Note: Descriptions are shown in the official language in which they were submitted.
~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
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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 :~ ~
:; .
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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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 ~
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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.
~ r~ C~ o nq /
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".
._ -; ~9-
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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.
~ .
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
.
'~ 1 0
~L~9~
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
;,
- 1 1
~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
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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
.~
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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
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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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