Technical Field
Fork carriages for forklift trucks.
Background
[0001] A typical forklift carriage sideplate is illustrated in Figure 1. Sideplate 1 includes
rollers 4 that fit within mast channel 5 to enable the forklift carriage to be vertically
movable. As shown in Figure 1, sideplate 1 is a generally vertical element of a fork
carriage.
Summary
[0002] The present inventor has recognized that typical sideplates for forklift carriages
are formed in a substantially linear manner for (1) ease of manufacturing and (2)
load bearing capacity. The present inventor also recognized that sideplates may be
shaped differently such that a portion of a sideplate is contained within a mast channel
such that the portion is hidden from the view of an operator located at the operator
station of the forklift. The present inventor also recognized that such shaped sideplates
maintain an acceptable strength of the sideplate and do not substantially increase
manufacturing difficulty. For example, such sideplates may be manufactured by casting,
forging, additive manufacturing, welding, machining, or other suitable manner.
Brief Description of the Drawings
[0003]
Figure 1 illustrates a prior art sideplate for a forklift carriage.
Figure 2 illustrates an orthogonal, rear view of a forklift carriage with sideplates.
Figure 3 illustrates a rear view of the carriage with sideplates of Figure 2.
Detailed Description
[0004] With reference to Figure 1, sideplate 30 and sideplate 35 are attached to frame 40
to form a carriage that supports front end equipment for a forklift truck. Frame 40
comprises a top horizontal crossbar 45 and a lower horizontal crossbar 50 that are
connected by a left a vertical crossbar 55 a right vertical crossbar 60. Each of the
sideplates 30, 35 are secured to the top horizontal crossbar 45 and to the lower horizontal
crossbar 50.
[0005] Each of the sideplates 30, 35 carries a plurality of guides, such as rollers 65,
that facilitate moving the frame 40 in a vertical direction with respect to mast rails
70 and 75. Each sideplate 30, 35 comprises a 1
st upper portion 80, 85, respectively, a 2
nd intermediate portion 90, 95, respectively, and a 3
rd lower portion 100, 105, respectively. The rollers 65 are attached to the upper portions
80, 85 and to the lower portions 100, 105 of the sideplates 30 and 35.
[0006] Each roller 65 fits within a vertical channel 110 of mast rails 70 and 75. The upper
portions 80, 85 of the sideplates 30 and 35 are shaped and constructed such that when
the rollers 65 are within the mast channels 110 the upper portions 80 and 85 are held
externally of the mast channels 110. Likewise, the lower portions 100, 105 of the
sideplates 30 and 35 are shaped and constructed such that when the rollers 65 are
within the mast channels 110 the lower portions 100 and 105 are held externally of
the mast channels 110. However, the intermediate portions 90 and 95 of the sideplates
30 and 35 are shaped and constructed such that when the rollers 65 are within the
mast channels 110 the intermediate portions 90 and 95 are also within the mast channels
110.
[0007] Sideplates 30 and 35 are shaped and constructed such that when the rollers 65 are
within the mast channels 110 a distance "d" between an interior surface 115 of upper
portion 80 and an interior surface 120 of upper portion 85 is less than a distance
"D" between an interior surface 125 of intermediate portion 90 and an interior surface
130 of intermediate portion 95. Optionally, a distance "dd" between interior surfaces
of lower portions 100, 105 may be greater than distance "d", equal to distance "d",
or less than distance "d". Optionally, an exterior surface 135 of intermediate portion
90 does not contact the back wall 140 of mast rails 70 and an exterior surface 145
of intermediate portion 95 does not contact the back wall 150 of mast rails 75 when
the rollers 65 are within mast channels 110. Optionally, a wear plate, rubbing strep,
dry lubricant, or wet lubricant to be included if there is contact between exterior
surface 135 and back wall 140, or between exterior surface 145 and back wall 150.
[0008] A width "w" of the intermediate portions 90 and 95 is less than a width "W" of the
mast channels 110. Optionally, the interior surface 125 of intermediate portion 90
and the interior surface 130 of intermediate portion 95 are contained within each
of the mast channels 110 such that when the rollers 65 are contained within the mast
channels 110 the operator of a fork lift truck cannot see the interior surfaces 125
and 130 because they are blocked from view by the rear wall 155 of the mast channel
70 and by the rear wall 160 of the mast channel 75. Thus, all or substantially all
of the intermediate portions 90 and 95 are hidden from the view of an operator when
an operator is located in the operator compartment of a fork lift truck.
[0009] Optionally, the upper portions 80 and 85 and the lower portions 100 and 105 may have
a width that is equal to, less than, or greater than the width "w".
[0010] Optionally, the intermediate portion 90 is considered to be within mast channel 110
when no part of intermediate portion 90 breaks a plane 72 formed by an inner edge
165 of the front wall 170 and an inner edge 175 of the rear wall 155 of mast channel
70. However, transition portions 92 of the intermediate portion 90 that connect the
intermediate portion 90 to the upper portion 80 and the lower portion 100 of the sideplate
30 will break the plane 72. Likewise, and optionally, the intermediate portion 95
is considered to be within mast channel 110 when no part of intermediate portion 95
breaks a plane 77 formed by an inner edge 185 of the front wall 190 and an inner edge
195 of the rear wall 160 of mast channel 75. Likewise, transition portions 97 of the
intermediate portion 95 that connect the intermediate portion 95 to the upper portion
85 and the lower portion 105 of the sideplate 35 will break the plane 77. In other
embodiments, portions of, or all of, the interior surfaces 125 and 130 may break the
plane 72 and 77, respectively, preferably whilst maintaining "D" as a larger distance
than "d".
[0011] The foregoing is a detailed description of illustrative embodiments of the invention
using specific terms and expressions. Various modifications and additions can be made
without departing from the spirit and scope thereof. Therefore, the invention is not
limited by the above terms and expressions, and the invention is not limited to the
exact construction and operation shown and described. On the contrary, many variations
and embodiments are possible and fall within the scope of the invention which is defined
only by the claims that follow.
1. A carriage for a forklift truck comprising:
a frame;
a first sideplate secured to the frame, the first sideplate comprising an upper portion,
an intermediate portion, and a lower portion with a guide attached to the upper portion
and a guide attached to the lower portion;
a second sideplate secured to the frame, the second sideplate comprising an upper
portion, an intermediate portion, and a lower portion with a guide attached to the
upper portion and a guide attached to the lower portion;
wherein the first and second sideplates are constructed and shaped such that when
the first and second sideplates are secured to the frame a distance "D" between the
intermediate portions of the first and second sideplates is greater than a distance
"d" between the upper portions of the first and second sideplates.
2. A carriage for a forklift truck according to claim 1, wherein:
the first and second sideplates are constructed and shaped such that when the guides
attached to the upper portions and lower portions of the first and second sideplates
are within vertical channels of a mast the intermediate portions of the first and
second sideplates are within the vertical channels of the mast.
3. A carriage for a forklift truck according to claim 2, wherein the guides comprise
rollers.
4. A carriage for a forklift truck according to claim 1, wherein:
a width "w" of the intermediate portion of the first sideplate is less than a width
"W" of a channel of a mast that is configured to bear the carriage; and
a width "w" of the intermediate portion of the second sideplate is less than a width
"W" of a channel of the mast that is configured to bear the carriage.
5. A carriage for a forklift truck according to claim 1, wherein:
the first and second sideplates are constructed and shaped such that when the first
and second sideplates are secured to the frame the distance "D" between the intermediate
portions of the first and second sideplates is greater than a distance "dd" between
the lower portions of the first and second sideplates.
6. A carriage for a forklift truck according to claim 5, wherein:
the distance "d" and the distance "dd" are equal.