US2732522A - Cable drum operating and control system - Google Patents

Description

Jan. 24, 1956 J. T. HILL 2,732,522

CABLE DRUM OPERATING AND CONTROL SYSTEM Filed March l, 1955 5/ 39 /wamf/a/y 40 v6 5 38 34 L41/ 4f .fm/617751 cfesse T [177/ United States Patent O CABLE DRUM OPERATING AND CONTROL SYSTEM Jesse T. Hill, Jacksonville, Fia.

' Application March 1, 1955, Serial No. 491,316

i 6 claims. (ci. sis-266) My invention relates to cable drum operating and control system, and particularly pertains to a motor operated drum together with an electrical control system for manually starting and automatically stopping and reversing the drum drive. It is a general object of my invention to provide an improved operating and control arrangement for a cable drum.

y lt is a further object of my invention to improve the reliability and to decrease the complexity of automatic cable drum operating equipments.

- A specific object of my invention is to provide an improved motor control arranged to start in response to a single remote pushbutton switch and thereafter to be self-operable to one or the other of two predetermined limit positions, and self-conditionable upon reaching either such limit to be started in the opposite direction upon the next closure of the remote Switch.

A further specic object of my invention is to provide a remote controlled relay for actuation by means 'of a remote control switch and which comprises a latch trip mechanism, of improved reliability and simplicity.

' The novel features which are believed to'be characteristie 'of this invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and method of operation, together with further objects and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawing,V in which:

Fig. lis a partially diagrammatic presentation of a cable drum operating and control system in accord with my invention;

Fig. 2 is a partially diagrammatic view of the remote control relay portion of the apparatus showing the condition established by closure of the remote control switch to'initiate a cycle of operation; and

Fig. 3 is a view similar to that of Fig. 2 but showing the relay in the condition corresponding to motor operation following release of the remote pushbutton and prior to the actuation of the limit trip lever.

lReferring now to Fig. l, my system is particularly adaptable to the operation of a cable drum, such as drum 1, onlwhich may'be wound a cable 2 which,lin turn, may be coupled to oper.ate,a gate, garage door, or the like, or for any such'similar purpose. Druml may be arrangedfor rotation in bearings 3`and may be-chain .driven by means of chain 4, which couples a shaft 5 to the shaft of the drum. It is important to the proper operation of the system that a chain or gears couple the shaft 5 to the drum to prevent such slippage as would occur with belt drive. The portion of shaft 5 between stationary-nbearings 6 and 7 is 'threaded-forming elongated-screw 8, andcarries-thereonatraveling nut V9. nShaft 5,- including screw; 8,'is rotated by means of a `belt which engages shaft pulley 10', the belt being driven by a reversible electric motor 11.

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The lower end 12 of nut 9 is flat and engages a stationary flat surface 13, whereby rotation of screw 8 causes nut 9 to travel in a direction corresponding to the direction of rotation of the screw. An upper portion of nut 9 has mounted thereon a lost motion yoke comprising a pair of arms 14 and 1S carrying posts 16 17, respectively. The arms are adjustably connected to the nut 9 by means of bolt 18. A lever 19 is pivotally attached at 2i) to a stationary base 21 and comprises an over-center mechanism at its lower end comprising a roller 22 rolling on and following the stationary ltriangular cam surface 23 under the influence of compression spring 24. Stop members 25 and 26, connected to the stationary base, limit the rotation of lever 19 about its pivot 20 in the respective opposite directions. A pin 24 attached to the movable shaft 22 may be employed if desired to retain shaft 22 in the hollow lower end of lever 19 during assembly of the apparatus.

When motor 11 is operated to rotate screw 8 in the direction to move nut 9 to the left, as seen in Fig. l, post 16 will finally engage lever 19 and continued operation of the screw will cause roller 22 to roll up the inclined cam surface 23, whereupon the roller rolls rapidly down the opposite incline until the lever 19 comes in contact with-stationary stop member 26. Upon this operation of lever 19, as later explained, the motor will be de-energized and portions of the connections thereto reversed.

The upper end of lever 19 comprises a reduced portion 27 which is included in a lost motion connection with lever 2S. The portion 27, upon over-center opera tion of lever 19, moves between posts Z9 and 30, carried on lever 28, and causes lever 28 to rotate rapidly about its pivotal support 31, by which it is attached to stationary base 32, in such a manner as alternately and with snap action to close movable contacts 33 and 34 against stationary contacts 35 and 36 and, in the opposite direction, to close movable contacts 37 and 38 against stationary contacts 39 and 40, respectively. Stationary contacts 3S and 46 are interconnected by conductor 41, and stationary contacts 36 and 39 are interconnected by conductor 42. Conductors 41 and 42, in turn, are connected respectively to terminals 43 and 44 of the starting winding ot' motor 11. Movable contacts 34 and 38 are connected together and are connected through conductor 45 to power bus conductor 46, whereas movable contacts 33 and 37', being interconnected, are arranged for connection through conductor 47 and through relay switch means later described to the other bus conductor 48. With lever 28 in the position indicated in Fig. l, starting winding terminal 43 is connected through stationary contact 4i? and movable Contact 38, through conductor 4S to bus conductor 46, whereas starting winding terminal 44 is connected through contacts 39 and 37 to conductor 47. It is readily seen that upon operation of lever 28 into the position to close contacts 33 and 34 against contacts 35 and 36, respectively, starting winding' terminal 43 will be connected through contacts 35 and 33 to conductor 47, whereas starting Winding terminal 44 will be connected through contacts 36 and 34 to conductor 45 and bus conductor 46. Accordingly, when power is supplied to the running windings of motor 11 through conductors 49, the motor will start in a direction of rotation which will depend upon the position of lever 28.

The upper end portion 50 of lever 28 functions as a trip means engageable with a latch or catch member 51,

V'and 'the catchmember is associated in a relay indicated generally at 52. The relay comprises a solenoid coil 53 operatively associated with armature 54. The relay mechanism further includes a pair of levers 55 and S6 ansaeaa 3 disposal in ide-by-side relation and pivotally interconnected by a link 57. The link is attached to generally atei-mediate portions of the levers and maintains a predetermined spacing between these respective intermediate portions. The link 57 is shown as pivotally attached to each respective lever 55 and 56, and as comprising an extended portion 58 cooperating with a suitable'stationary guide or base support 59. Compression spring 66 urges the link 57 toward the left as seen in Fig. 1.

Lever 55 is pivoted at one end by a pivot 61' to a stationary base member 6i, and the opposite end 62 is arranged to be engaged and held by hook 63 of catch member 51. Respective pairs of cooperating contact elements are disposed on respective opposite sides of link 57. Thus elements 64 and 65 comprise a normally closed pair of elements carried by levers 55 and 56 respectively on one side of link 57, while elements 66 and 67 comprise a normally open pair of contact elements carried by the respective levers on the other side of the link. Contact element 67 is connected through conductor 68 to bus conductor 48, while contact 66 is connected through conductor 47 to the reversing switch contacts 33 and 37 and to one side of the running winding of motor 11, the other side of the winding being connected to bus conductor 46. Accordingly, closing of contact elements 66, 67 causes application of power from bus 46, 48 through running winding conductors 49 to the motor, and application of power to starting winding terminals 43, 44. It has been assumed in this description that the motor 1i is an alternating current induction motor with a starting winding, although it will be understood that other types of A. C. or D. C. motors may be used. With the suggested type of induction motor, the usual centrifugal switch for disconnecting the starting winding after the motor reaches a predetermined speed may be disposed within the motor housing in a well known manner.

Closure of main motor switch contacts 66, 67 is accomplished by means of a remote manual switch 69 which is of the momentary circuit making type and which may be of the common push button type. Switch 69 is connected in series between bus conductor 48 and contact element 64, and since contact element 64 normally contacts element 65, as when the relay is in the dropped-out condition of Fig. l, and since solenoid 53 is connected between element 65 and bus conductor 46, closure of switch 69 causes excitation of solenoid 53 to pull armature 54 against the force of compression spring 60, which bears against base portion 71. Armature 54 is pivotally and loosely coupled at 72 to lever 56, and excitation of solenoid 53 causes the relay to be actuated into the energized condition of Fig. 2. It will be seen that contacts 64 and 65 are engaged in the cie-energized dropped-out condition of the relay shown in Fig. 1, and the motion of the arma ture 54 in response to solenoid energization rotates both levers together about pivot 61' in a direction to compress both springs 6d and '70. In the construction shown, spring 60 should exert substantially greater force than spring 76.

Accordingly, in the energized condition of the relay, corresponding to closure of switch 69, as seen in Fig. 2, end 62 of lever 55 is brought into a position behind hook 63 of catch member 5ft, compression spring 73 being arranged to load or bias catch member 51. in the directionv to raise hook 63 above the end 6.?. of lever 5S. Springs 6i) and 79 are both compressed, and hook 63 is now in position to prevent return of lever 55 into dropped-out position. However, when switch 69 is opened, lever 56 and armature Se are free to move under the influenc of spring 7i?.

The release and opening of switch 69 therefore causes the relay 5.2i to assume the latched or pull-in condition of Fig. 3, wherein the relay comprises portions engaged against catch 63, while the solenoid 53 is dta-energized. It will be understood that, with de-energization ofsolenoid 53, spring 70 expands, rotating or pivoting lever 56 about a pivot associated with link 57. Lever 56 thus pivots in a manner and direction to bring contact elements 66, 67 rmly into engagement, while causing separation or opening of elements 64, 65 to isolate switch 69 from the circuit. Closure of contacts 66, 67 results in the starting of motor 11, as previously described, and the motor operates until trip portion 50 of lever 28 strikes catch member 51. A cam surface 74 on an end of catch 51 is provided to cause member 51 to be pivoted against spring '73 upon being engaged or struck by trip Si) while moving from right to left at the end of one cycle of operation as well as while moving from left to right at the end of the next cycle. Thus motion of trip 50 in either direction past portion 74 causes release of end 62 of lever 55. Upon tripping of catch 51, the relay, under the iniiuence of spring 60, immediately resumes the de-energized rest condition of Fig. l, the motor contacts 66, 67 being opened and the solenoid control circuit contacts 64, 65 being closed to permit initiation of the next cycle of operation by the next closure of switchv 69.

it will be seen that switch 69 is disconnected from solenoid 53 during the whole period of operation of the motor. If the drum 1 is being used during one operating cycle to open and during the next cycle to close a door or gate, accordingly, it is not possible inadvertentlyto stop or reverse the motor before it has reached the end of its predetermined travel. Thus the motor travel may be pre-set by appropriate adjustment of the arms 14 and 15, by loosening bolt 18, moving the arms to the desired position and then re-tightening the bolt, and the preset operation may result in opening of the door or gate to the point necessary to admit an automobile to pass freely and, alternatively, to close completely, and, in use, itis not possible by inadvertent operation of switch 69 to provide less than the desired opening or closing movement.

The arrangement of the adjustable lost motion coupling between nut 9 and lever 19 provides ready adjustment of the extent of travel of the mechanism and trouble free operation. The lost motion connection between portion 27 and lever 28, and the overcenter operation of lever 19,.provide snap actuation of reversing switch contact elements 33, 34, 37, 38 as well as rapid and trouble free tripping of catch 51.

While only certain preferred embodiments of this invention have been shown and described by way of illustration, many modifications will occur to those skilled-in the art and it is, therefore, desired that it be understood that it'is intended in the'appended claims to cover all Such modifications as fall within the true spirit and scope of this invention.

What is claimed as new and what it is desired to secure by Letters Patent of the United States is:

l. A cable drum operating and control system compris` ing a drum, a threaded shaft, a motor connected to drive said drum and said shaft, a traveling nut on said Shaft, a relay, a remote momentary closing manual switch Connected to actnate said relay from de-energized into an energized condition, catch means engageable by a portion of said relay upon release thereof from said energized condition, trip means for engaging said catch means to release said relay into said iirst de-energized condition,

` said relay comprising iirst switch means closed when said relay is in said dre-energized condition and when said `relay isl in said energized condition and open when fsaid relay is engaged against'said catch means, said iirst switch means being connected in series with said manual switch,

said relay comprising second switch means closed only when said relay is engaged against said catch means, said motor being connected for operation in response to closing of said second switch means, lost motion over-center coupling 'means connecting said nut and said trip means for actuation of said trip in response to predeter;

mined travel ci said nut, saidl coupling means compris ing a reversing switch for said motor operative to reverse 4the vconnections to said motor upon each operation ofseid coupling means to actuate said trip means.

2. In a combined reversing switch and limit switch unit, a traveling nut and screw device, a lever connected through a double acting lost motion connection to said nut, over center means connected to impart snap action to said lever, reversing switch means connected to said lever for operation thereby, a relay having two pairs of alternately closeablc contacts and comprising biasing means tending to close one pair of said contacts, trippable catch means to retain the other pair of contacts in closed condition, electromagnetic means connected in series circuit with said one pair of contacts and with external control switch means and operable to establish the holding condition of said catch means, and means engageable by said lever t0 trip said catch means.

3. In an operating system for a cable drum, a screw and traveling nut mechanism, said screw being positively connected for non-slipping rotation with said drum, electric motor means for rotating said screw and drum, a pivotally mounted arm and an over-center mechanism for said arm, a double-acting lost motion connection bef.

tween said nut and said arm, a pivotally mounted reversing switch and trip bar, a double acting lost motion contion between said arm and said bar, electrical contact means associated with said bar and connected to said motor means for reversing said motor means, bus means for supplying electric power to said motor through said electrical contact means, electrically operated switch means interposed between said bus means and said motor means, said switch means comprising a rst lever and a second lever, a stationary base member, said first lever being pivotally mounted at one end to said base member, a pivotal interconnection between said levers comprising a link attached to each said lever at a respective portion generally intermediate the ends thereof and spacing said intermediate portions of said levers, means providing a biasing force between said link and said base and tending to urge said interconnected levers to rotate in a predetermined direction about said pivotal connection of said one end, a solenoid assembly comprising an energizing coil and an armature, said armature being connected to said second lever at a point remote from said link and oriented upon energization of said coil to pivot both said levers about said pivotally mounted end against said spring bias, a catch engageable upon said last pivoting with the other end of said rst lever, a spring operatively connected to said armature effective to return said armature toward the unenergized position upon de-energization of said solenoid, a respective switch contact on said second lever adjacent each respective end thereof and spaced on opposite sides of said link, a respective cooperating contact on said first lever for each said respective switch contact, one switch contact of the first lever being normally in contact with the cooperating contact of the other lever, an external switch connected in series with said last mentioned normally closed contacts, with said solenoid and with said bus means, said second lever being arranged to pivot on said link pivot upon de-energization of said solenoid and engagement of said other end of said first lever with said catch to open said normally closed contacts and close the other contacts of said levers, said motor being connected to said bus means through said last mentioned other contacts.

4. In a motor control arrangement, a solenoid and an armature member responsive to energization thereof, a bar connected adjacent one end to said armature member, a spring loaded elongated movable pivot member arranged for longitudinal movement and pivotally connected to an intermediate portion of said bar, said bar having a respective contact element on each side of and spaced from said intermediate portion, a second bar having an intermediate portion, a coupling for pivotally coupling said bars at said intermediate portions thereof in spaced apart relation, a respective contact element spaced on each side of said intermediate portion ot said second bar positioned and adapted alternately and respectively to engage said respective contact elements of said rst bar, said second bar having one end adjacent sai-d one end of said tirst bar, stationary pivotal mounting means for the other end of said second bar, a stop positioned to limit the travel of said armature in the direction corresponding to de-energization of said solenoid, and catch means selectively engageable with said one end of said second bar.

5. In the combination of claim 4, a momentary circuit closing switch connected in series circuit with said contact elements which are positioned toward said other ends of said respective bars and in series circuit with said solenoid.

6. in a motor control system, a switch assembly comprising base means, first and second levers disposed in side-by-side relation, a pair of cooperating normally closed switch contact elements attached to said respective levers adjacent respectively adjacent first ends of said levers and a second pair of cooperating normally open switch contact elements attached to said respective levers adjacent respectively adjacent second ends of said levers, a link pivotally interconnecting generally intermediate portions of said levers and maintaining a predetermined spacing between said portions, said first end of said first lever being pivotally connected to said base means, a irst spring positioned and arranged to apply biasing force between said base and said link and as a result of said force on said link urging said first lever to pivot in a predetermined direction of rotation about said pivotally connected end thereof, a second spring positioned and arranged to apply force between said base and a portion of said second lever spaced from said link toward said other end thereof and tending to urge said second lever to pivot about said link in a direction corresponding to said predetermined direction of rotation, stop means to limit the motion in said direction of said last mentioned portion of said second lever thereby normally to cause contact of said normally closed contact elements, solenoid means arranged when energized to apply a moving force opposite to said force of said second spring and operative to swing both said levers together about said pivotally con nected end in a direction opposite to said predetermined direction into a predetermined energized position, catch means positioned and arranged to restrain said lirst lever in substantially said predetermined position upon subsequent de-energization of said solenoid, means to energize said solenoid comprising switch means connected in series with said pair of normally closed switch contact elements, and mechanical means to trip said catch.

No references cited.

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