U.S. patent application number 14/352615 was filed with the patent office on 2014-09-11 for deck panel, load platform, clamp and tensioner.
The applicant listed for this patent is Web Rigging Services Ltd.. Invention is credited to Gordon Irvine Bisset.
Application Number | 20140251730 14/352615 |
Document ID | / |
Family ID | 45373507 |
Filed Date | 2014-09-11 |
United States Patent
Application |
20140251730 |
Kind Code |
A1 |
Bisset; Gordon Irvine |
September 11, 2014 |
DECK PANEL, LOAD PLATFORM, CLAMP AND TENSIONER
Abstract
A decking panel is provided having first and second ends and
fasteners at each end for releasably clipping the panel to a pair
of support or catenary wires. The fasteners comprise hooks for
supporting the panel on the wires and at least one finger for
resisting lift of the panel from the wires, wherein the hooks and
finger or fingers at one end are offset from the hooks and finger
or fingers at the other end. In embodiments a cross-member at each
end of the panel pivotally supports a lever carrying the finger or
fingers, the lever being rotatable between a vertical position
where the fingers are clear of the hooks and a lowered position
wherein the fingers underlie the hooks for clamping a catenary
cable between them, gravity biasing the levers towards the lowered
position. At either end of the panel treadplates may be hinged to
the panel at pivot axes spaced from the ends of the panel with free
ends at least partially overlying the levers, the treadplates being
liftable form a normal lowered position in which the fingers are
covered to a vertical position where the levers are
user-accessible. The invention also provides a load platform
comprising catenary wires and panels as aforesaid clipped to the
catenary wires for providing the platform. In an embodiment
adjustable support chains are connected to the catenary wires at
intervals between their ends for supporting vertical load, and the
adjustable support chains are connected to catenary wires by
friction clips that surround the catenary wires and frictionally
engage therewith to inhibit the catenary wires from being pulled
through them in the event of wire failure. In a further embodiment
tensioners in the catenary wires are fitted with in-line load cells
permitting the tension in the wires to be set to a desired
value.
Inventors: |
Bisset; Gordon Irvine;
(Edinburgh, GB) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Web Rigging Services Ltd. |
Inverkeithing |
|
GB |
|
|
Family ID: |
45373507 |
Appl. No.: |
14/352615 |
Filed: |
October 26, 2012 |
PCT Filed: |
October 26, 2012 |
PCT NO: |
PCT/GB2012/052664 |
371 Date: |
April 17, 2014 |
Current U.S.
Class: |
182/150 |
Current CPC
Class: |
E04G 1/154 20130101;
E04G 3/00 20130101; E01D 19/106 20130101; E01D 22/00 20130101 |
Class at
Publication: |
182/150 |
International
Class: |
E04G 3/00 20060101
E04G003/00; E01D 22/00 20060101 E01D022/00 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 27, 2011 |
GB |
1118568.3 |
Claims
1-69. (canceled)
70. A decking panel comprising: first and second ends, a pair of
longitudinal stiles between which decking is supported and
fasteners at each end of the decking panel for releasably clipping
the panel to a pair of wires by which it is to be supported; said
fasteners comprising hooks provided at first and second ends of
said first and second stiles for supporting the panel on the wires
and catch assemblies for resisting lift of the panel from the
wires, each catch assembly comprising a cross-member pivotally
supporting one or more levers each carrying a catch finger, the or
each lever being rotatable between a raised position where the
finger or fingers are clear of the hooks and a lowered position
where the finger or fingers register with the hooks from underneath
for clamping a support cable between the hooks and the fingers; and
treadplates at each end of the panel, hinged thereto at pivot axes
spaced from the ends of the panel and with free ends facing towards
the ends of the panel, the treadplates being liftable from a normal
lowered position in which the or each catch assembly is concealed
by the treadplate to a raised position in which the or each catch
assembly is user-accessible.
71. The decking panel of claim 70, wherein the panel comprises
ladder-like cross-members or diagonal cross-members defining a
truss-type structure between the stiles.
72. The decking panel of claim 70, including one or more of the
following features: (a) the stiles are extrusions in aluminium; (b)
the extrusions each comprise a region of box section into which the
hooks fit; portions of the region of box section defining outer and
inner webs spaced apart transversely of the panel; one hook at each
end of the panel being fastened to the outer web of one of the
stiles and the other hook at each end being fastened to the inner
web of the other of the stiles; (c) the extrusions further comprise
portions of the region of box section that define an upper web from
which an upstanding wall arises; and portions that define a lower
web formed with a recess into which at least uppermost regions of
the upstanding walls can be received, whereby when one panel is
stacked on another lateral displacement of the upper panel is
resisted; (d) each stile is formed adjacent each end at its inner
vertical web with fixing formations for attachment of hooks and/or
fastening plates of a catch assembly, and is formed adjacent one
end at its outer vertical web with fixing formations for attachment
of a hook.
73. The decking panel of claim 70, including one or more of the
following features: (a) the stiles are of rolled steel; (b) the
stiles each comprise a portion defining a web to which hooks are
attached; one hook at each end of the panel is fastened to the web
of one of the stiles directly or at a relatively small spacing; and
the other hook at each end of the panel is fastened to the web of
the other of the stiles with a spacing that is larger than the
spacing for said one stile, the stiles and hooks being configured
so that the hooks at one end of the panel are offset transversely
of the panel relative to the hooks at the other end of the panel;
(e) the stiles further comprise portions that define an upper web
from which upstanding pins, ribs or other formations arise and
portions that define a lower web formed with recesses or sockets
into which at least uppermost regions of the upstanding pins, ribs
or other formations can be received whereby when one panel is
stacked on another lateral displacement of the upper panel is
resisted.
74. The decking panel of claim 70, wherein: the cross-members of
the catch assemblies each pivotally support a pair of levers spaced
apart transversely of the panel and interconnected at or adjacent
their ends facing away from a respective support cable by a handle;
and the treadplates are hinged to the panel for rotation about axes
spaced inboard and slightly above the pivot axes for the release
mechanism provided by said cross-members of the catch assemblies,
ends of the operating levers in the lowered position of the catch
assemblies being located almost immediately underneath inner hinged
ends of the treadplates, and on wind or other lift of the panel
lines through the points of contact of the levers with the
treadplates being close to the axes of the treadplate hinges
whereby upward load applied to the treadplates exerts little
rotational power on the treadplates.
75. The decking panel of claim 74, including any of the following
features: (a) the pair of levers is spaced apart by about one third
of the width of the panel; (b) each finger is formed with a recess
defining an upwardly-facing hook for engagement with the underside
of the support cable; (c) the fingers have plate-like surfaces
engageable with the support wire, friction between the fingers and
the support wire inhibiting lateral displacement of the panel.
76. The decking panel of claim 74, wherein free edges of the
treadplates extend beyond the styles and overlap the hooks.
77. The decking panel of claim 70, wherein each hook has a linear
lead-in region at its forward end, a quarter round upper forward
region and an upper linear central region leading to a curved rear
region.
78. The decking panel of claim 70, including: (a) wooden decking,
or (b) decking of sheet metal; or (c) decking in the form of a
grating or expanded metal.
79. A load platform comprising: spaced parallel support wires; one
or more slings, straps or legs thereof attached at their upper ends
to a structure beneath which the load platform is slung and
attached at their lower ends to the support wires at intermediate
positions along their length by clamps configured to frictionally
engage the wires for impeding the wires from travelling through
them; and either (a) decking comprising tensioned netting clipped
to the support wires or (b) a plurality of decking panels each
having first and second ends and fasteners at each end for
releasably clipping the panels in side-by-side relationship to a
pair of support wires, said fasteners each comprising hooks for
supporting the panel on the wires and at least one catch for
resisting lift of the panel from the wires.
80. The load platform of claim 79, including one or more of the
following features: (a) the support wires are secured to tensioners
configured for sensing tension and setting tension in the wires to
a desired value; (b) the tensioners comprise a body and oppositely
acting screw jacks together extensible from and retractable into
the body on rotation thereof; (c) the tensioners comprise a ratchet
for controlling rotation of the body and a handle for effecting
rotation. (d) opposed ends of the tensioners incorporate bifurcated
shackles and pins for attachment to wire eyes or the like, the
in-line sensor being between one of the screw jacks and a
shackle.
81. The load platform of claim 80, including one or more of the
following features: (a) said clamps are two-part hinged T-clamps
for fitting to said support wires and for attachment to the slings,
straps or legs thereof which in use are loaded in a direction
transversely of the support wires; (b) upper ends of the clamps are
formed with eyes for receiving hooks at the lower ends of the
slings or straps or legs thereof; (c) said clamps each comprise
first and second elongate members; hinge formations at one end of
said members forming parts of a hinge that connects the members
together for movement between an open position in which a support
wire is insertable into and removable from the clamp and a closed
position in which the first and second members contact one another
and the support wire is retained in the clamp; first and second
clamping jaws in said members for closing about and frictionally
engaging the support wire, one side of each clamping jaw being
adjacent the hinge; first and second stem regions of each of said
members arising from sides of the clamping jaws opposite to the
hinge and extending away from the hinge in a direction transversely
of the clamping jaw; and first and second eye regions extending
from ends of the first and second stem regions opposite to the
hinge and together defining an eye for receiving a hook of the
sling or strap or leg thereof, load on said first and second eye
regions urging the clamp towards its closed position. (d) apertures
in the first and second stem regions adjacent said first and second
eye regions for receiving a retaining bolt; (e) the first and
second stem regions and the first and second eye regions together
define planar surfaces that are in contact in the closed position;
(f) internal faces of the first and second eye regions at least
adjacent ends of the first and second members opposite to the hinge
are internally profiled to define a continuous curved surface for
receiving a hook of the sling or strap or leg thereof.
82. The load platform of claim 80, wherein the decking comprises
polyester netting.
83. The load platform of any of claim 80, comprising a plurality of
decking panels, the lower ends of the slings or straps or legs
thereof either being attached to the support wires between adjacent
pairs of panels or within the widths of individual panels.
84. The load platform of claim 83, wherein each panel includes:
first and second ends, a pair of longitudinal stiles between which
decking is supported and fasteners at each end of the decking panel
for releasably clipping the panel to a pair of wires by which it is
to be supported; said fasteners comprising hooks provided at first
and second ends of said first and second stiles for supporting the
panel on the wires and catch assemblies for resisting lift of the
panel from the wires, each catch assembly comprising a cross-member
pivotally supporting one or more levers each carrying a catch
finger, the or each lever being rotatable between a raised position
where the finger or fingers are clear of the hooks and a lowered
position where the finger or fingers register with the hooks from
underneath for clamping a support cable between the hooks and the
fingers; and treadplates at each end of the panel, hinged thereto
at pivot axes spaced from the ends of the panel and with free ends
facing towards the ends of the panel, the treadplates being
liftable from a normal lowered position in which the or each catch
assembly is concealed by the treadplate to a raised position in
which the or each catch assembly is user-accessible.
85. The load platform of claim 84, wherein in each panel: the
cross-members of the catch assemblies each pivotally support a pair
of levers spaced apart transversely of the panel and interconnected
at or adjacent their ends facing away from a respective support
cable by a handle; and the treadplates are hinged to the panel for
rotation about axes spaced inboard and slightly above the pivot
axes for the release mechanism provided by said cross-members of
the catch assemblies, ends of the operating levers in the lowered
position of the catch assemblies being located almost immediately
underneath inner hinged ends of the treadplates, and on wind or
other lift of the panel lines through the points of contact of the
levers with the treadplates being close to the axes of the
treadplate hinges whereby upward load applied to the treadplates
exerts little rotational power on the treadplates.
86. The load platform of claim 85, including any of the following
features: (a) the pair of levers is spaced apart by about one third
of the width of the panel; (b) each finger is formed with a recess
defining an upwardly-facing hook for engagement with the underside
of the support cable; (c) the fingers have plate-like surfaces
engageable with the support wire, friction between the fingers and
the support wire inhibiting lateral displacement of the panel.
87. The load platform of claim 85, wherein free edges of the
treadplates extend beyond the styles and overlap the hooks.
88. The load platform of claim 84, wherein each hook has a linear
lead-in region at its forward end, a quarter round upper forward
region and an upper linear central region leading to a curved rear
region.
89. The load platform of claim 84, including: (a) wooden decking,
or (b) decking of sheet metal; or (c) decking in the form of a
grating or expanded metal.
Description
FIELD OF THE INVENTION
[0001] The present invention provides a deck panel supportable on a
pair of spaced parallel support (catenary) wires and a platform of
a plurality of the catenary wires carrying a multiplicity of the
deck panels. It also provides a T-clamp useful e.g. in platforms of
the above kind for attaching tension members e.g. slings to the
wires. It further provides an in-line tensioning device for
catenary cables and its use in platforms supported by catenary
cables.
BACKGROUND TO THE INVENTION
[0002] U.S. Pat. No. 5,299,655 (Margaritis) discloses suspended
structures providing a workplace beneath bridges and other like
structures. Cables are each fixedly connected at opposite ends to
said underlying bridge supports and lie parallel to one another in
a substantially common horizontal plane spaced a predetermined
distance below the substructure, tension in the cables being
adjustable by means of turnbuckles. The two outermost cables are
spaced from one another by a distance at least substantially as
great as the width of said bridge. Load-bearing flooring is
supported by the cables and extends the full width between the
outermost cables and the full length between the bridge supports.
The floor is constructed of chain-link fence which is unrolled so
as to lay on the cables, and is wrapped around the cables and
secured thereto with clips, after which the chain-link fence floor
is covered with nylon tarpaulin or other fluid-impermeable
material.
[0003] U.S. Pat. No. 5,730,248 (Apostolopoulos) aims to provide an
improvement on such platforms by reducing the time needed to erect
and dismantle them, and to provide rigid support for workmen
standing or walking thereon. Flooring sections or panels of sheet
material of elongated rectangular shape corrugated for strength at
right angles to the cables together form a platform, are supported
by the under-bridge longitudinal cables in side-by-side
relationship and are removably connected thereto. Each connection
is formed by a plate which engages the upper surface of a panel and
a generally U-shaped member which is attached to the plate to
extend downwardly therefrom to be received in a panel opening and
to receive the cable. The free end of the member is threadedly
attached to another plate wherein the two plates generally cover
the opening with the cable securely received between the legs of
the U-shaped member. U.S. Pat. No. 6,138,793 (Apostolopoulos)
provides a connector assembly which has a manually operated lever
for selectively placing the connector assembly in clamped or
un-clamped positions relative to the cable and flooring section.
However, these connector arrangements have been criticised as
unduly complex. The first described arrangement it requires two
parts to be assembled as well as a nut which must be screwed onto
the free end of the member, i.e., a total of three separate parts
as well as an electric or other wrench for applying the nut
sufficiently tight. The second lever-based arrangement requires two
parts to be assembled as well as a pin (or nut and bolt) for added
safety.
[0004] A rope clamp having a pair of jaws for clamping about a rope
or cable and having an eye for attachment of a second rope is shown
in U.S. Pat. No. 0,779,019 (Agobian). The disclosed utility is for
uniting ends of ropes. Forming an attachment at an intermediate
position along a rope or cable for a second rope, wire, chain or
the like in tension in a direction out of alignment with the first
rope about which clamping is effected is neither disclosed nor
suggested. A clamp having a pair of jaws for fastening about a wire
rope and having a hook attached to one of the jaws for attachment
of a second wire rope, e.g. a guy rope is disclosed in U.S. Pat.
No. 0,928,367 (De Witt). However, it is apparent that load on the
hook from the guy rope in a direction out of alignment with the
main rope tends to pull the jaws apart rather than tighten them
about the rope. By way of background, a further clamp for gripping
a cable or rope based on a pair of jaws is shown in U.S. Pat. No.
4,143,446 (Down). The jaws are screw clamped together and can
accommodate in-line an accessory permitting attachment of a hook,
eye, shackle, swivel or the like. However, it will be apparent from
the drawings that the Down attachment only enables this to be
achieved at an end of the rope.
[0005] Some embodiments of the invention provide panels which can
be fitted easily and rapidly to catenary wires with minimal gaps,
or with gaps of predetermined relatively small dimensions, between
their ends to form a load platform.
[0006] Other embodiments of the invention provide panels that can
be fitted to at least three support wires in rows and columns with
at least two adjacent panels having a common support wire, the
panels being configured so that they may be fitted either in
aligned rows or in a staggered arrangement.
[0007] It is a further object of the invention to provide a
platform comprising panels clipped between catenary wires, wherein
the effects of failure of a catenary wire are relatively localised,
support along the length of the platform being at least partly
retained.
[0008] It is a further object of the invention to provide platforms
supported by catenary wires in which the cables are optimally
adjusted.
[0009] A yet further object of the invention is to provide friction
clamps e.g. for use in association with load-carrying members e.g.
straps, wires, chains or slings that are of improved structure and
properties.
[0010] It will be appreciated that the invention has a number of
diverse aspects, and individual embodiments may not achieve ann or
indeed any of the above objects.
SUMMARY OF THE INVENTION
[0011] In one aspect the invention provides a decking panel having
first and second ends and fasteners at each end for releasably
clipping the panel to a pair of wires by which it is to be
supported, said fasteners comprising hooks for supporting the panel
on the wires and catch assemblies each including at least one
finger for resisting lift of the panel from the wires, the catch
assemblies being covered by treadplates hinged to the panel with
free ends facing outwardly and at least partly overlying the hooks,
raising the treadplates from the panel providing access to the
catch assemblies. Clipping can be achieved without the use of
tools, which is an advantage in such areas as an underdeck of
jetties, rigs, bridges and pipe racks. The underdeck can provide a
solid and stable work platform that feels like scaffolding and
users may be able to carry out a variety of heavy work tasks off
the deck as if it were scaffolding.
[0012] In a further aspect the invention provides a decking panel
having: first and second ends; and fasteners at each end for
releasably clipping the panel to a pair of wires by which it is to
be supported, said fasteners comprising hooks for supporting the
panel on the wires and at least one catch for resisting lift of the
panel from the wires; wherein the hooks and a catch or catches at
one end are offset from the hooks and a catch or catches at the
other end.
[0013] In a further aspect the invention provides a decking panel
having: first and second ends and fasteners at each end for
releasably clipping the panel to a pair of wires by which it is to
be supported; said fasteners comprising hooks for supporting the
panel on the wires and catch assemblies at each end of the panel
for resisting lift of the panel from the wires, each catch assembly
comprising a cross-member pivotally supporting one or more levers
each carrying a catch finger, the or each lever being rotatable
between a raised position where the finger or fingers are clear of
the hooks and a lowered position where the finger or fingers
register with the hooks from underneath for clamping a support
cable between the hooks and the fingers; and treadplates at each
end of the panel, hinged thereto at pivot axes spaced from the ends
of the panel and with free ends facing towards the ends of the
panel, the treadplates being liftable from a normal lowered
position in which the or each catch assembly is concealed by the
treadplate to a raised position in which the or each catch assembly
is user-accessible.
[0014] For use in an inter-tidal zone there may be provided a
decking panel for forming a load platform, said panel having first
and second ends and fasteners at each end for releasably clipping
the panel to a pair of wires by which it is to be supported, the
panel comprising a pair of longitudinal styles, cross-members
between the styles and decking in the form of a grating or expanded
metal.
[0015] In a further embodiment the invention provides a load
platform comprising spaced parallel wires supporting a plurality of
panels as defined above.
[0016] In a further aspect the invention provides a T-clamp for
fitting to a rope in tension and for attachment of a member which
in use is loaded in a direction transversely of the rope, said
clamp comprising: first and second elongate members; hinge
formations at one end of said members forming parts of a hinge that
connects the members together for movement between an open position
in which the rope is insertable into and removable from the clamp
and a closed position in which the first and second members contact
one another and the rope is retained in the clamp; first and second
clamping jaws in said members for closing about and frictionally
engaging the rope, one side of each clamping jaw being adjacent the
hinge; first and second stem regions of each of said members
arising from sides of the clamping jaws opposite to the hinge and
extending away from the hinge in a direction transversely of the
clamping jaw; and first and second hook or eye regions extending
from ends of the first and second stem regions opposite to the
hinge and together defining an a hook or eye for receiving an eye
or hook of the member, load on said first and second eye regions
urging the clamp towards its closed position.
[0017] The invention also provides in combination a clamp as
aforesaid and a wire or chain sling, the first and second members
having eyes and the sling having a hook.
[0018] A load platform according to the invention comprises support
wires, decking clipped to the support wires for providing the
platform, and one or more slings or straps attached at their upper
ends to a structure beneath which the load platform is slung and
attached at their lower ends to the wires at one or more
intermediate positions along their length, the attachment being by
T-clamps as aforesaid and lower ends of the slings being said
members, the clamps being configured to frictionally engage the
wires for impeding the wires from travelling through them.
[0019] In another embodiment the invention provides a load platform
comprising support wires and panels clipped to the support wires
for providing the platform, wherein adjustable support chains are
connected to the support wires at intervals between their ends for
supporting vertical load, and the adjustable support chains are
connected to support wires by friction clips that surround the
support wires and frictionally engage therewith to inhibit the
support wires from being pulled through them in the event of wire
failure.
[0020] A further aspect of the invention provides a platform
comprising: decking panels each having first and second ends and
each comprising (a) fasteners at each end for releasably clipping
the panel to a pair of wires by which it is to be supported, said
fasteners comprising hooks for supporting the panel on the wires
and catch assemblies for resisting lift of the panel from the
wires, and (b) treadplates at each end of the panel, hinged thereto
at pivot axes spaced from the ends of the panel and with free ends
facing towards the ends of the panel, the treadplates being
liftable from a normal lowered position in which the or each catch
assembly is concealed by a treadplate to a raised position in which
the or each catch assembly is user-accessible; at least three
spaced parallel wires supporting a plurality of decking panels
arranged in at least two columns, adjacent decking panels of
different columns having a common support wire; one or more slings
or straps attached at their upper ends to a structure beneath which
the platform is slung and attached at their lower ends to the
support wires at intermediate positions along their length; and
clamps providing attachment of the lower ends of the slings or
straps or legs thereof to the support wires, the clamps being
configured to frictionally engage the wires for impeding the wires
from travelling through them, the clamps being located on the
support wires within the widths of individual panels and free edges
of treadplates of adjacent panels at a common support wire being
spaced apart to permit portions of the clamps attached to the
support wire to pass upwardly between the treadplates.
[0021] It will be appreciated that in this embodiment by locating
the clamps on the support wires within the widths of adjacent
panels it is not necessary to space apart decking panels of the
rows at the sling or strap positions. In embodiments upper ends of
the clamps are formed with eyes for receiving hooks at the lower
ends of the slings or straps or legs thereof. In further
embodiments the clamps may comprise first and second members hinged
together below the support wires, said members having concave
clamping regions for fitting about the support wires and stems
extending from the clamping regions to above the treadplate,
portions of the stems defining eyes that coincide for receiving
hooks of the slings or strap or legs thereof.
[0022] A further embodiment of the panel comprises a decking panel
having first and second ends and fasteners at each end for
releasably clipping the panel to a pair of wires by which it is to
be supported, the panel comprising decking and a support framework
including a pair of longitudinal styles, wherein the upper regions
of the styles have upstanding formations and lower regions of the
styles having matching recesses or sockets in which at least
uppermost regions of the upstanding formations can be received,
whereby when one panel is stacked on another, displacement of the
upper panel laterally is resisted.
[0023] Another aspect of the invention provides a load platform
comprising support wires and panels clipped to the support wires
for providing the platform, wherein the support wires are secured
to tensioners configured for sensing tension and setting tension in
the wires to a desired value. Although turnbuckle tensioners are
known, the applicants have not found a turnbuckle tensioner with a
built-in load cell or other tension-measuring device. In
applications involving load-carrying generally horizontal wires in
tension, as in the present load platforms, it is desirable to be
able to set a determined tension in the wires without
over-tensioning.
[0024] A yet further embodiment of the invention comprises a
tensioner for a support wire, rope or the like comprising a body
and oppositely acting screw jacks together extensible from and
retractable into the body on rotation thereof, attachments at the
ends of the screw jacks for wire eyes or the like, and a measuring
device for measuring tension applied to the wire.
[0025] It will be appreciated that the features set out above may
be used in combination with one another and in sub-combinations.
Thus any of the preferred decking panels, support chain and clamp
arrangements, tensioners and load platform arrangements may be used
in association with one another and, for example the support chain
and clamp arrangements and the tensioners may be used with other
types of decking panels.
[0026] Thus the invention further provides a load platform
comprising support or catenary wires and panels clipped to the
catenary wires for providing the platform, wherein adjustable
support chains and clamps are connected to the catenary wires at
intervals between their ends for supporting vertical load, and the
adjustable support chains are connected to catenary wires by
friction clips that surround the catenary wires and frictionally
engage therewith to inhibit the catenary wires from being pulled
through them in the event of wire failure, the catenary wires being
secured to tensioners configured for sensing tension and setting
tension in the wires to a desired value.
BRIEF DESCRIPTION OF PREFERRED FEATURES
[0027] The above decking panel in embodiments is generally
rectangular and comprises a pair of longitudinal styles and
cross-members between the styles. The cross-members may include
ladder-like cross-members and/or diagonal cross-members defining a
truss-type structure.
[0028] Embodiments of the styles are extrusions in aluminium. Such
extrusions may in embodiments each comprise a region of box section
into which the hooks fit, portions of the region of box section
defining outer and inner webs spaced apart transversely of the
panel, one hook at each end of the panel being fastened to the
outer web of one of the styles and the other hook at each end being
fastened to the inner web of the other of the styles. Such
extrusions may further comprise portions of the region of box
section that define an upper generally horizontal web from which an
upstanding wall arises and portions that define a lower generally
horizontal web formed with a recess into which at least uppermost
regions of the upstanding walls can be received, whereby when one
panel is stacked on another lateral displacement of the upper panel
is resisted. Each style may be formed adjacent each end at its
inner vertical web with fixing formations for attachment of
fastening plates of a catch assembly and/or for attachment of
hooks, and may be formed adjacent one end at its outer vertical web
with fixing formations for attachment of a hook.
[0029] In alternative embodiments the styles are of rolled steel,
e.g. in channel, I or Z-section. In this case, the styles may each
comprise a portion defining a web to which hooks are attached, one
hook at each end of the panel being fastened to the web of one of
the styles directly or at a relatively small spacing, and the other
hook at each end of the panel being fastened to the web of the
other of the styles with a spacing that is larger than the spacing
for said one style, the styles and hooks being configured so that
the hooks at one end of the panel are offset transversely of the
panel relative to the hooks at the other end of the panel. The
styles may further comprise portions that define an upper generally
horizontally-directed web from which upstanding pins, ribs or other
formations arise and portions that define a lower generally
horizontally-directed web formed with recesses or sockets into
which at least uppermost regions of the upstanding pins, ribs or
other formations can be received whereby when one panel is stacked
on another lateral displacement of the upper panel is resisted.
[0030] In embodiments of the above panel, the cross-member carries
a pair of levers spaced apart transversely of the panel and
interconnected at or adjacent their ends facing away from the
support cable by a handle. For ease of fitting to support wires in
both aligned and staggered arrangements, the pair of levers is
conveniently spaced apart by about one third of the width of the
panel. Each finger may be formed with a recess defining an
upwardly-facing hook for engagement with the underside of the
support cable or it may have a plate-like surface engageable with
the support wire, friction between the fingers and the support wire
inhibiting lateral displacement of the panel.
[0031] Decking may be wooden e.g. of plywood, may be of metal or
may be of expanded metal especially where the decking is to be used
in tidal conditions and may be submerged at some states of the
tide.
[0032] For support at intermediate longitudinal positions the above
load or work platform may further comprise one or more slings or
straps attached at their upper ends to a structure beneath which
the load platform is slung and attached at their lower ends to the
support wires at one or more intermediate positions along their
length. Lower ends of the slings or straps or legs thereof may be
attached to the support wires between adjacent pairs of panels or
may be attached to the support wires at locations within the widths
of individual panels. In either case, the lower ends of the slings
or straps or legs thereof may be attached to the support wires by
clamps (e.g. two-part hinged T-clamps) configured to frictionally
engage the wires for impeding the wires from travelling through
them. Free edges of treadplates of adjacent panels at a support
wire may spaced apart for access of the support wire and
upwardly-facing portions of clamps attached to the support wire may
extend between the treadplates.
[0033] For tensioning the support wires the tensioners may comprise
a body and oppositely acting screw jacks together extensible from
and retractable into the body on rotation thereof. They may further
comprise a ratchet for controlling rotation of the body and a
handle for effecting rotation, and their opposed ends may
incorporate bifurcated shackles and pins for attachment to wire
eyes or the like, the in-line sensor being between one of the screw
jacks and a shackle.
[0034] With reference to the above clamp, there may be further
comprised apertures in the first and second stem regions adjacent
said first and second hook or eye regions for receiving a retaining
bolt. In some embodiments the first and second stem regions and the
first and second hook or eye regions together define planar
surfaces that are in contact in the closed position. To reduce
point loads and permit the member to be at an angle relative to the
clamp, in some embodiments internal faces of the first and second
hook or eye regions at least adjacent ends of the first and second
members opposite to the hinge are internally profiled to define a
continuous curved surface for receiving an eye or hook of the
member.
[0035] In general in relation to load platforms, the decking may
comprise panels clipped or otherwise releasably fastened to the
wires, in which case embodiments of the panels comprise a pair of
longitudinal styles and cross-members between the styles. Lower
ends of the slings or straps or legs thereof in some embodiments
are attached to the support wires between adjacent pairs of panels
and in other embodiments are attached to the support wires within
the widths of individual panels. Alternatively in some embodiments
the decking comprises tensioned netting clipped to the support
wires, e.g. polyester netting.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] How the invention may be put into effect will now be
described by way of example only with reference to the accompanying
drawings, in which like parts are so far as practical represented
by the same reference numerals, and in which:
[0037] FIG. 1 is an isometric view of a short section of a first
embodiment of a suspended load platform and associated support or
catenary wires with treadplates of deck panels together providing
the load platform shown in their raised position to reveal the
catenary wires and parts of opening mechanisms of the deck
panels;
[0038] FIG. 2 is a plan view of a first embodiment of a deck panel
forming part of the load platform of FIG. 1 and FIG. 3 is plan of
one end of the panel on a larger scale;
[0039] FIG. 4 is a side view of a casting forming part of an
opening mechanism for the deck panel of FIGS. 2 and 3;
[0040] FIG. 5 is an end view of the deck panel with its treadplates
in their closed flat position;
[0041] FIG. 6 is a partial section of the deck panel on the line A
of FIG. 3 showing part of a style and of the opening mechanism;
[0042] FIG. 7 is a section of a style forming part of the deck
panel of FIG. 2;
[0043] FIG. 8 is an oblique view of an end of the load panel with
its treadplate raised showing the release mechanism and a short
length of support or catenary wire;
[0044] FIG. 9 is a perspective view of a first embodiment of a
clamp forming part of a support strap for supporting a catenary
wire at an intermediate position along its length;
[0045] FIG. 10 is a plan of a tensioning device useful in
tensioning catenary cables of load platforms of the general kind
illustrated in FIG. 1, the device being in its fully retracted
state;
[0046] FIG. 11 is an oblique view of the tensioning device of FIG.
10 in its fully extended state;
[0047] FIG. 12 is a view on an enlarged scale of an in-line load
cell forming part of the tensioning device of FIGS. 10 and 11.
[0048] FIG. 13 is a perspective view of a pair of styles forming
part of a second embodiment of the deck panel;
[0049] FIG. 14 is a side view of a hook and a lever forming part of
the deck panel of FIG. 12, said lever incorporating an
underhook;
[0050] FIG. 15 is a partly exploded perspective view of one end of
a deck panel according to the second embodiment, and FIG. 16 is an
underneath view of said end in in an assembled state;
[0051] FIG. 17 is an underneath perspective view of the panel of
FIG. 12 with one treadplate in a partly raised state and the other
treadplate in a lowered state and showing solid decking;
[0052] FIG. 18 is an underneath perspective view of a third
embodiment of the panel employing expanded metal decking and FIG.
19 is an enlarged top perspective view of the panel of FIG. 18
showing a treadplate and an adjacent region of decking;
[0053] FIG. 20 is an underneath view showing six decking panels in
position on support wires;
[0054] FIG. 21 is a view showing five decking panels in position on
support wires, with two of the decking panels staggered relative to
the other three;
[0055] FIG. 22 is an exploded perspective view of part of a style
of a further embodiment of the panel together with a spacer, hook
and cross-member fixing plate, the style being in rolled steel;
[0056] FIG. 23 is a side view of portions of adjacent deck panels
adjacent a common support wire, styles and hooks being removed to
reveal the support wire, overlapping underhooks and a second
embodiment of a T-clamp fitted to the support wire;
[0057] FIG. 24 is a front view of the T-clamp shown in FIG. 23;
[0058] FIG. 25 is an enlarged perspective view of part of the
support wire, the T-clamp shown in FIG. 23, and a hook and part of
a chain forming part of a chain sling for supporting a load
platform; and
[0059] FIGS. 26 and 27 are perspective views of first and second
members together forming a clamp as illustrated in FIG. 23, the
views showing the inner faces of the members.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0060] FIG. 1 shows a short section of work platform erected for
demonstration purposes. Catenary wires (also referred to herein as
support wires) 10a, 10b, 10c are supported under tension in spaced
parallel relationship from a fixed structure, in this instance
posts 17 and rails 16, the ends of the catenary wires being
attached to the rails 16 by attachment fittings 18a-18c. The
catenary wires in an embodiment may be 16 mm diameter wire rope,
6.times.36 lay with an internal wire rope core, the internal core
imparting resistance to stretching. For demonstration purposes in
the illustrated embodiment an upper set of catenary wires 12a, 12b,
12c is provided. Adjustable support chains 14 or slings with
attachments 15 at each of their ends are provided at intermediate
longitudinal positions for supporting the catenary wires 10a, 10b,
10c from an overlying structure, in this instance the catenary
wires 12a, 12b, 12c. In this embodiment the attachments 15 at each
end of the chains take the form of friction clamps e.g. as
described below. Deck panels 20a-20l e.g. of length 2-4 metres
(e.g. 2 metres, 3 metres or 4 metres) fit onto and are supported by
the catenary wires 10a-10c in abutting relationship side-to-side
and end to end in a column and row arrangement as shown. UK working
at height regulations require that the deck should have a minimum
of gaps or spaces through which tools or other items could be
inadvertently dropped, and similar requirements exist in other
countries. Further, there is a risk of lateral displacement of the
panels e.g. during the course of erection of the platform and it is
desirable to provide means for increasing the resistance of the
load platform to such displacement.
[0061] The arrangement of FIG. 1 is only diagrammatic, and the
support for the load platform will vary widely depending on the
structure to which the load platform is fitted and the task to be
performed. The structure may be e.g. a steel bridge, a concrete
bridge, a jetty, a marine platform or any other large structure
where an underneath temporary work platform needs to be provided
e.g. for inspection or maintenance purposes. In many instances the
overlying structure may incorporate or be fitted with eyes which
provide convenient attachment points for an under-slung work
platform. For example in the case of a concrete bridge structure,
eye-bolts can be fitted to the sides and underside of the bridge.
Slings may be fastened between the eyes and the load platform
catenary wires and may e.g. be single leg or two leg slings e.g. in
chain or wire rope. An oblong master link at the upper end of each
sling may be connected to a respective eye by a hook, e.g. a
latched or locking hook, or by a shackle or by other fastening
means. The or each sling leg may have a hook at its lower end that
fits under and supports the catenary wire, but preferably is fitted
at its lower end with a friction clamp that surrounds and
frictionally engages the catenary wire to both provide local
support for that wire and resist it sliding through the clamp as
described below. In the case of a jetty having one or more large
steel pipelines passing along it, adjustable support chains may be
passed over the pipelines from one side to another and the ends of
the adjustable support chains may act as the adjustable support
chains 14 of FIG. 1 carrying clamps 15. The number of catenary
wires and of rows of deck panels will depend on the size of the
structure that it is needed to inspect or maintain and in some
embodiments the platform will extend the whole length and width of
the overlying structure or it may extend over or along a region of
that structure where inspection or repairs are to be carried
out.
[0062] As is apparent from FIG. 2, the deck panels 20 may
conveniently take the form of ladder-type structures with styles
22, 24 and cross-members or rungs 26. Such structures are more
convenient and may carry greater loads than corrugated metal sheet
panels.
[0063] Styles 24 which are conveniently aluminium extrusions are
shown in enlarged section in FIG. 7 and are of box-section with at
their upper outer edges upstanding stepped walls 60 and at their
lower outer edges matching recesses 62. Panels can be stacked one
on top of another for storage or transport with the upper step
regions of the walls 60 fitting into the recesses 62 to avoid
lateral displacement of one panel relative to another and to hold
the upper panels at a predetermined spacing just above the lower
panels. In the embodiment shown the height of the box-section is 50
mm and its width is 35 mm, its side webs are 2 mm thick and its top
and bottom walls are 4 mm thick. The wall 60 has a total height of
12 mm or 15 mm, a width at its base of 6 mm and a width at its
stepped top region of 3 mm. The relatively thick base region of the
wall 60 and the top wall of the box portion together define a step
into which wooden decking or metal sheet or mesh can fit and be
retained. The 3 mm thick top region of the wall 60 fits into the
recess 62 of an overlying style which is 3 mm wide and 3 mm high.
The dimensions given above can be varied without departing from the
invention, but are intended to provide a general teaching as to
preferred dimensions and proportions for some, but not all,
embodiments of the invention. The cross-members or rungs 26 may be
square, oval or any convenient section and are attached to the
styles to form a rigid structure. Further, parallel ladder-type
cross-members as illustrated are only one possible form of
construction and other forms of framework e.g. planar truss
frameworks e.g. with a single diagonal pair of cross-braces, two or
more pairs of cross-braces or Allan or Howe-type truss
configurations could equally be used, the over-riding requirement
being for a lightweight open framework with sufficient strength for
the intended load and giving sufficient support for the intended
decking.
[0064] Decking 40 is laid on the ladder-type or other framework
structures and is attached thereto, the decking being of timber,
metal sheet or metal mesh or grating, aluminium or steel being
preferred. Where the platform is of mesh or grating, it may
conveniently be used to erect a platform in tidal conditions where
it will be covered with water at some states of the tide. In the
present embodiment the decking may be of plywood.
[0065] Opposed ends of the deck panels are formed with hooks 28a,
28b, 30a, 30b attached to the styles 22, 24 for fitting opposed
ends of the deck panels onto respective pairs of catenary wires
10a, 10b or 10b, 10c as shown in FIG. 1. As can be seen in FIG. 3,
hooks 30a, 30b are attached asymmetrically to styles 22, 24 within
the box section of each style. Hook 30a is attached to the outer
vertical web of style 22 and hook 30b is attached to the inner
vertical web of style 24, the corresponding hooks at the opposite
end of the panel having the reverse fixing arrangement. The hooks
have a thickness in this embodiment of 6 mm and resist bending. The
staggered arrangement of the hooks at each end when a pair of
panels 20a, 20g has adjacent ends supported by a common catenary
wire 10b allows the panels to be in alignment without interference
between the adjacent hooks of the two panels.
[0066] Each deck panel is provided at each end with a catch
sub-assembly or operating mechanism 32, 34 for retaining the panel
in position on its catenary wires against lifting or other
displacement forces e.g. from wind or in the case of a load
platform that may be submerged at some states of the tide from
estuarine or tidal currents. The catch sub-assemblies are normally
covered by hinged treadplates 52 which normally lie flat but which
can be rotated upwards to give access to the underlying catch
sub-assembly 32 or 34. Retaining fingers 36a, 36b, 38a, 38b are
movable into contact with the catenary wires from below to prevent
the deck panels being inadvertently lifted off the catenary wires
e.g. in high winds. Again as seen in FIGS. 3 and 5 the fingers 38a,
38b are laterally offset in one direction and the corresponding
fingers at the opposite end are laterally offset in the opposite
direction so that fingers of adjacent panels do not clash when a
pair of panels 20a, 20g has adjacent ends supported by a common
catenary wire 10b.
[0067] As apparent from FIG. 3 a catch sub-assembly for an end of a
treadplate comprises a tubular cross-member 54 which provides a
pivot axis for a pair of operating levers 42a, 42b and generically
indicated as 42 in FIG. 4. Each operating lever which can be made
as a casting comprises a base 46, an upstanding web 48 formed with
apertures into which handle 44 fits, an aperture 50 for forming a
bearing with cross-member 54 which fits into that aperture, and a
finger or under-hook generically indicated as 38 which projects
forwardly and is movable into and from engagement with the
underside of catenary cable 10 as shown in FIG. 8. The fingers 38
in this embodiment are bar-shaped and have width greater than their
depth, this aspect ratio being selected so that they present
relatively wide friction surfaces to the catenary cable. The width
of the fingers in an embodiment may be about 35 mm. When the deck
panel is in position on a pair of cables, gravity maintains the
fingers 38a, 38b in engagement with the undersides of the cables
and the weight of the base 46 and web 48 acting about the pivot
provided by cross-member 54 urges the fingers upwardly. The
resulting frictional force at each end of the panel provides
resistance to the panel becoming displaced laterally on the cables
e.g. because of slight slope the cable as when workers are standing
on the platform created by the deck panels or heavy objects are
placed on it, or as previously mentioned by wind and/or tide. An
advantage of the present mechanism is that it can operate purely by
gravity, no additional clip or fastening mechanism being needed,
although the use of such additional mechanisms is not excluded if
additional reassurance is required. As is apparent from FIG. 5, the
cross-member 54 is located a short spacing inboard of the ends of
the styles 52, 54 and at a vertical position below the top of the
styles. Compared to a front-hinged treadplate carrying locking
fingers, the pivot axis can be moved further away from the wire.
The position of the cross-members longitudinally and vertically
relative to the ends of the styles can be adjusted for specific
tasks so that e.g. if a deck panel is required to clip onto
something other than a cable e.g. a support of steel angle, then
only minor adjustment of the position of the cross-member 54 is
needed.
[0068] A first cross-member 64 extends between styles 22, 24
immediately behind the operating levers 42 and carries hinges 66. A
second side of the hinges attaches to a second cross-member 68 of
angle section fitted to the treadplate 52. Thereby the treadplate
52 is hinged to the panel for rotation about an axis spaced inboard
and slightly above the pivot axis for the release mechanism
provided by cross-member 54. As previously explained, it will
normally lie flat as shown supported by the horizontal top walls of
the styles 22, 24 as in FIG. 5 (where a slight gap is shown for
clarity) or by support pads on the upper surfaces of the styles but
can be lifted by raising its forwardly-facing free edge as in FIG.
8. In the illustrated embodiment the cross-member 54 is located 40
mm inboard of the ends of the styles 22, 25, whereas the treadplate
hinge is located about 201 mm inboard. It will be noted that the
ends of the operating levers 42 are located almost immediately
underneath the inner hinged ends of treadplate 52. If the panel is
subject to lift e.g. by wind the fingers 38a, 38b will tend to be
rotated away from register with the brackets 30a, 30b, tending to
release catenary wire 10. As most clearly apparent in FIG. 6 the
levers 42 then contact the treadplates 52, but are unlikely to lift
the treadplates 52. The reason is that the line through the points
of contact of the levers 42 with the treadplate 52 is close to the
axes of hinges 66 and although upward load may be applied to
treadplate, that load exerts little rotational power on the
treadplate. Magnetic catches (not shown) adjacent the free end of
the treadplate provide additional resistance to unintended lifting
of the treadplate and since the catches can be spaced along the
styles 22, 24 from the axis of hinge 66 they can offer significant
resistance to inadvertent rotation. The free edge of the treadplate
extends beyond the styles 22, 24 and overlaps the hooks 30a, 30b,
almost overlying the centre of the hooks with the shortfall in this
embodiment being about 3 mm. Accordingly when two panels are
assembled end-to-end on a common cable, the gap between the support
surfaces that they provide can be as little as 6 mm and the
treadplates almost meet one another with no downwardly curved
region between them where articles can lodge. However, the position
of the free edges of the treadplates is arbitrary and a wider gap
can be adopted e.g to permit the stem of a T-clamp on the wire rope
to pass upwardly between them as described below.
[0069] Laying a deck panel on its catenary wires is a two-person
operation. A person at each end of the panel lifts the treadplates
52 to a vertical position, grips handle 44 and lifts that handle to
a vertical position, rotating the fingers 38a, 38b clear of hooks
40a, 40b. The handles 44 are then conveniently positioned for
carrying the panel. At the start of laying, the panel is positioned
over the catenary wires e.g. 10a, 10b and lowered into place.
Release of the handles 44 permits the opening mechanisms to rotate
by gravity until the fingers 36 engage the catenary wire, after
which a small force on the treadplates 52 allows them to fall under
gravity into their fully lowered position. The mechanism is
therefore robust and simple to operate, and it is resistant to
inactivation as a result of paint or other materials which are
likely to become deposited on it during service and which in other
designs of deck panel jam the release mechanism and may prevent
operation.
[0070] FIG. 8 shows the treadplates 52 partially raised to reveal
the release mechanism. Spacer tubes 70a, 70b on cross-member 54
between the styles 22, 24 and the operating levers 42a, 42b define
asymmetric locations for the levers and fingers 38a, 38b. In this
way the fingers of adjacent deck panels at ends facing one another
on the same catenary wire do not interfere.
[0071] FIG. 9 shows a generally T-shaped strap clamp 15 used in
particular to fasten a strap 14 to a catenary wire 10a, the strap
providing support to the catenary wire at a position partway along
its length. Up to now attachment between the adjustable support
chains and the catenary wire has been via hooks as are conventional
for rope or chain slings, but although these provide lift they
offer no resistance to pulling the catenary wire through them.
There is no reason to expect a catenary wire to break or be cut
through, but provision for very rare events with serious
consequences is desirable. Strap clamps 15 are formed in halves 80,
81 pivoted together at 82 and together define a cavity 84 which
surrounds and frictionally engages the catenary wire. Through holes
86 receive a captive bolt and integral threaded fitting to receive
the threaded end of the bolt. (not shown) to hold the parts firmly
together about the wire and exert a frictional load on the wire
preventing it being pulled through the clamp even if the wire
should break or be cut. The upper end 88 of the clamp in this
embodiment is bifurcated to receive an eye of a support wire or
chain which can be attached to the clamp by a pin inserted into
through-holes 90. In consequence, should the catenary wire be cut
or break, vertical support is maintained and the damage to the load
platform is localised. In this embodiment owing to the close
spacing between treadplates of adjacent decking panels the strap
clamps 15 are fitted to the support wires between adjacent deck
panels and fitting within the width of a deck panel is not
possible. As apparent in FIG. 1, therefore, small gaps are present
between adjacent panels 20c, 20d, 20i, 20j to permit stems of the
strap clamps to pass upwardly above the level of the deck panels
and provide attachment for wire or chain slings or the like.
[0072] Deck panels in aluminium according to the embodiments
described above may be lightweight e.g. about 14 kg/m.sup.2 and may
for example have a loading capacity of 0.5 kN to 5.5 kN UDL/m.sup.2
depending upon the requirements of a particular job. They are
easily maneuverable and easy to rig, and installation time may be
reduced compared to scaffolding.
[0073] The combination of catenary wires, support straps and clamps
is also useful where polyester tension netting is provided between
catenary wires in place of the panels described in the previous
Figures.
[0074] It has been found that the catenary wires of load platforms
of the present kind give optimum performance and stability when the
catenary wires that provide support are tensioned at or adjacent a
best value which will, of course, vary depending on the particular
structure under which the load platform is to be slung, and that
excessively high or low tensions are better avoided. For that
purpose the catenary wires may incorporate in-line load cells of
the kind illustrated in FIGS. 10-12. Thus such a tensioning device
may have body 100 fitted with oppositely acting jack screws 102,
104 shown fully retracted in FIG. 10 and fully extended in FIG. 11.
A reversible ratchet mechanism 116 and handle 118 enables body 100
to be rotated in either direction, so as to extend or retract the
screw jacks and hence increase or decrease the tension of a
catenary wire into which the tensioner is incorporated In an
embodiment the handle and ratchet mechanism enable a person to
develop approximately 50 N (50 kg) force to wind the tensioner in
or out. The pre-tension on the catenary wire is important as if the
tension is too high it is necessary to reduce the load capacity of
the decks. So in some embodiments applicants pretension between 5
and 10 kN, using the handle. The screw jacks terminate at a first
end fitting 106 and a second end fitting 108 each connected to a
shackle 112, 114 for receiving an eye of a catenary cable or the
like which is securable in place by pin 120, 122. The pins are
inserted into holes in the shackle and are held in place by smaller
retaining pins 126.
[0075] Between the end of jack screw 104 and shackle 114 the end
fitting 108 is an in-line load cell incorporating a pre-calibrated
spring-operated load measuring arrangement providing an output by
movement of indicator member 128 through a calibrated window, the
member indicating by its position the load which e.g. may be
between 0 and 30 kN. It will be appreciated that other types of
load cell may be employed, e.g. based on strain gauges and
electronic devices including a display, but a simple spring-loaded
device may be more convenient especially where the platform is to
be in place for extended periods and is subject to adverse weather.
However a transducer could be incorporated to provide an overload
indicator alarm.
[0076] FIG. 13 is perspective and partly inverted view of styles
22, 24 forming part of a load platform according to a second
embodiment of the invention, the styles being aluminium extrusions
having the same cross-section as in FIG. 7 and provided with hooks
28a, 28b at one end and hooks 30a, 30b at the other end. Each style
is formed with a region defining a box section formed in an inner
face or web 212 adjacent the ends thereof with patterns of fixing
holes 218, 218a, in this case four, for attachment of a catch
sub-assembly and/or for attachment of hooks 28a, 28b; 30a, 30b.
Apertures 218 also adjacent the ends and coinciding with the
patterns of fixing holes correspond to tubular cross-members 54.
The region of box section also has an outer face or web 210 formed
adjacent one end with fixing holes 214 for a hook 28a, 28b; 30a,
30b. With this arrangement the hooks may be fitted to the outer or
inner webs or faces of the box section as appropriate, using fixing
holes in the same spatial arrangement, and fixing plates for the
catch sub-assemblies may use the same spatial arrangement of fixing
holes on the inner webs 212. However on each style only a single
hook can be attached to the outer face or web. The inner webs 212
are also formed adjacent their ends with fixing holes 222, 222a for
hinge plate pivots and fixing holes 220, 220a for decking
cross-members.
[0077] FIG. 14 shows a hook plate 28 and a lever 36a' forming part
of a catch sub-assembly 32 or 34. The hook plate has a
downwardly-facing hook region 224 having at its forward end a
linear lead-in region 232 leading to a quarter-round upper forward
region 234, an upper linear central region 236 which in the case of
16 mm wire rope may be about 5 cm in length (i.e. about a third of
the diameter of the rope) and leading to a curved rear region 238.
With this hook profile, the panel may be fitted onto a support wire
10a, 10b or 10c with a certain amount of misalignment or twisting
being accommodated without damage to the rope. The hook plate is
formed with a pattern of fixing holes 230 corresponding to those in
the styles and also at its lower edge with a recess bounded by
faces 226 and 228 to permit the plate to slide into the hollow box
region of a style without interference from recess 62. Catch lever
or underhook 36a' is formed with aperture 244 so that it can fit
rotatably onto cross-member 54 and adjacent its rear or inner end
with fixing hole 246 for attachment of handle 44. It has an
outwardly or forwardly facing finger 240 formed at its upper edge
with an arcuate recess 242 for receiving a support wire, the centre
of the hook and the centre of the recess 242 coinciding at line
248.
[0078] In FIG. 15 which is a view of an end of a deck panel in
partly exploded view, there appears one of the two decking
cross-members 250 which is of inwardly-facing angle-section so as
to underlie and support the ends of decking 40 with side plates of
said cross-members fastened to the styles 22, 24 at fixing holes
220. Treadplate 52 has attached to its rear end on the underside
thereof an attachment member 252 also of angle-section formed with
side plates 254a, 254b with through holes for hinged attachment at
fixing holes 22 of the styles, the position of the hinge axis for
each treadplate being defined by the location of the fixing holes
222. Also appearing in FIG. 15 is catch sub-assembly 32 comprising
cross-member 54 which has forwardly and rearward-facing curved
regions and upper and lower planar regions that non-rotatably fit
into apertures 278 (FIG. 22) of mounting plates 256a, 256b. The
levers or underhooks 36a'', 36b'' fit rotatably onto the
cross-member 54 and are positioned transversely of the cross-member
by friction collars 36a''. As may be seen, their spacing is about
one third of the width of a deck panel to facilitate positioning of
adjacent panels on different support wires both in alignment and in
staggered relationship as described below. Handle 44 is connected
between the levers or underhooks adjacent inner ends thereof. The
mounting plates 256a, 256b are each formed with fixing holes 258
disposed in a pattern corresponding to those in the styles. FIG. 16
shows an end of the deck panel with both the treadplate 52 and the
catch sub-assembly 32 attached between the styles. The underside of
a deck panel with one of its treadplates raised appears in FIG. 17,
the decking 40 being of plywood or other sheet material. FIG. 18 is
an underneath view of another embodiment of the decking panel with
decking 260 of expanded aluminium mesh or honeycomb or aluminium
grating. Since this form of decking is more flexible than plywood,
a longitudinal stiffening bar 262 is fitted. In the above deck
panels, catches may be provided, e.g. magnetic catches, for holding
the treadplates in their lowered position when installed as part of
a load platform in a work area against inadvertent lifting through
the action of wind or water currents e.g. in an intertidal
zone.
[0079] FIG. 19 is an underneath view of panels 20a-20c of one
column and 20g-20i of an adjacent column, the panels being in
alignment and alignment being facilitated by the offset
relationship in the hooks and the catch sub-assemblies 32, 34. FIG.
21 is an underneath view on an enlarged scale showing ends of
panels 20a-20c of one column and panels 20h, 20i of another column,
this staggered relationship within rows being facilitated by the
relatively close spacing of the underhooks of the catch
sub-assemblies 32 and 34.
[0080] Although aluminium is a preferred material, generally square
sections in steel may be rolled for some markets where steel is
more practical and the rolled sections may have complementary
protuberances and recesses on their upper and lower faces which
interfit to allow stable stacking as described above although the
precise shapes for aluminium cannot be duplicated in rolled steel
and rolled steel styles will differ from those shown Rolled steel
sections may be of any conventional shape provided that a vertical
web portion is provided, and they may, for example be of channel, I
or Z-section, channel section being convenient in some embodiments.
Further sections are C- or channel section with their flanges
formed at their ends with return (in-turned) regions or flanges
which in some embodiments can significantly increase strength and
stiffness. In FIG. 22 a style 274 of channel section is formed
adjacent its ends with a pattern of fixing holes 276 corresponding
to the pattern of fixing holes 230 in hook member 28. A spacer
block 270 is provided and has fixing holes 272 in a pattern
corresponding to that in the style 274. Also shown is fixing plate
256a of a catch sub-assembly. It will be appreciated that a spacer
block 270 may be provided at each end of the resulting decking
panel in the style 274 on one side but not the other, and in this
way the hooks 28 may be attached in a similar staggered arrangement
to those in the previously described embodiments. As regards
stacking the panels, the styles may further comprise portions that
define an upper web from which upstanding pins, ribs or other
formations arise and portions that define a lower web formed with
recesses or sockets into which at least uppermost regions of the
upstanding pins, ribs or other formations can be received whereby
when one panel is stacked on another lateral displacement of the
upper panel is resisted, these pins, ribs, etc. are not shown but
can easily be implemented.
[0081] In FIGS. 23-25 there is shown end regions of a pair of
adjacent load platforms having a common support wire 10b to which
the load platforms are clipped inter alia by brackets 28a, 30b and
underhooks 36a' and 36b'. Above support wire 10b the free ends of
treadplates 52 are spaced apart to define a gap of e.g. about 25
mm. The wire 10b carries a T-clamp generally indicated by the
reference numeral 280 having a clamping region that fits tightly
around and friction grips the wire 10b and a stem that arises from
the support wire and passes between the support plates so that its
upper regions are accessible above the support plates. The T-clamp
comprises clamping members 282, 284 interfitting at their base with
a pair of spaced barrel hinge formations 310, 312 on the first
member 282 between which fits barrel hinge formation 314 on the
second member 284, the hinge being completed by hinge pin 286.
Above the barrel hinge the members 282, 284 are formed with
generally semi-cylindrical clamping regions 281, 283 which fit
around and grip the cable 10b, their axes being parallel to and
spaced from the hinge axis. Inner faces of the clamping regions
281, 283 are formed with inclined gripping teeth 315 matching the
lay of the wire rope 10b, the inner diameter of the clamping
regions being slightly smaller than the wire rope, e.g. 15.75 mm
for a wire rope of diameter 16 mm so that they can firmly grip the
rope but not crush it. Each member 282, 284 has a stem region 316,
318 arising from the clamping region, the stem region having a
width greater than its depth and the two stem regions together
having a depth of e.g. about 17 mm so that the stem can pass
between the plates 52. Adjacent the upper end of the stem region
the member 284 is formed with a socketed through-hole 288 for
receiving the head and threaded region of clamping bolt 301 and
member 282 is formed with a corresponding threaded through-hole 290
for receiving the threaded region of bolt 301 to permit the halves
of the clamp to be fastened firmly together about the support wire.
Each of the clamping members 282, 284 is formed at its head with a
formation defining an eye region 294, 296, the eye regions together
defining eye 292. As can be seen in FIGS. 23, 26 and 27 the inner
faces of the stems 316, 218 are planar and continue without change
of attitude into planar faces of eye regions 294, 296 so that in
the closed position the two members 282 and 285 touch one another
as apparent in FIG. 23. It will be appreciated that other profiles
are possible provided that the two members can close and touch one
another, but the illustrated profile is convenient and easy to
manufacture. The inner profiles of eye-regions 294, 296 are
generally quarter-round or otherwise form a generally continuous
smooth curve as best seen in FIG. 23 so that when engaged by a
clamping hook, rope other member to be tensioned, load on the
member to be tensioned is transferred equally to both eye regions
and the load can be applied in directions up to 45.degree. in any
direction whilst applying pulling force but not unacceptable
twisting force to the clamp. Without a smooth curved surface of
this kind, there would be an increased risk of a hook of a sling or
the line applying point loads which would limit the rated tensional
load that the T-clamp can accept. The members 282, 284 are
conveniently drop forgings in alloy steel e.g. Grade 100 alloy
steel and may be zinc passivized so that they can withstand harsh
external environments.
[0082] A hook 302, e.g. a safety hook, of a chain sling is
insertable into the eye 292 and provides a lower connection for the
chain sling. The eye region 292 is generally oval or otherwise has
extended height to allow the T-clamp to sit generally vertically on
support wire 10b, and the hook 302 is configured to be rotatable in
any direction at an angle of up to about 45.degree. to the
vertical, thereby permitting the loading on the individual
eye-regions 294, 296 of the clamping members to be equlised. It
will be appreciated that if a T-clamp as shown here is fitted about
a support wire 10b, hook 302 is engaged therewith and the cable 304
is tensioned, then the clamp will be held tightly about the wire
irrespective of whether bolt 301 has been inserted and a
substantial clamping force is exerted by simple tension applied to
the eye regions 294, 296, so that at least a temporary fixing to
the wire 10b can be made with a minimum of labour. The retaining
bolt and the sockets 288-290 are configured so that for an intended
support cable the clamp cannot be over-tightened, and one of the
major purposes of bolt 301 is to prevent a clamp once fitted to
support wire 10b from being inadvertently dropped before attachment
of a hook or other tensioning device.
[0083] It will be appreciated that various modifications may be
made to the embodiment described herein without departing from the
invention, the scope of which is defined by the accompanying
claims.
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