Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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POLE CLIMBING APPARATUS
FIELD OF THE INVENTION
The present invention relates to a pole climbing apparatus.
BACKGROUND
A pole climbing apparatus has various uses. It may serve as a
platform for automated sandblasting and painting of service poles and lamp
standards. It may be used as a platform for elevating lights, cameras or any
other equipment to desired heights on a standing pole.
Prior pole climbing apparatus has not proven truly reliable for a
number of reasons. These include difficulties in radially clamping the
devices to poles, especially to poles of varying size such as tapered lamp
standards. With lamp standards there is also a problem of following any
curvature of a standard where it bends to a horizontal orientation at the
lamp head. Prior designs have also required significant clearance around a
standard before the climbing apparatus could be attached.
The present invention is concerned with an improved pole
climbing apparatus.
SUMMARY
According to the present invention there is provided a pole
climbing apparatus comprising:
a frame having a pole receiving opening therein;
a plurality of pole engaging truck means mounted on the frame
at circumferentially spaced positions around the pole receiving opening, the
pole engaging truck means including:
first truck means at two circumferentially spaced
positions for engaging a pole at axially spaced positions along the pole; and
second truck means at a third circumferential position for
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engaging the pole at a position axially between the axially spaced positions
of the first truck means;
clamp means for urging the first and second truck means
towards one another for clamping a pole therebetween; and
drive means for driving the truck means along a pole clamped
therebetween.
Preferably the apparatus includes a fixed truck with rollers
arranged in a V-formation array along one side of the pole, and a moving
truck with a roller that can be driven against the opposite side of the pole.
This produces the necessary lateral stability with a relatively simple
operating system. The second, moving truck is preferably biased against
the pole by a pneumatic cylinder so that variations in pole size will not
produce a significant effect on the clamping force.
In the preferred embodiment of the climber, both trucks are
driven by a common gear train to maintain a uniform speed of the two
trucks. The gear train may include a self-locking component, for example a
worm gear drive, for safety purposes.
The unit is preferably driven pneumatically using a double
redundant air motor. This includes three pneumatic motors driving a single
planetary gear train. Failure of any one of the motors still allows operation
of the apparatus at a reduced speed.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings, which illustrate an exemplary
embodiment of the present invention:
Figure 1 is an isometric view of a pole climbing apparatus
according to the present invention;
Figure 2 is a schematic isometric showing the roller layout of
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the two trucks;
Figure 3 is a plan view with the cover omitted and the frame
shown in broken line for the sake of clarity;
Figure 4 is a back view of the fixed truck drive mechanism;
Figure 5 is an isometric of the pneumatic motor assembly; and
Figure 6 is a schematic of the pneumatic circuit.
DETAILED DESCRIPTION
Referring to the accompanying drawings, Figure 1 illustrates a
pole climbing apparatus 10. It is shown mounted on a pole 12 illustrated in
broken line. The apparatus 10 has a rectangular housing 14 providing a
platform on which a variety of appliances or devices may be mounted. The
housing has an opening 16 in one side for receiving the pole 12.
At one end of the housing 14 is a fixed truck 18 facing one
side of the opening 16. At the opposite side of the opening is a clamping
15 truck 20 that is retracted into the housing and will extend into clamping
engagement with the pole 12 when the climber is in use. The arrangement
of the drive rollers of the two trucks is illustrated most particularly in Figure
2. As shown in that Figure, two parallel fixed truck rollers 22 and 24 are
spaced axially along the pole 12 to engage the pole tangentially. Two
20 additional parallel fixed truck rollers 26 and 28 are likewise spaced axiallyalong the pole 12 to engage the pole tangentially. The rollers 22 and 24 are
spaced circumferentially from the rollers 26 and 28 to provide a V
configuration. The clamping truck 20 carries a roller 30 that is
circumferentially spaced from the fixed truck rollers 22 - 28 and engages the
25 pole tangentially, midway between the two sets of fixed truck rollers. This
provides a stable support for the climbing apparatus on the pole, resisting
tilting of the climbing apparatus in any direction.
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The internal construction and operation of the apparatus is
illustrated most particularly in Figures 3 and 4. As shown in Figure 3, the
apparatus is mounted in a rectangular frame 32 fabricated from light weight
metal channel. The frame provides the support for the external housing
5 illustrated in Figure 1.
The fixed truck assembly 18 has two box-like housings 34 and
36. The housing 34 accommodates the rollers 22 and 24, while the housing
36 accommodates the rollers 26 and 28. These two housings are mounted
on the frame 32 in a V-arrangement, with both housings opening to the
10 center of the frame, where the rollers will confront the pole. A V-shaped
web 38 joins the two housings to maintain their proper alignment. The
rollers are mounted in the two housings using appropriate bearings (not
shown) .
The rollers 22 and 26 are coupled by an upper drive shaft 40
15 with two universal joints 42 and 44. This ensures that the two rollers rotatein unison at the same speed. Similarly, a lower drive shaft 46 connects the
two rollers 24 and 28 to ensure that they also rotate in unison. To drive the
rollers, the outer ends of rollers 22 and 24 are fitted with chain sprockets
52 and 54 respectively. A chain 56 engages around the sprocket 52 and a
20 sprocket 58 located between the two rollers. Similarly, a chain 60 links the
sprocket 54 to a center sprocket 62, coaxial with the sprocket 58. Idlers 64
and 66 mounted on the housing 34 maintain tension in the chains. The
sprockets 58 and 62 are mounted on a common drive shaft 68 so that
rotation of the drive shaft will drive all of the fixed truck rollers at the same
25 speed and in the same direction. The drive shaft 68 is connected through a
set of bevel gears 70 to a drive shaft 72. For the sake of clarity, the
support bearings for the drive shafts 68 and 72 are not shown.
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The drive shaft 72 is driven through a chain drive 74 from a
gearbox 76. The input of gearbox 76 is an output shaft 78 of a worm gear
gearbox 80. The worm gear is driven from below by an air motor that will
be described more fully in the following. The gearbox 80 has another
5 output shaft 82 that leads to a further right angle gearbox 84. The output
of gearbox 84 is through a drive shaft 86 to the clamping truck 20. To
accommodate movements of this truck, the drive shaft 86 incorporates two
universal joints 88 and 90 and a spline 92 that allows the shaft to expand
and contract in length.
The clamping truck roller 30 is mounted in a clamping truck
housing 94. This is supported on the frame 32 by a four bar linkage 96.
The linkage includes two arms 98 and 100 connected to the housing 94 by
respective pivots 102 and 104 and to the apparatus frame by pivots 106
and 108 respectively.
Movement of the clamping truck is effected using two
pneumatic cylinders 110. Only one of these is illustrated, the other being
directly below the illustrated cylinder as shown in Figure 3. The cylinder is
connected to the frame by a lug 112 and a pin 114. The rod end of the
cylinder is connected to a lug 118 that is pinned to the housing 94 by the
pivot 102. Actuation of the cylinders 110 will move the clamping truck
housing 94 and thus roller 30 towards and away from the V formed by the
rollers 22 - 28 to clamp a pole between the two trucks. When the gearbox
80 is driven, it drives all of the rollers in the same direction, causing the
climbing apparatus to travel up or down a pole on which it is mounted.
The worm gear is driven by a motor 120 illustrated in Figure 5.
The motor has a housing 122 containing three identical motor units 124,
126 and 128. These are pneumatic or air motors of the type used in
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pneumatic drills or wrenches. They are highly reliable, relatively high speed,
low torque motors fitted with integral planetary gear trains to provide a
reduced speed, higher torque output. The three motors are arranged in
parallel to drive a common planetary gear train 130. The gear train includes
5 three planet gears 132 connected to the output shafts of the respective
motors and a sun gear 134 coupled to the output shaft of the composite
motor. This composite motor is relatively light in weight and provides the
requisite high torque output while providing an added safety factor in that if
any one of the motors should fail, the other two will carry on operating.
The pneumatic circuitry for the apparatus is illustrated in Figure
6. That drawing illustrates six air lines 136 for the three motors. These are
all connected through a manifold 138 to two lines 140. The lines 140
extend to a remote console 142 where they are connected to a three-way
valve 144 that allows the motors to be driven in either direction. The
15 console is connected through two air lines 146 to the cylinder 110. A valve
148 on the console is used to control the application of air pressure to these
lines.
The climbing apparatus described in the foregoing is a compact
unit with a relatively simple operating system. It can be used reliably on
20 poles of a variety of different sizes, including poles that taper and that are
curved to a horizontal orientation near the top. The location of the fixed
truck adjacent one end of the climbing apparatus allows it to be used where
there is very little clearance between the pole and some other object. No
variable position or pressure sensitive controls of the rollers is required as
25 the clamping roller automatically follows the contour of the pole, exerting asubstantially uniform force on the pole under the influence of a constant
pneumatic pressure applied to the cylinder 110.
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While one embodiment of the present invention has been
described in the foregoing, it is to be understood that other embodiments
are possible within the scope of the invention. The invention is to be
considered limited solely by the scope of the appended claims.
