US2513433A - Elevator for raising workpieces - Google Patents

Description

July 4, 1950 R. E. sKow 2,513,433

ELEvAToR FOR RAISING woRKPIEcEs Filed Aug. 6, 1947 b5 sheets-sheet 1 fat 1 suuentor Ross E. Ska w.

MWI *WM Gttorneg 5 July 4, 1950 R, E, SKOW 2,513,433

ELEVATOR FOR RAISING WORKPIECES AT' TORNEYS.

July 4, 1950 R, E, SKOW 2,513,433

'ELEVATOR FOR RAISING WORKPIECES Filed Aug. 6, 1947 5 Sheets-Sheet 3 nuentor Ross E. S/row.

MK L 70M- Gttorneg s Patented July 4, 1950' ELEVATOR FOR RAISING WORKPIEC'ES Ross vE. Skow, Kansas City, Mo., assignor to Baltimore Paper Company, .Kansas City, M0., a. corporation of Missouri Application August A6, 1947, Serial'No. 766,665

. 12 Claims.

This invention relates to -elevators for raising and/.or llowering workpieces relatively to -the working levelof a machine in which the workpieces `are processed; for-eXam-plastacks o-f paper -to the table of a die or .cutting press.

In presses of this character it has been the practice to lload a stack of paper .sheets upon a low platform truck and to wheel the loaded truck into la position adjacent the press. The operator `of the press would then remove stacks of the sheets vand lift themto the cutting table. Such sheets are usually yof relatively large area and the sheets to be lifted are heavy vand difficult to handle with the result that the operator becornes fatigued or he may strain or even-injure himself.

Therefore, the principal objects of the -present invention are to provide an elevator for this purpose `that is of simple, inexpensive construction that may be operated with a small inexpensive motor so that when the operator takes on" one v`.lift of paper the elevator automatically raises the next lift to the proper height.

Other objects Vof the invention are to provide an elevator with an automatic control for automatically stopping the elevator when the stacks of sheets vo r othei` workpieces reach the desired levelg-and to provide for adjustment of the automatic control to maintain a proper level or height of the stack for the convenience of the individual .operator of the machine, that is, if a tall operator working with the aid of the elevator, the cont-rol would be set to stop the lift at a higher point than for a shorter operator.

In `accom-plishing these and other objects of the invention hereinafter .pointed vout, I have provided improved structure, the preferred form of which isfillustrated in the accompanying drawings wherein:

Fig. 1 is a yperspective view of an elevator constructed in :accordance with the present invention and which is adapted for raising Workpieces such as stack-s of paper to a convenient level relative to a machine in which lthe paper is to be processed.

Fig. 2 is a side elevational view.

Fig. l3 is an end elevational view.

Fig. 4 is a wiring diagram of one type of electric circuit that may be employed in the elevator.

Fig. 5 is fragmentary cross section through one side of the frame particularly illustrating the rollers for guiding the lifts of the elevator.

Fig. 6 is la detail section showing the anchorage for the fixed ends of the elevating cables.

Fig. 7 is a view vof the cam of the automatic level control switch forv controlling the level of a lifting type of elevator.

Fig. 8 is a view of the cam for the level control switch vfor a lowering type of elevator.

Referring more in detail to the drawings:

Cil

I designates, an elevator constructed in accordance with the present :invention and which may include a gauntry-shaped frame having laterally spaced uprights 2 .and 3 connected at their llpneiyends by a cross member 4. The uprights 2 and-3 Keach include an Yangle-shaped base member Shavingvertical flanges 6 to which are rattached spaced lchannels 'l and l8 comprising the uprights. The channels 'l and B are arranged with the side flanges -9 and I0 in facing relation .to cooperate with the web portions II andv .I2 of the channels in forming vertical ways I3 -for pairs of wheels I4 and I5 of travelers of carriages .I6 and Il that are yadapted to move up and down theways `of the Vrespective uprights .as later described. The channels are supported in .upright position -by braces rI8 and I9 having the lower ends .fixed to the ends Vof the flanges 6 and their upper -e-nds'xed to cross members 20 that tie ,the channels in spaced relation .as shown in Fig. 1. 'The cross vmember 4 includes spaced angle members 2l and .22. The angles are arranged so that one jof their ilang'es turns kdownwardly for attachment to the webs II and I2 `of .the upright channels, and the other flanges 23 thereof turn outwardly for mounting the lifting machinery later to be described. The connections of the .ang-le members with .the channels yare further reinforced by ygusset plates or corner braces to provide operating rigidity without anchoring of the base .angles 5.. However, small screws may .beused -tosecure the base angles to the floor to prevent .-skidding of the machine vout of position. The travelers-cr :carriages I6 and I'I include elongated body members y25 adapted to move in the spaces between the channels of the uprights and which carry cross shafts 26 and 21 adjacent the upper and lower ends for mounting wheels I4 and I5 that roll .in the ways when the travelers are raised and lowered as later described. Fixed to the lower ends of each membei' v25 are transverse angles 28 having vertical flanges 29 and horizontal ilanges 30 which con- .stitute Ashelves or lifts for carrying the workpieces tobe raised `as later described.

AFixed to the upper `end `of leach upright are brackets 3| and 32 having bearings 33 and 34 respectively for journalling the ends of a cross shaft 35.. Fixed to the cross shaft over the top of the uprights :2 and v3 are winding drums 36 and 31 carrying cables 38 and -39 presently described. Pivotally connected with the upper ends of the travelers by means lof straps 40 are grooved pulleys 4I and cooperating therewith below the respectivewinding drums are stationary pulleys 42 rotatably Vmounted, on pins 43 having the ends journalled in plates -44 .connecting the viianges of the upright channels. lQIhe cables have their free ends providedwith eyes 45 that are mounted on thecross pins v43 -on which the stationary pulleys rotate and the cables extend downwardly in the ways and are reeved `in the grooves ofthe trav-` eling pulleysfrom where theyexltendyupwardly and the upper ends areA attached to the winding drums.

The cables are of a length so that when they are substantially unwound from the winding t drums the travelers are in their lowermost posij tion with the horizontal flanges 36 of the angle members 28 substantially resting upon the floor.

The shaft 35 is rotated to wind the cables 38 and 39 on the drums 36 and 31 and effect raising of the travelers I6 and l1 by means of a` reduction mechanism including av-.worm gear 41 fixed to a projecting end of the shaft 35 which meshes with a worm 48 vthat iscarried in a housing 49 that isattaehed to the upper end of the upright 2. The worm 48 is mounted on a shaft 50 having oner end projecting laterally from the upright 2 to mount a relatively large diameter driven pulley 5| having its periphery provided with agroove '52 for receiving an endless belt 53 operating over a relatively small driving pulley 54 carried on the armature shaft 55 of a motor 56. The motor 56 is mounted on a suitable base 51 thatv is carried by the horizontal flanges 23 vof the angles 2l and 22 previously described.

-When the elevator is lifting, the thrust of the worm 48 on the 'worm gear 41 is toward the frame and against the bearing 34 so that the thrust doesv not tendto throw the frame out of alignment.

The combination ofthe small and large pulleys together with the worm and worm gearing permits'the use of a relatively inexpensive fractionalhorsepower motor for operating the elevator since the reductionin Vspeed is suihcient to rotate the winding drums'at speeds suitable to provide the desired movement of the lifts.

With the construction thus far described, -it

` is obvious that energization of the motor will operate the worm gear through the pulleysV 5| and 54 by means of the endless belt 53 so that the worm turns at a considerable lowerfspeed than the armature shaft y550i the motor 56. lThe worm 48 meshing with the worm gear '41 turns the drum shaft 35 at a substantially reduced In order to provide for automatic operation of the motor to limit the upper and lower travel of the carriages or vtravelers and to provide for automatically stopping the liftat any'intermediate positions, the elevator is equipped with an'up'per llimit or safety switch 58 depending from the cross member llyupper and lower control switches 59 and 60 attached to the upright 2and an inl crement stop or level control switch 62 adjust- `ably attached vto one of the upright'members of the frame at thelevel desired by theoperator ofthe machine A(not shown) "with vwhich the elevator is to be associated. The motor also controlled by va/manually operated reversing switch 63 thatfis preferably attached to theframe in convenient reach of the operator. 59 and 60 have rollers 64 and 65 that are respec- The switches tively actuated responsive to contacty by spring leaf actuators 66 'and 61 located on vertical'ange of theA angle 26 at that side of the machine (see c Fig. 2). rIche actuators thus move with the elevator carriage so that wheny the elevator carriages are in their lowermost position the actuator 61 will engage the roller 65 4of the lower switch vand when the elevator `carriages are in their upper position` the actuator 66 engages the roller 64 of the switch 59 to open circuit to the motor at predetermined upper and lower limits of the'carriages.

The level control or increment switch 62 has an actuating roller 68 which engages a cam 69 that is oscillatably mounted on the stud 10 projecting laterally from the upright 2 at a point above the upper .limit switch. Connected with the cam is an actuating arm 1I that projects over the stack 'of sheets as shown in Fig. 2. When the arm 1I is in down position as shown in Fig. 2, the 4roller 68 engages a. dwell 12 in the cam so thatthe leveling switch is in closed position but as the stack is raised the arm swings upwardly to move a lobe 13 of the cam into contact with the roller to open the switch and stop movement vof the stack as later described.

The motor 56 is connected with current supply conductors14 and 14 in which is interposed a main switch 15 that is operated by the switches previously described, by means of a solenoid 16 that is connected in circuit with the current supply conductors 14 and 14 by conductors 11 and 11". The conductor 11 connects the switches 59, 60 and 68 in series and circuit is completed by connecting the conductor 11 with the conductor 14'. Thus,when the switches 58, 59,- 60 and 62 are closed, current is flowing through the solenoid 16 to lhold the main switch 15 closed to effect operation of the motor 56, however, when any one of the switches 58, 59, 60 or 62 is open, circuitv is interrupted to the solenoid 16 and the main switch 15 opens to stop operation of the motor.

' vThe lmanually operated reversing switch 63 is connected by suitable conductors 18 and 18' with themairll circuit' supply wires and the eld windings 19 of the motor to effect reversal of the motor 56.r The reversal switch 63 may also includev contacts to control the current ow to the switches 59,v 66 and 58. When one of the control switches is open and the reversing switch has been actuated to operate the motor in the desired direction, the solenoid 16 is initially actuated by a push button switch 88 that is connected with the conductors 11 and 11 by conductors 8l and 8 l to establish direct flow of current through the solenoid 16 and effect closure of the main switch 15. The cam 69 also has a dwell 82 to permit closure of the level switch when the arm 1I is raised* to an out of the way position. When the elevator is used for lowering the work a cam 83 asshown in Fig. 8 is substituted for the cam 69. 'ln using the elevator constructed and assembled as described, and assuming that the carriages are in their lowermost position with the inturned flanges 39 of the angles 28 resting on the fioor, a platform 64 is placed on the truck or dolly (not shown) to carry a stack of sheets 85 and 'are transported to the elevator where the truck is moved between the lifts. The platform 84 has depending foot portions 86 that are spaced apart so that theypass over the flanges 36 of the lifts to be supported thereby when the motor isactuated to ,raise thecarriages and lift the platform from the truck. When the elevator is in its lowermost position the actuator 61 is engaging the roller of the switch 60. The motor, however, may be started by positioning the reversing switch 63 and closing the push button switch.: Closing of the push button switch 80 establishesa flow offcurrentfthroughitlre solenoid 16 ofthe'main switchx'l' so that themain switch is'closed and currentis supplied tothe motor 56. Assoonas the actuator .6 Tieaves the roller 265, the switchfficloses to complete and holdthe circ-uit throughfthe solenoid. If theincrement lstopor leveling fswitch y*t2 ais used, the platform will be raised .until thetop :sheet strikes theactuating arm 7H of `the .camli) .andthe .switch opens the circuit to the solenoidvlS and permits opening of the main switch 15. "The yuppermost -sheets .are then'in` kposition .to vbe:conveniently 'removed from the elevator .and slid onto lthe work table 4of :the press or other machine--whereupon the switch arm 'H .drops to againsclose the circuit tothe motor .andthe `platform llI is raised until 4is again stoppedfbyfthe :stach of .sheetsfengaging the arm 11. The operationsvare 'thus continued until allot fthe-.sheets have'been removed yor untilthe actuator '28:6 l.engages the roller 614 ...of the l.switch 5 9 Whichstops upward `movement ofthe elevator.

fShouldfthe stop switchi'zinot :be used and an exceptional high stackfof sheets applied in the elevator, the motor will be automatically stopped by contact of the uppermost sheet with the upper limit switch 53, which stops the motor and prevents'injury to any of the operating mechanism of the elevator.

'fWhen fthe platform is in its uppermost position `and the sheets have 'been removed therefrom, the platform is lowered by positioningrthe reversing switch "63 andclosing the lpush 'button switch Bil which eti-acts closingof the main .switch to operate the .motor in -thedirectionto `lowerthe platform. ":When thecarriag-eshave reached their lowermost :position .the vactuator 611 4engages the roller @5to-effect opening ofthe solenoid circuit. The platformfmay then 'be removed vfrom the rails for reloading with .another stack of sheets.

it is to fbe noted in lifting-.heavy loads land the i use of wider lplatforms does `notgreatly increase the stress upon the .angle `members of `the carriages since the supports "forthe platforms .lare close to the -ver'tical 'flanges of the' angle `members. Lighter and narrower .platforms result in increasing thespacing 'between the points ofv support and the 4vertical flanges but 'the lighter loads-make compensationand the :stress curve is substantially ila-t. ilihisis'salso true 'ofthe stresses in the fmain :channel members of the frame.

.From the .foregoing Vit isobviousthat I have provided 'an elevator vwhich .is `-o'f simple :and inexpensive conslnuction and Iwhich 'may be frea'dily adjusted to positiona Istack of sheets relative to the Work table .of av ymachine so that theoperator may remove :a predetermined number :ofthe sheets onto the 'work :table .with a minimum -of lifting effort. n vvWhat I claim and :desire to :secure by Letters Patentsis:

. 1. .An velevator of the character described yincludinga fname, 'lifting meansmounted for vertical movement on the frame for elevating a stack of workpieces, winding drums rotatably mounted on the frame, cablesuoperable on the winding drumsv and connected with the lifting means, :a motor, aspeedfreduction driving mechanism connecting the motor with Ythe winding drums, an electric circuit connected. with the motor for supplying current r'to the motor, a reversing switch connected in the circuit for -re- Ver'sing` rotation of the motor `toeffect `alternate raising and floweringcf the lifting mean-s, limit switches in said circuit te `limit'the up and -down movement of the lifting means, means movable with theliifting means for actuating :the ziimit switches, .and an increment .stop and leveling switch in said circuitfor .stopping theA lifting means :at increments yint'ermediatefthe stops .by said limit switches. y

- 2. 4An .elevatorof the-character described in-f cluding 'fa vframe :provided with :spaced uprighta lifts yrnountedyfor vertical movement :on the uprights and adapted .for carrying sagstack of workpieces to :be elevated, va cross A:shaft :rotatably mounted ontheframe at the-.upper ends 'of the uprights, winding drums on the shaft, cablesiopenable ion'zthe Winding.v drums and :connected with the lifts, Aa finotor, a speed :reduction Vdriving mechanism connecting the :motor lwith vsaid shafts, an electric-'circuit connected-with thefmotor for supplying current to y.the motor., agreversing -switch connected in the circuit for reversing rotation of the motor to effect alternate 'raising and lowering of the lifts, limit lswitches iniisaid circuitto limit the upand downimovementofxthe lifts, .and means movable with'one'of'thelifts .for actuating the limitaswitches. i

3. An elevator =of the Vcharacter .:described iincluding a l'frame provided `with :spaced y.uprighta liftsmounted V-for vertical movement on the uprightsland adapted for ecarrying astack of Workpieces 'to be elevated, :across shaft.'..rotatabis mounted on the :iframe at'fthe upper endswo'f the uprights, Win-ding drums on the shaft, .cables y'operable on the vwinding `drums and connected with the -liits,a motor., a worm gear on :the shaft, a worm :meshing with the worm .gaan-ia pulley fconnected with .the worm, a pulley von theme-tor, a belt operating overthe pulleys, anelcctric'circuit connected with the .motor lior supplying r:current to the motor, a reversing switch connected in the circuit for :reversing rotation of the ymotor to effect Aalternate raising .and .ioW-.ering of the lifts, limit switches :in said circuit tofiimitfthe upand down .movement of the lifts, andmeans movable with 'one lof the lifts :for actuating the v limit switches.

4. vAn elevator of the 'character described iricluding fa fgauntry-shaped .frame provided with spaced uprights, carriages vmounted for vertical movement on Athe uprights 'lifting :rails -on` `the carriages and adapted for carrying stacks -fof workpieces to be elevated, ya :cross shaft rotatably vmounted on the frame on the @upper ends of the Yuprights, winding y.drums V:on the shaft, cables operableon the winding drums yandronnected with the carriages, .a motor, a 'speed reduction .driving mechanism .connecting the'motor with saidshaft, ancelectric circuit connected with the motor for supplying current to -t-he motor, a reversing :switch connected in the circuit for reversing rotation loi `the motor tofeifect alternate raising and lowering of :the carriages, .limit switches .in said circ-uit to li-mit the up and down movement of the carriages, means .movable with one of the Vcarriages `Jfor actuating the limit switches, and an yincre-ment switch in said circuit having an actuator en-gageable with the workpieces -to stop the motor intermediate the stops effected bythe limit switches. g

5. An yelevator of 'the character described r-in'- Cluding a frame provided withxspa-ced uprights having vertical ways, .carriages inountedsin said ways -and adapted for carrying workpieccs -to be elevated, a cross shaft rotatably mounted lon the frame on theupper ends o'f the uprights, winding drums on the shaft, -pulleyson the carri-ages, pull leys mounted at the upper lends of theuprights, cables having ends anchored adjacent said last- 2,513,4ssf

1 named pulleys andi-'reeved over said pulleys with opposite ends attached lto the winding drums, a

motor on the frame, a speed reduction driving mechanism connecting the motor with the cross shaft, an electric circuit connected with the motor for supplying current to the motor, a reverse switch connected with the motor to eiect raising and lowering of the carriages in said ways, limit switches in said circuit to limit up and down movement `of the carriages,.and means movable with one of the carriages for actuating the limit switches. I

6. An elevatorof the character described inleys with their oppositey endsvattached to the winding drums, a motor on the frame, speed reduction driving mechanism connecting the motor with the shaft, an electric circuit connected l with the motor for supplying current to the motor, a reverse vswitch connected with the motor to effect raising and lowering of the carriages in said ways, limit switches in said circuit to limit up and down movement of the carriages, means movable with one of the carriages for actuating the limit switches, and an increment switch in said circuit having an actuator engageable with the workpieces to stop the motor intermediate the stops effected by the limit switches.

7. An elevator of the character described including a frame provided withspaced uprights having vertical Ways, carriages mounted in said ways and adapted for carrying workpieces to be I elevated, a shaft rotatably mounted on the frame l at the upper ends of the uprights, winding'drums 1 on the shaft, pulleys on the carriages, pulleys mounted lat the upper ends of the uprights,

, cables having ends anchored adjacent said lastnamed pulley andvreeved over said pulleys with their opposite ends attached `to the winding drums, a motor on the frame, speed reduction driving mechanism connecting the motor with the shaft, and means for controlling the motor.

f 8. An elevator of the character described including a frame provided with spaced uprights having vertical ways, carriages mounted in said ways and adapted for carrying workpieces to be elevated, a cross shaft rotatably mounted on the frame at the upperends of the uprights, winding drums on the shaft, cables operable on the winding drums and connected with the carriages,

` a worm gear on the shaft, a worm carried by the frame and meshing with the worm gear, a motor on the frame, a pulley and belt connection between the motor and the worm for driving the worm at a reduced speed with respect to the 3 motor, an electric circuit for supplying current to the motor, and means in said circuit auto- 1 matically operable by one of the carriages for stopping operation of the motor in different posii tions of the carriages.

9. An elevator of the character described including a frame, lifting means mounted for vertical movement on the frame, means including an electrical motor for actuating the lifting members to elevatea stack of workpieces, an electric 1 circuit connected with the motor for supplying 8 current to the motor, e, reversing switch connected in the circuit for reversing rotation of the motor to effect alternate raising and lowering of the lifting means, limit switches on said frame and connected in said circuit to limit the up and down movement of the lifting means, and limit switch actuators movable with one of the lifting means for actuating the limit switches.

10. An elevator of the character described including a frame, lifting means mounted for vertical movement on the frame, means including an electrical motor for actuating the lifting means to elevate a stack of workpieces, an electriccircuit connected with the motor for supplying current to the motor, a reversing switch connected in the circuit for reversing rotation of the motor to effect'alternateraising and lowering of the lifting means, limit switches on said frame and connected in said circuit to 'limit the up and down movement of the lifting means, means movable with one of the lifting means for actuating the limit switches, and an increment stop and leveling switch on the frame and connected in said circuit for stopping the lifting means at increments intermediate the stops by said limit switches.

1l. An elevator of the character described including a frame, lifting means mounted for `vertical movement on the frame, means Iincluding an electrical motor for actuating the lifting means to elevate .a stack of workpieces, an electric circuit connected rwith the motor for supplying current to the motor, a reversing switch connected in the circuit for reversing rotation of the motor to effect alternate raising and lowering of the lifting means, limit switches on said frame and connected in said circuit to limit the up and down movement of the lifting means, means movable with one of the lifting means for actuating the limit switches, an increment stop and leveling switch on the frame and connected in said circuit, a cam oscillatably supported on said framev for actuating said stop switch, and an arm connected with the cam and projecting into the path of the workpieces for moving the cam to effect stopping of the lifting means at increments intermediate the stops by said limit switches.

12. An elevator of the character describedA including a frame provided with spaced uprights having vvertical ways, carriages mounted in said ways and adapted'for caarrying workpieces to be elevated, a shaft rotatably mounted on the frame at the upper ends of the uprights, winding drums on the shaft, pulleys on the carriages, pulleys mounted at the upper ends of the uprights, cables having ends anchored adjacent said last-named pulley and vreeved over said pulleys with their opposite ends attached to the winding drums, a motor on the frame, speed reduction driving mechanism connecting the motor with the shaft, and means responsive toy predetermined movements of the carriages for controlling the motor.

ROSS E. SKOW;

REFERENCES CITED The following references are'of "recordf'in'the i'lle of this patent: Y f

UNITED 'STATES P'Amiwrs` Date A French Feb. ,26, 1924

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