U.S. patent application number 13/534564 was filed with the patent office on 2012-10-25 for hyraulic elevating platform assembly.
This patent application is currently assigned to John W. Boyd. Invention is credited to John W. Boyd, Timothy J. Dimmick, George Hicks, Ronnie D. Hicks, William P. Whitwell.
Application Number | 20120267196 13/534564 |
Document ID | / |
Family ID | 40405656 |
Filed Date | 2012-10-25 |
United States Patent
Application |
20120267196 |
Kind Code |
A1 |
Boyd; John W. ; et
al. |
October 25, 2012 |
HYRAULIC ELEVATING PLATFORM ASSEMBLY
Abstract
An elevating platform assembly is provided. In accordance with
one exemplary embodiment a platform is present and is moveable
along a travel distance of a mast. A cylinder is provided and is
capable of being actuated. The cylinder is used to move the
platform along the travel distance.
Inventors: |
Boyd; John W.; (Denmark,
SC) ; Whitwell; William P.; (US, SC) ; Hicks;
George; (Maylene, AL) ; Hicks; Ronnie D.;
(Brierfeld, AL) ; Dimmick; Timothy J.; (Anderson,
SC) |
Assignee: |
Boyd; John W.
Denmark
SC
|
Family ID: |
40405656 |
Appl. No.: |
13/534564 |
Filed: |
June 27, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11897558 |
Aug 31, 2007 |
8210319 |
|
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13534564 |
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Current U.S.
Class: |
182/145 |
Current CPC
Class: |
B66B 9/04 20130101 |
Class at
Publication: |
182/145 |
International
Class: |
E04G 1/18 20060101
E04G001/18 |
Claims
1. An elevating platform assembly, comprising: a mast; a platform
carried by said mast and moveable along a travel distance of said
mast; and a cylinder capable of being actuated, wherein said
cylinder is used to move said platform along the travel
distance.
2. The elevating platform assembly as set forth in claim 1, wherein
said cylinder is a hydraulic cylinder.
3. The elevating platform assembly as set forth in claim 1, further
comprising a cable that is used in order to place said cylinder
into communication with said platform.
4. The elevating platform assembly as set forth in claim 3, further
comprising a load cell assembly configured for measuring the amount
of tension in said cable, wherein measurement of tension in said
cable is used for conducting a self-diagnostic.
5. The elevating platform assembly as set forth in claim 1, further
comprising a counterweight attached to said platform and movable
with respect to said mast, wherein the weight of said counterweight
is selected so as to be less than the dead weight of said
platform.
6. The elevating platform assembly as set forth in claim 1, further
comprising: a braking plate carried by said mast, wherein said
braking plate is arranged so as to extend substantially along the
travel distance of said mast; and a hydraulic brake carried by said
platform, wherein said hydraulic brake is capable of engaging said
braking plate in order to lock the position of said platform at a
location along the travel distance of said mast.
7. The elevating platform assembly as set forth in claim 6, wherein
said hydraulic brake is normally locked so as to lock the position
of said platform at a location along the travel distance of said
mast, and wherein said hydraulic brake is capable of being
hydraulically actuated in order to be unlocked so as to permit
movement of said platform along the travel distance of said
mast.
8. The elevating platform assembly as set forth in claim 1, further
comprising a pulley system configured for translating a distance of
movement of said cylinder into a greater distance of movement of
said platform along the travel distance.
9. The elevating platform assembly as set forth in claim 1, wherein
actuation of said cylinder is synchronized with rotation of a shell
adjacent to said platform such that said platform is moved along
the travel distance as said shell rotates in order to aid in
applying fiberglass to the shell to form a fiberglass tank.
10. An elevating platform assembly, comprising: a mast; a platform
carried by said mast and movable along a travel distance of said
mast; a hydraulic cylinder capable of being actuated; a cable
configured for transmitting motion of said hydraulic cylinder to
said platform for use in moving said platform along the travel
distance; and a hydraulic brake configured for locking said
platform to said mast such that said mast is fixed at a particular
position along the travel distance.
11. The elevating platform assembly as set forth in claim 10,
further comprising a load cell assembly configured for measuring
the amount of tension in said cable, wherein measurement of tension
in said cable is used for conducting a self-diagnostic.
12. The elevating platform assembly as set forth in claim 10,
further comprising a counterweight attached to said platform by a
counterweight cable, wherein said counterweight is supported by
said mast and is movable with respect to said mast, and wherein the
weight of said counterweight is selected so as to be less than the
dead weight of said platform.
13. The elevating platform assembly as set forth in claim 10,
wherein said hydraulic brake has a pair of caliper brake pads
carried by said platform, and wherein said mast has a braking plate
that is arranged so as to extend substantially along the travel
distance of said mast, wherein said caliper brake pads are arranged
on either side of said braking plate and are capable of engaging
said braking plate in order to lock said hydraulic brake to lock
said platform to said mast.
14. The elevating platform assembly as set forth in claim 10,
wherein said hydraulic brake is normally locked so as to lock said
platform to said mast, wherein application of hydraulic pressure to
said hydraulic brake acts to unlock said hydraulic brake so as to
allow said platform to be moved along the travel distance.
15. The elevating platform assembly as set forth in claim 10,
further comprising a pulley system located between said cable and
said hydraulic cylinder, wherein said pulley system is configured
for transmitting motion of said hydraulic cylinder to said cable,
wherein said pulley system is configured so that a specific
distance of movement of said hydraulic cylinder is translated into
a greater distance of movement of said platform along the travel
distance.
16. The elevating platform assembly as set forth in claim 15,
further comprising a hydraulic cylinder cable connecting said
hydraulic cylinder to said pulley system, wherein said pulley
system is arranged so as to translate approximately one foot of
movement of said hydraulic cylinder into approximately four feet of
movement of said platform along the travel distance.
17. The elevating platform assembly as set forth in claim 10,
wherein actuation of said hydraulic cylinder is synchronized with
rotation of a shell adjacent to said platform such that said
platform is moved along the travel distance as said shell rotates
in order to aid in applying fiberglass to the shell to form a
fiberglass tank.
18. The elevating platform assembly as set forth in claim 10,
further comprising a pair of sheaves mounted onto said mast,
wherein said cable engages both of said sheaves.
19. The elevating platform assembly as set forth in claim 10,
further comprising at least one platform guide bearing carried by
said platform, wherein said mast has a track that is engaged by
said platform guide bearing in order to render said platform
movable with respect to said mast.
20. An elevating platform assembly, comprising: a mast, wherein
said mast has a braking plate; a platform carried by said mast and
movable along a travel distance of said mast, wherein said braking
plate is arranged so as to extend substantially along the travel
distance; a hydraulic cylinder capable of being actuated; a pulley
system in communication with said hydraulic cylinder; a cable
attached to said pulley system, wherein said cable is configured
for transmitting motion of said hydraulic cylinder to said platform
for use in moving said platform along the travel distance, wherein
said pulley system is arranged so that an amount of movement of
said hydraulic cylinder is translated into a greater amount of
movement of said platform along the travel distance; and a
hydraulic brake carried by said platform and configured for
engaging said braking plate in order to lock said platform to said
mast, wherein said hydraulic brake is normally locked so that said
platform is locked to said mast, wherein said hydraulic brake is
capable of being hydraulically actuated so as to be urged into an
unlocked configuration to allow said platform to move along the
travel distance.
Description
FIELD OF THE INVENTION
[0001] The present invention relates generally to elevating
platforms for use in raising and lowering workers at a construction
or assembly site. More particularly, the present application
involves a hydraulic elevating platform assembly that makes use of
hydraulics to raise and lower a platform along a mast and to unlock
a brake that normally locks the platform to the mast.
BACKGROUND OF THE INVENTION
[0002] Platform assemblies are used during construction in order to
support workers and equipment at desired elevations. Platforms of
this kind include stationary scaffolding that requires a
significant amount of labor to set up and subsequently modify
should a change in elevation be desired. As such, in order to save
both time and labor elevating platform assemblies are useful for
quickly and effortless moving workers and equipment to desired
elevations. Elevating platform assemblies typically include a mast
that is erected adjacent to the object being constructed or
assembled. The mast carries a platform onto which the workers or
equipment are supported. The platform can be moved vertically along
the mast to a particular point and can be locked into place once
the particular elevation is achieved.
[0003] One known way of moving the platform up and down along the
mast involves the use of a drum and cable system. Here, a cable is
attached to the platform and is wound around a drum that is located
either on the mast or on the ground. Although suitable for their
intended purpose, cable and drum systems are typically disfavored
as a result of certain disadvantageous present in these types of
designs.
[0004] Another means used to motivate platforms vertically along
the mast is a rack and pinion drive assembly. The rack is oriented
in a vertical manner along a portion of the mast. A plurality of
drive pinions are rotatably mounted onto the platform. An
appropriate driving means, such as a motor, is located on the
platform and rotate the pinions in order to raise and lower the
platform along the rack. A safety device such as an overspeed
pinion can be incorporated in order to brake the platform along the
rack should the platform travel too quickly.
[0005] Although rack and pinion systems are capable of moving a
platform along the mast, the drive mechanism for the system is
included on the platform. The pinion driving mechanism may take up
space on the platform that could be used for holding workers or
equipment. Additionally, should something happen to the pinion
driving mechanism it cannot be repaired from the ground thus
forcing additional, potentially costly, measures to be taken to
remove the workers and equipment from the platform and to then
access the platform to make the appropriate repairs. Also, the
pinion and gearing components in the driving mechanism can be
damaged through side impacts of the platform during loading and the
construction process. These impacts on components could cause their
failure, result in their damage thus reducing overall performance,
and necessitate costly repair. As such, there remains room for
variation and improvement within the art.
SUMMARY OF THE INVENTION
[0006] Various features and advantages of the invention will be set
forth in part in the following description, or may be obvious from
the description, or may be learned from practice of the
invention.
[0007] One aspect of one exemplary embodiment provides for an
elevating platform assembly that has a mast that carries a
platform. The platform is moveable along a travel distance of the
mast. A cylinder is present and is capable of being actuated. The
cylinder is used to move the platform along the travel
distance.
[0008] Another aspect of an additional exemplary embodiment resides
in an elevating platform assembly as immediately discussed in which
the cylinder is a hydraulic cylinder.
[0009] An additional aspect of a further exemplary embodiment
includes an elevating platform assembly as previously mentioned
that further has a cable that is used in order to place the
cylinder into communication with the platform.
[0010] One aspect of another exemplary embodiment involves an
elevating platform assembly as mentioned above that additionally
includes a braking plate carried by the mast. The braking plate is
arranged so as to extend substantially along the travel distance of
the mast. A hydraulic brake is carried by the platform. The
hydraulic brake is capable of engaging the braking plate in order
to lock the position of the platform at a location along the travel
distance of the mast.
[0011] Yet another aspect of a further exemplary embodiment is
found in an elevating platform assembly as immediately discussed in
which the hydraulic brake is normally locked so as to lock the
position of the platform at a location along the travel distance of
the mast. The hydraulic brake is capable of being hydraulically
actuated in order to be unlocked so as to permit movement of the
platform along the travel distance of the mast.
[0012] A further aspect of another exemplary embodiment includes an
elevating platform assembly that has a mast and a platform carried
by the mast. The platform is movable along a travel distance of the
mast. A hydraulic cylinder capable of being actuated is included.
Also present is a cable configured for transmitting motion of the
hydraulic cylinder to the platform for use in moving the platform
along the travel distance. A hydraulic brake is likewise included
and is configured for locking the platform to the mast so that the
mast is fixed at a particular position along the travel
distance.
[0013] Another aspect of a further exemplary embodiment includes an
elevating platform assembly as immediately mentioned in which the
hydraulic brake has a pair of caliper brake pads carried by the
platform. The mast has a braking plate that is arranged so as to
extend substantially along the travel distance of the mast. The
caliper brake pads are arranged on either side of the braking plate
and are capable of engaging the braking plate in order to lock the
hydraulic brake to lock the platform to the mast.
[0014] A further aspect of yet another exemplary embodiment
includes an elevating platform assembly as mentioned previously in
which the hydraulic brake is normally locked so as to lock the
platform to the mast. The application of hydraulic pressure to the
hydraulic brake acts to unlock the hydraulic brake so as to allow
the platform to be moved along the travel distance.
[0015] One aspect of one exemplary embodiment provides for an
elevating platform assembly that has a mast with a braking plate. A
platform is carried by the mast and is movable along a travel
distance of the mast. The braking plate is arranged so as to extend
substantially along the travel distance. A hydraulic cylinder that
is capable of being actuated is also present. A pulley system is
included and is in communication with the hydraulic cylinder. Also
present is a cable that is attached to the pulley system. The cable
is configured for transmitting motion of the hydraulic cylinder to
the platform for use in moving the platform along the travel
distance. The pulley system is arranged so that an amount of
movement of the hydraulic cylinder is translated into a greater
amount of movement of the platform along the travel distance. A
hydraulic brake is carried by the platform and is configured for
engaging the braking plate in order to lock the platform to the
mast. The hydraulic brake is normally locked so that the platform
is locked to the mast. The hydraulic brake is capable of being
hydraulically actuated so as to be urged into an unlocked
configuration to allow the platform to move along the travel
distance.
[0016] These and other features, aspects and advantages of the
present invention will become better understood with reference to
the following description and appended claims. The accompanying
drawings, which are incorporated in and constitute part of this
specification, illustrate embodiments of the invention and,
together with the description, serve to explain the principles of
the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] A full and enabling disclosure of the present invention,
including the best mode thereof, directed to one of ordinary skill
in the art, is set forth more particularly in the remainder of the
specification, which makes reference to the appended Figs. in
which:
[0018] FIG. 1 is an elevation view of an elevating platform
assembly with the platform in the upper raised position in
accordance with one exemplary embodiment.
[0019] FIG. 2 is an elevation view of the elevating platform
assembly of FIG. 1 with the platform in the bottom lowered
position.
[0020] FIG. 3 is a section view taken along line 3-3 of FIG. 1.
[0021] Repeat use of reference characters in the present
specification and drawings is intended to represent the same or
analogous features or elements of the invention.
DETAILED DESCRIPTION OF REPRESENTATIVE EMBODIMENTS
[0022] Reference will now be made in detail to embodiments of the
invention, one or more examples of which are illustrated in the
drawings. Each example is provided by way of explanation of the
invention, and not meant as a limitation of the invention. For
example, features illustrated or described as part of one
embodiment can be used with another embodiment to yield still a
third embodiment. It is intended that the present invention include
these and other modifications and variations.
[0023] It is to be understood that the ranges mentioned herein
include all ranges located within the prescribed range. As such,
all ranges mentioned herein include all sub-ranges included in the
mentioned ranges. For instance, a range from 100-200 also includes
ranges from 110-150, 170-190, and 153-162. Further, all limits
mentioned herein include all other limits included in the mentioned
limits. For instance, a limit of up to 7 also includes a limit of
up to 5, up to 3, and up to 4.5.
[0024] The present invention provides for an elevating platform
assembly 10 that can be used to position workers and equipment at
different elevations at a construction or assembly site. The
workers and/or equipment may be located on a platform 14 that is
carried by a mast 12 and is movable vertically therewith. A
cylinder 18 that may be a hydraulic cylinder 18 is provided and is
actuated in order to move the platform 14 with respect to mast 12
so that the workers and/or equipment can be located at a desired
elevation. A hydraulic brake 30 can also be included in order to
lock the platform 14 to the mast 12. The hydraulic brake 30 can be
arranged so that it is normally locked and must be actuated through
hydraulic pressure in order to be unlocked so as to allow the
platform 14 to be able to move with respect to mast 12.
[0025] One exemplary embodiment of the elevating platform assembly
10 is shown in FIG. 1. Here, the elevating platform assembly 10 is
located adjacent a shell 36 that is used in the construction of a
fiberglass tank. A worker may use elevating platform assembly 10 in
order to be located at various elevations of the shell 36. The
worker can spray fiberglass onto the shell 36 that may rotate about
its axis, in order to form a wound fiberglass tank. Although shown
for use in constructing a fiberglass tank, the elevating platform
assembly 10 can be used in a variety of applications and it is to
be understood that the disclosed application is but one
example.
[0026] The elevating platform assembly 10 includes a mast 12 that
is made of a generally open steel framework. The mast 12 can
include I-beams that are arranged vertically and are tied together
though a system of interconnecting trusses. However, it is to be
understood that the disclosed arrangement of mast 12 is but one
example and that others are possible in accordance with various
exemplary embodiments. A platform 14 is located at and can move
along an end of mast 12. FIG. 3 is a section view taken along line
3-3 in FIG. 1 and shows various features of the platform 14. The
platform 14 can be made by a series of longitudinally and laterally
positioned steel members. A grate can be placed upon the steel
members to form a floor 68 of platform 14 onto which workers and
equipment may rest. Although not shown for purposes of clarity,
safety railing can extend from the floor 68 of platform 14 to help
contain workers and equipment therein. A gate 74 is also present in
order to afford a portal through which workers and equipment may be
transported onto and off of the platform 14. The mast 12 includes
an emergency ladder 78 that extends vertically along mast 12 and is
located proximate to the gate 74 of platform 14 throughout its
travel distance 16. Should the platform 14 become disabled the
emergency ladder 78 can be utilized in order to evacuate workers
from the platform 14 or to allow repair personal to access the
platform 14 and other areas of the mast 12.
[0027] The mast 12 has a pair of I-beams 70 and 72 located on the
same side of mast 12 as the platform 14. Each of the I-beams 70 and
72 carry a track 52 along at least a portion of their lengths.
Platform guide bearings 50 are carried by the platform 14 and
engage the track 52. The platform 14 is thus rendered mobile with
respect to the mast 12. Additional guide bearings 50 are located
below the two illustrated in FIG. 3 so that a total of four guide
bearings 50 are present in the described elevating platform
assembly 10. However, it is to be understood that other
arrangements of the elevating platform assembly 10 are possible in
which any number of guide bearings 50 can be employed. For example,
up to sixteen guide bearings 50 can be used in accordance with
various exemplary embodiments. Further, it is to be understood that
the described manner of rendering the platform 14 mobile with
respect to the mast 12 is but one example and that others are
possible.
[0028] FIG. 1 shows the platform 14 in its upper most location on
mast 12. The elevating platform assembly 10 is designed so that the
platform 14 has a travel distance 16 along mast 12. The travel
distance 16 may be sixty feet in accordance with one exemplary
embodiment when the elevating platform assembly 10 is used to
construct a fiberglass tank. Other embodiments are possible in
which the travel distance 16 may be from thirty to two hundred
feet. A counterweight 26 is included that is used to at least
partially balance the weight of platform 14 and its associated
cargo. The counterweight 26 is attached to a counterweight cable 38
that engages sheaves 64 and 66 that are rotatably mounted onto an
upper portion of the mast 12. The counterweight cable 38 can be
three quarter inch diameter 6.times.37 wire rope in accordance with
one embodiment. It is to be understood that as used herein, the
term "cable" is broad enough to encompass wire, rope, any
combination of the two or any other equivalent structure. The
sheaves 64 and 66 may be fourteen inch outer diameter #S14ACF
sheaves in accordance with one exemplary embodiment. The
counterweight cable 38 is attached on an opposite end to a lifting
lug 34 of the the platform 14. Although the counterweight 26 can be
selected to be of any desired weight, in certain embodiments the
counterweight 26 is sized so as to be approximately three hundred
pounds less than the dead weight of the platform 14. In this
manner, should approximately three hundred pounds of weight be
placed onto the platform 14 by way of workers and/or equipment the
resulting arrangement will only need a minimal amount of force to
be applied thereto in order to move the platform 14 to a desired
location. Additionally, should the applied force or braking device
fail, the presence of counterweight 26 will act to balance the
platform 14 so that it does not uncontrollably fall along mast
12.
[0029] The platform 14 is moved along the travel distance 16
through the use of a cylinder 18. The cylinder 18 may be any type
of cylinder. For example, the cylinder 18 can be a pneumatic
cylinder or may be a hydraulic cylinder in accordance with various
embodiments. In the embodiment shown, cylinder 18 is a hydraulic
cylinder 18. Also, in accordance with one exemplary embodiment the
hydraulic cylinder 18 has a four inch bore, one hundred and eighty
inches of stroke 20, and is operated at three thousand PSI.
Although not shown, a hydraulic fluid source, a hydraulic fluid
pump, a pressure relief valve and other components common to a
hydraulic system may be present in order to actuate the hydraulic
cylinder 18. Actuation of the hydraulic cylinder 18 causes movement
of a cable 22 that is attached to the platform 14 on one end.
Sheaves 46 and 48 are present and are rotatably attached to an
upper portion of the mast 12. The sheaves 46 and 48 may be fourteen
inch outer diameter #S14ACF sheaves in one embodiment. The cable 22
is supported along a portion of its length by the sheaves 46 and
48.
[0030] Application of hydraulic pressure to a rod 54 in the
hydraulic cylinder 18 causes the rod 54 to be moved in the vertical
direction as shown in FIG. 2. The rod 54 has a stroke 20. Movement
of the rod 54 causes a corresponding movement of cable 22 that in
turn cause a movement of platform 14 along the travel distance 16.
The elevating platform assembly 10 can be arranged so that for
every foot of movement of the rod 54 the platform 14 experiences
one foot of movement along mast 12 in the travel distance 16. Other
arrangements are possible so that a particular stroke 20 of rod 54
translates into a greater distance of movement of platform 14 along
the travel distance 16. FIGS. 1 and 2 show one such embodiment in
which a pulley system 32 is employed in order to cause a particular
stroke 20 to be translated into a greater distance of movement of
the platform 14. A pulley system 32 is present in order to cause a
particular distance of travel of rod 54 to be translated into a
greater distance of travel of platform 14. The pulley system 32
employs a pair of double pulleys for causing a 4:1 distance
translation. The cable 22 runs over a first pulley 56 that in this
case is the sheave 46. Cable 22 is then run down across a fourth
pulley 62 and subsequently back up and across a second pulley 58
that is rigidly connected to the first pulley 56. From here, the
cable 22 runs down and across a third pulley 60 that is rigidly
connected to the fourth pulley 62. Finally, cable 22 runs from the
third pulley 60 upwards and is connected on its end to a hook
extending from the second pulley 58. A hydraulic cylinder cable 44
can be present and can connect the fourth pulley 62 to an end of
the rod 54.
[0031] The cable 22 can be a three quarter inch 6.times.37 wire
rope in accordance with one exemplary embodiment. The pulley system
32 thus makes use of a four part load line in order to achieve a
desired distance translation. In one embodiment, the pulley system
32 can be a Crosby McKissick 680 block with two fourteen inch
diameter sheaves. The model number for this type of pulley system
32 is C10D14BH and is provided by the Crosby Group, Inc. having
corporate headquarters at 2801 Dawson Rd., Tulsa, Okla. 74110.
[0032] FIG. 1 shows the hydraulic cylinder 18 arranged so that the
rod 54 is located at its lowest vertical position. The hydraulic
cylinder cable 44 is likewise pulled to its lowest vertical
position which forces the pulley system 32 to be extended so that
the pulleys 56 and 58 are located their greatest distance from
pulleys 60 and 62. Cable 22 is thus arranged so that the platform
14 is located at its upper most position on the mast 12. When the
platform 14 is at this position, the counterweight 26 is located at
its lowest vertical position. Application of hydraulic pressure to
the bottom of rod 56, or alternatively lowering of hydraulic
pressure on the upper side of rod 56, causes it to be moved
vertically upwards into the position shown in FIG. 2. Here, the rod
56 has been actuated so that it has traversed its entire stroke 20.
Doing so causes the pulley system 20 to be moved so that the
pulleys 56 and 58 are located in close proximity to the pulleys 60
and 62. The pulley system 32 is thus moved generally upwards which
causes the cable 22 to be moved generally to the right in FIG. 2 so
that the platform 14 is moved into its lowest vertical position.
The counterweight 26 is likewise moved in response to force being
varied to the platform 14 so that it is located in its highest
vertical position in FIG. 2.
[0033] Movement of the full stroke 20 of the hydraulic cylinder 18
between FIGS. 1 and 2 causes the platform 14 to be moved between
its highest and lowest point. As the distance ratio of the pulley
system 32 is 4:1, the platform 14 is moved four times as far as the
rod 54 upon comparison between FIGS. 1 and 2. In the exemplary
embodiment shown, the stroke 20 of rod 54 is fifteen feet thus
resulting in sixty feet of travel of the platform 14 along the
travel distance 16. Although the presence of pulley system 32
causes a desired travel increase of platform 14 it necessarily
causes a greater force to be applied by the hydraulic cylinder 18
in effecting this increase. Typically, if a 4:1 travel ratio is
achieved through the pulley system 32 the hydraulic cylinder 18
must exert four times the weight of platform 14 in order to effect
this movement. However, the presence of counterweight 26 can cause
this force to be relatively small and within the operating limits
of the hydraulic cylinder 18. Also, friction in the pulley system
32 and along the sheaves 46 and 48 will result in a less than 4:1
ratio of force being needed. Application or removal of hydraulic
pressure to the top of rod 54 can cause the rod 54 to be moved
vertically lower so that the platform 14 and other previously
discussed components are moved back into the positions shown in
FIG. 1.
[0034] The elevating platform assembly 10 may include a hydraulic
brake 30 for use in locking the platform 14 to the mast 12 so that
its position along the travel distance 16 does not change. A
braking plate 28 can be arranged on the mast 12 so that it extends
in the vertical direction. The braking plate 28 may extend the
entire length of the travel distance 16 and can be connected to an
I-beam or other member making up the mast 12. A hydraulic brake 30
can be carried by the platform 14 and can be of a caliper type. In
accordance with one exemplary embodiment, hydraulic brake 30 is a
TWIFLEX .RTM. brake of The Hilliard Corporation having offices
located at 100 West Fourth Street, Elmira, N.Y. 14902-1504. The
hydraulic brake 30 has a pair of caliper brake pads 40 that engage
the braking plate 28 in order to lock the position of the platform
14 with respect to the mast 12. The caliper brake pads 40 are
normally urged to the locked position so that they engage the
braking plate 28, and hence lock the platform 14 in place, without
the application of any hydraulic pressure to the hydraulic brake
30. In this regard, springs or other urging components or other
configurations can be implemented to cause the hydraulic brake 30
to be normally locked. The locking force can be such that
application of full hydraulic pressure to hydraulic cylinder 18
does not cause enough force to be imparted onto platform 14 to
overcome the locking force of hydraulic brake 30.
[0035] The hydraulic brake 30 may thus cause the platform 14 to
remain locked in place in the travel distance 16 should an event
such as a snapping of cable 22 or counterweight cable 38 occur.
Further, the loss of hydraulic pressure will not function to drop
the platform 14 as the hydraulic brake 30 is normally locked onto
the braking plate 28 without the need of hydraulic pressure. When a
user wants to move the platform 14, hydraulic pressure can be
applied to the hydraulic brake 30 in order to cause the hydraulic
brake 30 to become unlocked. In this regard, the caliper brake pads
40 will disengage from the braking plate 28 to allow the platform
14 to move along the mast 12 in the travel distance 16. However,
due to particular loading on the platform 14, the amount of
counterweight 26 present, or the application or non-application of
hydraulic pressure to the hydraulic cylinder 18 the platform 14 may
or may not move. Hydraulic pressure can then be applied to the
hydraulic cylinder 18 in a desired fashion in order to move the
platform 14 either up or down in the travel distance to a desired
elevation on the mast 12. Although shown as incorporating both a
cylinder 18 and a hydraulic brake 30, it is to be understood that
other arrangements of the elevating platform assembly 10 need not
have both of these components or be configured in the illustrated
and described manners. For example, in one particular embodiment,
the elevating platform assembly 10 can have a hydraulic brake 30
but does not include a cylinder 18.
[0036] The elevating platform assembly 10 may also feature a
self-diagnostic check upon start-up. A load cell assembly 24 can be
included and may be attached on one end to the cable 22 and on the
other end to the lifting lug 34 of the platform 14. The load cell
assembly 24 can measure the amount of tension in the cable 22. Once
the elevating platform assembly 10 is turned on, the system can
introduce slack in the cable 22 that is measured by the load cell
assembly 24. Slack in cable 22 may be representative of a fall of
the platform 14, snapping of cable 22, or a loss of hydraulic
pressure to the hydraulic cylinder 18. The self-diagnostic may be
able to recognize slack in cable 22 and ensure that sufficient
locking force is provided by the hydraulic brake 30 to ensure that
the platform 14 does not fall vertically along the mast 12. Also,
the self-diagnostic feature may be capable of imparting tension
onto the cable 22 that can be read by the load cell assembly.
Excessive tension on cable 22 may be indicative of too much weight
being placed onto the platform 14. The self-diagnostic feature can
detect the excessive tension on cable 22 and ensure that sufficient
braking force is being applied by the hydraulic brake 30 and/or
that sufficient holding force is being applied by the hydraulic
cylinder 18 to ensure that platform 14 does not fall.
[0037] Although described as being implemented in a self-diagnostic
check, the aforementioned checks and corrections can be implemented
during operation of the elevating platform assembly 10 if desired.
Various systems of the elevating platform assembly 10 can be in
communication with a microprocessor that is capable of providing
corrective action to the assembly 10 based upon measured readings.
If too little tension is sensed in the cable 22, the safety system
may function to shut down the cylinder 18 and apply the hydraulic
brake 30 to lock the platform 14 in place. Should too much tension
be measured in the cable 22, the cylinder 18 can once again be shut
down and the hydraulic brake 30 can be applied to lock the platform
14 in place.
[0038] The elevating platform assembly 10 is located next to a
shell 36 as shown in FIGS. 1 and 2. Shell 36 is used in the
construction of a fiberglass tank. Track 80 is present so that the
shell 36 can be rotated about its axis. The mast 12 can be
constructed so that the platform 14 is capable of traversing the
engire shell height 82 of shell 36. During construction of the
fiberglass tank, the shell 36 can be rotated about track 80 and
fiberglass can be applied by a worker standing on the floor 68 of
platform 14. The worker is positioned proximate to shell 36 through
the placement of platform 14 and can apply the fiberglass via an
applicator. Once a desired amount of fiberglass has been applied to
a particular spot of the shell 36, the platform 14 can be raised so
that a new section of shell 36 is exposed for the application of
fiberglass thereon. The rotation of shell 36 and movement of
platform 14 can be made manually or automatically. Further, their
movements can be synchronized with one another in accordance with
one exemplary embodiment. For example, a microprocessor may be
capable of recognizing the rotation of shell 36 such that the
platform 14 is moved in response so that an even amount of
fiberglass is applied to each section of the shell 36.
[0039] Although described as being capable of traversing the entire
shell height 82, the platform 14 may be capable of traversing only
a portion of the shell height 82 in other embodiments. Further,
although described as being positioned adjacent a shell 36 for use
in manufacturing a fiberglass tank, the elevating platform assembly
10 need not be used for this purpose in other embodiments. In this
regard, the elevating platform assembly 10 can be used in a variety
of applications in which the elevation of workers or equipment is
desirable. When used for the purposes of manufacturing a fiberglass
tank, the tank can be constructed in a manner described in U.S.
patent application Ser. No. 11/323,215 filed on Dec. 30, 2005
titled "Apparatus and Method for Making Large Diameter Wound-Fiber
Reinforced Tanks" the entire contents of which are incorporated
herein by reference in their entirety for all purposes.
[0040] While the present invention has been described in connection
with certain preferred embodiments, it is to be understood that the
subject matter encompassed by way of the present invention is not
to be limited to those specific embodiments. On the contrary, it is
intended for the subject matter of the invention to include all
alternatives, modifications and equivalents as can be included
within the spirit and scope of the following claims.
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