US2259253A

US2259253A - Block and tackle

Info

Publication number: US2259253A
Application number: US378588A
Authority: US
Inventors: Kozlovskis Oskar
Original assignee: Individual
Current assignee: Individual
Priority date: 1941-02-12
Filing date: 1941-02-12
Publication date: 1941-10-14
Anticipated expiration: 1958-10-14

Description

Oct. 14, 1941- o. KOZLOVSKIS BLOCK AND TACKLE Original Filed Jan. 14, 1937 INVENTOR 1:- OSKAR KOZLQVSKIS O Z' W W,

ATTORNEYS Patented Oct. 14, 1941 UNITED STATES PATENT OFFICE BLOCK AND TACKLE Oskar Kozlovskis, New York, N. Y.

Substituted for abandoned applicationSerial No.

120,552, January .14, 1937.

This application February 12,1941, Serial-No. 378,588

16 Claims.

The invention relates to a block and tackle and the present application constitutes a development of the invention disclosed in my copending application. This application constitutes a substitute for abandoned application Serial No. 120,552, filed January 14, 1937.

The present invention specifically relates to a lifting device designed for elevating enormously heavy weights over relatively short .distances by manual or mechanically applied power.

The primary object of this invention, as was the object of the invention in the copending disclosure, is to provide and make more eflicient lifting devices of the block and tackle type and at the same time to provide a compact, extremely simplified form of construction and. one which will be of small extent particularly in the horizontal dimensions.

It has been found in the operation of block and tackle devices, especially in those situations where abnormally heavy weights must be elevated that the usual arrangement of leading the free end of the pulley rope or cable off from the same in a more or less horizontal direction to a winding drum or other power actuated take-up, there is developed a transverse pull or force component acting on the device which tended to move the pulley blocks out of their initial, normal, vertically disposed relation With a resulting cant of the several pulley wheels on their supporting axles and this interferes not only with the necessary freedom of movement of the different lengths of pulley ropes as they fall freely between the blocks and which, especially in those cases where the rope lengths must necessarily be located close to each other, interferes with the efiic-iency of the lifting device but the canting or tendency to twist of the pulley wheels introduces additional frictional resistance to the freedom of rotary movement of the several pulley wheels.

Accordingly, one of the objects of the present disclosure is to provide a construction which not only features the use of a large number of pulleys confined to a small space but also to provide a structure in which the pulleys are maintained in their initially set positions on their respective axles and in which the falls or lengths of rope'or equivalent draft elements are thus maintained in non-contacting arrangement free of any scraping or other mutual interference, even though a laterally directed pull on the free end of the rope may displace or tend to displace the pulley blocks from their initial position.

Anotherob-ject of the invention is to'provide a block and tackle an extremely 'ruggedformof pulley block and, like the disclosure in the copending application, there is featured .an up:- standing block of hollow cylindrical form which gives the maximum resistance to distortional strain while limiting the structural mass of the block.

However, where heavyweights are to be lifted the resulting strains are very apt to distort, crush or twist the cylinder of which the block is formed unless it is made unusually thick in its cylindrical .wall thickness and any abnormal increase in mass. of material used defeats the desire fora light weight structure.

Accordingly, anotherobject of the invention is.

to provide reinforcing features to the tubular or cylindricalform of block with the reinforcements limited in amount of material used justsufiicient to resist .such crushing or distorting action, and atthe same time to utilize the reinforcing elements :to vprovide other functional attributes desirable in such devices such, for instance, as the providing ,of side guide plates for the pulleys and the utilization of pivot pins for both the suspension elements and for the weight engaging hook at the bottom of the assembly of pulley blocks herein featured as additional reinforcements to .the cylinder.

Various other objects and advantages of the invention .be in part obvious from an inspection of the accompanying drawing and in part will be morefullyset forth in the following particular description of one form of device embodying the invention, and the invention also consists in .certainnew and novel featuresof construction and combination of parts hereinafter set. forth and claimed.

In the accompanying drawing:

Fig. 1 is a view in side elevation illustrating a preferred embodiment .of the invention in its normal hanging suspended .position when weighted but free of .a .pu1l on the pulley rope and showing in dotted lines the upper portion of the structure an off-set position from its normal positionland which dotted line position is grossly exaggerated in its ofi-set relation so as to clearly show the relationof the parts;

Figs. 2 and 3 are horizontal, sectional views taken respectively on the lines 2 2 and 3-3 of Fig. 1 looking downwardly as indicated by the arrows;

Fig.4 a detail view of the upper portion of thestructure viewing the same from the left of Fig.

Fig. 5 is -a detail view of-the hook-connection with the bottom of the cylinder shownin Fig. 1

block B. Each of the main blocks is provided.

with a plurality of pulleys C through which is" trained a pulley rope D. Each of the main" blocks A and B is formed of a hollow, open end metal cylinder E. Preferably, each pulley C is actually a set of pulleys or pulley-wheels K of which there are illustrated three pulleys to each 7 set and each set mounted on an axle M. The cylindrical wall of both blocks A and B is slotted at opposite sides to form three pairs of transversely aligned vertical slots I and J. The sets of groovepulley wheels K are contained for the most part within their associated cylinder and each has its opposite edges fitted to extend through the slots I and J so that the slots in the absence of the side plates hereinafter described coact to limit lateral movement. of the pulley wheels axially. Each Wheel projects slightly beyond the outer peripheral face of the cylinder a distance sufiicient to bring the lengths L of the pulley rope B slightly outwardly away from and thus clear of the cylinder walls as shown in Figs. 2 and 3. The axle M is in the form of a solid metal cylinder which extends across the interior of the blocks diametrically thereof, and has its opposite ends secured as by welding at N to the opposite sides of the blocks.

The pulleys of each block are arranged in superposed relation, that is, are disposed with their axis of rotation indicated at a,b in vertically spaced planes and preferably equidistantly spaced apart. Not only are the pulleys of each block arranged in superposed planes but the pulley wheels are arranged to extend in different verticalplanes, one offset circumferentially from r the other. The axis of rotation of the several sets of pulleys is so disposed that when projected vertically into a plane containing the axis of the next adjacentpulley, the angle formed therebetween is almost one hundred and eighty degrees (180) divided by three (3), the number of sets of pulleys illustrated, so as to form an included angle of aboutsixty degrees (60). It will be noted, however, from the showing in Figs. 2 and '3 that the circle representing either the cylinder A or B, and hereinafter referred to as the circle of reference, is divided,'not into six times three but into twenty, approximately equal, divisions of about eighteen degrees (18") each, one division designated X inFig. 3 provided for receiving the end of the rope attached to block B as indicated inFig. 1, and another division Y opposite the same as shown in Fig. 2 forming a V-shaped guideway for receiving the upward reach of the endof the rope passing from block B through pulley block P as hereinafter described. It therefore follows that the circle of reference is divided intotwenty equal spaces, two for receiving the opposite ends of rope'D.

The other eighteen spaces of the division are arranged in opposing sets of three receiving spaces as shown in Figs. 2 and 3. More specifically defined, the different sets of pulleys are arranged in pairs, of which the lowermost set I ofblock A is vertically abovethe uppermost set steam II of block B and forms one coact ing pair. The intermediate set I2 of the block A is vertically above the intermediate set I3 of block B and forms a second pair. The uppermost set I4 of block A is vertically above the lowermost set I5 of block 18.

In assembling the parts as thus far described, it will be understood that the rope D is fastened to the lower block at X, extends upwardly therefrom and is trained over the right pulley wheel of the lowermost set II! of pulleys in block A. It then extends downwardly therefrom along the reverse side of the cylinder shown in Fig. 1 and is trained under the vertically aligned pulley wheel,

that is, the right pulley wheel of the uppermost set I I of the lower block B, and hence again upwardly to the intermediate pulley wheel of the lowermost set I0 and is thus progressively trained conventionally through all of the pulleys 0f the pair forming the sets I0 and I I and which in the illustrated showing are closest together. Then, from the left pulley wheel of the set II, the rope crosses over at a slight angle to the vertical as indicated at I6 to the right hand pulley wheel of the next highest set of pulleys I2 in the block A. The rope istrained over this right hand wheel of set I2, extends downwardly therefrom on the reverse side of the showing in Fig. 1, hence to the right hand pulley wheel therebelow in the next lower set I3 of block B and hence after being trained successively through the several pulleys of the intermediate pair formed of sets I2 and I3, the rope again crosses over as indicated at H to the right pulley wheel of the uppermost set I4, then as before down to the right hand pulley wheel of set I5, and hence as before successively through the several pulleys of these two furthermost removed sets I4 and I5. Finally, the end reach or length marked I8 passes from the last, that is, the left pulley of the lowermost set I5 over pulley wheel I 9 of the supplemental block P from which the free end 2 0 extends downwardly as indicated in full lines or outwardly as indicated in dotted lines in Fig. 1. It will be seen from the arrangement of the eighteen different lengths of the rope in Figs. 2 and 3 and which will also be the arrangement of the rope lengths in the space between the main block A and B, that these rope lengths form a polygonal, in this case, a sixsided figure, that is, twice the number of sets of pulleys in each block with three lengths forming each side of the figure.

It is a feature of this disclosure that the blocks A and B be maintained in their normal vertical position at all times. For this purpose, this upper block A is pivotally connected to the supplementalblock P and in turn the supplemental block and thus the entire block and tackle is hung so as to be free to move in any direction. The entire device is supported from a suspension 2I in this case shown to be a hanging cable having a loop end 22 which engages a suspension pin 23 extending between the upper ends of a pair of

parallel cheeks

24 and 25 forming the sides of the supplemental pulley block P. The lower ends of the cheeks protrude into the upper end of the cylinder A as particularly shown in Fig. 4. A pair of

straps

26 and 21 have their" upper ends inturned and lap the cheeks midheight thereof. A pulley fulcrum pin 28 extends through the upperends of the

straps

26 and 21, through the

cheeks

24 and 25 and provides an axle on which the pulley I9 is loosely journalled for free rotary movement. A pivot pin 29 extends across the upper end of the cylinder A,

passes through the lower end of the straps. 26 and 21 and

cheeks

24 and 25 and thusprovides a four point support and pivotal connection between the supplemental block P and the upper main block A. It isa feature of this disclosure that the pivot pin 29 extends perpendicular to the plane containing the pulley l9 so that the main blocks may hang, perpendicularly below the pin 29 even when the supplemental pulley is at an angle to the vertical as shown in dotted lines Referring to the structure at the lower end of the-device asby reference to Fig. :5, a pair of hook straps :30 and 3| lap oppositesides, of the lower end of the cylinder B, have their lower ends converged towards each other below the cylinder B, and a hook pin 32 secures the hook H pivotally supported from the lower main block. In order to resist the tendency of the opposite sides of the lower end of the cylinder to crush towards each other under the squeezing action of the hook straps, a spacing sleeve 33 is fitted between the opposite sides of the cylinder wall and a sleeve pin 34 is passed through the hook straps, through the cylinder and through the spacing sleeve. Preferably, the hinge straps are extended upwardly along opposite sides of the cylinder and the pulley axle 35 for the lowermost set of pulleys 15 passes through and connects the upper ends of the hook straps.

In order further to tend to reinforce the cylinders A, and B against rotary twist and at the same time to provide side or guide plates for each set of pulleys, a pair of flat disc-like side plates 36and 31 (see Fig. 2) extend chordinally across the cylinder and project beyond opposite sides thereof and beyond the sets of pulley wheels fitted therebetween. The side plates are heldby their engagement in the opposite disposed slots and J- and tend to transmit any wobbling action of the .pulley wheels to the cylinder block in the part thereof which is braced together by the diagonally extending rugged axles M.

In order to supply lubricant to the bearings for the pulley wheels, it is suggested that the axles M 'be drilled from oneend axiallyas shown in Fig. 6 to prov-idea twice reduced bore 38, the inner portion of smallest diameter of which forms a lubr icant reservoir normally closed by a ball valve 39 in the bore of next largest diameter and .pressed outwardly by a spring 4-3 in engagement with a sleeve 4 l-forming a valve seat at its inner end. A closure cap 42 at the cuter end of the bore normally closes the same. It is herein suggested that the inner wall of the sleeve 41 be provided with a bayonet slot 43 adapted to receive either the cap lZ-or the fitting on the end of a lubricant supply device. In this way the cap maybe removed from time to time, a connection made with a grease gun such as is used in the supply of lubricants "to the grease cups commonly found onautomatic vehicles and suitable lubricant 'is'supp'lied to the reservoir under pressure sufficient to unseat the valve 39. From the reservoir, leaking passages 44 extend from the reservoir '38 outwardly to the smooth cylindrical outer faceo'f the axle which forms a bearing for the threelpu lley wheels K.

In-operation and assuming the block-and tackle assembly as shown in-Fig. 1 to be hung from a suitable support by means of the suspension 2|, a weight on the hook -'H will tend to cause the several rope lengths to straighten out and be placed under tension and thus assume the :position indicated at Fig. *1, if not already in such position. A pull on the free end 20 of the rope will cause the hook H with the weight thereon to be elevated and thus drawn upwardly as is well known in other forms of block and tackle devices. Any such pull on the. free end of the rope will tend to shift the supplemental pulley P to the right in the showing in Fig. 1 from the full line towards the dotted line position and this lateral shifting tendency will increase as the angle of the rope approaches the horizontal as indicated in the dotted line showing of the rope end. It will be understood, however, that the dotted line showing of the supplemental block P in Fig. 1 has been grossly exaggerated in order to separate the two positions of the supplemental block P and with it the main blocks A and 'B. will be displaced only slightly from their initial position with the weight on the hook and before pull has been exerted on the free end of the rope.

It is a feature of this disclosure that irrespective of how slight may be the olfsetting of the blocks A and B in practice, these main blocks will maintain their relative initial position with the cylinders A and B concentric to a vertical line c-d passing through their axes, and in this way the several lengths of ropes between the different sets of superposed pulleys will be maintained in their vertical and non-interfering relation. In this way the pull on opposite sides of each pulley wheel is maintained in the medial plane of each pulley Wheel and thus maintained accurately at right angles to the axis of rotation of each pulley wheel in its engagement with its associated axle. This has the effect of minimizing side thrust between each pulley wheel and its axle and tends to maintain a freedom of rotary movement of each pulley wheel on its axle even though each wheel is supporting its proportionate share of an enormous load.

While there have been shown, described and pointed out in the annexed claims, certain novel features of the invention, it will be understood that various omissions, substitutions and changes in the form and details of the device illustrated and in its operation may be'made by those skilled in the art without departing from the spirit of the invention.

I claim: I

1. In a block .and tackle, the combination of two main pulley blocks each comprising a hollow tubular cylinder and normally disposed in axial alignment, a plurahty of sets of pulleys with the pulleys 'of each set :mounted in each block for relatively free rotation about a common axis and said sets of pulleys disposed with their axes of rotation in progressively higher planes and the axis of each set of pulleys when projected vertically into the plane containing the axis of'the next adjacent :set of pulleys forming an angle with such axis, there being more than twosetsol pulleys in each block, each of more than two pulleys each and a supplemental pulley block pivotally connected to one .ofthe main pulley blocks and provided with a. single pulley, and a rope having one end secured'lto one of the main blocks, trained successively through a pulley of one of the main blocks and then through a-pulley of the other main :blockand having its free end threaded through the single pulley of the supplementalblock.

,2. .-A block :and tackle comprising an upper and a lower block, each block provided with more than two. sets of pulleys, each set having .an axis 'of rotation'fixed relative to :its associated block, and :each set comprising more than one pulley rotatable about its associated axis independently .of all the other pulleys of the set, the axis ofwrotation of each set intersecting a single vertical axis of reference and disposed one above the other and one of each pair of adjacent axes when projected vertically into the plane of the other forming an angle therebetween equal approximately to 180 divided by the number of sets of pulleys in the associated block and a pulley rope threaded successively through the pulleys of the two blocks.

3. A block and tackle comprising an upper and a lower block, each block provided with more than two sets of pulleys, each set having an axis of rotation fixed relative to its associated block, and each set comprising more than one pulley rotatable about its axis independently of all the other pulleys of the set, the axis of rotation of .each pulley intersecting a common vertical axis and disposed one above the other and a pulley rope threaded successively through the pulleys of the two blocks with the lengths of rope between the blocks threaded first through the sets oi pulleys nearest to each other and then succes sively through the sets of pulleys next nearest to each other and finally through the sets of pulleys farthest separated from each other.

.. v4. In a block and tackle, two pulley blocks, each of cylindrical form and disposed in axial alignment, each block provided with a plurality of sets of pulleys, each set comprising more than one pulley and having a common axis of rotation, each pulley having its opposite sides projecting laterally beyond the adjacent side of its associated block and each set having its axis extending across the vertical axis of its associated cylinder and each pulley axis being in circumferentially spaced relation with the axis of its next adjacent pulley considered vertically and a pulley rope threaded first through all of the pulleys of a pair of vertically related sets, one in each block and then through all of the pulleys of another similarly related set and the lengths of said rope between the blocks being spaced and forming a polygon having a number of sides equal to twice thenumber of sets of pulleys in one of the blocks.

5. A pulley block provided with more than two sets of pulleys, each set having an axis of rotation fixed relative to the block and comprising more than one pulley each rotatable about its associated axis independently of all the other pulleys, said axes intersecting a common vertical line and disposed one above the other, each one of a pair of adjacent axes of each block when projected vertically into the plane of the other forming an angle therebetween equal approximately, to 130 divided by the number of sets of pulleys.

6. A pulley block of cylindrical form with opposite sides provided with transversely aligned slots, a pair of side plates extending chordinally across the cylinder and projecting at opposite edges beyond the same, and a plurality of pulleys mounted on. an axle fixed to the cylinder and said pulleys fitted between the side plates and said side plates coacting to limit axial play of the pulleys.

7. A hollow pulley block of cylindrical form, a pair of side plates extending chordinally across the block projecting beyond the cylindrical surface of the block and forming guide plates for the pulley parts which project exteriorly of the outlines of the cylindrical block, an axle extending across the block and secured thereto and extending through the side plate and a plurality of pulleys rotata ly mounted on the axle and fitted between the side plates and held thereby from axial movement.

8. A pulley block of cylindrical form and slitted to form two superposed pairs of transversely aligned slots, with a slot of one pair circumferentially offset slightly from the slot of the other pair, each pair of aligned slots provided with a pair of side plates extending chordinally across the cylindrical block and having opposite edges fitted in the associated slots and projecting outwardly from the cylindrical block, a set of pulleys for each pair of slots fitted between the associated pair of side plates, the projecting edge of a plate of one pair of slots forming an acute angle with the adjacent projecting edge of one of the side plates of the other pair of slots to form a V-guideway for one of the lengths of an associated pulley rope.

9. A hollow pulley block of cylindrical form provided with a plurality of vertically extending slots in superposed and circumferentially displaced relative position and arranged in opposing pairs, reinforcing side plates extending in pairs across the block, projecting through each pair of slots and connecting opposite sides of the block and tending to resist torsional twisting of the cylindrical block and a pulley fitted between each pair of side plates.

10. In a device of the class described, the combination of a pair of parallel cheeks, a pulley mounted between the cheeks, a suspension pin connecting the cheeks adjacent their upper ends and adapted to engage a support for the device, a pulley block of cylindrical form into the upper end of which the lower ends of the checks intrude, a pair of straps having their lower ends lapping the outside of the cylindrical block and tending to prevent spreading of the upper end of the cylindrical block, a pivot pin extending through the upper end of the cylindrical block and through the lower ends of the cheeks and straps and an axle passing through the upper ends of the straps, through the cheeks and pulley and forming an axle on which the pulley is rotatably mounted.

11. In a device of the class described, the combination of a pulley block of cylindrical form, a pair of straps having their upper ends secured to the outside of the block and depending therefrom, a pulley axle extending across the block and extending through the upper portion of the straps, a bolt extending across the lower portion of the block and extending through the straps, and a spacing sleeve on the bolt and extending between opposite sides of the block and tending to resist collapsing of the lower end of the block when a pull is exerted on the straps.

12. In a block and tackle, the combination of two pulley blocks and a pulley rope threaded therethrough, each block provided with more than two sets of pulleys in vertically spaced relation, each set of pulleys comprising a plurality of pulleys which are mounted for rotary movement about a common horizontally extending axis and each of said axes when projected into a plane containing any one of the axes extending at an angle to every other axis in the associated block and said sets of pulleys of each block arranged to group the lengths of the rope between the blocks approximately in a circular arrangement hanging free of each other.

13. In a block and tackle, the combination of two pulley blocks each of cylindrical form and disposed normally to hang concentric relative to a common vertical axis, each block provided with rope threaded through all of the pulleys of each block.

15. In a block and tackle, the combination of two pulley blocks, each block provided with more than two sets of pulleys, in vertically spaced relation, each set of pulleys comprising a plurality of pulley wheels mounted in parallel relation to each other on a common axle and each pulley wheel extending in a plane at an angle to the planes containing the pulley wheels of every other set.

16. A pulley block including a single cylindrical shell provided with a plurality of vertically spaced sets of pulleys, each set comprising a plurality of parallel pulley wheels, with the wheels of each set mounted for rotary movement about a common horizontal axis, each axis substantially intersecting a common vertical line extending in non-parallel relation and spaced vertically from every other axis.

' OSKAR KOZLOVSKIS.