Note: Descriptions are shown in the official language in which they were submitted.
CA 02208472 1997-06-23
JNL/A9095CA/lOB
Title: Material Handling Implement.
Description of Invention
This invention relates to a material handling implement which may be
carried by a boom of a material handling vehicle. The material handling
implement may have a load engageable device which is engageable with a load
for example, a load engageable device may comprise a pair of forks of each of
which may be received in, for example, a socket of a pallet or the like or it
maybe
of a block tine type of the kind commonly used in the USA or maybe any other
suitable load engageable device.
The material handling vehicle may be of the kind, hereinafter referred
to as being of the "kind specified" comprising a structure having ground
engageable propulsion means and a material handling means comprising a boom
mounted on the structure for raising and lowering swinging movement relative
to
the structure and driven for said raising and lowering movement by a first
drive
means and said boom being extendable and being driven for extension or
retraction by a second drive means and a material handling implement carried
by
an outer end part of said boom.
Generally it is desirable to be able to move the loading engageable
device of the material handling implement in a sideways direction for example
sideways generally normal to a boom to which the material handling implement
may be attached so as to provide a side shift facility to facilitate sideways
alignment of the loading engageable device with the load to be handled by the
implement.
Such a side shift facility is particularly useful when the implement is
intended to be carried by a boom of a material handling vehicle particularly
when
it is of the kind specified.
When the implement is intended to be used on a rough terrain
material handling vehicle the load engageable device is provided so that it
can
move or float relative to the vehicle to facilitate engagement with the load
even
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when the vehicle is not accurately in aligned with the load by virtue of being
provided on rough terrain.
It is desirable that the material handling implement is provided with
such a side shift facility which is capable of attachment to or dis-assemble
from
a material handling vehicle.
It is also desirable to minimise the additional weight to be carried by
such a vehicle.
An object of the present invention is to provide a material handling
implement whereby at least one of the above mentioned problems is overcome
or is reduced.
According to one aspect of the present invention we provide a material
handling implement comprising a carrier, a load engageable device movable
relative to the carrier in a sideways direction and side shift means to cause
movement of the load engageable device relative to the carrier in said
sideways
direction.
The load engageable device may be movable relative to the side shift
means and fixing means may be provided releasably to fix the load engageable
device to the side shift means.
The fixing means may comprise a first set of abutments mutually inter-
engageable with at least one further abutment.
Said first set of abutments and at least one further abutment may be
fixed relative to one of said load engageable device and said side shift means
respectively.
Said fixing means may comprise a dog movable with the load
engageable device and releasably engageable with a plurality of teeth fixed
relative to the side shift means.
The side shift means may comprise a fluid operated piston and
cylinder device.
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The load engageable device may be mounted for sideways sliding
movement on a bar extending transversely of the carrier and so that the load
engageable device is rotatable relative to the carrier.
The load engageable device may be provided with one of said
abutments and may be pivotable so as to move said abutments between an
engaged and a dis-engaged position whereby the load engageable device may be
positioned at a desired sideways position relative to the side shift means.
The bar may be mounted for up and down movement relative to the
carrier.
The bar may be non-rotatably connected to the load engageable device
and the bar may be rotatable relative to the carrier.
The load engageable device may comprise a pair of sideways spaced
elements for engagement with a load.
Each element may comprise a fork.
Each fork may comprise a generally downwardly extending limb
connected adjacent one end to the bar and, having at or adjacent the other
end,
a forwardly extending tine for engagement with a load.
In this case the side shift means may comprise a pair of side shift
elements each of which may comprise a piston and cylinder device.
The pair of side shift elements may be inter connected by a member
which is non-slideably mounted relative to the carrier.
Where the side shift elements comprise a piston cylinder device the
inter connecting member may be a member which provides a pair of piston rods
one for each cylinder and may be non-slideably connected to the carrier at a
position adjacent its mid point.
The bar may be carried in a slot of a support member adjacent its mid
point as may be the member inter connecting the side shift means.
The bar may also be mounted in slots at or adjacent its ends.
According to a second aspect of the invention we provide a material
handling vehicle of the kind, hereinafter referred to as being of the "kind
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specified" comprising a structure having ground engageable propulsion means
and
a material handling means comprising a boom mounted on the structure for
raising and lowering swinging movement relative to the structure and driven
for
said raising and lowering movement by a first drive means and said boom being
extendable and being driven for extension or retraction by a second drive
means
and a material handling implement according to the first aspect of the
invention
carried by an outer end part of said boom.
A mechanical handling implement and a mechanical handling vehicle
embodying the invention will now be described by way of example with reference
to the accompanying drawings wherein
FIGURE 1 is a diagrammatic illustration of a material handling
vehicle embodying the invention and showing graphically alternative positions
of
a load handling implement therefore,
FIGURE 2 is a diagrammatic section on the line 2-2 of Figure 1 drawn
to an enlarged scale,
FIGURE 3 is a fragmentary diagrammatic side view, drawn to a still
larger scale, and looking in the direction of the arrow "A" in Figure 2,
FIGURE 4 is a fragmentary perspective view with parts omitted for
clarity showing part of the vehicle shown in Figure 1,
FIGURE 5 is an enlarged, perspective view showing a material
handling implement of the vehicle of Figure 1 with parts omitted for clarity,
FIGURE 6 shows a fragmentary hydraulic circuit of the vehicle of
Figures 1 and 2,
FIGURE 7 shows a fragmentary electrical circuit of the vehicle of
Figures 1 and 2,
FIGURE 8 is a perspective view showing a carrier of an alternative
material handling implement which may be used in the machine of FIGURES 1
to 7,
FIGURE 9 is a front elevation showing a loading engageable device
for use with the carrier of Figure 8,
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FIGURE 10 is a side view of the device of Figure 9, and
FIGURE 11 is a plan view of the device of Figure 9 and showing a
part of the carrier of Figure 8 in cross section.
Referring to Figures 1 to 7, a material handling vehicle is shown
generally at 10 in Figure 1 and comprises a body structure 11 having ground
engageable propulsion means 12 comprising front and rear wheels which are
driven from a prime mover, not shown, in conventional manner. The structure
11 has a driver's cab 13 of generally conventional configuration and a rear
part
of the structure, which may comprise a chassis 14, is provided with a pair of
uprights 14a_ on which is mounted a material handling means comprising an
extendable loader arm in the form of a boom 15 mounted on the chassis 14 for
raising lowering and swinging movement relative to the structure about a
horizontal axis 16 which is perpendicular to the fore and aft axis of the
vehicle.
In this example, the horizontal axis 16 is provided by a pivot axle shown at
16a_
which is fixed to the uprights 14a on which the boom 15 is free to rotate. The
boom 15 is driven for said raising and lowering movement by a first drive
means
comprising an hydraulic ram 17.
The boom 15 is extendable comprising a rearward part 18 in which
forward part 19 is telescopically slidably mounted in conventional manner. If
desired, and as illustrated, the boom 15 may be in three parts, there being an
intermediate part 19a_between the rearward and forward parts 18,19
respectively.
The intermediate part 19a is driven for extension or retraction within the
rearward part 18 by a ram 20a of a second drive means 20, best shown in Figure
4, whilst the forward part 19 is driven for extension or retraction relative
to the
intermediate part 19a_ by a ram 20b of the second drive means 20. As best
shown
in Figure 4, the ram 20a is disposed exteriorly to the rearward boom part 18
and
the intermediate boom part 19a whilst the ram means 20b is disposed interiorly
of the intermediate and forward boom parts 19a 19 respectively. A compensating
ram 70 is pivotally connected between the rearward part of the boom 15 and the
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chassis 14 on the opposite side of the pivot axis 16 to the forward end of the
boom
A cam 71 is mounted on an extension part 72 of the pivot axle 16a so as to be
free to rotate relative thereto under the influ~ce of a pendulum mass 73. A
cam follower
roller 74 is carried on an arm 75 which is pivoted at 76 to a body of a switch
77 carried on
a bracket 78 fixed to the boom 15.
A suitable proximity switch arrangement may be provided to minimise any
affect on operation of the pendulum device instead of the mechanical
arrangement
described above.
The material handling means also comprises a material handling implement 21
pivotally mounted on the outer part 19 of the boom for relative angular
adjustment for
operator induced crowd or dump movement by means of a crowd ram means 22
connected
between the implement 21 and the outer part 19 of the boom for said pivotal
adjustment
about a horizontal axis 24 which is parallel to the axis 16. The crowd ram
rreans 22 is
connected in series circuit with the compensating ram 70 thus, in use, the
material handling
implement 21 is maintained in a fixed juxtaposition relative to the chassis of
the vehicle
irrespective of raising or lowering movement of the boom 15 about the axis 16,
so long as
valve 48 for operator induced crowd movement of the ram means 22 is not
implemented.
The mechanical handling implerr~ent 21 comprises, as best shown in Figure 5, a
carrier 25 providing a means 26 to receive a pivot pin for pivotal movement of
the earner
25 about the axis 24 and a means 27 to pivotally connect the crowd ram 22
thereto. The
earner 25 has mounted thereon, or relative thereto, a load engageable device
30 which in
the present example comprises a pair of forks, only one of which is shown for
clarify in
Figure 5. Each fork 30 is clamped, for transverse adjustment, by a suitable
lock screw 31
to a bar 32 which, in the present invention, is mounted adjacent the opposite
end ofthe bar,
for up and down movement in a pair of longitudinally extending slots 33. The
bar 32 is
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retained in the slots 33 by end plates 34 which are fastened in a convenient
manner by lugs
35 to side wall parts 3G of the earner 25.
The bar 32 is also pivotable relative to the carrier within the slots 33 and
carries a pair of collars 37 for rotation with the bar 32. Each collar 37 has
a target 38
mounted thereon for rotation with the bar 32 and for up and down movem~t with
the bar
32. The angular position of one of the targets 38 is detectable in
conventional manner by
one proximity device 39, whilst the up and down position of the other of the
targets 38 is
detected, in conventional mariner, try a second proximity device 39. The
proximity devices
39 are mounted on the earner. In the present example, one of the proximity
devices is
adapted to be most sensitive to angular movement of a target 38 whilst the
other proximity
device is most sensitive to up and down movement of the associated target 38.
Accordingly, if, as hereinafter to be described, a pallet is engaged primarily
with a tip part
of a fork 30 so that a maximum amount of rotation takes place, then the
relevant proximity
device will be operable, whilst when the fork 30 is fully engaged with the
pallet so that
primarily up and down movement of the bar 32 occurs then, again, the relevant
proximity
device is operated.
Alternatively, if desired only a single proximity device may be provided of
appropriate sensitivity to both modes of operation as described hereinbefore.
If desired, alternatively, or in addition, the proximity devices may be
provided
adjacent the top and bottom of the slots or at least one slot 33 so that the
position of the
bar 32 relative to the top or the bottom ofthe slot 33 can be detected.
If desired, the forks 30 may, instead of being provided in a form of
conventional pallet forks adapted to be received in a socket of a pallet, be a
of a block type
of the kind commonly used in USA, or may be of any other suitable load
engageable
device.
Referring now to Figure G, the hydraulic circuit for the hydraulic rams 17, 20
and 22 is illustrated and will now be described.
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The hydraulic circuit comprises a reservoir 40 from which hydraulic fluid is
fed
by a main pump 41 via a load sensing valve 42, and a suction strainer 43 in
conventional
manner so as to be fed on a line 44 to a four-spool valve block 45. Within the
valve block
45 are four manually operable valves 46-49. Hydraulic fluid is fed under
pressure from the
line 44 by operator actuation of the valve 46-49 in the appropriate direction
to the
appropriate one of the exit lines 46a,46tr49a,49b respectively and hence to
the respective
side, under pressure, of the associated ram Fluid is returned from the
appropriate other
side of the ram on the other line 46a_,46b-49_a,49b and hence on return line
50 via a cooler
51 and a return line filter 52 to the reservoir 40.
In the present example, the valve 46 is connected to a ram, not shown, in
order
to provide a desired auxiliary function.
The valve 47 is connected to the lift ram means 17 so that when the line 47a
is
pressurised the boom is lowered whilst when the line 47b is pressured ram
means 17 is
raised.
The valve 48 is connected to crowd ram means 22 so that when the line 48a is
pressurised the ram means 22 is operated to dump the mechanical handling
implement,
whilst when the line 48b is pressurised the mechanical handling implement is
actuated in a
direction so as to crowd the mechanical handling means, ie, referring to
Figure 1,
mechanical handling implement 21 is pivoted in a clockwise direction for
crowding and an
anti-clockwise direction for dumping. Superimposed on the crowd ram means 22
is the
series connection of the compensating ram 70.
The valve means 49 is connected to the ram means 20 for extension of the
boom and is arranged so that when the line 49a is pressurised, the boom is
extended, whilst
when the line 49b is pressurised, the boom is retracted.
A three position flow diverter valve means 55, operable by
solenoid means 56a. _ _and 56b, is connected in the line 49a,49b so that the
lines
49a,49b _ _ - -are connected respectively by lines 49a',49b' to the lines
47a,47b which
lead to the boom raise and lower ram means 17 when either sol~oid means 56a or
56b is
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energised. It will be noted that lines 49~,49~ are connected respectively, to
lines 49~.',49~'
when solenoid means S6a is energised, but are connected, respectively, to
lines 49b',49a'
when solenoid means S6b is energised.
Referring now to Figure 7, there is shown an electrical circuit in which item
S1
comprises a manually operable system enabling switch from which, when manually
closed,
current is fed via a line 61 to a pendulum switch device 62 provided on the
earner and
shown in Figure S and referred to in Figure 7 as switch S2 and which detects
whether or
not carrier 25 is vertical. If the carrier ZS is detected as vertical, the
switch S2 is closed and
current is fed on a branch line 61 a to a retract/extend engage system
available light 63 and
on an extension of the main circuit 61 to a manually operable extend/retract
selection
switch S3 provided on a lever ofthe hydraulic valve 49.
The circuit 61 extends from switch S3 to a fork proximity switch S4 provided
by the
proximity devices) 39 which is connected in circuit with a boom, lower
quadrant, double
changeover switch shown at SS/1 and SS/2 in Figure 7 and provided by the
switch 77.
Outputs from one contact of the double switch SS/1, SS/2 extend to one contact
of
an extend switch S6 operated as a result of movement of an operating member of
the valve
49 in the direction to cause extension of ram 20, whilst the other contacts of
the switches
SS/1, SS/2 extend to a second contact ofthe extend switch S6. The output from
the switch
S6 extends to a boom upper quadrant switch S7 provided by the switch 77, one
contact of
which is converted to the solenoid S6a of the valve SS, whilst the other
contact ofthe boom
upper quadrant switch S7 is connected to sol~oid 56b of the valve SS.
In Figure 7, the schematic electric circuit indicates a situation where, for
the
sake of example, the boom 1 S is in its upper quadrant and the forks 30 are at
rest in the bottom of the slots 33 with no tilting of the forks 30 taking
place
away from the carrier. In this condition, all the devices are considered to be
in a
"0" state, whilst any change in state is indicated by "1". Furthermore, it is
to be
noted that the solenoid 56~, S6b of the valve SS are required to be in the
positions
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indicated in Table 1 to "engage" or "disengage" the forks 30 in respect of a
socket
means of a load.
TABLE 1
Upper QuadrantNeither A nor B Retract ) Disengage
-
" A not B Lift )
-
Upper Quadrant A not B Lower ) Engage
-
" Neither A nor B Extend )
-
Lower Quadrant B not A Lower ) Disengage
-
" Neither A nor B Retract )
-
" B not A Lift ) Engage
-
" Neither A nor B Extend )
-
Table 2 sets out the necessary conditions of the various components
to achieve the desired functions by operating the control member of the valve
49
to engage or disengage the load as desired.
TABLE 2
UPPER LOWER
QUADRANT QUADRANT
Disengage Engage Disengage Engage
S1 1 1 1 1 1 1 1 1
S2 1 1 1 1 1 1 1 1
S3 1 1 1 1 1 1 1 1
S4 0 1 0 1 0 1 0 1
SS/1 0 0 0 0 1 1 1 1
SS/2 0 0 0 0 1 1 1 1
S6 0 0 1 1 0 0 1 1
S7 0 0 0 0 1 1 1 1
Sol A 0 1 1 0 0 0 0 0
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SO1B 0 0 0 0 1 0 0 1
Retract 1 0 0 0 0 1 0 0
Extend 0 0 0 1 0 0 1 0
Lift 0 1 0 0 0 0 0 1
Lower 0 0 1 0 1 0 0 0
1n Table 2 there are two fundamental modes. On the left-hand side of the
function part of
Table 2 there are stated the conditions required for disengagement of the
forks from a load
such as a pallet, or engagement of the forks into such a load when the boom is
in its upper
quadrant, ie above horizontal, whilst on the right-hand side of the function
part of Table 2
the conditions required are stated for when the boom is in its lower quadrant
and the forks
are required to disengage from the load or gage with the load.
Of course, why it is desired to engage the load engageable device 30 with a
load, an end part of the load engageable device 30 must initially be
manipulated manually
into engagement with the load.
When it is desired to dis~gage the load engageable device 30 and the boom is
in its upper quadrant. The conditions are as shown in the first, ie left-hand,
column of
Table 2. The valve 49 is initially operated so as to pressurise the line 49b
so as to cause the
ram 20 to retract the boom until, in accordance with a signal from the sensors
39. The
state of switch S4 is changed so that the conditions of column 2 of Table 2
apply and,
hence, the solenoid S6g is actuated so as to feed fluid from line 49_b on to
line 49b_' so as to
raise the boom using the ram 17. Then when the sensors 39 detect that the
forks 30 have
reached the bottom of their extent of movement the state of the switch S4 is
again changed
back to the first column of Table 2 condition and the solenoid S6~ is de-
~ergised and
retraction of the boom 15 recomrryences. The procedure is repeated as
necessary.
When the boom is in its upper quadrant and it is desired to
engage the load, the conditions of column 3 of Table 2 apply. The valve 49 is
initially
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operated in the reverse direction to that described previously which changes
the
state of the switch S6 to the condition shown in the third column of Table 2,
which causes the solenoid A to be energised so that operation of the valve 49
causes fluid pressure to be relieved in the line 49~ ~ and this relieved
pressure to
be returned to the valve 49 on line 49b_ so that the boom is lowered. This
continues until, in accordance with a signal from the sensors 39, switch S4
changes
state to the condition shown in the fourth column of Table 2 so that solenoid
56a_
is de-activated to de-energise the boom lowering action and to start the boom
extension action since fluid pressure will be reduced on line 49b_ and
increased on
line 49~ This continues until the sensors 39 sense that the forks have reached
the bottom of their extent of movement so that the conditions of the third
column
of Table 2 re-apply an extension of the boom is interrupted and operation of
boom lowering continues as described previously.
Conversely, when the boom is in its lower quadrant, operation of the
valve 49 to disengage the forks from the pallet causes the conditions of
column
to apply. Accordingly, initially solenoid B is energised so that operation of
the
valve 49 initially causes the boom to lower because the pressure in line 49b_'
is
reduced which is transmitted by the valve SS to the line 49a_. This continues
until
the proximity sensors 39 cause the switch S4 to change state to the conditions
shown in the sixth column of Table 2, whereupon neither solenoid A nor
solenoid
B are activated so that the above-mentioned reduction in pressure in line 49a
is
transmitted to the ram 20 on the larger diameter side thereof so as to cause
retraction of the boom. This continues until the sensors 39 again cause the
switch
S4 to change state back to the condition shown in column 6 of Table 2,
whereupon the retraction of the boom is interrupted and lowering of the boom
continues.
Finally, when the boom is in the lower quadrant and is desired to
engage the load, initially operation of the valve 49, in the opposite
direction to
that described in the preceding paragraph, causes the conditions of column 7
to
apply so that neither solenoid is energised so that, in this case, increase in
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pressure in the line 49~ is transmitted to the larger diameter size of the ram
20
to cause extension of the ram and, hence, of the boom. This continues until
the
sensor 39 causes the switch S4 to change state so that the conditions shown in
the
eighth column of Table 2 apply and the solenoid B is energised. As a result,
fluid
under pressure in line 49a_ is supplied to line 49~ ~ and hence to the larger
diameter side of the lifting ram 17 and thus causes lifting of the boom to
occur.
This continues until the sensors 39 cause reversion to the condition shown in
column 7 of Table 2, whereupon lifting of the boom is interrupted and
extension
repeated.
If the boom 15 is horizontal then operation of the valve 49 in the
direction to pressurise the line 49a causes the ram means 20 to be extended
and
will cause the load engageable device 30 to engage in, for example, a socket
of
a pallet without requiring any angular movement of the boom. Similarly, if it
is
desired to retract the load engageable implement 30 it is simply necessary to
operate the valve 49 to pressurise the line 49b to cause retraction of the ram
20.
If desired, relays may be provided.
Although in the above-described example the diverter valve 55 is an
on/off valve so that it operates in only one of the desired three positions,
if
desired it may be provided as a proportional valve so that the amount of fluid
flowing to the outlets described hereinbefore can be proportioned as desired,
according to the extent of movement of the valve.
Furthermore, if desired, instead of the valve 55 interrupting the fluid
flowing to first outlets in initial condition, the fluid flowing in the
initial condition
may continue to flow in the second condition, with the fluid flowing to second
outlet of the second condition, in addition to the fluid flowing to the first
outlets
of the first condition.
Referring now to Figures 8 to 11 there is illustrated and described
below an alternative form of material handling means which may be used in
place
of the material handling implement 21 described hereinbefore or which may be
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used independently of a material handling vehicle of the kind described and as
described and illustrated herein, before as the material handling implement of
Figures 8 to 11 may be capable of being attached to or disassembled from a
tool
carrier or carriage of any desired vehicle.
Referring now to Figures 8 to 11 the material handling means
comprises a material handling implement 121 which, as mentioned before may be
mounted in the same manner as the material handling implement 21 or in any
other desired manner. The implement 121 comprises a carrier 125 comprising an
upper cylindrical bar 126 connected to a lower cylindrical bar of larger
diameter
127 by a first pair of side plates 128 on one side of the carrier and a second
pair
of side plates 129 at the opposite side of the carrier.
The lower bar 127 has a fabrication 130 welded thereto. The
fabrication 130 comprises a pair of end members 131 and a pair of intermediate
members 132. A torsion bar 133 is received in appropriate apertures of the
members 131, 132 and is welded thereto and carries a slotted element 134. The
slotted element 134 has a first slot 135 and, disposed to the rear thereof a
second
slot 136. The slot 135 is aligned with a pair of slots 137, 138 provided in
the
inner plates 128, 129 whilst a latch member 139, 140 is pivotally mounted by a
pivot pin 141 between the plates 128, 129 respectively. The latch members 139,
140 have a hand engageable member 139a 140a respectively and the member 139
is shown in an operative position whilst the number 140 is shown in an
inoperative position. The members 131 and 132 provide, as shown at 142, a pair
of bosses for connection to a loader arm, if desired, in a manner similar to
the
bosses 126 shown in Figure 5.
Referring now to Figures 9 to 11, releasably mounted on the carrier
121 is a load engageable device 150 which comprises, in the present example, a
pair of forks 151, 152. The load engageable device 150 also comprises a bar
153
which is received within the slot 135 of the member 134 at a reduced diameter
part 154 thereof adjacent the mid point. The bar 153 is of hexagonal section
over the majority of its length 155 but has circular end portions 156, 157.
The
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1S
end portions 156, 1S7 are received within the slots 137, 138 and are retained
therein by the
latches 139, 140 when they are in their operative position. As a result the
bar 1S3 is free to
move up and down or float relative to the Garner 12S and can also rotate
relative thereto.
Axial movement of the bar is prevented by ~gagement of the produced diameter
part 1 S4
in the slot 13S whilst up and down movememt is permitted by virtue of the
shape of the slot
135. The bar 1S3 is fwther received in an aperture in a bracket means 170, the
bar IS3
passing through apertures in an°ns 170x, 170b provided on the bracket
means 170 such that
the arms 170x, 170 are disposed either side of the reduced diameter part 154
of the bar
153.
The forks 1 S 1, 152 comprise a downwardly depending part 1 S 1 a, 1 S2a and a
load
engageable part 1 S I b 1 S2~ which extends perpendicularly forwardly relative
to the
downwardly extending part 15 I . The downwardly extending parts 1 S 1 a 1 S2a
have at their
upper end a boss part 158, IS9 respectively welded thereto, having an
hexagonal bore so as
slideably and non rotatably to receive part ISS of the bar 153. As a result
the forks 1SI,
152 may be slid sideways manually relative to the bar 1S3 and h~ce relative to
the carrier
1SS.
The tubular part 158, 159 is provided with a dog 160 which is engageable
between a
desired pair of a plurality of teeth 161 which extend part circumferentially
around first and
second cylinders 162, I63 of piston and cylinder devices. The piston rods
162a_, 163x, of
which are interconnected by, in the present example, a reduced diameter
portion 164 which
is received within the slot 136 of the member I34 of the carrier and member
134 being
received between a pair of abutments 16S fixed to their respective piston rod
162, 163a
Of course the means whereby the piston rods and the member 164 are connected
together
may be provided as desired and indeed the components may be provided
integrally with
each other if desired.
Each cylinder 162, 163 has a pair of mounting elements 166, 167 respectively
which
are provided as extensions of a pair of the teeth 161 and have lugs 166a 167a
which are
provided with apertures which are to receive a rod 168. The rod 168 has a
reduced
diameter end part 168a at each ~d which is received within a correspondingly
dimensioned
aperture of the outer of the lugs 166a 167a and which is clamped by a bolt 169
against a
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16
shoulder between the main part of the rod 168 and the reduced dia~ter parts
168a The
inner of the lugs 166x, 167 are provided with an aperture in which the main
part of the rod
168a is received. The rod I68 is also received in an aperture provided in the
bracket means
170, such that the rod 168 is held in a constant orientation relative to the
bar 153.
'The rod 168 thus serves to link the cylinders 162, 163 together and the rod
168 is linked to the bar 153 by the bracket means 170.
In use, the forks 151,152 may be pivoted upwardly ie. in a clock wise
direction
as shown in Figure 10 so as to disengage the respective dog 160 from a pair of
the teeth
161. It will be appreciated that pivotal movement of one of the forks will
result in pivotal
movement of the other fork because of the non rotational engagement between
the forks
and the bar 153.
With the forks thus dis~gaged the spacing between the forks desired for the
Ioad to be manipulated is adjusted and then the forks are pivoted downwardly
to engage
the respective dog 160 between a desired pair of the teeth 161.
Thereafter, when it is desired to side shift the forks in to alignment with a
desired load, for example, sockets of a pallet, hydraulic fluid is fed to the
cylinders 162, 163
to effect appropriate side shifting of the forks because of engagement of the
dogs 160
between the pairs of adjacent teeth. Because the piston rods 162a 163 are
linked as
described hereinbefore then the forks 151, 152 will move sideways, ie. to the
left or to the
right together.
It will be appreciated that the hydraulic circuit to the cylinder 162, 163 is
arranged accordingly. Each cylinder may be a single acting cylinder or a
double acting
cylinder as desired.
If desired the cylinders 162, 163 may not be linked by a rod 168 and the
hydraulic circuitry may be arranged so that the cylinders may be operated
independently so
that the forks may be moved independently.
The present invention has the advantages that an additional carriage or
carrier
is not required, the total Berating of the lifting ability of a machine
equipped with the
implement is lirrtited essentially by the weight of the hydraulic actuators
ie. piston and
cylinder devices 162, 163 and these are essentially the only extra components
of any
CA 02208472 2003-09-04
17
significant weight required to be provided. Furthermore there is no additional
load due to
the weight of the sliding forks carrier usually associated with side shifting
forks when they
are provided as an additional component. Accordingly the load capacity of an
operating
machine is not reduced as a result of having to provide an additional carrier
extending the
load forwardly from that where it is normally carried and where it is carned
in the present
invention.
As mentioned above the forks can be easily engaged with or dis-engaged from
the hydraulic actuators allowing the spacing of the forks to be adjusted to
suit a desired
load. Importantly, the forks may be dis-engaged so that they can be folded
backwards over
the carriage and retained by a suitable latch means, not shown, for safe road
use.
Provision for fork ret~tion is provided to eliminate inadvertent lateral fork
movement in operation of the device by virtue of the above referred-to inter-
engagement.
The features disclosed in the foregoing description, or the accompanying
drawings, expressed in their specific forms or in terms of a means for
performing the
disclosed fimction, or a method or process for attaining the disclosed result,
or a class or
group of substances or compositions, as appropriate, may, separately or in any
combination
of such features, be utilised for realising the invention in diverse forms
thereof.
