US2776032A - Cam turn-off device and control therefor - Google Patents

Description

Jan. 1, 1957 J. KELLOGG 2,776,032

CAM TURN-OFF DEVICE AND CONTROL THEREFOR Filed May 23, 1.952 T Sheets-Sheet l Inventor .J'os e ak feilqgy Jan. 1, 1957 -J.'KELLOGG 2,775,032

CAM TURN-OFF DEVICE AND CONTROL THEREFOR Filed May 23, 1952 T Sheets-Sheet 2 Ill" " J76 6 26 ZQ/Zqyg Jan. 1, 1957 J. KELLOGG CAM TURN-OFF DEVICE AND CONTROL THEREFOR Filed May 23, 1952 7 Sheets-Sheet 3 fin e)? &

Jan. 1, 1957 J. KELLOGG 2,776,032

CAM TURN-OFF DEVICE AND CONTROL THEREFOR Filed May 23, 1952 7 Sheets-Sheet 4 Jan. 1, 1957 J. KELLOGG CAM TURN-OFF DEVICE AND CONTROL THEREFOR 7 Sheets-Sheet 5 Filed May 23, 1952 Jan. 1, 1957 J. KELLOGG CAM TURN-OFF DEVICE AND CONTROL THEREFOR 7 Sheets-Sheet 6 Filed May 23, 1952 Jan. 1957 J. KELLOGG CAM TURN-OFF DEVICE AND CONTROL THEREFOR 7 Sheets-Sheet 7 Filed May 25, 1952 United States Patent CAM TURN-OFF DEVICE AND CONTRO THEREFOR Joseph Kellogg, Milwaukee, Wis., assignor to Nordberg Manufacturing Company, Milwaukee, Wis, a corporation of Wisconsin Application May 23, 1952, Serial No. 289,515 3 Claims. (Cl. 192-141) My invention relates to improvements in controls for hoists, for example mine hoists, one purpose of which is to privide an improved control system.

Another purpose is to provide an improved turnoff device or assembly.

Another purpose is to provide a cam turn-01f device or assembly, of which one is shown for each of two drums.

Another purpose is to provide an improved lever control assembly for ready manually controllable actuation of multiple drum hoists.

Other purposes will appear from time to time in the course of the specification and claims.

I illustrate the invention more or less diagrammatically in the accompanying drawings wherein:

Figure 1 is a plan view of the hoist assembly with parts broken away and parts in section;

Figure 2 is a section with parts in elevation, the section being taken on the line 22 of Figure l; a

t Figure 3 is a section on an enlarged scale on the line I 33 of Figure 1, with parts of the operators console being seen in elevation from the direction of the arrows 33 in Figure 1; a Figure 4 is a section on an enlarged scale on the line 44 of Figure 3;

Figure 5 is a section on an enlarged scale on the line 5-5 of Figure 3;

Figure 6 is a section on an enlarged scale on the line 6-6 "of Figure 3; l

Figure 7 is a section on an enlarged scale on the line 7-7 of Figure 4;

Figure 8 is a partial plan view of the turn-of device with parts omitted;

Figure 9 isan end view of the structure of Figure 8, as seen from a point to the left of Figure 8; and

Figure 10 is a section through the locking device taken on the line 10-10 of Figure 7.

Like parts are indicated by like symbols throughout the specification and drawings.

I illustrate my invention as applied to a double drum structure. As a matter of illustration, I illustrate a drum member A and a drum member B, of which one, for example the drum member A may be fastened to the hoist shaft 1, whereas the other is loose on the shaft and is provided with a clutch connection which will later be described. It will be understood that the general details of the hoist structure itself do not form. part of my invention and are illustrated only so far as is necessary for the understanding of my invention. However, it will be seen for example from Figure l, I employ a suitable drum shaft 1 mounted at its ends in any suitable bearing assemblies 2 on any suitable foundation structure 3, the details of which form no part of the present invention.

Any suitable clutch 5, with its associated clutch cylinder 5a, the details of which do not form part of the present invention, may be employed to clutch and .declutch the loose drum B in relation to the shaft 1, where some ad- Patented Jan. 1, 1957 justment of the hoisting excursion is necessary, as in mine hoist pracatice.

It will be understood that any suitable means for rotating the shaft 1 may be employed, but since such means do not form part of the present invention, none is illustrated. However, as shown in Figure 1, the shaft 1 may be outwardly extended as at 1a and may receive and be connected to any suitable driving connection from any suitable power source.

As shown in Figure 1, brake assemblies C and D may be employed, associated with the drums A and B respectively. I find it practical to employ a conventional hydraulic brake, with a weight application and a hydraulic cylinder for hoisting this weight. I illustrate for example, and more or less diagrammatically, the respective brake cylinders 10 and 11 as shown in Figure 1. 10a and 11a indicate emergency solenoids for applying the brake. In my structure these solenoids, which are ordinarily used in emergency use, are employed as regular operating elements. In other words, they act not only as emergency brake actuating means, but also as regular brake applying means.

I employ a cam turn-off device or assembly for each drum, one such device or assembly being illustrated in Figure 7, the drive connections for two turn-oft devices being shown for example in Figure l. The drive from the hoist drum is illustrated for example in Figures 1 and 2.

Each drum may carry a gear 15 with which meshes the pinion 16 on the shaft 17. The shaft 17 in turn, through a suitable beveled pinion connection 18, 19, drives a vertical shaft 20'which, in turn, similarly drives a horizontal shaft 21. The horizontal shaft 21 similarly drives the vertical shaft 22, which extends upwardly at its outer end. The upper end of the shaft 22 is shown for example in Figure 7 and carries at its upper end a beveled pinion 23 in mesh with the gear 24 on the shaft 25. The shaft 25 carries a gear 26 in mesh with the gear 27 on the shaft 28. It will be understood that the gears 26 and 27 are change gears, the relative ratios of which are proportioned to the particular installation or hoisting conditions with which they are to be used. The shafts 25 and 28 are mounted in suitable anti-friction bearings 25a and 28a respectively secured in the frame member E.

The shaft 28 additionally carries the gear 29 of sub stantial length, along which travels the gear 30. The length of the gear 29 must be suflicient to allow for a travel of the gear 30 enough for the operating conditions of theparticular hoist with which the device is used. When the gear 30 is driven by the gear 29, it rotates the screw 31 to which it is suitably attached. The screw 31 rotates in a suitably screw-threaded cavity 322 within the cam head indicated at 32, which is rotatably mounted in anti-friction bearings 32a carried by the frame member E. The cam head 32, which is normally not rotated, may carry secured to it suitable cams, for example 33 and 34. As a matter of convenience, cam 33 may be used to operate the below-described brake arm and cam 34 the controller arm. Loose on the cam head is a collar 35.

With reference for example to Figure 7, let us assume that a hoisting excursion is beginning, with the gear 30 in the dotted line position of Figure 7. As the appro priate drum rotates, and drives the gear 29 through the above-described line of drive and thus rotates the gear 30, it is moved from the dotted line position to the full line position of Figure 7. The collar 35 is freely rotatable on the cam head 32, and serves as an intermediate friction drive element between gear 30 and the cam head 32. When the gear 30 reaches the full line position of Figure 7, and contacts the free collar 35 and forces the free collar into contact with the end of the cam head 32, then the cam head 32 and its associated parts begin to rotate and the parts are preferably so proportioned that the cams 33 and 34, together with the rest of the cam head structure 32 rotate through an excursion which may be of the order of three-fourths of a revolution. The cams 33 and 34 then operate the brake arm and the controller arm, as will now be described.

Referring first to Figure 5, the cam 33 is shown at approximately the end of its brake operating movement. The arm 36 may form part of a bell crank structure, having an upper or outer arm 36a, which is connected by a link 36b to a brake lever 37 and sleeve 38 on the cross shaft 50 within the console, to which the manually engageable brake operating lever 39 is secured.

As will be seen from Figure 5, the brake operating cam 33 has a portion, approximately one-fourth of a turn, indicated at 33x, which, by contact with the roller 33a, imparts rather sharp or quick movement of the brake arm or lever toward the braking position. The rest of the cam surface, as at 33y, constitutes a dwell of about one-half a revolution. This quick movement of the brake arm toward braking position reduces to a minimum any lost time in applying the brakes and constitutes a safety factor for the quick and eflicient operation of the brake. I provide a toggle structure which includes the spring link 40 pivoted at its upper end 41 to a fixed point and pivoted toward its lower end as at 42 to an arm 36b and the bell crank structure 36, 36a. When the parts are in the position in which they are shown in Figure 5, the effect of the spring link is to hold the cam roller 33a against the cam 33. However, if the hand lever 39 is moved clockwise through a sufficient excursion, the spring link is moved off center in relation to the axis of the above-described bell crank structure and it then tends to hold the cam roller 33a away from the cam 33, which is the manual completely on position of the brake. Under these conditions, the cam 33 has no control, the intent being that the hoist remain at rest for an indefinite period.

I illustrate at Z a cam lever controller shaft structure, one end of which is adjacent each of the two abovedescribed cam turn-off units. It will be understood that one of these units is geared to each of the drums, but since the drive is substantially identical, the single description above given will be understood to apply to both. It will be understood that toward each end of the shaft Z a control lever is provided. In Figure 4 such a lever is shown at 422, extending downwardly from the shaft Z, whereas at the opposite end of the shaft Z, the corresponding lever 43x will be understood to project inwardly. This is because of the dual direction of the drive of the drums. Considering the downwardly extending arm 422 as typical, it will be seen in Figure 4 that it carries a cam roller 42a opposed to a cam 34. In the position of the parts in Figure 4, the turn off is practically complete. The result has been to rotate the shaft Z clockwise, with reference to the position of the parts as shown in Figure 4, and this clockwise rotation, as will be clear from Figure 6, has rotated the control arm 43, which is connected by any suitable link 44, to the bell crank lever 45, the opposite end of which is connected by a link 46 to an arm 47, connected to the manually operable control handle 48, the members 47 and 48 being mounted or being free onthe hand lever shaft 50. In other words, when the cam 34 moves to the position in which it is shown in Figure 4, it moves the hand lever 48 of Figure 6 toward the neutral position.

It will be understood that there is a similar connection between the upwardly extending and 43x atthe opposite end of the shaft Z which, when rotated by its associatede'arn, also moves the shaft Z inopposite direction of rotation with alike resultot'moving themanual lever '48 toward a neutral position. As will be'seen in Figured, the bell crank lever is also connected bya suitable link 45x to any suitable master switch of the reversible type which operates to control the movement of the hoist in either direction and which is not shown, since it does not form part of the present invention and can be any standard master switch.

Figure 10 illustrates the structure operated to maintain the cam head fixed until it is released or rotated by the lutching contact of the collar 35. Before the collar 35 begins to rotate the cam head, or after the cam head has been rotated back to its original position by a retrograde rotation, it is held in position by the cam head locking lever 60, which is spring thrust by any suitable spring 61 and which is formed to receive a tooth or lever 62 which is fixed to and forms part of the cam head structure. The locking lever 60 and spring 61 serve to maintain the cam head in a stationary position until the screw 31 has carried gear 30 into positive driving engagement with the collar 35 and cam head 32. In other words, the cam head cannot rotate until the driving pressure between the gear 30, collar 35 and cam head, and the resultant torsional force are sufficient to force the lever 60 down against the action of spring 61. Thus the cam head is held in a predetermined position during the free run of the hoist, but is rotated from that position, through a predetermined arc of rotation, at the end of the free run of the hoist, and then it is thereafter rotated back into fixed position where it stays during free rotation in the opposite direction.

Fixed to the cam head as shown for example in Figure 9, is a cam lever 65 opposed to a cam roller 66a on the lever 66 of a suitable limit switch generally indicated at 67. It is preferably a switch having a snap action, but the details of the switch do not of themselves form part of the present invention. It will be understood that at the end of the rotation of the cam head 32, in response to its clutched contact with the collar 35, the last thing that happens is the actuation of the snap switch 67 in response to movement of the cam lever 65. The switch 67 is connected in the control circuit in such a way that a neutral position of the control circuit is established and simultaneously the brakes are completely applied through the medium of the solenoid valves, being the earlier mentioned solenoid valves 10a, 11a. Thus, in effect, the above-described cam action eliminates or practically eliminates brake clearance and the final application of the brakes is effected by electrical operation. Thus no further operation of the hoist in that direction is possible and the final end of its movement in that direction is thus made.

It will be understood that while I may use any desired wiring arrangement, I employ a circuit which permits rotation of the hoist in the opposite direction, until such time as the turn-off device on the opposite drum comes into effect and the whole process is then reversed. Thus the hoist has gone to the limit of one run and the operator is free to start its run in the opposite direction, which has a similar ending. In other words, one of the control units operates to terminate the rotation of the drums in one direction and the other operates to terminate the rotation of the drums in the other direction. It is arranged in the wiring that when the hoist comes to a predetermined stop in one direction, the operator by merely throwing the control lever 48 in the opposite direction, will energize solenoids 10a and 11a, releasing the brakes at the same time that power is applied for the opposite run. It will be understood, of course, that I am talking in terms of balanced hoisting, in which cable is paid out at the top of one drum and taken in at the bottom of the other, or vice versa.

I make provision so that when one drum is unclutched, the turn-01f lever automatically moves oi the controller cam, 'so'that the other drum can be turned freely in either direction without cam interference. This provision is necessary only when making an adjustment, as when changing from one level to another for balanced hoisting.

In changing or resetting the hoist drum, it is necessary to prevent cam interference in my turn-off device and also to interrupt the operation of the electric limit switch 67 in Figure 9. This latter is accomplished by an extra set of contacts in the clutch in position switch 70 diagrammatically shown at the left end of Figure l which shorts out'the action of switch 67 in Figure 9. It is thought unnecessary to show a wiring diagram, since this result can be obtained in so many difierent ways or by such a variety of wiring. The function of switch 70 is to guarantee or insure that the clutch is fully engaged before release of the brake assembly D of the drum B.

The actual construction for removing the cam lever 42 from the cam 34 isshown for example in Figures 3 and 4. The brake shaft 50 of Figure 3 carries the brake lever 75 at one end and the brake lever 39 at the other. Whereas the brake lever 75 is fixed to the shaft 50, the brake lever 39 is pivoted to it as at 77. When it is in the full line position in which it is shown in Figure 3, it is held against rotation about the axis of the shaft 50 by any suitable positioning device 78. When it is rotated to the dotted line position, it then exerts no control whatsoever on the brake shaft 50, which may then be rotated by the brake lever 75, or by the operation of the fixed drum. However, movement of the brake lever 39 from the full line to the dotted line position, moves also its associated control arm or lever 79 and through a link 80 rotates the bell crank lever 81. This, through the link 82, actuates the lever 83 on the shaft 84, on the opposite end of which is the yoke lever 85. The yoke lever then moves the lever 422, which is suitably splined on the shaft Z. Thus one result of moving the brake lever 39 from the full line to the dotted line position of Figure 3 is to move the cam arm 422 and the cam roller 42a out of line with the cam 34. Movement of the lever 81 in a counter-clockwise direction as shown in Figure 3 actuates a switch 200, which, through an appropriate control circuit (not shown) actuates a control valve 201 for the clutch cylinder 5a to disengage the clutch from the drum B. Thus, upon movement of the lever 39 to inoperative position, the drum B is unclutched from the shaft 1, and the drum A may be moved without interference from drum B. Because brake control lever 75 is fixed to shaft 50 and control lever 39 is freely rotatable thereon, it will be apparent that brake control lever 39 will exert no control on shaft 50 when in the dotted position of Figure 3 unless control lever 75 is in full on position where the bifurcated portion of element 78 may receive the lever 39, upon movement thereof to the full line position. In other words, neither drum may be moved when the clutch is being engaged. It will be understood that no lateral movement of the brake lever 39 can take place unless it is at the brake full on position. In other words, the lever 39, which passes through a slot 76 in the console generally indicated at 100, cannot be moved laterally until it is at the brake on position or brake on end of its excursion in the slot 76, where lateral space is given for movement of the brake arm 39 and provides for the disengagement of the clutch in the brake on position of the drum B. This will be clear from Figure 1.

It will be realized that whereas I have described and shown a practical and operative device, nevertheless many changes may be made in size, shape, number and disposition of parts without departing from the spirit and scope of my invention. I therefore wish my description and drawings to be taken as in a broad sense illustrative or diagrammatic, rather than as limiting me to my specific showing herein.

The use and operation of my invention are as follows:

In considering the employment of controls for the large drums of mine hoists, an accurate and shock-free control of the brakes is important. The brakes are applied automatically and smoothly at the end of a given run.

In considering, for example, the structure of Figure 1, the solenoids 10a and 11a, which in current mine hoist practice are employed for emergency use, are in my system employed as regular operating elements or as regular brake applying means, in addition to their emergency brake operating action. I provide for each drum of my two-drum assembly an individual control unit for each drum. A typical control unit is shown for example, in Figure 7. Each unit includes an actuating member or screw 31 driven from the drum to be controlled or braked, and a normally inoperative work performing member in the form of a cam head or control member 32. When the parts are properly set, the screw 31 winds in until a driving contact is made between the two members. The driving connection may be made, for example, by the collar 35, which is loose on the cam head or control member 32. At the end of the inward excursion of the screw 31, the loose collar 35 is urged against the opposed end of the cam head 32 and the cam head or control member 32 and its associated cams 33 and 34 rotate to perform their control function. In the device as shown, the cam 33 operates the brake arm and cam 34 the controller arm, but they do not come into operation until the screw 31 has been entirely wound in by its driving connection with the drum to be controlled.

Where an adjustment is to be made, for example to control the device at the end of an excursion of the hoist, the movable manual control lever 39 maybe moved from the full line to the dotted line position of Figure 3. When so moved, it exerts no control whatsoever on the brake shaft 50. At the same time,, through linkage 80, 81 and 82, it interrupts the operating alignment between the cam roller 42a of Figure 4, and the opposed cam 34.

It will be understood that one of the cams 33, 34 automatically turns off the controller to the particular point necessary to keep the hoist running slowly as the returned skip or cage approaches the landing point. The other cam serves as the controlling factor for the brake. As the skip or cage, not shown in the present application, approaches a predetermined landing point, the appropriate cam will begin to take out the slack or brake clearance. In so doing, the brake lever will automatically be moved through an excursion of the order of eighty percent of its total travel from the full-01f brake position toward the full-on brake position before the brake actually takes and exerts its full braking operation. Since the brake mechanism as such does not form part of the present invention, the parts are not shown in detail. It will be clear, however, that the control unit shown in Figure 7 permits a very precise adjustment and timing of the application of the braking power, it being kept in mind that the operator does not himself manually directly actuate the cam turn-off device. The controls are in response to the relatively slow motion of the hoist drum to be controlled. It however is stopped by the action of the limit switch 67.

I claim:

1. In a control structure for multi-drum hoists, a pair of hoist drums and a pair of control assemblies, one for each drum, a common brake shaft for the two drums, a plurality of brake levers for said shaft, at least one said lever being movably mounted on the shaft, for movement between an operative and an inoperative position, means for maintaining said lever against rotation about the axis of the shaft when in operative position, said shaft being rotatable in relation to the lever when the lever is in inoperative position, and means responsive to the movement of said lever to inoperative position for rendering one of the drum control assemblies temporarily inoperative.

2. The structure of claim 1, characterized by and including an actuating connection between each said drum and one of said control assemblies, each such actuating connection including a cam and an opposed cam engaging member, and a disengaging connection extending be- '7 tween. the movably mounted. lever and one of said cam engaging members.

3. In a control assembly for multiple drum hoists, a

control, unit for each drum, including a work-performing member, an opposed control element, an actuating member for the work-performing member, and a connection between the actuating member and one of the drums, a brake lever movably mounted on a shaft for movement between. an operative and an inoperative position, means for maintainingsaid brake lever. against rotation relative to the axis. of the shaft when said lever is in operative position, said lever. being. rotatable about the axis of said shaft. when; in, inoperative: position; and means. responsive.

to the movement. of said lever to inoperative position for rendering; one ofv thedrum. control assemblies temporarily inoperative-, including means for disconnecting its work-performing member, and opposed. control element.

References Citedinthe file of. this patent UNITED STATES PATENTS Whitney Oct. 3, Lasar May 10, Dillon Oct. 17, Darlington Dec. 26, Kramer Feb. 18, Du Pont Nov. 27, Hess et al. May 17, Neighbour Feb. 13, Barth et al; Feb. 20, Schon Sept. 24,

FOREIGN PATENTS Great Britain Aug. 21,

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