US1877171A - Switch control mechanisms - Google Patents

Description

2 Sheets-Sheet l H. E. HALLENBECK swxwcn comm MECHANISMS Filed Feb. 11, 1932 Sept. 13, 1932.

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HE. HALLENB ECK SWITCH CONTROL MECHANISMS 2 Sheets-Sheet 2 Filed Feb. 11, 1952 H INVENTOR" j ATTO Patented Sept. 13,1932

uNrrso STATES PATENT orrics HAROLD E. HALLENBEOK, OF HUDSON, new YORK, ABSIGNOB TO GUIDED-WOOD (DI- PANY, OF HUDSON, NEW YORK, A CORPORATION OF NEW YORK SWITCHCONTROL ator to control the travel of a carrier, such as I a gig, which is moved between certain limits of'travelby means of a motor driven unit, to stop preferably at a fixed level in its descent and at a plurality of predetermined levels in its ascent. The invention can be adapted to control traverse motion, instead of hoisting,

- unit in a switch box.

ployed in connection with ice .tierinf also to control stopping of a carrier in either or both directions at fixed or variable points.

Referring to the drawings showing a preferred embodiment of the invention:

Fig. 1 is an elevation of part of a drum of a tiering machine, showing also the control mechanism driven by the drum;

Fig. 2 is a vertical section through the control unit, on an enlarged scale;

Fig. 3 is'another vertical section of the same, 011 the scale of Fig. 2; and

Fig. 4 is a wiring diagram.

The switch control mechanism of the present invention .is very advantageously emmachines in which a cake of ice is sli onto a gig substantially flush with the floor and elevated to a point Where it can be slid of on to the tops of other cakes already tiered. In order to prevent cracking or chipping of the ice cakes when they are slid onto the g the gig must descend exactly to the floor surface and stop. Then when a cake of ice is elevated, the gig must stop at just the right level so that the bottom of the cake lifted will be substantially flush with the top of the block on which it is to he slid. The present invention provides a cam actuated switch for automatically stopping the gig in its descent at a fixed level, i. e., the floor, a dial adjustment which can beset automatically to stop the gig in its ascent at exactly the right level of any one of several tiers, and safety stop means to prevent over travel of the gig past its upper limit, all incorporated in a single Such a unit is capable of being mounted at various places, or-even added to old installations controlled entirely by hand to make them automatically controlled.

Referring more particularly to the drawings, there IS shown in Fig. 1 a limit switch control unit having a control box 5 and a power driven shaft ficonnected with a gig hoist drum 7 through spur gears 8 and 9. Drum 7 is directly driven by a motor, shown diagrammatically in Fig. 4. The ear 8 is keyed on shaft 6 and has hubs on eit er face, Fig. 3. The outer hub has a large; bore than the inner hub, providing a shoulder and a space around the shaft for a spring 10, which with a washer 11, secured on the end of the shaft by a screw 12, holds'the gear normally in mesh with gear 9. However, the gear may be drawn outfrom its normal meshm position, as indicated in dotted lines in ;i 1, and remeshed after the shaft 6 has geen rotated through one or more revolutions, or through a small fraction of one revolution ghe smallest fraction permitted bein the action which the width of one tooth 0 gear 8 is of the pitch circle of said gear). A dial 13.is located at the front of the box and has a pointer 14 fastened to the cover, and is used in ad'usting the action of the limit switches as will be described.

Referring now to Fig. 2 showing a cross section of the switch operating mechanism, there is shown a dial shaft 15 colinear with a cam shaft 16 both rpendicular to the driven shaft 6. The :11 shaft is of relatively large diameter and has an axial bore 17 in its inner end to sleeve the inner end of the cam shaft. A ball 18 in the bore serves as a thrust bearin The outer end of the cam shaft is journal in a b 19 and has a collar 20 pinned adjacent the ushing. The outer end of the dial shaft is journaled in a flanged bushing 21 and has a thrust washer 1 22 between the bushing flange and the box cover. by keys 23, and adjacent the dial is a knurled hand nut 24screw-threaded on the dial shaft.

The dial 13. is fastened to its shaft V The cam shaft 16 is driven from the shaft flange of a brass bushing 28 which in turn is fixed on the shaft by a pin 29. Thus the cam 27 rotates whenever the drum hoist of Fig. 1 is in motion. The dial shaft 15 carries a second bakelite cam 30, fastened to the flange of the bushing 21 by screws 31, but free to remain in a fixed angular position while the shaft rotates. This cam, in fact, is restrained by stops from turning through any but a small central angle, as will be described later. Adjacent the cam 30 is a drive flan e 32 having a hub 32 keyed to the dial s aft by a tangential pin 33, as shown. The hub 32 has a radial pin 34 which engages a perpendicular stud 35 in the cams 27 when this member is rotated. It will be observed that the hub of the knob 24, which serves also as a nut, does not bear against the shoulder 36 of the shaft, but is adapted to be tightened against the dial, which tightening draws the drive flange 32 against the face of the cam 30 providing a friction grip whereby the flange can drive the cam until the rotation of the latter is checked by the aforementioned stops. The flange also carries a radial pin 37 which will engage a perpendicular in 38 in the cam 30 in case slipping occurs hetween the drive flange and the cam. The pin 37 may be set in the flange at the time of assembly to conform to the maximum travel of the gi The cam 30 has an axial hole large enoug to provide space around the shaft 15 for a coil sprin 39 which serves merely to spread the mem ers 32 and 30 when the nut 24 is loosened. The pin 40 fastened to the front cover plate of the box, and a spring plunger 41, better shown in Fi 3 acts as stops to constrain the rotation of t e cam 30 to a small central angle including its tripping and release position.

Referring now toFig. 3, the cam 30 is shown as having a radial projection 42, one side of which bears against the stop in 40 to prevent any further counter-clockwise rotation of the cam than shown. The opposite side has a cavity 43 to receive the head of the lunger 41. The plunger is mount d in a racket 44 which is secured to the front cover plate of the box by a bolt 45. The plunger 41 is provided with a coil spring 46 so that when a clockwise torque is applied to the cam 30, it rotates through an angle large enough to cause the tripping of a contact arm, compressing the spring, and then, when the torque is released it springs back against the stop pin 40.

The electrical contact members are supported by a block of insulating material 47 which is spaced from the top of the box by spacers 48 and fastened thereto by screws 49. At one end of the block 47 there are fastened two hinge blocks 50 to which the contact arms 51 and 52 are fastened by ears 53 and hinge pins 54. On the opposite end of the block 47 there is fastened another insulating block 55 to which are attached contact holders 56. Screwed into the end of the holders are adjustable contact points 57 one of which is directly behind the other in Fig. 3 and consequently is not shown. The contact arms 51 and 52 have contact buttons 58 and 59 on their ends to contact with the points 57. In Fig. 3, the button 58 contacts withone of the points 57, while the butlon 59 contacts with the other point, not visible, behind this point. Midwaybetween the contact buttons and the hinges, the arms are provided with rollers 60 which roll on the cam surfaces when the arms are being tripped. The contacts are normally kept closed by the pressure of the springs 61 on the contact arms.

--Referring now to the functioning of the mechanism described, the two switches shown in Figs. 3 and 4, that is contacts 58 and 59, are connected in series with the operating coil of a magnetic reversing switch 62, and contacts 57 and 59 are connected in series with the operatin coil of a magnetic switch 62a, said magnetic switch controlling the direction of rotation of an electric motor. The tripping of either of the arms 51 or 52 will break its respective circuit and stop the rotation of the motor. An automatic solenoid brake (not shown) is usually employed to stop the drum immediately when the motor circuit is broken. The motor circuit also includes a main switch and fuses (not shown) and there is a two-button switch 63, 63 by which the circuit may be initially closed to either coil of the magnetic switches by pressin one ofthe buttons for hoisting and the ot er for lowering.

In Fig. 3, the open switch 52 is actuated by cam 27 to stop the gig at a fixed level in its descent, and the switch 51 shown as closed is tripped by cam 30 to stop the gig in its ascent at a level indicated on the dial 13. Thus, referring to Fig. 3, the cam 27 is shown as having just completed a counterclockwise rotation tripping the roller of the arm 52 against the cam surface 64, which would stop the gig at the floor level. Obviously. the cam 27 can be set to stop the gig each time at the desired fixed level by the proper adjustment of the gear 8 on the drive shaft 6.

When it is desired to elevate the gig. button 63 is pressed, closing the circuit to the operating coil ofmagnetic switch 62, causing the motor to start drum 7 in a direction to raiw the gig. This movement allows the arm 52 to spring back against the contact 57. The gig now rises and when it reaches :1 tier corresponding to that indicated on the dial, the cam 30 has rotated in a clockwise direction sufliciently' far to engage the drive flan." 32 through the engagement of the pins 34 and 35. The friction grip between the drive flange and the cam 30 now causes the latter to rotate slightly in a clockwise direction against the pressure of the spring plunger 41 and to trip the arm 51, opening the contacts 57 opening the circuit to the operating coil of magnetic switch 62 and thus breaking the motor circuit and stopping the gig. If the gig has traveled to its maximum height, the cam 27 will have rotated through almost a complete revolution, and the pin 37 will have engaged the pin 38 to insure positive tripping of the arms 51.

In lowering the gig, the button 63a is pressed, closing the circuit to the operating coil of magnetic switch 62, which closes the motor circuit to cause a down motion of the gig. This motion allows the cam 30 to spring back against the stop pin 40, allowing the arm 51 to spring back against the contact 57. The gig is then lowered and the cam 27 rotates in a counterclockwise or reverse di-' rection back to its startin point, where it again trips the arm 52 an stops the gig at the floor level.

It should now be clear that the interval between the releasing of the arm ,51 and the tripping of the arm 52 depends on the initial angular displacement between the in 35 in the cam 27 and the pin 34 in the drive flange 32. Thus if it were desired to stop the gi at the second tier, the dial would be rotate until the pointer indicated 2. This would bring the pin 34.- around to a position just ahead of the in 35 where the cam 27 would engage the rive flange 32, after rotating through only a small an le. The maximum rise of the gig would evidently be obtained by rotating the drive flange to a position where the cam 27 would have to make almost a complete revolution before the pin 35 engaged the pin 34. With the flange in this angular position, the pin 37 would engage the pin 38 in the cam 30 so that a positive engagement of the flange and cam in addition to the frictional grip between them is provided at this point. In case the maximum travel of the. gig in its frame is less than that which would be permitted by one almost complete revolution. of the cam 27, the pin 37 would be placed in a different angular position relative to the pin 34 to limit the maximum tripping intervals between the two cams accordingly. When the dial shaft is rotated by means of the knob 24, the drive flan e obviously tends to carry the cam 30 -aroun with it, but rotation of the cam is'prevented by the stops 40 and 41 so that after the torque on the knob exceeds the frictional torque between the flange and the cam, the flange rotates with respect to the cam to its proper position.

The switch mechanism described thus provides automatic means for breaking a motor circuit at two different intervals, one of said intervals corresponding to a fixed position in one direction of the motor driven part or unit, and the other adjustable to correspond to any desired position, within limits, in the opposite direction. The dial and pointer obvously make possible a very fine adjustment to stop the unit at exactly the desired position.

Although this switchcontrol unit is especially adapted to control the travel of a gig in ice tiering machines, it may be very advantageously employed to control any motor driven carrier which travels in opposite d 1- rections between two points. In case 1t 1s desired to vary the stopping point in e ther direction of travel, this ma be accomplished by a combination of two 0 the dial elements described. I

In the event the cable on drum 7 stretches, the gig will not stop at exactly the right point, either in hoisting or when descending. To make possible an adjustment of the angular position of both the cams, without affecting their relative position, and without ro tating the drum and motor or taking u the cable on the drum, the gear 8 isslidab e on shaft 6, as previously described, thus making possible instantaneous disengagement of gear 8 from gear 9 and rotation of shaft 6' through any desired angle, thus rotating both cams in the direction to cause proper functionin of the apparatus.

Obvious y, the present invention is not restricted to the particular embodiment thereof herein shown and described. Moreover, it is not indispensable that all the features of the invention be used conjointly, since they may be employed advanta eously in various combinations and sub-com inations.

What I claim is 1. In a switch actuating mechanism for controlling an electric motor circuit, the combination of a pair of rotating cams adapted to trip switches, one of the cams being geared to the motor, and the other cam being adapted to be engaged by the first and rotated to its tripping position after a predetermined and variable angular advance of the first with respect to the second.

2. In a switch actuatingmechanism, the combination of rotating cams, a driving member between two of the cams adaptedto be engaged by the first cam after a predetermined angular advance of the first with respect to the second cam, and to transmit said rotary motion to the second cam, said driving member being angularly adjustable with respect to both cams to vary the said predetermined angular advanceof the first. 3. In a switch actuating mechanism, the combination of rotating cams and a driving member to link the rotation of one cam to the other after an initial angular advance of one cam with respect-to the other; and dial means to indicate and adjust said angular advance of the one cam with respect to the other before linking occurs.

4. In a switch actuating mechanism adapt- 3- 59 said breaking 65 and trip a swit ed to control the travel of an electric motor driven gig or the like, the combination of rotating cams adapted to trip switches in the motor circuit; safety engagement'means to limit the maximum rotation of one cam with respect to the other to conform to the maximum travel in one direction of the motor driven gig, said maximum rotation of the one cam with respect to the other correspond- Sing to a maximum interval between the tripping of the two switches by the cams.

5. A switch actuating mechanism for elec-' tric motor operated gigs and the like comprising, in combination, a pair of contact arms and points connected to control the stopping of an electric motor; a cam gear driven from the motor, adapted to trip one of the contact arms at a point in the reverse rotation of the motor corresponding to a limiting position of one direction ofthetravel of a gig driven b the motor; a second cam adapted to trip t e other contact arm at a predetermined, indicated and variable point in the forward rotation of the motor corresponding to a position of the gig in a travel oppositely directed from the limiting position; meansmter osed between the two cams to link the rotation of the first cam to the second after a predetermined angular ad vance' of the first cam with respect to the second; additional safety link means between the two cams to limit the maximum possible rotation of the first cam with respect to the second to conform to the maximum travel in one direction of the gig; and .dial means to indicate and determine the interval between i the releasing of one contact arm by the first cam and the tripping of the other contact arm by the second cam.

6. A gig travel limit switch, comprising, in combination, automatic means comprising va pair of motor driven cams, and a air switch contact arms arranged to be H d by the cams, to break an electric motor circuit at a point in the reverse rotation of the motor the first cam and turned to its trip in position after a variable and indicate angular advance of the first cam-from its release position.

7. A switch actuating mechanism adapted to be gear driven from an electric motor and having cams to trip switches which will break the motor circuit; a cam shaft geared to the motor; an insulating cam secured to the cam shaft and havin an edge adapted to engage cii contact arm at the endl o a reverse rotation of the cam and motor; a dial shaft colinear with the cam shaft; a dial ke ed on the outer end of the dial shaft; a clutc member keyed on the inner end of the dial shaft; a second insulating cam adapted to be turned with the dial shaft by the friction grip of the clutch member and having an edge adapted to engage and trip a switch contact arm at the end of a forward rotation of the cam and motor; means on the dial shaft to ti hten the clutch member against the secon cam; stops adapted to restrain the rotation of the second cam to a small central angle including the trippingand release positions of the cam, one of said stops having spring means to hold the cam geared to the driven shaft a ke a spur gear secured to the shaft and adapte to mesh with a drive gear to be driven thereby; said spur ear having hubs on both sides, one hub havmg a bore to fit the driven shaft, and a slot for the key, and the other hub having a larger bore ending in a shoulder at the other bore;

a coil spring around the driven shaft within the larger bore; a circular disk at tho end of the driven shaft secured thereto;

said spring acting against the disk and the shoulder to hold the gear normally in mesh; said gear being slidable towards the disk end of the shaft to permit disengagement of the spur gear from its driving gear and rotation of the driven shaft with respect to the drive gear; said arrangement rmitting proper adjustment of the cam re ative to'the drive gear.

9. In a device of the character described, the combination of a motor; a motor-driven gear; a second gear meshing with the motordriven gear; a shaft carrying the second gear; co-operating means on the shaft and second gear so that the second gear is slidable on the shaft and disengageable from the driven gear; yieldable means to hold the second ar in meshing position; a worm on the sha' a worm ear driven by the worm and secured to anot er shaft; a pair of cams secured to the second-named shaft; a pair of spring-closed switches each adapted to be opened b one of said cams; and 'a circuit comprising the motor and the switches whereby the motor is stopped by said switches, and reversing connections whereby two-way travel of the motor is verned.

10. A switch contro mechanism comprising, in combination, a shaft; a reduction ing position, so that its shaft may be rotated by hand and the gear then restored to meshing position.

11. A gig travel limit switch and switch actuating mechanism comprising, in combination, a box-like housing; a pair of switches within the housing connected in series in an electric motor circuit and adapted to be tripped open by rotating cams; a cam geared to the motorand adapted to trip one of the switches at a point in the reverse rotation of the motor corresponding to a fixed position of the gig; a second cam adapted to trip the other switch at a variable point in the forward rotation of the motor corresponding to a variable and dial indicated position of the gig; a dial shaft colinear with a cam shaft carrying the first cam, projectin through the front of the box and journale in the same and carrying the second cam; a friction disk secured to the cam shaft between the two cams and adapted to be tightened against the second cam and rotate the same; an indicating dial on the outer end of the shaft; ins in the first cam and friction disk where y the first cam can engage the friction disk and thereby the second cam after an adjustable angular advance of the first cam from its release position; safety engagement pins in the friction disk and second cam which engage each other when the friction disk has been rotated with respect to the second cam to a position where the maximum tripping interval between the two cams is obtained, said pins serving also to limit the maximum tri ping interval between the two cams to con' orm' to the maximum continuous travel of the gig; the initial angular displacement of the two cams from then engaging position adjustable by means of the friction dials which can be rotated with repinned on the cam shaft adapted to operate in a central angle less than 360 and to trip a switch arm at a point in the reverse rotation of the motor corresponding to a fixed position of the carrier under control; means 1 in the cam shaft gearing b which the cam may be set to trip the switc at a point cor responding to a limiting position of one direction of the carrier travel; a dial shaft colinear with the cam shaft; a dial outside the box rkeyed on the end of the dial shaft;

a second cam mounted on the dial shaft rotatable with respect to the same; stop means to restrain the rotation of the end cam to a small central angle including its tripping and release position and to hold the end cam normally in a release position; a friction flange keyed on the dial shaft between the two cams; means on the dial shaft to tighten the friction flange against the second cam to provide a friction grip whereby the flange can drive the cam; a driving pin in the first cam; a driving pin in the friction flange engageable by the pin of the first cam; safety stop pins in the friction flange and second cam which provide positive means of engagement in addition to the friction gripbetween the two members when the friction flange is set in a position to cause a maximum interval between the tripping points of the first and second cams, said interval corresponding to a maximum travel in one direction of the carrier; the second cam adapted to trip a second switch in the motor circuit at a point in the forward rotation of the motor after a .variable interval from the releasing of the first cam switch; the interval between the closing of either of theswitches and the tripping of the other being variable and dependent on the dial setting, said dial indicating the point where the carrier will stop.

13. A switch actuating mechanism com-- of which is journaled in the housing, and the.

other end in the axial bore of a colinear dial shaft; a dial shaft colinear with the cam shaft having an axial bore in one end to serve as a sleeve for the inner end of the cam shaft and having its outer. end projecting through the. housing and journaled therein; a drive shaft at right angles to the cam shaft bearinged in one end of the box and having on one end a spur gear outside the box by which the drive shaft may be driven by an electric motor, and on its inner end a worm; a Worm wheel secured on the cam shaft to engage said worm; an insulating tripping cam secured on the shaft; said dial shaft havin keyed -on its inner end a driving flange having a hub adjacent the pinned cam of the cam shaft; an indicating dial keyed on the dial shaft; said dial shaft having a threaded portion; a hanll nut which may be tightened against the dial hub; a flanged bushing between the drive flange and the housing, a portion of which projects through the housing and contacts with the inner side of the dial hub, and having a friction grip with the same; a second insulating tripping cam secured to the flange of the bushing, both cam and bushing being rotatable with res ect to the cam shaft and to the housing; sai last-mentioned cam having an edge to contact with a switch arm, and diametrically opposite the tripping edge, a radial projection to restrain the rotation of the cam to a small central angle including the tripping and release positions of the cam; stops secured to the front cover plate, one stop consisting of a pin to limit the reverse rotation of the cam to a release position; the other stop comprising a sprin plun er which is compressed by the rotatlon of t e cam to its tripping position and which snaps the cam back agalnst the stop pin when the tripping torque is released; said first-mentioned cam having an edge oppositely inclined to that of the second cam and adapted to trip a contactarm in the reverse rotation of the cam; driving pins, one projecting at right angles from the inner face of the pmned cam, and the other projecting radially from the hub of thedrive flange; said pins furnishing means whereb the rst cam can engage the drive flan an thereby the second cam after a variab e and adjustable angular advance from its tripping position of the first cam with respect to the second; and safety enga ement pins, one projecting radially from-file drive flange, and the other rojecting at right angles from the adjacent ace of the second cam, to limit the maximum angular advance. of the first cm with respect to the second.

In testimony, that I claim the foregoing is my own, I have hereto aflixed m signature.

HAROLD E. HALL NBECK.

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