CA1097266A - Upright for lift truck - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
A truck upright having a fixed upright section, one or more telescopic upright sections, and a load carrier mounted on an inner upright section. An asymmetric lift cylinder assembly is located adjacent one side of the upright in a position which pro-vides improved overall operator visibility through the upright.
The lift cylinder is adapted to be operatively connected at its upper end to a telescopic upright section for operating lifting chain structure which traverses laterally across the upright and which is reeved on spaced and rotationally aligned sprockets sup-ported either from a telescopic upright section or from the lift cylinder assembly, the one chain end structure being connected in the two stage upright hereof substantially centrally of the lift-ing or fork carriage, and the other chain end structure being fixedly secured outwardly of one side of the cylinder assembly to a member, such as to the adjacent outer upright rail. The cylin-der assembly is operatively connected to the telescopic upright section at or near a location which is one-half the projected distance between the chain end connections, or in a broader sense, approximately midway between the vertical central plane of the load carrier and the chain end connection outwardly of the cylinder assembly. In the triple stage upright as disclosed the one chain end structure is connected substantially centrally of the inner telescopic upright section (load carrier) on which is mounted the lifting or fork carriage, and a cantilevered cylinder is mounted in the inner upright section for elevating thereon the lifting carriage to a full free-lift position. A fluid pressure supply hose is connected between the base ends of the primary and secondary cylinder assemblies, and is reeved in an inverted U-shaped loop between opposite sides of the upright. Otherwise Abstract continued:
the same principals of construction apply as expressed above.
In any multi-section upright using this invention, whether two of three or more sections and regardless of other variations in upright design, the asymmetric cylinder assembly is located such that it projects at least partially into the area of interference by the adjacent side of the upright when in a retracted or collapsed position with the visibility of the operator from his normal line of sight through that side of the upright.

Description

~0g~66 1 Back~ the Invention In li~t trucks oE the type contempla~ed it has been one of the most persistent problems encountered in the art over the years to provide an upright construction which both affords the operator of tha truck good visibility through the upright and which is of relatively simple and low cost construction, particularly in triple and quad sta~e uprights. Heretofore various means have been devised for improving, or which may in-cidentally improve, operator visibility through telescopic uprights in lift trucks, including upright structures such as are disclosed in U.S. Patents Nos~ 2,39~,458; 2,456,320; 2,855,071; 3,394,778;
3,830,342, and German Patent 1,807,169, but none have satisfied adequately the above criteria.

My invention is a major step forward in the art over any prior known telescopic upright structure for lift trucks ; in which operator visibility through the uprigh~ and relative . .
simplicity and low cost are of importance. In particular my in-vention provides an asymmetric lift cylinder assembly connected,or adapted to be operatively connected under certain conditions, at its upper end to a telescopic upright section and located adjacent one side of the upright in such a manner that it projects at least partially into the area of interference by the adjacent side of the upright when in a retracted or collapsed position with the visibility of the operator from his normal line of sight through , that side of the upright. The cylinder assembly operates a flexlble lifting element (chainl which is reeved to traverse ~ across a portion of the upright on a Pair of rotationally aligned ! spaced sheaves or sprockets twheel elements) supported from the ~ne telesco~csection or from the lift cylinder assembly. One end of theflexible lifting element, as disclosed, is connected substantially centrally of a load carrier mounted for elevation ~'3t~26~

1 on the one telescopic section and the other end structure of the flexible lifting element is connected to a relatively fixed member outwardly of the one side of the cylinder assembly, the cylinder assembly being connected or adapted to he operatively connected to the one telescopic section at or near a locatio~
which is one-half the projecked distance between the end connec-tions of the flexible lifting element~ In a broader se~se, the cylinder assembly is operatively connected to the one section ; approximately midway between the vertical central plane of the load carrier and the connection of the ~lexible element outwardly of the cyclinder assembly.
It is an important principle of the invention that the lifting force of the asymmetric cylinder and associated structure apply at least approximately balanced lifting force moments on the upright structure in the transverse plane of the upright.
It is a primary object of the invention to provide I
improved and novel upright structures for use on lift trucks and ~
the like in which improved operator visibility is provided -~ ;
through the upright.
Another important object is to provide improved operator visibility in such upright structures while providing an upright of relative simplicity and low cost. i Other objects, features and advantages of the invention will readily appear to persons skilled in the art from the detailed description of the invention which follows.
Brief Description of the Drawin~s ,:
FIGURE 1 is a front view of an industrial lift truck showing a load carriage lowered to the bottom of the telescopic upright section of a two-stage upright, and exemplifying ~he 3~ improved operator visibility which is pxovided through the upright;
FIGURE 2 is an cnlarged full rear view of the upright '' 726~ , I shown in FIG. 1. with tlle uprlght dismounted ~rom the truck;
FIGU~E 3 is an enlarged plan view of the upright shown in FIG. 2;
FIGURE 4 is a somewhat schemati~ed rear view reduced in scale and shown extended to full elevation;
FIGURE 5 is a plan view of the upright which shows a modi~ication of the structure shown in FIG. 3 FIGURE 6 is a plan view of the upright which shows another modification of the structure shown in FIG. 3;

FIGURE 7 is a view similar to FIG~ 1 showing a tripla stage upright construction;
Figure 8 is an enlarged full rear view of the upright :;
shown in FIG. 7 with the upright dismounted from the truck;
FIGURE 9 is an enlarged plan view of the upright shown in FIG. 8; ~:
- FIGURE 10 is a somewhat schematized rear vlew in reduced ~ , , I' ~ scale of the upright shown in FIG. 2 wherein the load carriage is :~ ~
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elevated by a primary cyl.inder to a full free-lift position; ~

FIGURE 11 is a somewhat schematized rear view of the ~:

upright at partial elevation;

FIGURE 12 is a partially cut-away rear perspective view of the upright with the load carriage at floor level;

Detailed Description Referring to the drawings,and first to FIGS. 1-4, a ~ , :
conventional industrial lift truck is shown at numeral 10 having a frame and body construction 12 mounted on a pair of ` steering wheels, not shown, at the rear end thereof and a pair of traction wh~els 14 forwardly thereof, and ~: 30 - 3 -'' ' ~: .
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~ L~9 ~26~j embodying suitable power components which may be either electric or gas for operating the truck from an operator's compartment 16. An operator is illllstrated in FIG. 1 at numeral 18 as he would appear when operating the truck to an observer in front of the truck.
The upright assembly of the present invention is illustraked generally at numeral 20~ the assembly being mounted on the -truck in kno~n manner, A fixed mast section 21 includes a pair of transversely spaced opposed ohannel members 22 arranged to receive a single telescopic mast section 24 formed of two laterally spaced I-beams 26~ mast section 24 being ~ ~
lo guide roller supported in mast section 21 and arranged for longitudinal ~-movement relatiYe thereto. A load or fork carriage 30 having a pair of ;~
transverse support plates 31 and 32 is guide roller mounted in known ~anner for elevation in the telescopic upright section.
Mast section 21 is cross-braced for rigidity by means of uppe~ and lower transverse brace members 36 and 38, and telescopic section 24 is cross-braced by upper and lower transverse members 40 and 42.
The I-beam mast section 24 is nested within the outer section 21 in ~;
known manner such that the forward flanges of the I-beams 26 are disposed outside of and overlapping the forward flanges of channels 22, and the ;
rear ~langes of the I-beams are disposed inside the adjacent channel portions and forwardly of the rear flanges of channels 22, pairs of rollers being suitably ~ounted between said a~jacent pairs of the I-beams and channels for supporting the I-beam telescopic section longitu~
dinally and laterally for extensible movement relative to the fixed ~ channel section. The support and guide- rollers of each said pair are`~ illustrated in FIG. 3 at numerals 33 and 34, while the upper rollers mounting the load carriage 30 in the inwardly facing channel portions of the I-beam section are illustrated at 37. Particulars of the nested offset I-beam upright structure, the mounting of the load carriage thereon, and the details of structure and mounting o-f guide and support roller pairs are explained in detail in Patent No. 3~213,967.

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~ s illustrated, a cylinder suppor-t block 50 is secured on brace 38 near the right hand s;de therc-~of and adjacen-t and partially behind the one I~beam rail 26, a hydraulic fitking 52 being mounted on -the block to cor,lmunicate E~ressure Eluid to and from a cylinder 54 of a lift cylinder assembly which is mounted on the block for co~munication with a lift truck hydraulic system, not shown. As extensible piston rod 56 is connected to mast s~ction 24 at the upper end by a bracket 53 which is secured to the piston rod end. Bracket 58 is connected, as by welding, to brace 40 and to a cantilevered support member 60, said member being secured to the rear flange of the adjacent I-beam rail. A
chain anchor block 62 is secured centrally of lower fork carrier plate 32 to which is secured at anchor 63 one end of a lifting chain 64, or other flexible lifting means, which extends upwardly and over a pair of spaced sprockets or sheaves 66 and 68, and then downwardly to a fixed anchor connection 70 located in a predetermined position adjacent the outer end of a stepdown support and braae plate 72 of brace member 36, the horizontal end - portions of brace 36 being connected by a vertical plate 74.
Sprocket 66 is mounted for rotation on a stub shaft 67 which is secured in a support block member 76 in turn secured to brace 40.
(Porconvenience herein sprocket or sheave (wheel) means may be referred to as "sprocket" or "sprocket means", it being under-~ stood that any suitable wheel means for performing a similar ; ~ function is intended to be included.) Sprocket 68 is si~ilarly mounted on a stub shaft 69 on support member 60, the lifting chain and sprockets being mounted on a bias to the upright assembly as is best shown in FIG. 3.
Although I have shown but a single relatiYely heavy chain 64, it should be understood that in practice it may well . .

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1 be found preEerably ~or safety reasons to use two or more smaller chains reeved in substantially the same manner as is single chain 64 on modi.Eied single sproc]cets or on multiple s.ide-by-side sprockets as desired. Reci-ta-tions in the claims of "sole flexible lifting means", and the like, i.nclude such mutliple side-by-side lif-ting alements which will perEorm the same func-tion as does the single liEting element 64 shown in the drawing. ;~
In order to substantially balance the force ~omentsacting in a transverse plane on the embodiment of the upright assembly as disclosed, ' ', ' ~: ~
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~he connection of the chain to anchor block 62 should be located at or substantially at the transverse center of carriage 30, and the connection of piston rod 56 to bracket 5~ in combinat;on w;th the location oF chain anchor 70 should be such that the piston rod is connected to the bracket at or near one-half the distance between the chain anchor locat~ons as projected in the transverse plane of the uprigh~. Then, the forces pass~ng through upright sections 21 and 24 create substantially no unbalanced moments or a calculated small unbalanced moment in the trans-verse plane of the upright, as v;ewed in FIGS. 2 and 39 for example, because the cylinder assembly is centered or approximately centered ~ between the said projected locations of the chain anchors.
; As wi71 be understood by persons skilled in the art, in a free body force mo~ent system, neglecting the weight of inner upright section 24, the vertically directed forces acting on the upright in the said projected transverse plane with the piston rod centered as aforesaid comprise a one unit force in an upward direction at each chain end, a one unit force in a downward direction in each vertical run of chain, a two unit force directed upwardly at the center o~ the piston rod connection to plate 58, and a two unit force directed downwardly at the center of the cytinder on support 50. Thus~ the upright functions in theoretical force moment balance. Of course, such theoretlcal conditions do not exist in practice, and side thrusts or torque loading on the upright such as result from unbalanced ~oments e~fected by o~f-center loads on the fork, for example, may be resisted by upper and lower pairs of carriage side thrust rollers 80 operating on the outer flange edges of . .
beams 26 ir known manner.
It should be noted that the weight of the inner upright section 24 will impart a sllght unbalanced moment in a counter-clockwise direction, as seen in FIG. 2~ on a centered asymmetric cylinder assembly, so that if desired the latter unbalanced moment may be compensated by adjusting the location of the cylinder assembly slightly inwardly of its said central position between the projected chain anchor locationsO On the ' :

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1 other hand any such inward acljustment of the cylinder assembly location may tend to interfere with maximum visibility through tha-t side of the upright, depending upon -the operator's normal location on the truck. Also, any such unhalanced Eorce moments are relatively minor and should, in most upright designs, be readily acceptable in the overall design, which usually includes some provision for resisting side thrus-t such as by rollers 80.
The designer o~ uprights of various widths, depths, seat locations, and the like may choose any one of a number of 10 viable combinations of such structure within the scope of my `~
invention. It should there~ore be understood that reci~ations in :
the claims hereof relating to the substantial or approximate balance of force moments in the upright, or to the asymmetric position of the cylinder substantially or approximately centered between the projected chain anchor locations or the like, shall be interpreted to include a range of posltions of the cylinder assembly between the sprockets which best effects the desired result of good operator visibility through the upright and adequately balanced force moments acting on the upright in ~ 20 operation. -: The design is such that the location of the cylinder assembly at one side of the upright combines with the location of ; ~ :
the operator, preferably offset a predetermined distance to the .
opposite side of the longitudinal axis of the truck, ~o provide an operatoris line o~ sight through the upright on the side at which the cylinder assem~ly is located so that the cylinder assembly interferes a relatively small amount or not at all with . the operator's visibility through that side of the upright. In other words, the cylinder assembly projects at least partially into the area o~ lnterference by the adjacent side of the upright ~ 7 ~

, 7~6i6 1 when in a retracted or collapsed pos.ition ~ith the visib:ility of the operator from his normal line of s:ight through that s.ide of the upright.
The pxinciples of the upright design as described hereinabove may be appl.ied to many and various types and designs oE multiple stage uprights, including, without limitation, free~ t and triple stage uprights as described later herein.

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References made in the specification and claims hereof to the longitudinal and/or transverse pl~nes of one side of the upright, or of the vertical rails of the upright, or terms of similar import, shall have the f.ollowing meanings:
The longitudinal plane of the one side of the upright shall mean a -ll r ~ n I ~ f~
ertical plane extending longitudinally of the upright assembly bounded by the outer and inner sur~aces of the vertical rail assembly on one side of the upright, while the transverse plane of the upright or of the - i.
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one side thereof shall mean a~vertical plane extending transversely of ~ :
the upright assembly bounded by the ~ront and rear surfaces of the vertical rail assembly of the upright~
Referring now to the modi~ications shown in FIGS. 5 and 6, I have shown exemplary modified structure wherein some of the parts are or may be the same as in FIG. 3, and these parts have been numbered the same as in FIG. 3. Exemplary similar but modified parts are identified by the same numeral as in FIG. 3, but carry a single or double prime designation, as~ ~or example, element 72,72' and 72" as between FIGS. 3, 5 and 6 ;~; respectîvely. Wholly new parts are identified by new numbers. For example, a long cantilevered new anchor block is identified by numeral 90 in FIG. 5, but by numeral 62' in FIG. 6 in which, in combination with support block 76' for mounting sprocket 66, the latter parts represent basically merely a difference in configuration when compared with the similar parts 62 and 76 in FIG. 3.
Referring now in detail to FIG. 5, the modified structure comprises mainly a relocation of sprockets 66 and 68 so that they are mounted in transverse relationship to the upright which effects incidentally a ~ shortening of the chain as shown at 64'. In order to accomplish this - mounting arrangement while maintaining the lift cylinder assembly 54955 in a similar adjacent ~elationship to the right hand side of the upright, the cylinder assembly ~s located somewhat longitudinally rearwardly of the position shown in FIGo 3 out of the transverse p1ane of the adjacent one side of the uprlght~ The cylinder assembly is thus 10cated by securing it between cylinder support block 50' and bracket 58', the f ~ _ ~

~72~ii6 latter being secured, as by ~elding, to the rear side of upper brace 40' of inner mast section 24 which is secured to the rear ~aces of the rear flanges of I-beams 26 and whlch extends outwardly o-f the right side of the upright as seen in FIG. 5 for supporting thereon adjacent the outer end the sprocket 68, as shown. Sprocket ~6 is aligned for rotation with sprocket 68 transversely of the upright, it being ~nounted also from the rear surFace of brace 40', li~t~ng chain 64' being reeved on the sprockets and secured at its one end at anchor 70 to step-down support p7ate 72' of modified con~iguration and secured at its opposite end at anchor 63 lo to an elongated cantileYered chain anchor support 90 which is s~cured from the rear of lower fork carriage plate 32, the same as is anchar block 62 in FIGS. 1-4. Sprockets 66 and 68 are cantilever supported ~rom brace ~0' in this embodiment by the stub shafts 67 and 69~ The lower brace member 42' secured between I-beams 26 is of a bowed config :~
uration as shown in order that anchor support member 90 may clear brace ~-42' during movements of the fork carriage near the lower end of the I -~
beam upright sectionO The mounting relationship between support block : 90 and a lower brace 38 of outer section 21 is~ of courseS such that there is no inter~erence between the support block and brace when the : 20 fork carriage is at its lowermost position in the upright.
Referring to FIG. 6, a modified construction is shown wherein provision is made for sprockets 66 and 68 to be mounted in aligned transverse relationship of the upright in a forward location relative to the location thereof shown in FIG. 5. In this construction a location .
of the lift cylinder assembly in relation to the adjacent one side of the upright may be provided~ as shown, which is approximately the same ~:
relative location as shown in FIGS. 1-4. Thus, the transverse upright braces 36, 38, 40 and 42 may be the same as in FIGS. 1-4, as shown, except that the configuratiorl of the step-down portion 72" of brace 36 ~ 30 is altered to provide a suitable location for anchor 70~ the cylinder :~
: assembly being mounted from support block 50 and secured at the upper ~ ;
end to bracket 58".

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As mentioned above sprocket 66 is supported From block member 76' and the chain is secured at anchor 63 to anchor b10ck 62', similarly as in FIGS. 1-4 except as modified to provide for a transverse aligned relationship between the sprockets. Sprocket 68 is mountetl from a ;~
cantilevered support plate 92 which is secured a~ its inner end to the outer surface of the forward fldnge of the one I-beam 26 and above the upper side thrust rollers 80.
In the operation of the various embodiments of FIGS~ 1-6 pressurized fluid is conducted to or exhausted from the single-acting lift cylinder assembly 54~56 which effects a simultaneous elevation or lowering, as the case may be, of fork carriage 30 in telescopic upright section 24, and of the latter upright section in fixed section 21 without free-lift o~ the load carriagQ in relation to upright section 24 during elevation.
The load carriage is elevated at a 2:1 ratio in relation to section 24 from the position shown in FIGS. 1 and 2 to that shown in FIG. 4, section ~4 being elevated with the piston rod in relation to outer section 21.
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Referring now to FIGS. 7-12, similar parts of the truck chassis and ~, :
body are numbered the same as in FIG. 1.
The triple stage upright assembly shown at numeral 100 comprises a fixed mast section 102 which includes a pair of transversely spaced ~` opposed channel members 104 arranged to receive an intermediate tele-scopic mast section 106 formed of two laterally spaced I-beams 108, mast section 106 being guide roller supported in mast section 102 and arranged ; ~or longitudinal movement relative thereto. An inner mast section 110 formed o~ two laterally spaced I-beams 112 is similarly guide roller supported in mast section 106 and arranged for longitudinal movement ~ relative thereto. A load or fork carriage 114 having a pair of transverse -- support plates 116 and 11~ is guide roller mounted for elevation in the nner upright section 110, all in known manner.
3~ Mast section 102 is cross-braced for rigidity by means of upper and lswer transYerse bnace members 120 and 122, intenmediate telescopic ~ section 106 is cross-braced by upper and lower transverse ~e~bers 124 .
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and 126, and inner sec-tion 110 is cross-braced by upper, intenmediate and lower transverse members 128, 130, 132, and 13~, members 130 and 132 also serving to support the primary lift cyl;nder, as will be explained.
The I-beam mast section 106 is nested within the outer section 102 in known manner such that the forward flanges of the I-beams iO~ are disposed outside of and overlapping the forward ~langes oF channels 104, and the rear flanges o~ the l-beams are disposed inside the adjacent channel portic,ns and forwardly of.the rear flanges of channels 104, pairs of rollers being suitably mounted between said adjacent pairs of the I-beams and channels for supporting the I-beam telescopic section longitudinally and laterally ~or extensible movemen~ relative to the fixed channel section. In a similar manner, inner I-beam mast section 110 is nested within inter~ediate section 106 for extensible movement relative to the intermediate I-beam section. The support and guide rollers of each said pair are illustrated in FIG. 9 at 140, 142 and 144, 146, while the upper rollers mounting the load carriage 114 in the inwardly facing channel portions of the inner I-beam section are il-lustrated in FIG. 9 at 148. Certain particularities of the tripla-stage nested offset I-beam upright structure, the mounting of the load carriage thereon~ and the details of structure and moun~ing of guide and support roller pairs are explained in detail in Patent 3,213,967.
A primary cantilevered lift cylincler assembly 150 is supported centrally of inner upright section 110 on brace members 130 and 132 by brackets 152 and~ ~ secured, as by welding to the cylinder and secured by studs to the transverse brackets 130 and 132 (FIG. 12). A single sprocket l~j6 is mounted for rotation by a bracket 158 at the end of a piston rod 1609 a lifting chain 162 being reeved on the sprocket and ;~
secured at one end to an anchor plate 164 located on the cylinder, and at the opposite end secured centrally of carriage plate 118 by an anchor block 166 (~IG. 9). The hydraulic lift cylinder 150 is substantially one-half the length of the inner upright section and when extendecl actuates the fork carrlage at a 2:1 ratio to a full free-lift position ;, ~7Zt~i6 ~ -as shown in FIG. 10 prior to the elevation of interrnediate and inner upright sections 106 and 110 by a secondary asymmetric hydraulic lift cylinder assembly 170, shown in a position of partial extension in FIG.

The cylinder 17û is supported near the bottom from brace member 122 by a collar 172 welded to the cylinder and to the top edge of the brace member, the piston rod 174 being secured by a pair oF studs 178 to a block member 180 which is welded ;to the rear surface of brace member 124, thus supporting the cylinder assembly ~rom the top and bottom 10 portions. A junction block 182 is located at the bottom of the cylinder for conveying pressure fluid to and from the cylinder from a hydraulic system, not shown, it being also connected to a junction block 184 of the primary cylinder by a fitting 186 in block 182, non-flexible conduits 188 and 190, and a flexible conduit 192 which connects conduits 188 and 190 and which is reeved on three sheaves 194 mounted for rotation in a bracket 196 which is supported from brace member 124 by a bracket 198.
The sheaves and conduit assembly are mounted in an inverted U-shaped , ~, position behind or adjacent certain upright rails so that interference thereof with visibility of the operator is minimized.
A chain anchor block 200 is secured centrally of inner upright transverse brace member 132 at an anchor connection 202 o~ a secondary lifting chain 204 which extends upwardly and over a pair of spaced sprockets 206 and 208, and then downwardly to a fixed, anchor connection 210 located in a predetermined position adjacent the outer end o~ a " .
~; step-down support and brace plate 212 of brace member 120, the hori-zontal end portions of brace 120 being connected by a vertical bar 214.
The sprockets are mounted for rotation as in the two-stage upright on stub shafts which are cantilever mounted in and secured to transverse ~ . ~
brace member 124.
The force moments acting on the upright assembly are, of course, balanced in respect of the operation of centered primary cylînder 150, ~; and in respect of operation of asymmetric cylinder 170,174 operating centrally or approximately centrally between the sprockets and having . ~ .

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the inner end of chain 204 connected substantia11y centrally of the inner upright. The forces passing through the respective upright sec tions create substantially no unba1anced moments, or create a calculated unbalanced moment in the transverse p`lane of the upright ~n a m~nner similar to that described in detail above in respect of the two-stage upright.
The structure and operation of the triple stage upright as disclosed will now be apparent, particularly when taken in conjunction with the more detailed description of the principles oF my invention and of some lo of the aYailable design variations thereof described above in connection with the two-stage upright. I have found that in order to achieve most ;~ desirable results in terms of operator visibility, that cylinder 170 should be located such that it proJects a distance into the aforementioned area of interference by the adjacent side of the retracted upright which ;
is equal to or greater than the radius~of the cylinder.
In operation to elevate the upright from the position in FIG. 8 to ~ `
that in FIG. 11, ~or example, pressure fluid is delivered by the hydraulic system simultaneously to cylinder assemblies 150 and 170 and, as is known, the cylinders operate automatically in a sequence related to the ~; 20 loads supported thereby, whereby cylinder 150 functions initially to elevate load carriage 114 in inner upri~ht section 110 to the full free-lift position illustrated in FIG. 10 at 2:1 ratio to the movement of piston rod 160. At the termination of this init~al stage of operation the pressure ~luid automatically sequences asymmetric cylinder 170 to ~; elevate the entire telescopic upright structure in outer section 102 while the load carriage is maintained by ~rimary cylinder 150 in the aforementioned full free-lift position; i.e.~ the direct connection of cylinder assembly 170 to intermediate section 106 effects an elevation thereof in section 1O2J as shown in partial elevation in FI~. 11, and simultaneously effects through the reeving and connection of chain 204 . , .
to inner upright section 110 an elevation thereo~ at a 2:1 movement ratio relative ~o section 106 to the position shown in FIG. Il, and : -13-`

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thence to a position of maximum elevation if the operator main-tains the supply o~ pressure fluid from the hydraulic system.
Lowering oE the upright is effected by venting the cylinders to the rluid reservoir, whereby a reversal of the above-mentioned sequencing occurs as cylinder assembly 170 first fully retracts to the position of FIG. lO, subsequent to which cylinder 150 xetracts the load carrier to the FIG. 8 position.
It will be understood by persons skilled in the art that many other design varia~ions in the upright designs than those identified and described previously may be found feasible without departing from the scope of my invention.
For example, although the basic design of the upright dis~
~` closed in all embodiments herein as being of the offset I-beam rol-ler mounted design is preferred because of the space provided be-hind the rear flange or glanges of the I-beam vertical rails for partial nesting of the asymmetric cylinder therein,as seen best in FIGS. 3, 6 and 9, it will be appreciated that the invention may be also used with many other known upr~ght designs, including coplanar (not offset) roller mounted channels or I-beams, fullv nested roller mounted I-beams inside of outer channels, non-roller mounted . .
~ ~ sliding inner channel in outer channel, a telescopic upright section ~;
mounted outwardly of an inner mounted fixed upright section, and the like. ~ `
The location of the fixed chain anchors 70 and 210 may,o course, be varied in different upright designs as desired,such as at di~ferent selected vertical locations on the outer rail,or loca-ted on a cantilevered anchor support which may be secured to the asymmetric cylinder! or in the case of an upright mounted from certain types of lift trucks without provision for fore and aft tilting thereof, the anchor can be located on the truck frame.
In the latter design it may be feasible, of .~

~ 7~6 course, to ~ount the bottom of the asynlmetric cylinder assembly also from the truck ~rame instead of directly from the bottom of the fixed upright section.
It may be found advantageous in some designs to mount the asymmetric cylinder assembly so that the cylinder 54 or 170 elevates on a fixed piston rod 56 or 174J in known ~anner; i.e., by reversing the position of the assemblies as shown, and utilizing the piston rod also as a pressure fluid conduit to the cylinder to be actuated.
; Depending upon such things as the axial distance of the operator from the upri~ht, the width of the upright, or the transverse position of the operator when seated or standing in a normal operating position on different lift truck types, the most desirable precise location of the asymmetric cylinder assembly based upon the various factors will be established, many of the major ones of which are discussed above. As noted previously the most critical combination of ~actors affecting the selection of a cylinder location is operator visibility and force moment balance on the upright, both of which may be compromised~from the ideal ~ w~thin the scope of my invention as required to effect the most desirable ; ~ combination. In this connection it will be understood that the asym~
~ 20 metric cylinder assembly may in different sizes and designs of uprights ,! desirably project partially into both the longitudinal and transverse planes of the one side of the upright, as best seen in FIGSo 3~ 6~ and g In a relatively wide upright, for example, and with the opera~or ~-located reldtively close to the upright in a forward direction and well off~center to the left thereof, i~ may be ~ound advantageous to locate the cylinder further forwardly than is shown in FIG~ 3, for example, necessitating a relocation thereof leftwardly and out of the longitudinal plane o~ the right side of the upright, in which event the cylinder would project partially into only the transverse plane of the upright without interfering unduly with operator visibility through the upright.
On the other hand~ it may be found under certain design conditions that ~ -- 1S
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the cylinder may be located further rearwardly so as to pr~jec-t into the longitudinal plane only, part;ally or even wholly/ of the one side of the upright, and not project at all into the transverse plane thereoF, as in FIG. 5 Again, it may be found desirab'le that the cylinder project into neither such plane, all within the scope of my inYention.
~ owever, before the particulars of any given upright design are finalized, it is important to understand that in any multi-section upright usin~ this invention, whether of two, three, or more stages, and ; regardless of other available numerous design variations such as are described herein, the asymmetric cylinder assembly should be located such that it projects at least partially, and preferably substantially, into the area of interference by the adjacent side of the upright when '` in a retracted or collapsed position ~ith the visibility of the operator from his nonmal line of sight through that side of the upright. Preferably the distance of cylinder projection into said'area of inter~erence should be equal at least to the radius of the cylinder, although this may not be achievable in certain standard or two stage upright design~
Although I have illustrated only certa~n embodiments of my inYention~
~ it will be understood by those skilled in the art that ~any modifications, ; 20 such as are discussed above, may be made in the structure, for~g and ' relative arrangement of parts without departin~ from the spirit and ~' scope of the'invention. Accordingly, I intend to cover by the appended claims all such modifications which properly fall within the scope of my invention, ~ :

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Claims (15)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. In an upright structure for lift trucks and the like having one upright section including transversely spaced vertical rails, a telescopic upright section including transversely spaced vertical rails mounted for elevation relative to said one section and an elevatable load carrier mounted for elevation re-lative to said telescopic section, the improvement comprising a sole asymmetric lift cylinder mounted in the upright structure which is operatively connected to said telescopic upright sec-tion, elongated flexible lifting structure operatively connected to said lift cylinder, to said one upright section and to said load carrier and having one end structure thereof secured a substantial distance outwardly of one side only of the lift cylinder and having the other end structure thereof secured to said load carrier, said lift cylinder together with said flexible lifting structure being adapted to elevate said load carrier relative to the telescopic upright section and the latter sec-tion relative to the one upright section, the lift cylinder being located substantially at one side of the upright structure such that it projects at least partially into the area of inter-ference by an adjacent vertical rail with the visibility of the operator from his normal line of sight through said adjacent vertical rail, the operative connection of said lift cylinder to said telescopic section in relation to said one and other end structures being such that at least approximately balanced lifting force moments act upon the upright structure in the transverse plane of the upright at least when a load is carried substantially centrally thereof.

2. An upright structure as claimed in claim 1 wherein the load carrier comprises a second telescopic upright section including transversely spaced vertical rails mounted for eleva-tion relative to said first mentioned telescopic upright section, a load carrier mounted for elevation relative to said second telescopic upright section, said flexible lifting structure having its said other end structure secured to said second telescopic section and actuatable with said asymmetric lift cylinder to elevate said first and second telescopic sections.

3. An upright structure as claimed in claim 1 wherein said flexible lifting structure is reeved on first and second wheel elements operatively connected to said lift cylinder, said first and second wheel elements being mounted in substantial longitudinal rotating alignment and spaced relation one to the other, said first and second wheel elements being mounted in such a manner that said other end structure of said flexible.
lifting structure is secured substantially centrally of said load carrier.

4. An upright structure as claimed in claim 3 wherein the load carrier comprises a second telescopic upright section mounted for elevation relative to said first mentioned telescopic upright section, a load handling carrier mounted for elevation relative to said second telescopic upright section, said flexible lifting structure having its other end structure secured sub-stantially centrally of said second telescopic section and actuatable with said asymmetric lift cylinder to elevate said first and second telescopic sections.

5. An upright structure as claimed in claim 1 where said lift cylinder projects into at least a portion of the longitudinal

Claim 5 continued ....
plane of an adjacent vertical rail on the said one side of the upright structure.

6. An upright structure as claimed in claims 1 or 2 wherein the location of said asymmetric lift cylinder is such that it projects substantially into said area of interference by an adjacent vertical rail.

7. An upright structure as claimed in claims 1 or 2 wherein said asymmetric lift cylinder is located intermediate said one and other end structures of said flexible lifting structure in such a manner that the lifting force of said lift cylinder is approximately midway between the central vertical plane of the load carrier and the effective location of securement of the said one end structure.

8. An upright structure as claimed in claims 1 or 2 wherein said flexible lifting structure is reeved on wheel elements, and the operative connection of said asymmetric lift cylinder to said first mentioned telescopic section in relation to said one and other end structures is such that at least approximately balanced lifting force moments act on the upright structure in the transverse plane of the upright.

9. An upright structure as claimed in claims 3 or 4 wherein the sole substantial interference with operator visibi-lity through that portion of the upright structure which com-prises said asymmetric lift cylinder and first telescopic section is a single run of said flexible lifting structure when the load carrier is lowered.

10. An upright structure as claimed in claims 1 or 2 wherein said asymmetric lift cylinder is connected at least

Claim 10 continued ....

approximately centrally of the projected one and other end structures of said flexible lifting structure.

11. An upright structure as claimed in claim 3 wherein the first wheel element is mounted intermediate the said spaced vertical rails and the second wheel element is mounted outwardly of the one side of the upright structure.

12. An upright structure as claimed in claim 2 wherein a second lift cylinder is adapted to elevate said load carrier relative to the second telescopic upright section independently of the elevation of the telescopic upright sections by said asymmetric lift cylinder and flexible lifting structure, a run of said flexible lifting structure which extends to said other end structure being located behind and in substntial longitudinal alignment with said second lift cylinder,

13. An upright structure as claimed in claim 12 wherein said second lift cylinder is a cantilevered cylinder operating a second sole flexible lifting structure which is operatively connected to the second telescopic section and to the load carrier for elevating the load carrier on the latter upright section, said second sole flexible lifting structure being in substantial longitudinal alignment with the said run of the first mentioned sole flexible lifting structure.

14. An upright structure as claimed in, claims 2 or 4 wherein a second lift cylinder is mounted for elevating said latter load carrier on said second telescopic upright section, and an inverted U-shaped conduit structure connects hydrau-lically the base ends of the asymmetric and second lift cylinders, said conduit structure being supported from the upper end portion of the first telescopic section.

15. An upright structure as claimed in claims 12 or 13 wherein an inverted U-shaped conduit structure connects hydrau-lically the base ends of the asymmetric and second lift cylinders;
said conduit structure being supported from the upper end portion of the first telescopic section.