US 3418861 A
Description (OCR text may contain errors)
1963 J. H. NEWHOUSE SHEAVE ASSEMBLY Filed April 14, 1967 IN VENTOR JAMES H. NEWHOUSE ATTORNEY United States Patent 3,418,861 SHEAVE ASSEMBLY James H. Newhouse, East Leroy, Mich., assignor to Clark Equipment Company, a corporation of Michigan Filed Apr. 14, 1967, Ser. No. 631,002 1 Claim. c1. 74-2165) ABSTRACT OF THE DISCLOSURE A dual sheave assembly for reeving a pair of flexible conduits in the same plane. The sheave assembly is connected to the extendible ram of a lift upright and a pair of flexible conduits are reeved over the sheave assembly. The conduits are fixed at one of their ends to a stationary portion of the lift upright and at the other of their ends to the upright carriage or to a device carried by the carriage.
Background of the invention The field of art to which the invention pertains includes machine elements and mechanisms, and more specifically pulleys and elevator mechanisms.
When a pair of conduits are mounted on an upright to extend between the stationary upright portion and the carriage, the conduits sometimes are reeved over a pair of sheaves fixed to the upright ram in side by side relation. This arrangement, however, has the disadvantage of reducing visibility through the upright. Consequently, it is desirable to locate the pair of conduits in the same plane, but in order to do this provision must be made for the relative movement between the conduits due to the different radii of the arcs through which the conduits pass over the sheave in order to prevent scufling and wear between the conduits. Therefore, it is a principal object of my invention to provide :a sheave assembly which permits relative movement between a pair of conduits trained over the sheave assembly and located in a single plane.
Summary of the invention In carrying out my invention in a preferred embodiment thereof I provide a first sheave with a groove therein. The groove has an inner portion and an outer portion which is wider than the inner portion. Disposed in the groove is a second sheave which is rotatable relative to the first sheave.
Brief description of the drawing FIGURE 1 is a front-quarter perspective view of a lift truck embodying my invention,
FIGURE 2 is an elevational View on an enlarged scale of my invention, and
FIGURE 3 is a cross-sectional view of my invention.
Description of the preferred embodiment Referring to FIGURE 1, the reference numeral denotes generally an industrial lift truck which is mounted on a pair of rear dirigible wheels 12 (only one of which is shown) and a pair of front drive wheels 14 (only one of which is shown). Truck 10 includes an operators seat 16 and various controls located conveniently adjacent the seat, including a steering control wheel 18. Mounted at the front end of truck 10 is a conventional telescopic lift upright 20. Upright 20 includes a stationary portion 22 formed by a pair of vertically disposed inwardly facing channels 24 which are connected by cross braces 26. Telescoped in stationary portion 22 is an inner slide 28 which is movable vertically. Movable vertically along inner slide 28 is a carriage 30. Connected to carriage 30 is a pair of chains 32 which are reeved over a pair of sprockets connected to a cross arm member 34 which is 3,418,861 Patented Dec. 31, 1968 "ice fixed to the top of the extensible portion of an extendible ram 36 that is disposed intermediate channels 24. The ends of chains 32 which are remote from carriage 30 are fixed to cylinder 38 of ram 36. All of the structure described thus far is conventional and does not by itself form any part of the present invention.
Sometimes, fluid operated attachments are mounted on carriage 30, and so means must be provided for supplying pressurized fluid to the attachment. In this regard a valve block 40 is connected to carriage 30 and is provided with suitable fluid outlet ports 42 through which suitable connections to the attachment may be made. A pair of fluid conduits 44 and 46 are connected at one of their ends to valve block 40, reeved over a pair of sheave assemblies 48 (only one of which can be seen) and connected at the other of their ends to cylinder 38 of ram 36 and hence to :a source of pressurized fluid carried by truck 10. It will be noted that each sheave assembly 48 is mounted for rotation on cross arms 34 outwardly of chains 32, as will be brought out in greater detail shortly.
Referring now also to FIGURES 2 and 3, one of sheave assemblies 48 is shown in greater detail. Each sheave assembly 48 includes a first sheave 50 which is generally annular in shape and has an opening 52 therein into which a bushing 54 is pressed so that sheave 50 may be mounted for rotation on a shaft 56. Sheave 50 is made up of two parts 58 and 60 which are held together by a plurality of rivets, or any other suitable fastening means. Also, sheave 50 has an outer periphery 64 in which a groove 66 is formed.
Groove 66 has an inner portion in which the sides 68 are substantially parallel and an outer portion in which the sides 70 are further apart than the sides 68 and are generally concave when viewed in cross section.
Disposed in groove 66 in the inner portion thereof is a second sheave 72 which is rotatable relative to sheave 50. Sheave 72 is generally annular in shape and has a shallow arcuate groove 74 in the outer periphery thereof. Sheave 72. is manufactured in one piece and placed in groove 66 before the two parts 58 and 60 of sheave 50 are riveted together.
As will be noted, two fluid conduits 44 and 46 are connected to valve block 40. Obviously, one of these conduits can serve as a supply conduit and the other as a return conduit. Where an attachment which has only a single function is mounted on carriage 30 nothing further is required insofar as fluid conduits are concerned. However, where the attachment has two functions which are fluid operated, such :as a rotating roll clamp which has a fluid motor for causing rotation and another fluid motor for controlling clamping, provision must be made for connecting the conduits 44 and 46 either to the fluid motor for controlling rotation or to the fluid motor for controlling clamping. This is accomplished by means of a solenoid operated spool in valve block 40. The solenoid which actuates the spool in valve block 40 is energized by means of an electric conductor 46 which is connected at one end thereof to the solenoid incorporated in valve block 40, reeved over sheave assembly 48 and fixed at the other end thereof to cylinder 38 of ram 36 and hence connected to a switch located adjacent the operators seat.
Since electrical conductor 76 is of substantially lesser diameter than fluid conduit 44, conductor 76 is reeved over sheave 72 while fluid conduit 44 is reeved over sheave 50 and engages sides 70 of groove 66 thereof. At this point, it will be seen that conduit 44 and conductor 76 both lie in the same plane, and so contribute to better visibility through upright 20. Further, since sheaves 50 and 72 are free to rotate relative to each other and conduit 44 is located away from conductor 76 there is no scrubbing orwear between conduit 44 and conductor 76, although conduit 44 and conductor 76 pass over sheave assembly 48 at different speeds due to the different radii of the arcs through which they pass over sheave assembly 48.
It will be understood that the foregoing detailed description is intended to be illustrative only, and that while only a single preferred embodiment has been described in detail that various modifications, changes and rearrangements in structure could be made without departing from the spirit and scope of my invention. For example, the sides of groove 66 could be tapered for the full length thereof. Further, while the preferred embodiment is shown in conjunction with two members which are reeved over the assembly it will be clear that the assembly could be modified so that more than two members could be reeved over it and still be free to move relative to one another without scrubbing or otherwise wearing on the adjacent members. Consequently, the limits of my invention should be determined from the following appended claims.
1. The combination comprising a shaft, a first sheave mounted for rotation on the said shaft, the said first sheave having a groove in the outer periphery thereof, the said groove having an outer portion and an inner portion, the said inner groove portion having a first pair of spaced apart sides, the said other groove portion having a second pair of sides which are spaced further apart than the said first pair of sides, a second sheave disposed in the said inner groove portion and rotatable relative'to the said first sheave, a first flexible elongated member reeved over the said second sheave, and a second flexible elongated member reeved over the said first sheave and engaging the said second pair of sides so that there is a clearance between the portions of the said elongated members which are reeved over the said sheaves.
References Cited UNITED STATES PATENTS 698,978 4/1902 Loffi 74-2303 FRED c. MATTERN, JR., Primary Examiner.
J. A. WONG, Assistant Examiner.