AU2014202184A1 - Holding device - Google Patents

Abstract

H:\cab\Intrwovn\NRPortbl\DCC\CAB\6240028_I.DOC-22/04/2014 A holding device suitable for use with a structure support prop comprising first and second tubular members the second member being at least partially receivable within said first member for enabling relative sliding movement therebetween the holding device being adapted to releasably hold the first and second members in a fixed position relative to one another, when in use. The holding device comprises a mounting section for fitting the device to the first member when in use, and a support section operatively connected to the mounting member and being adapted to releasably hold the second member when in use, the support section being configured so that it can be deflected relative to the mounting section so that in a locating position it can receive the second member and enable movement of the second member relative to the support section and is adapted to be urged into a gripping position in which it is caused to grip the second member and hold it in the fixed position relative to the first member. - 4/6 30o 48 43 C 54-5 51

Description

H:\cab\Intrwovn\NRPortbl\DCC\CAB\6240028_I.DOC-22/04/2014 HOLDING DEVICE TECHNICAL FIELD [0001] This disclosure relates to holding devices for enabling two members to be held in position relative to one another. BACKGROUND ART [0002] One application for which the holding devices which are the subject of this disclosure can be utilised concerns the temporary support of structures using props of the type commonly referred to as acrow props. Props of this type can be used for the support of overhead formwork, under beams and openings which require temporary support during renovations, repairs, construction of buildings, bridge construction as well as underground mining, tunnelling and rescue work. [0003] Acrow props generally comprise an upper inner tube and a lower outer tube, the inner tube being telescopically receivable within the outer tube. A base plate is provided on the lower end of the outer tube and a top plate is provided on the upper end of the inner tube. The inner tube has a series of holes therein which are typically spaced at 153 mm centres along a section of the length of the tube, each hole extending through the inner tube. The outer tube has a threaded section on its outer surface at its upper end and two opposed elongated slots in the tube wall in the region of the threaded section. A collar having an internal threaded section is arranged to be fitted to the threaded section of the outer tube. A pin attached to a fully closed loop frame is adapted to pass through the slots in the lower tube and a selected one of the holes in the upper tube. [0004] To install the prop the inner tube is raised to a position where the top plate is close to the structure which is to be supported and is physically held in this position by the installer to facilitate the insertion of the pin through the slots in the outer tube a selected hole in the inner tube and then under physical resistance lowered to abut H:\cab\Intrwovn\NRPortbl\DCC\CAB\6240028_I.DOC-22/04/2014 -2 the pin onto a shoulder section of the collar. By rotating the collar the pin is caused to move along the slots so that the inner tube can be moved relative to the outer tube so that the top plate is brought into firm abutment against the structure to be supported. [0005] The setting and removing of acrow props is a repetitive physical task especially more so when setting the longer acrow props of 4 meter lengths, or more. If the installer is unable to lift the inner tube to its required position in a grip, lift and hold action, the installer has to do a repeat grip, lift and hold, hand over hand action then finally hold the inner tube of the acrow prop whilst simultaneously inserting the locating pin through the outer vertical slots and inner hole of the acrow prop configuration so as to hold the inner tube up close to where it is required with the location pin resting on the top surface of the collar to enable the acrow prop to be tightened and set by the clockwise screwing of the collar. [0006] In less than perfect conditions, such as where the acrow props are wet or muddied or dusty, the inner tube tends to want to slip through the grip of the installer's hand and this requires increased grip, lift and hold to set the prop and increases the arduousness of the task providing a more rapid onset of fatigue and therefore producing a greater level of personal risk by extra exertion required to prevent the inner tube slipping and pinching the installer's hand. This can result in injury and cause frustration and reduced efficiency. SUMMARY OF THE DISCLOSURE [0007] According to a first aspect there is disclosed a holding device for holding a first member in a position relative to a second member, the holding device comprising a mounting section for fitting the device to the first member and a support section operatively connected to the mounting section and being adapted to releasably hold the second member, the support section being configured so that it can be deflected in a substantially resilient fashion relative to the mounting section from an unstressed state to a stressed state in which the support section can adopt a locating position in which it is adapted to receive the second member and a gripping position in which it can hold it in position relative to the first member.

H:\cab\Intrwovn\NRPortbl\DCC\CAB\6240028_I.DOC-22/04/2014 -3 [0008] According to another aspect there is provided a holding device suitable for use with a structure support prop comprising first and second tubular members the second member being at least partially receivable within said first member for enabling relative sliding movement therebetween the holding device being adapted to releasably hold the first and second members in a fixed position relative to one another, when in use the holding device comprising a mounting section for fitting the device to the first member when in use, and a support section operatively connected to the mounting member and being adapted to releasably hold the second member when in use, the support section being configured so that it can be deflected relative to the mounting section so that in a locating position it can receive the second member and enable movement of the second member relative to the support section and is adapted to be urged into a gripping position in which it is caused to grip the second member and hold it in the fixed position relative to the first member. [0009] In certain embodiments the support section is substantially resilient in nature and can be deflected from an unstressed state into a stressed state in which it can adopt the locating position from which as result of its resilient nature can be urged towards the unstressed state into the gripping position when the device is used with the structure support prop for example, when the support section is in the locating position the second tubular member can be received within the first tubular member of the prop. [0010] In certain embodiments the mounting section comprises a generally tubular body having a socket or hollow therein with an opening at one end and a through hole at the other end. [0011] In certain embodiments the cross-sectional dimension of the through hole is less than the cross-sectional dimension of the socket or hollow so as to provide an internal annular shoulder adjacent the through hole. When the device is used with the structure support prop for example an end of the first member can be located in the socket or hollow so that the device is fitted thereto. [0012] In certain embodiments the support section includes a connector leg extending from the mounting section and a braking or gripping arm with an aperture therein having gripping edge sections associated therewith. In certain embodiments H:\cab\Intrwovn\NRPortbl\DCC\CAB\6240028_I.DOC-22/04/2014 -4 the connector leg which comprise part of the support section provides for the resilient deflection thereof. [0013] In certain embodiments the aperture is in a plane which is inclined to the central axis of the socket, in an angular disposition which provides for the gripping edge sections. When the device is used with the support structure prop the second tubular member of the prop can pass through the aperture and into the first member when the support section is in the stressed state. The arrangement is such that the support section is urged into the gripping position on the second tubular member of the prop as a result of the resilient nature. [0014] In certain embodiments the aperture is in the form of a circular hole, the gripping edge sections being provided by opposed peripheral sections of the edges of the hole. [0015] In certain embodiments an actuating lever is provided on the arm for facilitating deflection of the support section to permit, in use, the inner tube to substantially freely move in the outer tube. [0016] In certain embodiments the holding may include an insert which is releasably mountable to the gripping arm, the aperture and gripping edge sections being part of the insert. In certain embodiments the insert is adapted to be mounted to the gripping arm in a plurality of different orientations relative thereto. In certain embodiments the insert is a ring shaped element having a peripheral side edge comprising a plurality of groups of opposed side sections each group being adapted to mount the insert to the gripping arm in a different orientation to the other groups. In certain embodiments the gripping arm comprises an insert mounting comprising opposed spaced apart slots, each slot being adapted to receive a respective one of side sections in one of the groups. [0017] In certain embodiments the holding device is comprised by a length of spring metal wire, the mounting section and support section each being formed by part of the length of the wire wound into a coil, the coils being spaced apart by another part of the length of the wire, forming a spacer between the coils each of the wire coils having a main axis, the axis of the coil forming the support section being inclined to H:\cab\Intrwovn\NRPortbl\DCC\CAB\6240028_I.DOC-22/04/2014 -5 the axis of the coil forming the mounting section. This is the holding device's unstressed aligned axis in this position with the spring steel vertical spacer undeflected the inner tube section could not pass through the inclined upper portion of the holding device and into the lower tube section, now by lifting or pushing the outer lever portion upwards causing the vertical support to flex backwards and allows the upper coil portion to lessen the inclined angle and simultaneously causing the inclined angle of the upper coils spherical diameter to increase due to the said upper coild diameter being encouraged closer to horizontal therefore creating clearance to allow the inner tube to pass through. [0018] According to a further aspect there is provided a method holding first and second members in position relative to one another, the second member being telescopically receivable within the first member, the method including the steps of providing a holding device as described above, mounting the holding device to the first member, deflecting the support section into the stressed state so that the second member can be inserted into the first member and when the support section is released it is urged towards its unstressed state and is caused to grip the second member and hold it in position relative to the first member. [0019] In certain embodiments the mounting section is fitted to one end of the first member, the support section comprising a hole through which the second member can pass, whereby in the stressed state the second member can pass through the hole and into the first member. [0020] In certain embodiments the first and second members are in an upright configuration with the second member above the first member such that the gravitational force on the second member causes it to grip the support section of the device. [0021] In certain embodiments position adjustments can be effected by moving the support section into a further stressed state to facilitate movement of the second member relative to the first member.

H:\cab\Intrwovn\NRPortbl\DCC\CAB\6240028_I.DOC-22/04/2014 -6 BRIEF DESCRIPTION OF THE DRAWINGS [0022] Notwithstanding any other forms which may fall within the scope of the methods and apparatus as set forth in the Summary, specific embodiments will now be described, by way of example, and with reference to the accompanying drawings in which: [0023] Figure 1 is a side elevation of a typical acrow prop; [0024] Figure 2 is a first perspective view of a holding device in accordance with one embodiment; [0025] Figure 3 is a second perspective view of the device as shown in Figure 2; [0026] Figure 4 is a schematic view of the device as shown in Figures 2 and 3 in an installed position on an acrow prop; [0027] Figure 5 is a sectional view of the device shown in Figures 2 to 4 without the inner tube, and the device in a fully installed but unstressed state; [0028] Figure 6 is a sectional view of the device installed on the outer tube in a substantially deflected position so as to permit the inner tube to telescopically slide into the outer tube; [0029] Figure 7 is a sectional view of the holding device with the inner tube inserted in the outer tube; [0030] Figure 8 is a perspective view of a holding device in accordance with another embodiment; [0031] Figure 9 is a side elevation of the holding device shown in Figure 8; and [0032] Figure 10 is a perspective view of a holding device in accordance with another embodiment.

H:\cab\Intrwovn\NRPortbl\DCC\CAB\6240028_I.DOC-22/04/2014 -7 DETAILED DESCRIPTIONOF SPECIFIC EMBODIMENTS [0033] Referring to Figure 1, there is illustrated a typical prop of the type commonly known as acrow props which are used for shoring or temporary supports during the construction, repair or alteration of buildings and other structures. [0034] The prop 100 comprises an upper inner tube 102 which has a top plate 104 at one end thereof and a series of holes 106 which are typically spaced at 153 centres which extend through the tube 102, the holes 106 being spaced apart along at least part of the length of the inner tube 102. The prop 100 further includes an outer tube 110 into which the inner tube 102 is telescopically receivable so as to be slidably adjustable relative thereto. The outer tube 110 further includes a threaded section 114 at one end 115 of the tube 110. A base plate 112 at the other end 116. Two opposed elongated slots 117 are provided in the wall of the outer tube 110 in the region of the threaded section 114. [0035] The prop 100 further includes a collar 120 having an internal thread therein which is complementary to the external threaded section 114 so that rotation of the collar causes it to move along the outer tube 110. A handle 121 is fitted to the collar 120 to facilitate rotation thereof. [0036] The prop 100 further includes a pin 122 which is through attached via a metal frame 124 to allow free vertical travel through elongated slot 117 by the pin 122 the metal frame 124 rests loosely around the outer tube 110 threaded portion 114 resting lightly on the upper outer surface of the collar 120. The props are often used in a generally upright orientation with the inner tube 102 being above the outer tube 110. [0037] To install the prop 100 the inner tube 102 is raised to a position where the top plate 104 is close to the structure which is to be supported. In this position the pin 122 is inserted through one side of the elongated slot 117 into one of the holes 106 in the inner tube 102 so that the pin 122 bears against the collar 120 by rotating the collar 120 the inner 102 tube can move relative to the outer tube 110 so that the top plate 104 is brought into firm abutment against the structure to be supported.

H:\cab\Intrwovn\NRPortbl\DCC\CAB\6240028_I.DOC-22/04/2014 [0038] Referring in particular to Figures 2 and 3, there is illustrated a holding device 10 according to one embodiment which comprises a mounting section 30 and a support section 40. [0039] The mounting section 30 includes a tubular body 20 with a socket or hollow 31 (Figure 5) therein which in use is adapted to receive the upper end 115 (Figure 1) of outer tube 110 through open side 34 (Figure 5). The mounting section 30 (Figure 2) further includes a through hole 32 through which the inner tube 102 (Figure 1) can pass. The diameter of the through hole 32 is less than the diameter of the socket or hollow 31 (Figure 5) so as to provide for an internal shoulder 33 adjacent the through hole 32. When the outer tube 110 is in the socket or hollow 31 the remote end of the outer tube 110 seats against the shoulder 33. The socket or hollow 31 may be configured so as to be a press fit onto the outer tube 110. Other arrangements are however contemplated. For example, the inner surface of the socket or hollow may be threaded such that the device can be screwed onto the threaded section 114 of outer tube 110. The through hole 32 (Figure 2) and socket 31 have a common central axis C-C (Figure 5). [0040] The support section 40 (Figure 2) comprises a connector leg 42 which extends from the mounting section 30 and a braking arm 43 which extends from the connector leg 42. The braking arm 43 has an aperture 44 therein which, in the form shown in Figures 2 and 3, is a circular hole 47. As shown, the aperture 44 is in a plane which is inclined to the axis C-C of the through hole and socket (Figure 6) by lifting or pushing up 49 of the braking arm 43 the aperture 44 inclined angle moves upwards towards horizontal creating a cross sectional increased in aperture 44 through the diminishing inclined angle thereby creating clearance at 53 and 54. [0041] The support section 30 is generally resilient in nature so that it can be deflected from an unstressed state (Figure 5) into a stressed state (Figure 6) and because of its resilience when in a stressed state as illustrated by dashed lines 55 in Figure 7, it is urged towards the original unstressed state (Figure 7). In the partially stressed state as shown in Figure 7 it is in a braking or gripping position. In the embodiment shown the connector leg 42 is resiliently deflectable. The braking or gripping arm 43 is relatively rigid. For example, it may be formed from metal such as steel. The braking or gripping arm 43 may have a tongue 51 extending therefrom H:\cab\Intrwovn\NRPortbl\DCC\CAB\6240028_I.DOC-22/04/2014 -9 which is embedded in the connector leg 42. The tubular body of the mounting section 30 and connector leg 42 may be formed in one piece from an elastomer such as polypropylene or polyethylene. The opposed edge sections 53 and 54 of hole 47 form gripping edges which when tube 102 passes through the hole 47 and it is in a stressed state causing it to bight into the tube 102 to effect a braking action thereon. [0042] An actuator 48 in the form of a knob or lever 49 is provided at the free end of the braking or gripping arm 43. The actuator 48 can be manually operated to cause further deflection via connector leg 42 from a partially stressed state (Figure 7) to an increased stressed state, as shown in Figure 6. [0043] Figure 10 illustrates a further embodiment which is similar in structure to the described with reference to Figures 1 to 7 and like reference numerals have been used to describe like parts. In this embodiment the device includes an insert 70 which is preferably made of metal. The insert 70 is generally ring shaped with an aperture therein defining the aperture 44 and associated edge sections. The insert shown is an octagon shape comprising eight straight side sections or flats 71. Opposed side sections can be received within locating grooves 76 and 77 formed by flanges 73 and 75 on the gripping arm. By this arrangement when the gripping edges wear, the insert can be removed and rotated so that new gripping edges can be used. [0044] A further embodiment of holding device is shown in Figures 8 and 9. The device illustrated in Figure 8 is different to that shown in Figures 2 and 3 but conceptually the same. As illustrated, the device 60 is comprised by a continuous length of spring metal wire; that is the wire which has a high yield strength which enables the wire to want to return to its original position after directional stress. A typical metal suitable for use is spring steel. [0045] The device 60 includes a mounting section 80 which comprises part of the wire formed into a coil with the same thread pitch so as to mate onto the threaded section (Figure 9) and having a central axis A-A. In other embodiments the mounting section 80 may be configured so as t be a force fit rather than a threaded fit. If desired, one of the wire coils may be of a lesser diameter so as to provide a shoulder similar to that shoulder 33 in the first embodiment. The device further includes a support section 90 which comprises part of the wire formed into a coil which may also H:\cab\Intrwovn\NRPortbl\DCC\CAB\6240028_I.DOC-22/04/2014 - 10 be helically wound and having a central axis B-B. A length of the wire interconnecting leg 82 interconnects the coils. Part of the wire is formed into an actuating lever 89. Mounting section 80, support section 90 and leg 82 function in substantially the same fashion as mounting section 30, support section 40 and leg 42 of the first embodiment. [0046] One method of fitting a holding device to an acrow prop is as follows. Firstly, with the inner and outer tubular members of the acrow prop separated from one another, the socket is fitted over the upper end of the outer tubular member as a push or knock on interference fit or screwed on the outer threaded portion of the outer tubular member. In this position, the inclined hole and the through hole are substantially aligned. The inner tube of the acrow prop is then inserted through the hole of the holding device. To achieve this it is necessary to lift the lever 89 to create a clearance for the inner tube to allow it to pass through and telescopically engage with the outer tube. This creates a preload condition. [0047] The connector leg is now in a stressed state as a result of the resilient nature of the arm. Because of the resilience or memory of the arm, it tends to urge the leg towards the unstressed state thereby causing a tightening effect between the tube and the leg. The weight of the tube and the gravitational effect thereon causes the gripping to become tighter. [0048] To install the prop raise the inner tube upwards the inner tube will pass through the holding device. To lower the inner tube incrementally to the outer tube, the operator "bumps" the actuator so that the leg is caused to move up and back towards a more stressed state. This action releases the inner tube and allows it to move. The inner and outer tubes can be positioned so that the pin can be inserted through the holes and slots so that the acrow prop is ready for normal use. [0049] In the foregoing description of preferred embodiments, specific terminology has been resorted to for the sake of clarity. However, the invention is not intended to be limited to the specific terms so selected, and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar technical purpose. Terms such as "front" and "rear", "inner" and "outer", "above", "below", "upper" and "lower" and the like are used as words of H:\cab\Intrwovn\NRPortbl\DCC\CAB\6240028_I.DOC-22/04/2014 - 11 convenience to provide reference points and are not to be construed as limiting terms. [0050] The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as, an acknowledgement or admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates. [0051] Finally, it is to be understood that various alterations, modifications and/or additions may be incorporated into the various constructions and arrangements of parts without departing from the spirit or ambit of the invention.

H:\cab\Intrwovn\NRPortbl\DCC\CAB\6240028_I.DOC-22/04/2014 - 12 LIST OF PARTS 100 Prop 102 Inner tube 104 Top plate 106 Holes 110 Outer tube 114 Threaded section 115 Upper end 116 Lower end 112 Base plate 117 Slots 120 Collar 121 Handle 122 Pin 124 Metal frame 10 Holding device 20 Tubular body 30 Mounting section 40 Support section 31 Socket 34 Open side 32 Through hole 33 Shoulder 42 Connector leg 43 Braking arm 44 Aperture 47 Hole 53, 54 Edge sections 55 Partially stressed 51 Tongue 48 Actuator 49 Knob 60 Holding device 80 Mounting section H:\cab\Intrwovn\NRPortbl\DCC\CAB\6240028_I.DOC-22/04/2014 - 13 82 Interconnecting leg 89 Actuating lever 90 Support section 70 Insert 71 Sides/Flats 73, 75 Flanges 76, 77 Locating Grooves

Claims (20)

1. A holding device suitable for use with a structure support prop comprising first and second tubular members the second member being at least partially receivable within said first member for enabling relative sliding movement therebetween the holding device being adapted to releasably hold the first and second members in a fixed position relative to one another, when in use the holding device comprising a mounting section for fitting the device to the first member when in use, and a support section operatively connected to the mounting member and being adapted to releasably hold the second member when in use, the support section being configured so that it can be deflected relative to the mounting section so that in a locating position it can receive the second member and enable movement of the second member relative to the support section and is adapted to be urged into a gripping position in which it is caused to grip the second member and hold it in the fixed position relative to the first member.

2. A holding device according to claim 1 wherein the support section is substantially resilient in nature and can be deflected from an unstressed state into a stressed state in which it can adopt the locating position from which as result of its resilient nature can be urged towards the unstressed state into the gripping position.

3. A holding device according to claims 1 or 2, wherein the first member has an open free end through which the second member can pass and the mounting section comprises a generally tubular body having a socket or hollow therein with an opening at one end and a through hole at the other end the free end being receivable within the socket or hollow when the holding device is fitted to the first member.

4. A holding device according to claim 3 wherein the cross-sectional dimension of the through hole is less than the cross-sectional dimension of the socket or hollow so as to provide an internal annular shoulder adjacent the through hole the free end of the first member having an annular edge which abuts against the shoulder when the device is fitted to the first member. H:\cab\Intrwovn\NRPortbl\DCC\CAB\6240028_I.DOC-22/04/2014 - 15

5. A holding device according to any preceding claim, wherein the support section includes a connector leg extending from the mounting section and a gripping arm with an aperture therein having gripping edge sections.

6. A holding device according to claim 5, wherein the aperture is in a plane which is inclined to be the central axis of the socket.

7. A holding device according to claim 6, wherein the aperture is in the form of a circular hole, the gripping edge sections being provided by opposed peripheral edge sections of the hole.

8. A holding device according to claim 7, including an actuating lever on the gripping arm for facilitating deflection of the support section.

9. A holding device according to claim 7 or claim 8 comprising an insert which is releasably mountable to the gripping arm, the aperture and gripping edge sections being part of the insert.

10. A holding device according to claim 9 wherein the insert is adapted to be mounted to the gripping arm in a plurality of different orientations relative thereto.

11. A holding device according to claim 10 wherein the insert is a ring shaped element having a peripheral side edge comprising a plurality of groups of opposed side sections each group being adapted to mount the insert to the gripping arm in a different orientation to the other groups.

12. A holding device according to claim 11 wherein the gripping arm comprises an insert mounting comprising opposed spaced apart slots, each slot being adapted to receive a respective one of side sections in one of the groups.

13. A holding device according to claim 1 or claim 2, wherein the device is comprised by a length of spring metal wire, the mounting section and support section each being formed by part of the length of the wire wound into a coil, the coils being spaced apart by another part of the length of wire, each of the wire coils having a main axis, the axis of the coil forming the support section being inclined to the axis of H:\cab\Intrwovn\NRPortbl\DCC\CAB\6240028_I.DOC-22/04/2014 - 16 the coil forming the mounting section.

14. A method holding first and second members in fixed position relative to one another, the second member being telescopically receivable within the first member, the method including the steps of providing a holding device according to any preceding claim, mounting the holding device to the first member, deflecting the support section into the stressed state so that the second member can be inserted into the first member and when the support section is released it is urged towards its unstressed state and is caused to grip the second member and hold it in position relative to the first member.

15. A method according to claim 14 wherein the mounting section is fitted to one end of the first member, the support section comprising a hole through which the second member can pass, whereby in the stressed state the second member can pass through the hole into the first member.

16. A method according to claim 15 wherein the first and second members are in an upright configuration with the second member above the first member such that the gravitational force on the second member causes it to grip the support section of the device.

17. A method according to claim 16 wherein position adjustments can be effected by moving the support section into a further stressed state to facilitate movement of the second member relative to the first member.

18. A method according to claim 17 wherein the mounting section is fitted to one end of the first member, the support section comprising a hole through which the second member can pass, whereby in the stressed state the second member can pass through the hole into the first member.

19. A method according to claim 18 wherein the first and second members are in an upright configuration with the second member above the first member such that the gravitational force on the second member causes it to grip the support section of the device. H:\cab\Intrwovn\NRPortbl\DCC\CAB\6240028_I.DOC-22/04/2014 - 17

20. A method according to claim 19 wherein position adjustments can be effected by moving the support section into a further stressed state to facilitate movement of the second member relative to the first member.