contactors have decided disadvantages in safety.

This is due to the fact that occasionally the contacts will stick relatively to the stationary segments, so that when the electromagnetic contactor relays are conditioned to open the speed circuits, the contacts will remain against their corresponding segments due to the inability of the springs to move the contacts away from the segments. As a matter of fact, in occasional cases, the contact members are welded against the segments, due to the passage of the heavy electric current between the two. Naturally, the springs will not function in such a case.

I overcome the disadvantages of the conventional contactors of the prior art by operating my series of contact members by a serles'of cams mounted on a controller shaft. This shaft is operated just as is the drum shaft of my patent supra, the difference being that while in my patent I rotate a conventional drum, in this application I rotate a series of cams. Cooperating with these cams there are a series of arms, each of which carries a contact. The cams are stepped so that in various positions, various ones of the contacts will be held in speed circuit closing position. Fairly heavy springs oppose the movement of the arms into circuit making position under the influence of the cams, so that when the cams and shaft are rotated into a position corresponding to neutral, the said springs will move the contact carrying arms to neutral position.

Should there be a welding or sticking of the contacts against the several segments, then my cams are so constructed that they will cooperate with portions of the several contact carrying arms to force those arms and their contacts out of circuit making position. In other words, the normal operation provides for a cam closing of the speed circuits, with springs opening the said speed circuits when the cams move to neutral position, with the provision, however, of means whereby should the springs fail to move the contacts out of speed circuit closing position, the cams will force the contacts out of speed circuit closing position. Naturally, while my preferred modification will show the cams themselves actually moving the contacts into circuit closing position, it is apparent that an indirect movement of said contacts is possible without affecting the basic conception of my invention as just described.

I have arranged also for a very novel mounting of my contact arms and the contacts, in order to provide a compact arrangement of the parts while insulating the live contacts. Those skilled in this art willappreciate that a compact arrangement is highly necessary in controllers used in electric trucks because of the nature of such trucks. I shall not now describe the means generally, but shall describe them in detail later in the specification.

A further feature of the invention which is of considerable importance is the arrangement of permanent magnets relatively to the stationary segments and movable contacts for controlling the arcing, and to provide a permanent magnet blow-out. Other detailed features and advantages of my construction will be pointed out in the specification and will be set forth in the claims appended hereto. Naturally, I consider my contribution to the art to be relatively broad, and I do not wish to be limited in my monopoly except as is required by the state of the art.

I shall now describe the drawings in which my invention is shown, and shall then present a detailed description of the invention. I do wish to point out before proceeding, that in so far as the present invention resembles the controller shown in my patent already referred to, I shall refer to that patent rather than describe here in detail the various features which are part of the invention claimed in the said patent.

In the drawings, Fig. 1 is a side view of the operating end of an electric truck, while Fig. 2 is an end view of the said end. Fig. 3 is a front view of my controller in its casing with the cover of the casing removed. Figs. 4, 5, 6 and 7 are views taken along lines 4-4, 5-5, 66 and 1-! respectively of Fig. 3. Fig. 7a is a section taken along lines Ia-la of Fig. 7. Fig. 8 is a view of the parts of Fig. 7 in a slightly different position. Fig. 9 is a section taken along lines 8-4 of Fig. 7 showing the mounting of the permanent blow-out magnets. Fig. 10 is a wiring diagram of the controller circuits. Fig. 11 is a perspective view of one of the contact carrying arms of my invention, while Fig. 12 is a perspective view of a movable contact carried by each of the arms of Fig. 11.

Referring now more particularly to the drawings, and especially to Figs. 1 and 2, there is shown an industrial truck 10 having the identical control mechanism illustrated in my patent. 'Describing the construction briefly, there are driving wheels H and an operators platform l2. Pivoted to this platform l2 are pedals l3 and I 4, which through rods l6 and H operate to move the direction and speed portions of my controller,

just as is set forth in my patent. A handle l9 is mounted on the side of the controller casing II for moving the direction controlling portion of my controller, while the handle moves the speed controlling portion of my controller, just as in my prior patent. It is to be understood that just as in my patent, there are means of intercontrol between the pedals I3 and H and the handles i9 and 20. The truck is steered through a lever 2|, a rod 22 and appropriate linkage, as is well understood by those skilled in the art.

Referring now more particularly to Fig. 3, it will be noted that the right half of the controller, which is the direction controlling portion thereof, is practically identical with the direction controlling portion set forth in Fig. 3 of my patent. In Fig. 5, I show mechanism which is practically identical with that shown in Fig. 7 of my patent, illustrating the manner in which the truck controller is eased into its neutral position through the use of the relatively powerful spring 12, the cam member 69, the lugs 61, the spring 84, the spaced levers 62, detent rollers 63 and the depressions 51 of the star wheel 55. I have used the same reference numerals in Fig. 5 as are used in Fig. 7 of my patent, so that it will be comparatively simple to compare the constructions.

Fig. 6 of the drawings of this application shows parts practically identical with those of Fig. 10 of my patent. As in Fig. 10 of my patent, the direction controller drum is supported on the hollow shaft 24 through which traverses the shaft 26 of the speed controller. V brackets 21 and 28 support the contacts 36 for rotation against fixed contacts 35 to close the circuits corresponding to forward or reverse, just as in my patent.

In Fig. 8 of my patent, I show interlocking means whereby when the speed controller is in any particular speed, it will be impossible to rotate the direction controller to reverse the direction of movement of the truck. In Fig. 6 of this application, I illustrate means functioning similar to that of my patent, but somewhat different in construction. Thus, I use an arm H3 having a lug H2 adapted to enter a notch ill in a cam H0, whenever the speed controller is in any speed position. The cam H0 is fixed to the direction controller drum, and naturally the locking of cam H0 against movement locks also the controller drum against direction reversing movement, all as will be quite clear to those skilled in the art.

A screw H5 traverses the arm 3 and rests on the extension lever N6 of one of my contact carrying arms III, to be described later, under the pressure of a spring 8. It is of course quite apparent that when the extension lever H6 is in its position of Fig. 6, that is, in a position corresponding to neutral of the speed controller, the direction controller will be free to rotate in either direction.

On the other hand, when the extension lever I I6 moves to its position of Fig. 8, or into a position corresponding to one of the speeds of the controller, then the screw H5 will allow the arm Hi to drop. This will position lug H2 in the notch III of cam H0 to lock the direction controller against movement. In describing Fig. 6, and the interlocking relationship between the speed and direction controllers, I have used the same reference numerals as I used in connection with Figs. 8 and 10 of my patent.

In Fig. 4, I show parts which are practically identical to the parts shown in Figs. 6 and 9 of my patent, and which parts are used for moving the speed controller shaft through the foot treadle l4, and for easing the movement of the speed controller shaft into its various speed positions, and from a speed position into neutral.

The star wheel ll of my application corresponds to the star wheel of my patent, and is moved by the rod 86, Just as in the patent, against the pressure of the relatively powerful spring 90. The star wheel 80 is secured about a splined portion 23 of the speed controller shaft 26, this splined portion 23 being substituted for the square portion 24 of the speed shaft shown in Fig. 6 of my patent. Other than this, the various other means comprising the levers II, springs 84, detent roller 85, dog I03 and sleeve 89 all cooperate as in my patent supra, and need not be described more in detail here.

Reviewing the construction so far described, it is quite apparent that the direction controller of this application is constructed and operated in the same way as it is in the controller of my patent supra. It is also apparent that in the present controller, the speed controller shaft 26 is rotated through the rod 86, star wheel III and its splined shaft portion 23 into various speed positions at the will of the operator, and through the foot pedal I l or the handle 20, and is otherwise controlled just as'in my patent. The invention hereinafter to be described is independent of the particular form of the actuating and control means so far described. It is immaterial to the construction which I have conceived and developed as to just how the controller shaft 28 with its splined portion 23 is rotated and controlled, so far as my present invention is concerned, so long as this operation and control function in a required manner.

Mounted on the splined portion 23 of the speed controller shaft 26 are a series of cams I20, I2I, I22 and I23, corresponding respectively to the first, second, third and fourth speeds. In Fig. '7, the profile of the first speed cam is shown in full lines, while the corresponding profiles of the other cams are shown in dotted lines. Cooperating with each of the cams is a contact carrying arm II-I pivoted on the shaft I24. One of these contact carrying arms III is shown in perspective in Fig. 11, and since all of these arms are the same, it is necessary to describe only the construction of one.

As is apparent, each of the arms I" includes spaced side bars I25 and I26, each of which is bored at I21 for supporting a shaft I28 on which is mounted a roller I29 cooperating with its one of the speed controller cams I20-I23. A lever II6 extends from each of the arms Ill, and in the case of the first speed contact carrying arm I I1, is used for controlling the interlock between the direction and speed controllers, as was previously described. Each extending lever II6 has a further function, however, and for this further function it cooperates with the portion I30 of the speed cams, as will be described later.

Each of the contact carrying arms III carries a contact I3I-, shown best in perspective in Fig. 12, the mounting of this contact on its arm III being best illustrated in Fig. 7a. There it will be noted-that the side bars I25 and I26 carry a pin I32 about which is supported a metal bearing sleeve I33. Mounted about this bearing sleeve I33 are a pair of fiber insulating sleeves I34 each of which has a fiange I35. The sleeve portion I36 of the contact I3I fits about the fiber sleeves I34 and is thus insulated from the bearing sleeve I33, the flanges I35 of the fiber sleeves serving to insulate the contact from the side bars I25 and I26.

A pigtail I3I connects each of the contacts I3I to a binding post I38, from whence leads an insulated cable I39. The series of binding posts I38 are supported on an insulation base I40, which supports also a bar I40a which carries a series of stationary speed circuit segments I, all as will be quite clear to those skilled in the art.

The tail portion I42 of each contact member I3! is pressed against a fiber insulation insert I43 on its arm III by a spring I44 fitting at one end in a cup portion I45 of the contact I3I, and fitting at its other end about the guide pin I46 of a fiber insulation member I41. The insulation member I4I has a pin I48 which is inserted in an opening I49 of the contact carrying arm I", the pressure of the spring I44 serving to hold the member I41 assembled relatively to its arm 1.

A relatively powerful spring I50 is positioned between a cupped portion II of the back plate of the casing I8 of the controller, and an abutment I52 on the contact carrying arm Ill, and urges the contact carrying arm into the position shown in Fig. '7 and with its roller I29 against the cam I20. Naturally, each of the other contact carrying arms I I1 will be urged by its spring against its particular one of the cams I2I, I22 and I23.

Referring now more particularly to Figs. '7 and 8, I shall describe the operation of one of the contact carrying arms I" and its contact I3I under the influence of the rotation of the cam I20, using that cam as an example. Cam I20 when rotated from the position of Fig. '1 towards the position of Fig. 8, will act on roller I29 of the arm I, first moving the arm against the opposition of the spring I50 to a point where the contact I3I is in its dotted line position, illustrated in Fig. 8. It will be observed that in this position, there will be a line contact only between contact I3I and the segment I4I.

Continued rotation of the cam I20 to its position of Fig. 8 will act to move the arm III and therefore pivot shaft I32 about which the contact member rotates, to the position of Fig, 8. At the same time also, the spring I44 will be compressed more fully, and this combined action will cause the contact I3I to assume a new position. This is the solid line position illustrated in Fig. 8, wherein a surface contact will be made between the said contact I3I and the segment I4I. This movement between the contact I3I and the segment I causes a wiping of the two contacting surfaces, so as to clean the said surfaces and give a better action, all as will be apparent.

Upon reverse movement of the cam I20 from Fig. 8 to Fig. 7, it is quite apparent that when the portion I20a of the cam I20 comes opposite the roller I29, the spring I50 will tend to force the arm II! and its contact I3I back from the position of Fig. 8 to the position of Fig. '7. This motion will be swift, in order to prevent undue arcing.

Should it happen that the contact I3I sticks relatively to the segment I4I, or welds to the segment I4I, so that the spring I50 is unable to do the work for which it is designed, then continued rotation of cam I20 will cause portion I30 of the cam I20 to strike the extending lever H6 and force the lever, together with the arm II'I, into the position of Fig. 7. ment of the arm 1, the fiber plug I43, which is really a limit stop against which the tail piece I42 of the contact I3I acts, will be th actual forcing member for forcing the contact I3I out of contact with the segment I4I. Thus, we have the combination of an electric circuit closed by cam action, and opened by spring action, with the feature that should the spring action fail, th cam will open th circuit. We have also the feature that the circuit is closed through the intermediary of a spring, and the additional contribution of the wiping contact action.

Referring now more particularly to Figs. 3, 7 and 9, it will be noted that at each side of each corresponding pair of contacts I3I and segments I4I, there is an insulation member I55. These insulation members are shaped as is best shown in section in Fig. 9, and are adapted for mounting through a series of sleeves I56 about a shaft I5I supported by brackets I58 extending upwardly from the controller casing. Each of the opposite end insulation members I55 carries a permanent magnet I59, while between each of the middle insulation members I55 there is located a like permanent magnet I59. The action of these permanent magnets is to blow out any arcing which may occur between the contacts I3I and the segments I4I.

In Fig. 10, I illustrate a wiring diagram of the circuits of my controller. The field coils are designated by referenc numerals I60, while the armature is designated by reference numeral IGI, the traction resistance by reference numer- During this move- I al I62. Th various contacts I3I, the base a and segments I4I are shown in their proper relation. Since the direction controller is the conventional type disclosed in my patent supra, I shall describe only the speed circuit through but two of the speeds to illustrate just how the circuits function. Those skilled in the art will readily understand the remaining speed circuits without any further explanation.

The current passes from the plus side of the battery I63 through the conductor I64 to the post 2 of contact bar Milo, thence through a segment Hi to the first speed contact I3I, thence to binding post 5, through resistance I62, to conductor I65, through the armature I6I to the binding post 6, from which it goes through the field coils in either forward or reverse, as determined by the direction controller.

For the second speed, the first speed contact I3I will remain in its first speed position, and contact will be made in addition between the second speed segment MI and the second speed contact l3I. The circuit will be as follows: From the plus side of the battery I63 through contact I64 to the second speed segment I4I, second speed contact member I3I, binding post 4, though a portion of the resistance I62, conductor I65, through armature I6I, binding post 6, thence through the field coils ISO in the particular direction for which the direction controller is set.

I now claim:

1. In a'controller of the class described, a rotatable contact carrying arm comprising ,spaced plate portions, a contact supported on a pivot;

shaft mounted on the spaced plate portions of said contact carrying arm, an insulation sleeve for said pivot shaft insulating said contact from the plate portions of said contact carrying arm, a spring mounted between said arm and contact, insulation means between said spring and said contact carrying arm, limit means for limiting the rotation of said contact relatively to said arm by said spring and against which said contact is normally positioned when said contact is in open circuit position, said limit means comprising an insulation member whereby to insulate said contact from said arm, a cam for rotating said arm together with its contact until said contact makes an electric circuit with a stationary segment, further rotation of said arm by said cam acting to compress said spring to better hold said contact against said segment while moving said limit means beyond said contact, a second spring for rotating the said contact carrying arm in a reverse direction when said cam is reversed, whereupon said limit means moves said contact away from said segment, and an extending arm formed on said contact carrying arm and engageable with said cam to move said arm and contact away from said segment should said second spring fail to do so.

2. In a controller of the class described, a contact carrying arm, a live contact, a fiber sleeve whereby said live contact is insulated from said arm and through which said contact is supported on said arm, a shaft traversing said sleeve and through which said live contact rotates relatively to said arm, an insulating plug having a spring guide pin and a mounting pin, and a spring operating between said contact and said arm and pressing at one end on said fiber plug and about said guide pin, said spring being the means through which movement is imparted to said live contact from said arm, said spring retaining said fiber plug in position through pressing said plug mounting pin into an opening in the arm provided therefor.

3. In a controller of the class described, a contact carrying member comprising a pair of spaced plate portions terminating at one end in a bored sleeve connecting said portions and whereby said member is pivotaily mounted in said controller, a roller mounted on a pin extending between said plate portions and whereby movement is imparted to said member, a contact carrying shaft projecting between said plate portions, a contact pivoted on said shaft, an insulation sleeve on said shaft separating said member and shaft electrically from said contact, a compression spring resting at one end against said contact and pressing at its other end against said member, and an insulation piece between said spring and said member maintained assembled to said member by the pressure of said spring.

4. In a controller of the class described, a contact carrying member comprising a pair of spaced plate portions terminating at one end in a bored sleeve connecting said portions and whereby said member is pivotally mounted in said controller, a roller mounted on a pin extending between said plate portions and whereby movement is imparted to said member, a contact carrying shaft projecting between said plate portions, a contact pivoted on said shaft, an insulation sleeve on said shaft separating said member and shaft electrically from said contact, a compression spring resting at one end against said contact and pressing at its other end against said member, an insulation piece between said spring and said member maintained assembled to said member by the pressure of said spring, and a further insulation piece on said member against which a portion of said contact strikes when pressed by said spring whereby to limit the rotation of said contact relatively to said member.

5. In a controller of the class described, a contact carrying member comprising a pair of spaced plate portions terminating at one end in a bored sleeve connecting said portions and whereby said member is pivotally mounted in said controller, an arm extending from said sleeve and whereby said member is rotated about the axis of said bored sleeve, a roller mounted on a pin extending between said plate portions and whereby movement is imparted to said member, a contact carrying shaft projecting between said plate portions, a contact pivoted on said shaft, an insulation sleeve on said shaft separating said member and shaft electrically from said contact, a compression spring resting at one end against said contact and pressing at its other end against said member, and an insulation piece between said spring and said member maintained assembled to said member by the pressure of said spring.

CHARLES S. SCHROEDER.

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