Note: Descriptions are shown in the official language in which they were submitted.
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TITLE OF THE INVENTION
GRAPPLE CLAMP
FIELD OF THE INVENTION
The present invention relates to a grapple clamp. More
specifically, the present invention is concerned with a grapple clamp
having a universal joint.
BACKGROUND OF THE INVENTION
The use of grapple clamps on logging skidders and
similar vehicles is well known. However, grapple clamps can be used
for a variety of purposes to securely clamp objects such as logs, dirt,
pieces of concrete and other refuse during excavation work and the like.
In brief, grapple clamps are used to clamp heavy objects and to
transport them usually to a stack of similar objects.
Grapple clamps usually include a relatively long and
mobile mechanical arm with a pair of opposite side tongs pivotally
secured thereto defining a clamp head or clamp hand. Usually a
hydraulic device such as piston cylinder device acts on one of the tongs
so as to move it from a clamping to a non-clamping or release position.
Figures 1 and 2 show an example of a prior art grapple
clamp 10 which includes an arm 12 having opposite side tong members
14 and 16 pivotally mounted thereto. An extensible hydraulic actuator
18 is pivotally mounted between the backside 20 of tong member 16
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and the arm 12 at pivot attachments 22 and 24, respectively. The
hydraulic actuator 16 includes a cylinder 26 and a piston rod 28.
Tong member 14 is pivotally mounted to one end 15 of
a pivot assembly 30; the pivot assembly being pivotally mounted on the
other end 17 to the arm 12. A joint support 35 is pivotally mounted
between the pivot assembly 30 and the arm 12. Tong member 16 is
pivotally mounted to the arm 12 via pivot attachment 32.
In this way, tong member 14 can move between a
clamping position, extending the joint support 34, as shown in figure 1,
and the unclamping position contracting the joint support 34, as shown
in figure 2. The hydraulic actuator 18 may move tong member 16
between positions shown in figures 1 and 2 by extending and
contracting the piston rod 28, respectively. A hydraulic actuator (not
shown) similar to actuator 18 may also act on tong member 14 so as to
pivot tong 14 between the clamping and non-clamping positions shown
in figures 1 and 2, respectively.
A drawback with prior art grapple clamps, such as the
one described above, is that the clamp head area or clamp hand is rigid
as it only performs clamping and releasing movements, hence, the
efficiency of the grapple clamp to reach objects is limited to the agility of
the arm. Therefore, the insufficient mobility makes it difficult and
sometimes impossible to clamp objects in tight corners or to place them
in a desired precise area.
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OBJECTS OF THE INVENTION
The general object of the present invention is
therefore to provide an improved grapple clamp.
Another object of the invention is to provide a grapple
clamp free of the above-noted disadvantages.
A further object of the invention is to provide a grapple
clamp comprising a universal joint between the grapple clamp arm and
the clamp tongs.
SUMMARY OF THE INVENTION
More specifically, in accordance with the present
invention, there is provided a grapple clamp to be mounted to the end of
an arm member, the grapple clamp comprising:
a clamp member comprising opposite side tongs; and
a universal joint assembly mounted between the arm
member and the clamp member, universal assembly
the joint
comprising two joints, of these joints havingpivot
each two a axis
substantially perpendicularto the other,for articulatingthe clamp
member.
Other objects, advantages and features of the present
invention will become more apparent upon reading of the following non-
restrictive description of preferred embodiments thereof, given by way
of example only with reference to the accompanying drawings.
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BRIEF DESGRIPTI~N OF THE DRAWINGS
In the appended drawings:
Figure 1 is a side elevational view of a prior art
grapple clamp in a non-clamping position;
Figure 2 is a side elevational view of the prior art
grapple of figure 1 in a clamping position;
Figure 3 is a side elevational view of the grapple
clamp according to the present invention in a clamping position and with
the clamp hand member being in an upward position.
Figure 4 is a side elevational view of the grapple
clamp according to the present invention in a clamping position and with
the clamp hand member being in a downward position;
Figure 5 is a perspective view of the grapple clamp
according to the present invention in a non-clamping position;
Figure 6 is a side elevational view of the grapple
clamp according to the present invention in a non-clamping position;
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Figure 7 is a top elevational view of the grapple clamp
according to the present invention with the clamp hand member being in
a leftward position; and
5 Figure 8 is a top elevational view of the grapple clamp
according to the present invention with the clamp hand member being in
a rightward position.
DESCRIPTION OP THE PREFERRED EMBODIMENT
Turning now to figures 3 to 8, a preferred embodiment
of a grapple clamp 36 according to the present invention will be
described.
Figures 3 and 4 show grapple clamp 36 comprising an
arm 38, a clamp head or hand clamp member 40 and a universal joint
assembly 42 therebetween, all of which will be described in detail
hereinbelow.
The clamp hand member 40 comprises a pair of
opposite side tong members under the form of a fingerplate tong 44 and
a thumb tong 46. Of course, other types of suitable tong members for
grabbing logs and the like may be contemplated. Preferably, tongs 44
and 46 are made of strong metallic material capable of clamping and
lifting large and heavy objects.
As better shown in figure 5, the fingerplate tong 44
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has five inwardly curved fingers 48 with webs 50 therebetween near
their respective fingertips 52. Advantageously, the fingertips 52 are
tapered so as to easily pierce through a stack of objects that are to be
clamped, while the inward curvature of the fingers facilitates scooping
up and holding therein a large amount of these objects. The fingerplate
tong 44 also defines an upper palm area 54.
Again with particular reference to figure 5, the thumb
tong 46 is inwardly curved and preferably has a toothed inner surface
56 which provides the clamp hand member 40 with a better grip when
clamping. The thumb tong 32 is pivotally mounted to the fingerplate
tong 44 via a thumb pivot assembly 58. The thumb pivot assembly 58
includes a longitudinal pivot rod 60 pivotally mounted at its longitudinal
ends 61 and 63 to both the thumb tong base 62 through apertures (not
shown) formed therethrough, and to the thumb tong pivot brackets 66
and 68 respectively, so as to pivot about a pivot axis 64. Brackets 66
and 68 are fixedly mounted to the upper palm area 54. In this way, the
thumb tong 36 can move, preferably by way of a hydraulic actuator 35
acting thereon, between a non-clamping position, shown in figures 5
and 6, and a clamping position, shown in figures 2 and 3. Preferably,
the hydraulic device 35 is a conventional cylinder piston assembly.
Referring now particularly to figures 3, 4 and 6, the
universal joint assembly 42 comprises, with respect to the clamp hand
member 40, a proximal portion 70, a distal portion 72, and an
intermediate portion 74 therebetween. Portions 72 and 74 provide a
respective joint area, as will be described hereinbelow. The universal
joint assembly 42 has similar left and right sides hence, only one side
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will be described hereinbelow since the other side is a mirror image
thereof.
The distal portion 72 is pivotally mounted to the arm
38 and includes a pair of similar opposite side double brackets 77 with
first apertures 79, for pivotally mounting thereto a first pivot rod 80, and
second apertures 81 for pivotally mounting thereto a second rod 82 (see
figures 3 and 4). These first and second pivot rods 80 and 82 are
pivotable about their respective longitudinal axis with each axis being
generally parallel to the other. The first rod 80 is also horizontally
journalled to the lower portion 84 of the arm 38. In this way, the clamp
hand member 40 can move between an "upward" position, as shown in
figure 3, and a "downward" position, as shown in figure 4.
With particular reference to figure 6, joint supports 86
are pivotally mounted at one end 85 to the second pivot rod 82, near
each longitudinal end thereof, so as to support the distal portion 72
during movement of the clamp hand member 40, as shown in figures 3
and 4. The joint supports 86 are pivotally mounted at their other end 87
to arm 38. Joint supports 86 are moved between a contracted position
when the clamp hand member 40 is in an "upward" position, as
illustrated in figure 3, and an extended position when the clamp hand
member 40 is in a "downward" position, as illustrated in figure 4.
Furthermore, the joint supports 86 include a pair of similar and pivotally
interconnected joint support bodies 88.
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Referring back to figure 5, the proximal portion 70 is
mounted to the clamp hand member 40 and includes a pair of similar
proximal portion opposite side brackets 90 with first apertures 91 for
mounting a first proximal portion rod 92 thereto, and second apertures
(not shown) for mounting a second proximal portion rod 94 thereto.
Furthermore, the first and second rods 90, 94 are mounted to brackets
68 and 96; brackets 68 and 96 being fixedly mounted to the fingerplate
tong 40. Bracket 68 also has a lower portion, which serves as part of
the thumb tong pivot assembly 58, as described above. Other known
ways to mount the proximal portion 72 to the clamp hand member 40
may also be used.
The proximal 70 and distal 72 portions are pivotally
linked at the intermediate portion 74 of the universal joint 42. The
intermediate portion 74 includes inner and outer pairs of intermediate
pivot brackets 100 and 102, respectively. The inner pivot brackets 100
are fixedly mounted to the distal portion brackets 80, defining a single
multi-bracket unit, and the outer pivot brackets 102 are fixedly mounted
to the proximal portion brackets 90, also defining a single multi-bracket
unit. An intermediate pivot rod 104 is pivotally mounted at each
longitudinal end thereof to the intermediate pivot brackets 100, 102
through their aligned pivot rod receiving apertures. The pivot axis of this
intermediate pivot rod 104 is substantially perpendicular to the pivot axis
of the distal portion pivot rods 80, 82. In this way, the hand clamp
member can move from side to side, as shown in figures 7 and 8.
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The present grapple clamp 36 may also include an
extensible hydraulic actuator 106, which acts on the hand clamp
member 40. These types of hydraulic devices commonly include a
cylinder 108 provided with a piston rod 110 extending outwardly of the
cylinder 108. The hydraulic actuator 106 is mounted only on one side of
the universal joint 42 with the cylinder 108 being securely mounted on
one of the distal portion brackets 90 by means of attachment 112, and a
pivot assembly 114 being mounted on one of the proximal portion
brackets 90 for pivotally connecting the piston rod 110 thereto. The
hydraulic actuator 106 can therefore move the hand clamp member 40
from side to side by acting on the proximal portion bracket 90 by either
extending to move the hand clamp member to one direction, as shown
in figure 8, or by contracting to move the hand clamp member to the
other direction, as shown in figure 7.
Hence, the universal joint member 42 acts like a wrist
and provides for the clamp hand member 40 with sufficient agility to be
articulated in a variety of directions with respect to the arm. The grapple
clamp 36 can therefore easily reach and grip hard-to-reach areas in a
stack of articles such as logs and the like with relative ease.
Although the present invention has been described
hereinabove by way of preferred embodiments thereof; it can be
modified without departing from the spirit and nature of the subject
invention, as defined in the appended claims.
