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Publication numberUS2480865 A
Publication typeGrant
Publication dateSep 6, 1949
Filing dateAug 14, 1946
Priority dateAug 19, 1943
Publication numberUS 2480865 A, US 2480865A, US-A-2480865, US2480865 A, US2480865A
InventorsLofstrand Anders R
Original AssigneeLofstrand Anders R
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Leverage pulley
US 2480865 A
Abstract  available in
Previous page
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Claims  available in
Description  (OCR text may contain errors)

- Sept. 6, 19 A. R. LOFSTRAND LEVERAGE' PULLEY Original Filed Aug. 19, 1945 Patented Sept. 6, 1949 2,486,8 Iij v -I4EVERAGE PUBLEY AndetsefiLofstrand, SilverlSpring, I Original "application "August 19," 1943,- Serial %No; 1 4993271. Divided"and this application August 2 '14, 1946, Serial No; 690,504

' This invention: relatesatorwindingsdrums and; the like =and;isi a,divisionsof myi present appliea- Glassware-washing machines..= I

vIn a glassware mashingqmachine set :forth ini my above-1mentionedzpriorcapplication;pthere is provided:sanlelevatorefersraislngsandlowering.v

the:g1assware;intoandifroma washing tub. The weight of the elevator is balanced or compensated by a spring whichis fixedon to the machine and thGaBleVAtOli is ,connected, .to tha spring by a cable or cord trained over a plllley iirsucmar manner that as the elevator is lovvered a com pression force-is exerted on thespring tending to return the elevator tositsgraised or original,

o n: Br s n a eqav iem i eyr'fq s leli e iqe ap lied t masterin i -tense: quent return force applied to the cable would increase proportionately with the travel of the elevator, so that by the time the elevator had reached the lowest limit of its travel a very great return force would be applied and it would require much strength to hold the elevator in this position.

The most desirable condition in an elevator of this kind would be to have a. constant return force applied to the elevator. It is realized that such a constant force may be applied by the use of a compensating weight in place of the spring, but the disadvantages of using such a weight do not justify its use, for the weight is much more awkward to handle and requires more room in which to operate than a spring structure. By using a lever pulley so designed as to permit the cable to be trained over it and that more cable leaves the pulley on the elevator side than comes onto the pulley on the spring side and that the amount of cable leaving the pulley increases with rotation thereof while the amount going on remains constant, the advantages of both the spring compensating means and the weight balancing means are utilized and their disadvantages are minimized.

It is, therefore, an object of this invention to provide a leverage pulley of the kind hereinafter described, whereby the increase of return spring force on the compensating spring will vary in inverse relation to the travel of the elevator so as to provide a substantially constant return force on the elevator.

Another object of this invention is to provide a spiral pulley or plate which may be used with a conventional symmetrical pulley to achieve the result as set forth above.

Still another object of this invention is to provide a spiral pulley mounted adjacent to-a conventionalcircular pul ley, and a transfer oradapter -plate--for;trainin g: thecord from the -; the spiral ,;p ulley-,

for thepurpose as herein set forth.

:With, .the above and otherobjeots; in viewg; my;

invention consists in:the;arrangement combina tion; and details ofv construction :disclosed lin the, drawings and specification, and then-:more par ticularly pointed out: inzthe a pendedzclaim In the, drawin s .-Whe1fein;-:.similar reference characters I designate ,si-milahmpallts throughout. the; respective views,

- :Eigu-re .1 is a 1side;.e1evatiQn::0f;-,a;leverage ,p llley: constructed ,according .;to =,an ;embodiment of my, inventiom, e

Figure -2 PiSI an: end

rfiisur Figure 3 is a vertical section taken on the line 33 of Figure 1,

Figure 4 is a vertical section taken on the line 44 of Figure 1.

Referring to the drawings; the numeral 10 designates generally a leverage pulley constructed according to an embodiment of this invention, particularly adapted for use with the glassware washing machine as set forth in my copending application as set forth above.

The leverage pulley l0 comprises a plate ll, an annular pulley I2, and a transfer block M. The plate II is formed of a flat plate of a substantially spiral configuration, the spiral outline extending approximately three hundred and sixty degrees around a bushing 15. The plate ll between the extremities of the periphery thereof is formed with a cut-out Or recess l6 providing a reduced part I! at the outermost end of the spiral plate II. The plate II has a groove I8 about the outer edge thereof which terminates at the inner portion of the reduced part ll. The plate II is further formed on one side with an opening l9 therethrough above the inner end of the recess [6 and oppositely inclined grooves 20 and 2| extending from the opening H) to the outer end of the recess IS. A groove 22 on the other side extends from the opening l9.

An annular grooved pulley I2 is disposed in face abutting relation to the spiral pulley H and is secured on a cylindrical bushing I5 which extends through both pulleys H and I2.

An arcuate block M is secured to the pulley II by fastening members 24 and is formed with a groove 25 on the outer edge thereof in which a cable 26 is adapted to be engaged.

In the use of this pulley ID, the cable 26 zviewzs en'; from:- the right or plate which-- may= bev 3 brought upwardly over a P r f th annular pulley l2, reverted onto the block H, through groove 22, hole l9, grooves 20 and 2|, and is reverted again over the arm I1 and through the groove I8 about plate ll, thence downwardly to the elevator. In this manner the movement down of the elevator will cause the pulley II! to rotate clockwise, increasing the lever arm on the elevator side, thereby providing for an increase in elevator downward travel upon rotation of the pulley 10 while the increase oi. spring tension on the other end of the cable 26 remains constant. 7

I do not mean to confine myself to the exact details of construction herein disclosed but claim all variations falling within the purview of the appended claims.

Having thus described my invention, what I claim is:

1. A leverage pulley comprising a plate of substantially spiral configuration having a groove in the outer edge thereof, an annular grooved pulley secured to One face of said plate, and a block secured to said plate and formed with a longitudinally curved grooved outer edge, said plate having an opening therethrough whereby a cable may be extended from'the grooved outer edge of said block through said opening and into the groove of said plate.

2. A leverage pulley comprising a plate of substantially spiral configuration having a groove in the outer edge thereof, an annular grooved pulley on one side of said plate, a bushing securing said plate and annular pulley together, a block having an inner edge substantially contacting with an edge of said pulley, and means securing said block to said plate, said block having a grooved longitudinally curved outer edge, said plate having an opening therethrough adjacent one end of said block whereby a cable may be trained partially about said annular pulley underneath said block, over the groove in said block, through said openin and then trained in the groove of said plate starting from said lever arm.'

3. A leverage pulley comprising a plate of substantially spiral configuration, having a groove in the outer edge thereof, said plate being formed with a cut-out between the extremities of said groove, and an opening on one side thereof, said plate being formed with a second groove communicating between said opening and said cutout, an annular grooved pulley secured to one .face of said plate, and a grooved block secured to said plate adjacent said annular pulley for training a cable from said annular pulley into said REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,178,122 Ostler et a1. Oct. 31, 1939 2,081,737

Chlttick May 23, 1937

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2081737 *Sep 6, 1934May 25, 1937Anderson Products IncBrake booster for automotive vehicles
US2178122 *Jan 11, 1938Oct 31, 1939Deckel FriedrichPower equalizing device
Referenced by
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US3095922 *Apr 4, 1958Jul 2, 1963Overhead Door CorpCounterbalance and stop means for upwardly acting closures
US3211049 *Sep 17, 1962Oct 12, 1965Mcpherson Instr CorpUltraviolet monochromator
US3604274 *Nov 10, 1969Sep 14, 1971Gen ElectricUniform-torque escapement mechanism
US4409861 *Dec 15, 1980Oct 18, 1983Nissan Motor Co., Ltd.Dial type wire control device
US4768762 *Apr 27, 1987Sep 6, 1988Lund Kurt OMeans and method to counterbalance the weight of a body
US6997422Aug 20, 2003Feb 14, 2006Ergotron, Inc.Stand
US7252277Jan 17, 2004Aug 7, 2007Ergotron, Inc.Support arm
US7506853Nov 3, 2004Mar 24, 2009Ergotron, Inc.Methods and apparatus for generating force and torque
US7658359Feb 9, 2010Steelcase Development CorporationLoad compensator for height adjustable table
US7677523May 23, 2005Mar 16, 2010Nxp B.V.Gravity compensation device for a chip transfer apparatus
US8020670 *Sep 5, 2008Sep 20, 2011Kone CorporationArrangement for equalizing elevator rope force and elevator
US8091841Jan 10, 2012Steelcase Inc.Load compensator for height adjustable table
US8228668Jul 26, 2007Jul 24, 2012Ergotron, Inc.Balanced moment lift system and method
US8286927 *Apr 7, 2010Oct 16, 2012Ergotron, Inc.Lift mechanism systems and methods
US8925154Nov 23, 2011Jan 6, 2015Ergotron, Inc.Pivot mechanism for adjusting a position of an electronic display
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US20060130713 *Dec 16, 2005Jun 22, 2006Steelcase Development CorporationLoad compensator for height adjustable table
US20060130714 *Dec 16, 2005Jun 22, 2006Steelcase Development CorporationLoad compensator for height adjustable table
US20060145036 *Dec 16, 2005Jul 6, 2006Steelcase Development CorporationHeight adjustable table
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U.S. Classification74/517, 187/404, 74/589
International ClassificationA47L15/28, A47L15/00
Cooperative ClassificationA47L15/28
European ClassificationA47L15/28