US3769480A

US3769480A - Hoist electric control handle with first operating means, including a movable s-shaped resistor, and second operating means

Info

Publication number: US3769480A
Application number: US00263031A
Authority: US
Inventors: K Lee
Original assignee: Eaton Corp
Current assignee: Duff Norton Co Inc
Priority date: 1972-06-15
Filing date: 1972-06-15
Publication date: 1973-10-30
Anticipated expiration: 1990-10-30

Abstract

A pendant electric control handle for a power operated hoist comprises molded plastic side portions of complementary shapes, that are assembled to form a hand grip extending in a downwardly directed longitudinal axis and an inner control chamber within the hand grip. An outer surface of the hand grip offers clearance for an angular position of the thumb of a hand whose fingers encircle the hand grip, in which position the thumb may conveniently operate either of two push buttons that are connected to an electric control assembly in the chamber of the hand grip. The push buttons then are utilized to operate the control assembly to actuate lifting and lowering directional control circuits. There also may be a trigger in position to be moved in horizontal direction by finger for further actuation of the control assembly so as to control one or more speed circuits. The assembly has somewhat the shape of an inverted L inside the hand grip while enabling the trigger and push buttons to be mounted in appropriate positions. The control assembly is constructed for mounting current control elements in various combinations and shapes, including fixed contacts and a trigger operated S-shaped resistor that will proportionally control current of two circuits while requiring no flexible leads or further contacts. The handle can mount resistors and contacts in various combinations that enable the construction to have substantially universal utility and reducing costs when building control handles for hoists that require widely differing types of speed control.

Description

States Patent 1 [1 1 Lee [ 1 Oct. 30, 1973 HOIST ELECTRIC CONTROL HANDLE WITH FIRST OPERATING MEANS, INCLUDING A MOVABLE S-SHAPED RESISTOR, AND SECOND OPERATING MEANS [75] Inventor: Kirkwood M. Lee, Ogden, Utah [73] Assignee: Eaton Corporation, Cleveland, Ohio [22] Filed: June 15, 1972 [21] Appl. No.: 263,031

Primary Examiner-Robert K. Schaefer Assistant ExaminerRobert A. Vanderhye AttorneyE. B. Brownson 57 7 ABSTRACT A pendant electric control handle for a power operated hoist comprises molded plastic side portions of complementary shapes, that are assembled to form a hand grip extending in a downwardly directed longitudinal axis and an inner control chamber within the hand grip. An outer surface of the hand grip offers clearance for an angular position of the thumb of a hand whose fingers encircle the hand grip, in which position the thumb may conveniently operate either of two push buttons that are connected to an electric control assembly in the chamber of the hand grip. The push buttons then are utilized to operate the control assembly to actuate lifting and lowering directional control circuits. Therealso may be a trigger in position to be moved in horizontal direction by finger for further actuation of the control assembly so as to control one or more speed circuits. The assembly has somewhat the shape of an inverted L inside the hand grip while enabling the trigger and push buttons to be mounted in appropriate positions. The control assembly is constructed for mounting current control elements in various combinations and shapes, including fixed contacts and a trigger operated S-shaped resistor that will proportionally control current of two circuits while requiring no flexible leads or further contacts. The handle can mount resistors and contacts in various combinations that enable the construction to have substantially universal utility and reducing costs when building control handles for hoists that require widely differing types of speed control.

17 Claims, 8 Drawing Figures memo sum 3 or 3 ."u I 'Hlll IIOIST ELECTRIC CONTROL HANDLE WITH FIRST-OPERATING MEANS, INCLUDING A MOVABLE S-SHAPED RESISTOR, AND SECOND OPERATING MEANS My invention relates to a novel electric control handle for controlling the movements of power operated hoists.

As will be appreciated, the operation of hoists by power offers potential danger to men and materials and it is important that a power operated hoist be held under close control at all times. Therefore, manually operated controls of a power operated hoist should be easy to manipulate and of a nature that will enable the hoist operator to control the hoist conveniently and almost automatically while he directs his attention to a load handled by the hoist. Where the controls utilize a pendant handle that is connected through a flexible cable to the hoist, as is quite usual, the handle should have no great size and should be light in weight.

The novel contribution of my invention enables me to construct a hoist control handle that will very well fill the needs 1 have mentioned, and what is important moreover, to construct the handle so as to serve with extremely good effect the differing types of hoist control that must be offered the market.

In the control handle of my invention, there is an upper portion adapted for attachment to the cable containing the hoist control circuits, walls that extend from said upper handle portion and that are shaped to form a hand grip whose outer gripping surfaces are arranged about a downwardly directed longitudinal axis, and whose inner surfaces form a control chamber that contains current control means within the hand grip. Extending between an opening in the walls and the current control means are manually movable operating means that may comprise a thumb operated push button and a finger operated trigger.

As a particular feature, a portion of the hand grip walls is formedin an angular position relatively to the longitudinal hand grip axis so as to offer a clearance space for an angular position of a thumb that may operate a control while fingers of the hand encircle the hand grip.

A further part of my present invention resides in a part of the current control means that is movable in a direction transverse to the movement of the thumb operated means, including a trigger adapted to be moved by a finger of the hand engaging the hand grip. As a particular feature of this part of my invention, I equip the transversely moving part of the control means with a potentiometer resistor needing no integral connection to the hoist circuits and merely coacting with contacts that are mounted in fixed position on the control handle. In more detail, I may construct the potentiometer resistor so as to offer coextending portions that will effect proportional control of current between pairs of the fixed contacts. The resistor then need have but little travel and can be mounted within a hand grip while able effectively to control current through a wide range of values. As will be appreciated, it is necessary to manufacture hoists that will meet differing requirements of operation and cost. Among the hoists are those that operate merely at a single speed in each lifting and lowering direction, and rather simple circuit controls then suffice. Other hoists operate selectively at two speeds, or at three, five or even more speeds, the controls becoming more and more detailed. Also, hoists that operate at infinitely variable speed are coming into increasing use, and those hoists have complex circuitry that requires particular control.

Thus, as an extremely important feature of my invention, I have conceived a construction having a substantially universal utility that will reduce the cost of building control handles for hoists that require differing types of electric control. More in detail, my construction comprises current control contacts and members that can very readily be modified or substituted by other members so as to establish a type of electric control that will be needed for a particular hoist.

I have thus outlined rather broadly the more important features of my invention in order that the detailed description thereof that follows may be better understood, and in order that my contribution to the art may be better appreciated. There are, of course, additional features of my invention that will be described hereinafter and which will form the subject of the claims appended hereto. Those skilled in the art will appreciate that the conception on which my disclosure is based may readily be utilized as a basis for the designing of other structures for carrying out the several purposes of my invention. It is important, therefore, that the claims be regarded as including such equivalent constructions as do not depart from the spirit and scope of my invention, in order to prevent the appropriation of my invention by those skilled in the art. In the drawings:

FIG. 1 shows the control handle of my invention and a hoist on which it is utilized;

FIG. 2 shows an exploded view of side portions of the handle, with a current control assembly shown in phantom;

FIG. 3 shows an exploded perspective view of parts of the current control assembly;

FIG. 4 shows a side view of the control assembly;

FIG. 5 shows a side view of the trigger and resistor components;

FIG. 6 shows an opposed side view of the trigger;

FIG. 7 shows a cross section on the line 7-7 in FIG. 4, and

FIG. 8 shows a diagrammatic view illustrating circuit connections that may be utilized with my invention.

Referring now more particularly to FIG. 1 of the drawings, 1 indicate an electric hoist by the letter H, and I show the control handle 10 of my invention connected through a flexible control cable 11 in pendant relation to the hoist I-I. As will be understood, cable 1 1 will contain control circuits, not shown in FIG. 1, that will be actuated through operations of the handle 10 to control movements of the hoist.

To describe the construction of my control handle 10, I shall first indicate that the form of handle that I prefer will comprise two

complementary side portions

12, 13, best seen in FIG. 2, that will be assembled to one another. Those side portions are adapted to be formed by molding a plastic material, and are reversed in shape while having similar features. By considering features of one or the other of the

side portions

12, 13 as shown in FIG. 2 I believe that the features of both portions will be understood.

The side portions l2, 13 when assembled will comprise an upper handle portion 14 that is adapted for attachment to the control cable It, as for example through a connector housing 15 shown in FIG. 1. Walls 16 extend from the upper handle portion 14, as well shown in FIG. 2, and in my invention I particularly shape those walls to form a hand grip 17 whose outer gripping surfaces are arranged about a downwardly directed longitudinal axis, while offering inner surfaces that form a control chamber 18 within the hand grip Further, at a point near the upper handle portion 14, I form a portion l9-of the walls 16 in an angular position relatively .to the longitudinal hand grip axis so as to offer a clearance space for the thumb of the hand whose fingers engage the hand grip 17. The thumb then may extend in an angular position above the control chamber 18, in a convenient and natural attitude for operating a control element while the fingers encircle the hand grip 17. The value of that feature will be better appreciated as my description proceeds.

I mount a current control assembly 20, shown in phantom in FIG. 2, within the control chamber 18 of hand grip 17. I shall refer to FIG. 3 together with FIG. 4 to describe the construction of the assembly 20. Opposed

parts

21, 22 form a control housing of the assembly 20, and on each of those parts I mount a current control slide 23 M24 for movement substantially in the "longitudinal axis of hand grip 17. I further mount current control part 25 for sliding in a direction transverse to the direction of the

slides

23, 24 on the control housing. At this point I may indicate that the

housing parts

21, 22 have like features while being reversed in shape, and the

slides

23, 24 similarly have like features in reversed relation.

Each of the

current control slides

23, 24 has a generally rectangular outline adapted to slide in a guideway 26 that is formed in the outer surface .of a

respective housing part

21, 22, the guideway 26 on part 21 being visible in FIG. 3. A coil spring 27 is assembled in an opening 28-on a lower portion of each

slide

23, 24, both springs 27 being supported on a spring base 29 assembled-in oepnings 28 and in openings 30 on the

housing parts

21, 22 so as to press each

slide

23, 24 in upward direction toward what I shall term unactuated position, that being the position of slide 23 as shown in FIG. 4. The outer surface of each

slide

23, 24 is equipped with a stud 31;that-will accept the stem portion 32 of a

corresponding push button

33 or 34. Those push buttons will be moved selectively by thumb to control-lifting and lowering directions of hoist movement. Each

push button

33, 34 will be assembled through an opening 35, FIG. 2, that is formed on the angular wall portion l9'of the control handle. A split end portion 36 on the stem 32 of each push button will snap into interlocking position on the corresponding stud 31. The

push buttons

33, 34 then will be in positions readily enabling the thumb of a hand to operate

slide

23, or 24 alternately, moving the slide against its spring pressure from unactuated to actuated position. 4

One edge portion of each

slide

23, 24 is integrally formed with a yielding detent finger 37, the operation of which will be described presently in connection with the transversely moving part 25, and the opposed edge portion of each slide is equipped with an electrical contact 38.

In the particular construction that I have chosen to illustrate in FIG. 3, the slide contacts 38 will have associated with them two

contact members

39, 40 each having two contact surfaces, and contact members 41,

41a having each a single contact surface. Those contact members will be mounted in vertically arranged series of openings 42 extending through both

housing parts

21, 22, then being in positions enabling each contact 38 of

slides

23, 24 to make or to break a circuit between

members

39, 40 while enabling a contact 38 alternately to make and to break individual circuits between mem ber 40 and the corresponding

member

41 or 41a.

To describe the transversely slidable control part 25 and its associated means, I shall refer first to FIG. 3 of the drawings. That part 25 is formed with surfaces mounted to slide in a guideway 43 that is formed by the assembly of the two

housing parts

21, 22. Also, part 25 is equipped with an integral trigger portion 44 sliding in an opening 45, forming operating means for part 25. A coil spring 46 is mounted in a guide opening 47 formed by the

housing parts

21, 22 and acts to press part 25 and its trigger 44 in outward direction toward unactuated position. Trigger portion 44 will be depressed by finger to control one or more speeds of hoist operation.

The slidable control part 25 is I shaped in section as perhaps best seen in FIG. 7, presenting

side channels

48, 49. The channel 48 will accept a current control board 50, FIG. 3, and is formed with a lug 51 that will engage in an opening 52 in the control board 50, enabling that board or similar boards to be readily assembled in position to move integrally with part 25 as the latter slides.

As shown, the current control board comprises a substantially flat insulative mounting portion on which are coextending portions 53 of electrically resistive material. Those portions 53 are connected by strips 54 of low resistance material so arranged as to form a potentiometer resistor 55 shaped substantially like an S. The resistive material of portions 53 may for example be a carbonaceous material, and the potentiometer resistor 55 may be formed through the use of conventional printed or etched circuit board methods.

A series of spring contact members 56, FIG. 3, will be mounted in openings 57 in the housing part 21, one

in aligned relation with each coextending portion 53 of the S shaped resistor 55. The contact members 56 comprise contact surfaces 58 that will engage resistor por- 'tions 53 while the control part 25 slides, and that are so arranged as to coact with one end of portions 53, being the right hand end as viewed in FIG. 3, when the part 25 slides to its outward or unactuated position. Thereby the movements of the trigger 44 can very effectively achieve a proportional control of current between pairs of the contact member 56. It is important to realize, moreover, that the trigger movements will do that while requiring no flexible leads or further electrical connections relatively to the potentiometer resistor 55. Moreover, the S shape of resistor 55 enables it to offer effective current control while needing relatively little travel, permitting the resistor to be utilized within a hand grip of no great size, and reducing the amount of wear relatively to its contacts.

The side channel 49, which is at the side opposed to the channel 48 that contains potentiometer resistor 55, is equipped with a contact 59, FIGS. 3 and 6, that is mounted in an opening 60 on control part 25. That contact 59 will complete a circuit between two contact members 61, which are mounted in openings 62 in the housing part 22, when trigger 44 is depressed to fully actuated position. Thus, contact 59 may offer means that will act independently of the potentiometer resistor 55 to effect full speed of a hoist motor where lower speeds are controlled through resistor 55.

I have mentioned the yielding detent fingers 37 when describing the control slides 23, 24, and I shall now refer to FIG. 7 to explain an interlock utilizing those fingers. An upper portion of each

housing part

21, 22 presents a downwardly facing detent surface 63 adapted to coact with an end surface of a finger 37. FIG. 7 shows the control slide 24 in its upper or unactuated position, in which its finger 37 does not engage a detent surface 63. The slide 23 on the other hand is shown in depressed position and will serve to illustrate the appearance of either slide 23 or 24 when depressed. Thus, the finger 37 of slide 23 has snapped into position below the corresponding housing surface 63 and slide 23 cannot now return by its spring pressure to unactuated position. Now supposing that the transversely moving control part 25 starts to move by its trigger away from its unactuated position, a lower surface on that part 25 will move about a lug 64 that is formed on slide 23. Continued movement of control part 25 then will cause a cam surface 65 on one of its upper corners, best seen in FIG. 3, to press the finger 37 of slide 23 laterally away from surface 63. Then, by its position over the lug 64 on slide 23, the control part 25 will hold the slide depressed and will continue so to hold it until such time as control part 25 may return again to unactuated position.

Thus, I may equip the novel control handle of my invention with an interlock feature that will hold a push button actuated circuit in a particular condition so long as a trigger controlled circuit is in actuated condition.

It will be understood that the several contact members that are mounted on the housing parts 21, 22 (including

members

39, 40, 41, 41a, 56 and 61) will be electrically connected to control circuits of the control cable 11. The connections of those contact members may comprise a receptacle on the connector housing 15, FIG. 1, and a separable part a in the form of a printed circuit board mounted between the

handle side portions

12, 13, FIG. 2, that part 15a being connected through wires, not shown, to the appropriate contact members. In assembly, the connector housing 15 will be secured to the

handle portions

12, 13 through any desired means, as for example through pins, not shown, engaging-openings in housinglS and openings 12a, 13a

in the

handle portions

12, 13. To assemble the two side portions 12, 13 I prefer to utilize bonding to secure their opposed surfaces integrally to one another, those surfaces being formed with openings 12b and with pins (not visible in FIG. 2) that engage to assure proper alignment. I

The particular arrangement of electrical contacts that I have chosen to describe may be utilized in the manner illustrated by the circuit diagram shown in FIG. 8. Thus, lines C1 through C7 may be understood to represent lines contained in the control cable 11. In the diagram, C5 is a common line, and C6 and C7 are 0p- '41 or 4121 so as to complete a directional hoist circuit.

When considering FIG. 8, it will be recognized that this is a type of electrical interlocking arrangement that is quite usual, preventing actuation of two opposed circuits at the same time.

The three contacts 56 are shown connected respectively to lines C1, C2 and C3, thus enabling movements of the control board 50 by depression of trigger 44 to control a flow of current in variable proportions relatively to lines C2-C1 and lines C2-C3 for controlling infinitely variable speed circuitry with which the hoist H may be equipped. When control board 50 is fully actuated to full speed position, contact 59 will engage contact members 61, completing between lines C4, C5 a circuit that may effect the application of full power to the hoist while bypassing potentiometer resistor 55.

As I have indicated earlier in this specification, the novel electric control handle of my invention is adapted to offer differing types of hoist control, and I wish to emphasize that I have shown and described a particular construction merely by way of example. That particular construction will be utilized to extremely good effect where the controlled circuitry of a hoist is designed to offer infinitely variable speed control, the push buttons being utilized to select a direction of lifting or lowering movement, and the trigger then being actuated to control the speed of operation. However, simply by omitting the trigger and its associated contacts when assembling the handle, there will be formed a handle that has relatively simple circuits actuated by push buttons, and that is well adapted for production at a low cost which will be acceptable when the hoist is one that operates merely at a single speed in each lifting and lowering direction. When the hoist is one that operates at two speeds in each direction, my control handle naturally will require no potentiometer. Then the potentiometer current control board 50 can easily be omitted, and the second speed can well be controlled through the trigger contact 59, while first speed is controlled through operation of a push button whe selecting a direction of operation. In those cases where first speed is to be so controlled, it will be important that a push button be able to return to unactuated position though the trigger has not been actuated, and in such cases the fingers 37 may be removed from control slides 23, 24 so that the push buttons can automatically move to cancel speed. I

Actually, and this relates to a valuable feature of my construction, control of second speed or further speeds can very well be achieved while omitting contact 59, due to the fact that current control boards having widely differing control characteristics can easily be assembled to the trigger part 25 in the place of the board 50. Thus, for example there may be assembled a trigger operated board like the board 50 in outline but merely having a second speed contact, or multiple contacts where the control is to offer multiple speeds, or even a resistor that differs from the potentiometer resistor 55.

Moreover, once the features of my invention are known, persons skilled in the art will understand how to form the

contact members

56 and 61 so as to offer points of contact in positions that may be needed, or to substitute or to omit certain contact members, including

members

39, 40, 41 and 41a, should that be desired in order to achieve particular electrical control functions.

Therefore,'l believe it will be understood that I contribute by my invention an electric control handle that can very readily be assembled to serve differing types of hoist contorl, and that can be economically built at costs that will be appropriate when the handle is to be utilized with any of the various kinds of hoist that are offerred the market. In effect, my invention offers a construction that may have substantially universal utility when building electric control handles for hoists. While considering the universal character of my contribution, it will be appreciated particularly that the control handle of my invention can be gripped and operated while the hand is in a most natural and convenient position causing no distraction to the operator and, in addition, permitting him a strong grip tht will enable him easily to move the hoist when the hoist is one that is mounted on a movable trolley. While I have referred particularly to hoists, the control handle of my invention naturally may be found useful for controling further types of power operated apparatus, and therefore my invention should not actually be limited by hoist control. Haivng described the construction and the operation of my electric control handle, I believe that the very considerable value of my invention will be understood, and that its merits will be fully appreciated by those skilled in the art.

I claim:

1. A control handle for actuating electric control circuits of a power operated hoist, comprising an upper portion adapted for attachment to a cable containing the control circuits, walls extending from said upper handle portion and shaped to form a hand grip whose outer gripping surfaces are arranged about a downwardly directed longitudinal axis, inner surfaces of said first means in a locked actuated position upon manual actuation of said first means, and release means associated with said second means to release said locking means upon actuation of said second operating means.

2. The invention 'set forth in claim 1 in which a portion of said walls is formed in angular position relatively to the longitudinal hand grip axis so as to offer a cleartime space for the thumb of a hand whose fingers engage the hand grip, and said first operating means comprises a member extending relatively to said clearance.

space for actuation by an angular position of the thumb while the fingers encircle the hand grip.

3. The construction set forth in claim 2 in which said I current control means further comprise a part movable in directions transverse to the direction of movement of said element, and said second operating means includes a trigger in position to be actuated by a finger of the hand engaging the hand grip for moving said part of the control means.

4. The construction set forth in claim 3 in which said current control means further comprises a switch element mounted substantially for movement in the longitudinal axis of the hand grip, and said first operating means comprises a push button mounted in position to be actuated by the thumb of said hand.

5. The construction set forth in claim 4 in which said part that is moved by the trigger is equipped with electrical contact means that are mounted for movement integrally with the trigger, there being contacts mounted on said handle and coacting with said contact means that move with the trigger.

6. The construction as set forth in claim 5 in which an individual mounting member carrying said electrical contact means is keyed to said part that is moved by the trigger, readily enabling mounting members that have differing configurations of contact means to be assembled relatively to said part.

7. The construction set forth in claim 5 in which said contact means comprise a potentiometer resistor that slides relatively to a coacting contact.

8. The construction set forth in claim 7 in which said potentiometer resistor comprises coextending portions sliding each relatively to a contact mounted on the handle.

9. The construction set forth in claim 8 in which a portion of said walls of the handle is formed in an angular position relatively to the longitudinal hand grip axis so as to offer a clearance space for an angular position of the thumb of a hand whose fingers encircle the hand grip, and said current control means further comprising a current control element movable by said thumb in the longitudinal axis of the hand grip.

10. The construction set forth in claim 1 including interlocking means for maintaining said first operating means in an actuated position as long as said second operating means remains in an activated position after actuating said release means.

11. The construction set forth in claim 3 in which said locking means includes a control slide having a detent portion adapted to lock with a recessed surface.

12. The construction set forth in claim 11 in which said release means includes a cam shaped member mounted to said trigger portion of said second operating means adapted to release said detent from a locking position with the recessed surface.

13. A control handle for actuating electric control circuits of a power operated hoist, comprising an upper portion adapted for attachment to a cable containing the control circuits, walls extending from said upper handle portion and shaped to form a hand grip whose outer gripping surfaces are arranged about a downwardly directed longitudinal axis, inner surfaces of said walls forming a control chamber within said hand grip, current control means mounted in said chamber within said hand grip and adapted for connection to the cable circuits, manually movable operating means comprising a member extending between an opening in said walls-and said current control means for operating said control means, a portion of said walls being formed in angular position relatively to the longitudinal hand grip axis so as to offer a clearance space for the thumb of a hand whose fingers engage the hand grip, said manually movable operating means comprising a member extending relatively to said clearance space for actuation by an angular position of the thumb while the fingers encircle the hand grip, said current control means comprising an element that is mounted for movement substantially in the longitudinal axis of the hand grip, said current control means further comprising a part movable in directions transverse to the direction of movement of said element, said manually movable operating means including a trigger in position to be actuated by a finger of the hand engaging the hand grip for moving said part of the control means, and means interlocking between said transversely movable part and said longitudinally movable element of the current control means so as to hold said element in an actuated position while said part is in an actuated position.

14. A control handle having a finger actuated trigger for controlling current to an electric motor circuit comprising, a resistor assembly mounted for movement in a linear direction in response to the actuation of said trigger, stationary contacts connected to the motor circuit and mounted in positions coacting with said resistor assembly during the linear movements of said resistor assembly, said movable resistor assembly comprising an S-shaped resistor having three substantially parallel connected branches, said stationary contacts comprising at least three contacts with each contact positioned along one of said three parallel branches of said S-shaped resistor, and said resistor moving in response to trigger actuation to slide each of said parallel branches of said S-shaped resistor along said stationary contacts to provide different currents between said three contacts.

15. The construction set forth in claim 13 in which said S-shape resistor in cooperation with said three contacts provides a proportional control of current between pairs of the contacts.

16. The construction set forth in claim 13 in which said trigger is connected to a part that is movable in response to trigger actuation, and said S-shaped resistor is mounted on an individual mounting member having a keyed relation to said movable part, readily enabling said movable part to be equipped selectively with other S-shaped resistors that have different resistance values offering differing control characteristics.

17. The construction set forth in claim 16 in which said handle comprises a hand grip offering outer gripping surfaces and opposed inner surfaces forming a control chamber, said mounting member being mounted to slide in said control member within the hand grip.

Claims

1. A control handle for actuating electric control circuits of a power operated hoist, comprising an upper portion adapted for attachment to a cable containing the control circuits, walls extending from said upper handle portion and shaped to form a hand grip whose outer gripping surfaces are arranged about a downwardly directed longitudinal axis, inner surfaces of said walls forming a control chamber within said hand grip, current control means mounted in said chamber within said hand grip and adapted for connection to the cable circuits, first operating means for manually changing the direction of current flow in said current control means, second operating means for manually changing the magnitude of current flowing in the direction determined by said first means, locking means to retain said first means in a locked actuated position upon manual actuation of said first means, and release means associated with said second means to release said locking means upon actuation of said second operating means.

2. The invention set forth in claim 1 in which a portion of said walls is formed in angular position relatively to the longitudinal hand grip axis so as to offer a clearance space for the thumb of a hand whose fingers engage the hand grip, and said first operating means comprises a member extending relatively to said clearance space for actuation by an angular position of the thumb while the fingers encircle the hand grip.

3. The construction set forth in claim 2 in which said current control means further comprise a part movable in directions transverse to the direction of movement of said element, and said second operating means includes a trigger in position to be actuated by a finger of the hand engaging the hand grip for moving said part of the control means.

13. A control handle for actuating electric control circuits of a power operated hoist, comprising an upper portion adapted for attachment to a cable containing the control circuits, walls extending from said upper handle portion and shaped to form a hand grip whose outer gripping surfaces are arranged about a downwardly directed longitudinal axis, inner surfaces of said walls forming a control chamber within said hand grip, current control means mounted in said chamber within said hand grip and adapted for connection to the cable circuits, manually movable operating means comprising a member extending between an opening in said walls and said current control means for operating said control means, a portion of said walls being formed in angular position relatively to the longitudinal hand grip axis so as to offer a clearance space for the thumb of a hand whose fingers engage the hand grip, said manually movable operating means comprising a member extending relatively to said clearance space for actuation by an angular position of the thumb while the fingers encircle the hand grip, said current control means comprising an element that is mounted for movement substantially in the longitudinal axis of the hand grip, said current control means further comprising a part movable in directions transverse to the direction of movement of said element, said manually movable operating means including a trigger in position to be actuated by a finger of the hand engaging the hand grip for moving said part of the control means, and means interlocking between said transversely movable part and said longitudinally movable element of the current control means so as to hold said element in an actuated position while said part is in an actuated position.