US2348107A - Hand control unit - Google Patents

Description

May 2, 1944- c. BRONGERSMA 2,348,107

HAND CONTROL UNIT Filed June 21, 1941 59504541 44 Z 1) 4.1 454144247519 1li. 1=,'fr. l;

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/514 ,40 .l @Auml/M 9 254854 2546 zal 1 24. 5 25 z5 i .40242549 2546 z5 Patented May 2, 1944 HAND coN'raoL UNIT Cornelius Brongersma, Muskegon Heights, Mich., assigner to Manning, Maxwell & Moore, Inc., Muskegon, Mich., a corporation of New Jersey Application June 21, 1941, Serial N0. 399,138

(Cl. 20o-5) 6 Claims.

The invention relates to an improved hand control unit for electric hoists, cranes or other apparatus adapted for installation in an elel vated position and more particularly to a control unit embodying electrical switches arranged for direct manual actuation for controlling the direction oi' rotation oi' the driving motor for the apparatus.

The general object of the invention is to provide a control unit o! the above general character which enables the driving motor to be controlled with a high degree of precision.

It is also an object oi' the invention to provide a control unit of the above general character which can be used for extended periods without tiring the operator.

Another object is to provide a control unit having a hand gripping portion and a plurality of control switches arranged so that any selected switch may be operated conveniently by the thumb of the hand in which the gripping portion is held.

Still another object is to provide simple, positively acting switch interlocking means operative to prevent actuation of more than one switch at a time and eilective to provide a suiiicienil delay between the release of one switch and the actuation of the companion switch to insure effective reversal oi' the motor.

Other objects and advantages of the invention will become apparent from the following detailed description of the preferred embodiment illustrated in the accompanying drawing in which:

Figure 1 is a perspective view of a hand control uit embodying the features oi the invention.

Fig. 2 is a vertical sectional view of the unit.

Figs. 3, 4 and 5 are detailed views of the switch interlocking mechanism; Fig. 3 showing both switches in normal position; Fig. 4 showing the right hand operated and the left hand switch locked ininoperative position, and Fig. 5 showing the left hand switch operated and the right hand switch locked in inoperative position.

While I have shown and will herein describe a preferred embodiment of the invention, I do not thereby intend to limit the invention to the specific form disclosed but intend to cover all modifications, adaptations and alternativevconstructions falling 'within the spirit and scope of the invention as expressed in the -appended claims.

In carrying out the invention, I provide a light weight casing 9 or any suitable material capable of withstanding the hard usage to which control devices ofthe type under consideration are usually subjected. The casing, as shown, is particularly suitable for use with material handling apparatus such as electric hoists, overhead cranes. etc. and to this end is adapted to be suspended as a pendant from a control cable i0 connected with the driving motor of the apparatus to be controlled. In the preferred form illustrated, the casing comprises a hollow, generally rectangular body portion or switch housing I I having an inlet opening I2 in its upper Wall for the reception of the cable i0. The housing Il is suitably dimensioned to provide mounting space for a plurality of electrical switches and to accommodate the conductors of the cable I0 which connect with the switches as will appear presently.

In the particular control unit illustrated, the inlet opening l2 is formed in an upstanding neck portion I4 of the casing. This neck portion is provided at its upper or open end with an integral iixed clamping member i 5 in the form of a transverse bar grooved on one side to accommodate the cable. Cooperating with the fixed clamping member is an adjustable clamping member1 i6 secured thereto as by screws Il which serves to grip the sheathing of the cable to anchor the cable to the casing. Thus the clamping device and the cable sheath carry the weight of the unit So that no strain is placed on the individual conductors of the cable or on the terminals to which they are connected.

Projecting downwardly and forwardly from the bottom wall of the housing Il is a manual gripping member or handle 20 shaped for convenient gripping in the hand. In the particular form shown, the handle is generally rectangular in cross section with its front wall convex or bowed outwardly longitudinally of the handle as indicated at 2l so as to ilt snugly in the palm of the hand. A concave depression or notch 22 is formed in the rear wall of the handle closely adjacent the housing to receive the index linger of the hand and thus assist in maintaining a secure hold upon the handle. This notch additionally serves to locate the hand with respect to the housing so that the switches disposed therein are conveniently accessible for operation by the thumb as will appear presently.

The" type of switches and the number of such .switches incorporated in the control until will depend upemthe particular type of motor with whicl'rthe unit is to be used. Ordinarily two switches are sufficient, dne for effecting rotation of the motor in onee direction and the other for effecting rotation of the motor in the reverse direction. When incorporated in a conventional electric hoist, the switches thus control the lifting action and the lowering action of the hoist. respectively. The exemplary control -unit is provided with two switches which for convenience may be called a lifting control or "up" switch 23 and a lowering control or down" switch 24 (Figs. 3-5) arranged in side by side relation in the housing Il. These switches may be of any suitable type, those shown being conventional tumbler switches each having its switch contacts enclosed in an insulating cover or switch box 25 from which the outer end of a digitally operable switch actuating lever projects. Thus the switch 23 is provided with an actuating lever 2B and the switch 24 with a similar actuating lever 21 each movable between the normal or open position shown in solid lines in Fig. 2 and theoperated or closed position shown in broken lines in the same figure. The switch actuating levers are preferably yieldably biased to the open position and the circuits controlled by these switches are therefore closed only when the switch lever is held in the operated position. A button 23 may be placed on the outer end of each lever to facili- Y tate manipulation of the same.

Terminal posts 29 are mounted on each switch box 25 in well known manner for connecting the conductors 30 of the cable Il) to the switches, thus placing the switches in direct control of the motor with which they are associated. While only two of the conductors 30 have been shown in the drawing, it will be understood that the cable ordinarily contains more of these conductors and that the other conductors are connected to the switch terminals as illustrated. In addition to the control conductors 30, the cable may include a grounded conductor 3|. When the casing 3 is constructed of metal, the ground wire is electrically connected therewith as by a terminal screw 32 as a safety precaution. Y

While the switches 23 and 24 may be supported in the housing Il in any suitable manner, to facilitate assembly and to provide convenient access thereto, it is preferred to mount them on the front wall of the housing herein shown as a removable switch panel or cover plate 35 adapted to close an opening in the front wall of the housing. The cover plate or panel may be made of any suitable material and is provided with spaced parallel slots 36 for receiving the switch levers 26 and 21. Machine screws 31 threading into lugs 38 (Fig. 2) integral with the side walls of the housing secure the panel to the housing.

The switches 23 and 24 are removably mounted on the back of the panel 35 with their actuating levers projecting through the companion slotsv in the plate. As herein shown, the switches are secured to the panel by means of screws 33 threading into a mounting plate 4|I rigid with each switch box 25. Suitable index marks such as an inverted V and a plain V stamped on the panel serve to identify the switches respectively as the lifting or "up switch and the lowering or fdown switch when the unit is to be employed with an electric hoist. Other suitable indicia may be provided for units intended to be used with other types of apparatus.

As will be seen by reference to Figs. 1 and 2, the switches 23 and 24 are arranged so that the switch levers project forwardly through the panel 35 above and substantially in line with the sides and the handle 20. Moreover the switches are positioned so that the switch levers are disposed at the upper ends of their respective slots when the switchis in its normal or unoperated condition.

Thus a switch may be operated by simply pushing down on the lever with the thumb while the handle 20 is grasped in the hand. Thus by very small movement of the thumb, either switch may be operated to initiate operation of the motor in either direction as required. Moreover, operation of the motor can be interrupted by simply releasing the switch lever which immediately returns to the switch open position.

It will also be observed that the side walls of the housing I I taper gradually from top to bottom so that the panel 3l is inclined at an angle to the back wall thus providing a substantial space in Ythe upper portion of the housing for the accommodation of the conductors of the cable Il. Moreover, the angle of inclination of the panel is opposite to the angle of inclinatlon of the handle 2li, or, in other words, these elements are arranged to define an obtuse angle with the switch levers 23 and 24 projecting inwardly from the upper leg thereof. This angular relationship between panel and the handle is an important factor in reducing the strain and eilort required to operate the switches. With the preferred relatitmship illustrated, the handle may be grasped in a natural manner without cramping the hand and either switch lever may be conveniently manipulated by movements of the thumb. Since the switches return automatically tn their Upon position upon release, extremely accuratecomtrol of the motor is readily obtained.

As the switches 23 and 24 are ordinarily connected directly in the current supply circuit of the motor, simultaneous closure of both switches is to be avoided. Moreover, with certain types of motors, as for example single phase motors, an interval between successive switch operations is toallowthemotortostoporat least slow down enough for the starting winding to be reconnected so that the motor may be reversed. The invention provides a novel interlocking means for insuring operation of the switches in proper timed relation which means-is positive in its action yet of simple and rugged construction and capable of standing up under rough handling to which control umts of the type under consideration are frequently subjected. Y

In the preferred form ilhistrated, the interlockingmeans comprisesapairoflockingmembers 4I and 42 in the form of nat metal stampings or the like arranged in face to face relation. The members are pivotally secured to the back of the panel 2l intermediate the switches 23 and 24 by headed pins 43 and 44, respectively. As herein shown, the locking members are disposed between the panel 35 and the switch mounting plates 4l which are suitably spaced apart for this purpose by interposing spacing strips 4l (Fig. 2) therebetween As herein shown, the locking members 4I and 42 are alike in form and are simply arranged in reversed relation. Thus the member 4| has pro- Jecting laterally from one side edge thereof a pair of spaced generally parallel arms 4l and 41 adapted to straddle the actuating lever 2l of the switch 23. On the opposite side of the member is a laterally projecting ilnger 43 hrranged for cooperation with the lever 21 of the`switch 24. Similarly the member 42 has at one side a pair of spaced arms 49 and 50 similar in all respects to the arms 4l and 41 of the companion member but positioned to straddle the switch operating lever 21. On the side of the member opposite the arms I3 and 50 is a laterally projecting linger 3|, similar to the linger 43 but arranged for cooperation with the switch lever 2i.

The operation of the locking members will be readily seen by reference to Figs. 3, 4 and 5 of the drawing. Thus when both switches are in normal unoperated condition, the switch lever 26 coacts with the arm 41 and the switch lever 21 coacts with the arml 50 to hold the locking members in the positions shown in Fig. 3. With the members thus positioned, the tip of the finger 48 is disposed adjacent the path described by the switch lever 21 while the tip of the finger 5l is disposed adjacent the path described by the switch lever 26. Upon being depressed, switch lever 26 engages the arm 46 and rocks the locking member 4I to the position shown in Fig. 4,- thus swinging the finger 48 under the switch lever 21. Moreover, the switch lever moves into blocking relation to the finger 5i to prevent movement of the member 42 thus eilectually locking the member and switch lever 21 in unoperated position. The depression of switch lever 21 while lever 26 is in its unoperated position effectually locks the latter against operation as the lever 21 moves into blocking relation to the tip of the finger 48 as shown in Fig. 5. Thus the operation of either switch lever effectually locks the other against operation and positively prevents closure of both switches at the same time. Moreover, a predetermined delay is interposed between the release of one switch and the operation of the other switch since the released switch lever must return substantially to normal rest position and unblock the cooperating latch ilnger before the companion switch lever can be moved out of rest position. This insures proper conditioning of the motor for reversal by allowing suiicient time for the starting winding to be reconnected in' the usual and well known manner. Where no timed delay is required, one of the locking members may be dispensed with. In this case, the remaining locking member effectually presents simultaneous operation of both switches.

It will be apparent from the foregoing that the invention provides a hand control unit of novel and advantageous construction particularly suitable for use with overhead apparatus employing reversible electric motors. The unit is adapted to be suspended from a cable depending from the apparatus and includes simple efilcient control switches arranged for direct manual operation to govern the direction of rotation of the motor. By reason of the novel relationship of the switches with respect to a hand grip provided on the unit, the switches can be operated with a minimum of fatigue and without cramping the hand of the operator. More particularly,

the arrangement is such that the device may be gripped in a natural manner thus greatly facilitating accurate control of the apparatus, The invention also provides a simple rugged interlocking means which effectually performs. the dual function of preventing the operation. of more than one switch at a time and of introducing a predetermined delay between successive switch operations to insure proper conditioning of the motor for reversing.

I claim as my invention:

1. A hand control unit for electrically driven apparatus including, a switch casing, a switch panel at one side of the casing, a pair of switches cluding a flat metal plate pivoted on said panel intermediate said switches, a pair of spaced arms `projecting from one side of said plate to straddle pair of electrical switches disposed within said casing each having a digitally operable lever accessible from the exterior of said panel, a pair of interlocking members cooperating with said switch levers to interpose a delay between successive operations of the respective members, each of said members comprising a nat metal plate pivoted on said panel intermediate said switches, a pair of spaced arms projecting from one plate to straddle the operating lever of one of said switches, a similar pair of spaced arms projecting from the other plate to straddle the operating lever of the other of said switches, and a finger projecting from each plate toward the switch lever straddled by the arms of the other plate, said switch levers when operated moving into blocking relation to the respective ilngers to lock the companion switch against operation.

3. A hand control unit including, a switch casing, a switch panel at one side of said casing, a pair of electrical switches disposed within said casing each having a digitally operable lever accessible from the exterior of said pane., and mechanism for interposing a delay between successive operations of the respective switches including a pair of spaced members movably supported on said panel and operatively connected with the respective switch operating levers to move therewith, each of said members having means for locking its associated lever in'an inoperative position in response to the movement of the other switch operating lever to the operated position.

4. A pendant type hand control unit comprising, in combination, a hollow box-like casing open at the front, a cable inlet in theupper wall of the casing, cable clamping means eiIective to anchor the casing to a cable entering through said inlet, an apertured panel closing the front of the casing, a plurality of electrical switches mounted on said panel and enclosed within the casing, each of said switches having an actuating member projecting through the panel, and a manual gripping member rigid with the bottom wall of the casing and projecting downwardly and forwardly therefrom to define an obtuse angle with said panel to facilitate manipulation of the switch actuating members by the thumb when said gripping member is grasped in the palm of the hand.

5. A pendant type hand control unit comprising, in combination, a hollow box-like casing open at the front, a cable inlet in the upper wall of the casing, cable clamping means effective-to s anchor the casing to a cable entering through said inlet, an apertured panel detachably secured to the casing and closing the front thereof, a plurality of electrical switches mounted on said panel and enclosed within the casing, each of said switches having an actuating member projecting through the panel, a handle rigid with the bottom wall of the casing and projecting thereoi' the casing, a pair oi switches mounted on said' panel disposed within said casing, each of said switches having a digitally operable member pro- Jecting through a panel aperture, and a locking mechanism including a fiat plate pivoted on said panel intermediate said switches for preventing the operation of either switch when the other switch is operated, said plate having oppositeiy extending fingers projecting into the path of each oi said actuating members, whereby engagement ot one iinger by an actuating member during movement thereof to switch closing position holds l0 the other of said iingers in the path of the other switch actuating member.

CORNELIUS BRONGERSMA.

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