GB2099902A - Drop head for formwork prop - Google Patents

Drop head for formwork prop Download PDF

Info

Publication number
GB2099902A
GB2099902A GB8214898A GB8214898A GB2099902A GB 2099902 A GB2099902 A GB 2099902A GB 8214898 A GB8214898 A GB 8214898A GB 8214898 A GB8214898 A GB 8214898A GB 2099902 A GB2099902 A GB 2099902A
Authority
GB
United Kingdom
Prior art keywords
head
drop
supporting
wedge
shank
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
GB8214898A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Acrow Engineers Ltd
Original Assignee
Acrow Engineers Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Acrow Engineers Ltd filed Critical Acrow Engineers Ltd
Priority to GB8214898A priority Critical patent/GB2099902A/en
Publication of GB2099902A publication Critical patent/GB2099902A/en
Withdrawn legal-status Critical Current

Links

Classifications

    • E—FIXED CONSTRUCTIONS
    • E04—BUILDING
    • E04G—SCAFFOLDING; FORMS; SHUTTERING; BUILDING IMPLEMENTS OR AIDS, OR THEIR USE; HANDLING BUILDING MATERIALS ON THE SITE; REPAIRING, BREAKING-UP OR OTHER WORK ON EXISTING BUILDINGS
    • E04G11/00—Forms, shutterings, or falsework for making walls, floors, ceilings, or roofs
    • E04G11/36—Forms, shutterings, or falsework for making walls, floors, ceilings, or roofs for floors, ceilings, or roofs of plane or curved surfaces end formpanels for floor shutterings
    • E04G11/48—Supporting structures for shutterings or frames for floors or roofs
    • E04G11/486—Dropheads supporting the concrete after removal of the shuttering; Connecting means on beams specially adapted for dropheads
    • E—FIXED CONSTRUCTIONS
    • E04—BUILDING
    • E04G—SCAFFOLDING; FORMS; SHUTTERING; BUILDING IMPLEMENTS OR AIDS, OR THEIR USE; HANDLING BUILDING MATERIALS ON THE SITE; REPAIRING, BREAKING-UP OR OTHER WORK ON EXISTING BUILDINGS
    • E04G25/00—Shores or struts; Chocks
    • E04G25/04—Shores or struts; Chocks telescopic
    • E—FIXED CONSTRUCTIONS
    • E04—BUILDING
    • E04G—SCAFFOLDING; FORMS; SHUTTERING; BUILDING IMPLEMENTS OR AIDS, OR THEIR USE; HANDLING BUILDING MATERIALS ON THE SITE; REPAIRING, BREAKING-UP OR OTHER WORK ON EXISTING BUILDINGS
    • E04G25/00—Shores or struts; Chocks
    • E04G25/04—Shores or struts; Chocks telescopic
    • E04G25/06—Shores or struts; Chocks telescopic with parts held together by positive means
    • E04G25/065—Shores or struts; Chocks telescopic with parts held together by positive means by a threaded nut
    • E—FIXED CONSTRUCTIONS
    • E04—BUILDING
    • E04G—SCAFFOLDING; FORMS; SHUTTERING; BUILDING IMPLEMENTS OR AIDS, OR THEIR USE; HANDLING BUILDING MATERIALS ON THE SITE; REPAIRING, BREAKING-UP OR OTHER WORK ON EXISTING BUILDINGS
    • E04G25/00—Shores or struts; Chocks
    • E04G25/04—Shores or struts; Chocks telescopic
    • E04G25/06—Shores or struts; Chocks telescopic with parts held together by positive means
    • E04G25/066—Shores or struts; Chocks telescopic with parts held together by positive means by a wedge

Abstract

A drop-head unit for supporting shuttering members used in the construction of concrete floors and/or ceilings which is movable between supporting and stripping positions along a shank. The shank has a slot 20 extending along its length and a ledge member 24 formed on both sides of the wedge engages a shoulder 26 formed at the sides of the slot. When the wedge is withdrawn, its ledge falls down the slot. Means are provided to hold the wedge captive in the slot and to correctly position the drop-head in its supporting position. <IMAGE>

Description

SPECIFICATION Improvements in and relating to drop-heads for concrete formwork systems This invention relates to drop-head units for sup porting shuttering members used in the construction of concrete floors and/or ceilings.
A drop-head which is normally used at the top of a scaffold member is used to support shuttering members in two main positions, an upper position in which concrete (or other settable material) is cast onto the shuttering members, and a lower position in which the shuttering members are lowered to be stripped from partially set concrete and then removed from the drop-head for use elsewhere. The partially set concrete slab is then supported by spaced fixed head plates of the drop-head units.
A drop-head unit in accordance with the invention comprises a shank having a fixed head at one end and the other end being adapted for connection with a standard scaffold prop or the like, a drop-head slidably mounted on the shank and movable between a supporting position adjacent the fixed head and a "strip" position in which it is spaced from the fixed head characterized in that the shank is provided with a slot extending along its length between the supporting and fixed positions of the drop-head and a wedge member movable along the length of the slot between its supporting position in which a ledge formed on one or both sides of the wedge engages a shoulder (or shoulders) formed at one (or both) sides of the slot to support the drop-head in its supporting position and its strip position, wedge movement between the supporting and strip position being enabled by withdrawing the ledge(s) from the shoulder(s), means being provided to hold the member captive in the slot and to correctly position the drop-head in its supporting position relative to the fixed head.
In an aspect of the invention a formwork system for supporting concrete (or other settable material) during setting on a casting surface comprises a plurality of beams which in use span horizontally between and are supported by drop-head units, a plurality of casting panels supported by the beams and/or drop-head units, wherein each drop-head unitcom- prises a shank having a fixed head at one end and the other end being adapted for connection with a standard scaffold prop or the like, a drop-head which supports the beams and/or casting panels slidably mounted on the shank and movable between a supporting position adjacent the fixed head and a "strip" position in which it is spaced from the fixed head, characterized in that the shank is provided with a slot extending along its length between the supporting and fixed positions of the drop-head and a wedge member movable along the length of the slot between its supporting position in which a ledge formed on one or both sides of the wedge engages a shoulder (or shoulders) formed at one (or both) sides of the slot to support the drop-head in its supporting position and its strip position, wedge movement between the supporting and strip position being enabled by withdrawing the ledge (s) from the shoulder(s), the wedge member having means to hold the member captive in the slot and the slot being provided with a stop correctly to position the drop-head in its supporting position relative to the fixed head so that beams and/or drop-heads support casting panels to provide a flush casting surface.
Preferably, the wedge surface of the wedge member engages a corresponding surface on the drop-head.
The distance between the supporting surface of the drop-head when in its supporting position and the fixed head, is preferably equal to the distance between the top of a beam to be supported by the drop head, and its support means.
The shank is preferably rectangular in crosssection and the drop-head preferably has a plate depending therefrom extending at right angles to the shank and formed with a lower wedge surface to engage the wedge surface of the wedge member.
When the drop-head is held by the wedge member in its supporting position and isto be moved to its strip position, the wedge is tapered in the direction to lower the drop-head slightly before the ledges on the wedge member moves clear of the shoulders so that an initial gradual strip of the concrete formwork panels takes place before the beams and panels are dropped rapidly to the strip position. This helps to reduce stock loads on the partially set concrete slab and also relieves the wedge member of the load of the cast concrete.
The drop-head is preferably provided with a member which also engages in the slot in the shank.
Preferably the means to hold the wedge member captive in its supporting position comprises a first stop mounted at one end of the wedge member and a second stop mounted atthe other end of the wedge member such that the member is held captive in the slot when the drop-head is in its supporting or strip positions, and also when the drop-head unit is in use or in storage or being transferred from building site to buiding site. The means on or in the slot correctly positions the drop-head in its supporting position such that beams or the drop-heads support casting panels to provide a flush casting surface.
The invention will now be described, by way of example, with reference to the accompanying drawings in which: Figure 1 is a perspective view of one embodiment of drop-head according to the invention in its support position.
Figure 2 is a corresponding side view of the drophead, and Figure 3 is a side view of the drop-head in the lower or strip position.
The drop-head unit 10 shown in the drawings comprises a rectangular central shank 12 having a fixed upper head 14 and a lower plate 16forconnec- tion to a standard scaffold prop.
A drop-head 18 is mounted on the shank for sliding movement between an upper "supporting" position in which it is located adjacent the fixed head 14 (see Figures 1 and 2) and a lower "strip" position as seen in Figure 3.
The shank is provided with a slot 20 which extends along the length thereof between the fixed head and a position adjacent the lower plate 16. A wedge member generally indicated at 22 is held captive within the slot whilst being free to slide up and down the slot between a supporting position as shown in Figures 1 and 2 and a strip position shown in Figure 3.
In the supporting position a ledge 24 which is provided on each side of the wedge member, engages against a shoulder 26 cut out in each side of the slot as can clearly be seen in Figure 1. When in this position the wedge member is prevented from sliding down the slot and its upper wedge or tapering surface 28 is engaged against a corresponding tapered surface 30 formed on the lower edge of a plate 32 extending through the slot transversely to the shank and forming part ofthe drop-head 18. It will thus be appreciated that the drop-head is held fixed in its upper supporting position.
When in this position beams, such as that illustrated at33 which engage on upstanding knib 34 on the drop-head so as to be supported, thereby span between adjacent units with the top surfaces 35 of the beams flush with the top surface of the fixed heads 14 ofthe drop-head units. Formwork panels 36 are supported either by the upper surfaces 56 of beams 37, by ledges 52 of beams 33 or by dropheads 18. Various alternative arrangements of beams 33,37 and panels 36 are described in copending British Application No.8117524.
A cut-out 54 is provided in the top surface of the web to receive a pin, nail orthe like to lockthewedge in the supporting position during casting.
A concrete slab 38 (see Figures 2 and 3) is then cast over the panels, the top surfaces of which are flush with the top surfaces of the beams 33 and fixed heads, to produce a unitary slap.
When the concrete slab is partially set the drop heads are lowered resulting in the lowering of the beams 33,37 and panels 36 leaving the partially set concrete slab supported (as shown in Figure 3) by the fixed heads 14 of the drop-head units. The beams and panels can then be re-used elsewhere.
In orderforthe drop-heads to be lowered on the shanks the wedge members 22 are moved to the right (as shown in the drawings). During this movementthe drop-head moves gradually down due to the tapering of the corresponding surfaces 28 and 30 of the wedge member 22 and plate 32. This means that the initial strip of formwork panels and beams from the concrete is gradual which helps to avoid shock loads and the wedge is relieved of the load of the concrete.
Once the wedge member is moved to the position shown in Figure 3 in which the ledges 24, which only extend partially along the length of each side of the wedge member, are clear of the shoulders 26 in the slot, the wedge member is free to fall down the slot thus enabling the drop-head and the beams and panels supported thereby, also to drop down the slot to the strip position shown in Figure 3.
The wedge member 22 is further provided with means to hold the member captive in the slot 20.
This means comprises a first stop 40 at the smaller end of the member 22 and a second stop 50 at the larger end. These two stops40 and 50 prevent any possibility of the wedge being lost either when the drop-head 18 is in its supporting or strip position, or when the drop-head unit 10 is in use, in storage, or being transferred from one position to another.
A stop 51 is positioned on the shank 12 in siot 20 such that when the drop-head sin its supporting position the stop 51 engages the upper face of the head 18 (see Figure 2), the upper surface 35 of the beam 33 and top surface of the panel 36 are automatically flush with the upper surface of the head 14.
Accordingly a flush casting surface is achieved simply and efficiently by knocking the wedge member 22 along the ledges 24 until the stop 51 contacts the head 18.
The plate 30 attached to the drop-head is provided with two projecting pins 42 on each side which engage the sides of the shankto help two provide rigidity and to prevent the drop-head twisting relative to the shank. The drop-head is further provided with two downward projecting flanges 43 attached to two edges of the plate 30 to provide rigidity to the plate 30.
In accordance with standard practice the drophead unit 10 may either be supported on the top plate of a standard prop which may be bolted to the plate 16 of the drop-head unit, or alternatively a screwed shank 44 which extends down from the plate 16 may be engaged buy a nut member formed with a circular hub 46 which fits over the top of a standard tubular scaffold prop 48. This enables height of the top plate 14 of the drop-head unitto be adjusted relatively to the prop, for alignment and to ensurethatthe surfaces of the top plate 14 and of the beams 33 and panels 36 are atthe desired level.

Claims (14)

1. A drop-head unit comprising a shank having a fixed head at one end and the other end being adapted for connection with a standard scaffold prop or the like, a drop-head slidably mounted on the shank and movable between a supporting position adjacent the fixed head and a "strip" position in which it is spaced from the fixed head, characterized in that the shank is provided with a slot extending along its length between the supporting and fixed positions of the drop-head and a wedge member movable along the length of the slot between its supporting position in which a ledge formed on one or both sides of the wedge engages a shoulder (or shoulders) formed at one (or both) sides of the slot to supportthe drop-head in its supporting position and its strip position, wedge movement between the supporting and strip position being enabled by withdrawing the ledge(s) from the shoulde (s), means being provided to hold the wedge member captive in the slot and to correctly position the drop-head in its supporting position relative to the fixed head.
2. A drop-head unit as claimed in Claim 1 wherein the distance between the supporting surface of the drop-head in the supporting position and the fixed head, is equal to the depth of a beam supported by the drop head.
3. A drop-head unit as claimed in Claim 1 or 2 wherein the drop head has a plate depending there from extending at right angles to the shank and formed with a lower wedge surface to engage the wedge surface of the wedge member.
4. A drop-head unit as claimed in any preceding claim wherein the wedge is tapered so that on wedge movement from the supporting to strip position, the drop-head is lowered slightly before the ledges are withdrawn from the shoulders.
5. A drop-head unit as claimed in any preceding claim wherein the means to hold the wedge member captive and to correctly position the drop-head in its supporting position comprises two stops mounted on the wedge member, the first stop engaging the shank when the drop-head is in its strip position and the second stop engaging the shank when the drop-head is in its supporting position.
6. A formwork system for supporting concrete (or other settable material) during setting on a casting surface, comprising a plurality of beams which in use span horizontally between and are supported by drop-head units, a plurality of casting panels supported by the beams and/ordrnp-head units, wherein each drop-head unit comprises a shank having a fixed head at one end and the other end being adapted for connection with a standard scaffold prop or the like, a drop-head which supports the beams and/or casting panels slidably mounted on the shank and movable between a supporting position adjacent the fixed head and a "strip" position in which it is spaced from the fixed head, characterised in that the shank is provided with a slot extending along its length between the supporting and fixed positions of the drop-head and a wedge member movable along the length of the slot between its supporting position in which a ledge formed on one or both sides of the wedge engages a shoulder (or shoulders) formed at one (or both) sides of the slot to support the drophead in its supporting position and its strip position, wedge movement between the supporting and strip position being enabled by withdrawing the ledge(s) from the shoulder(s), the wedge member having means to hold the member captive in the slot and means being provided correctly to position the drop-head in its supporting position relative to the fixeed head so that beams and/or drop-heads support casting panels to provide a flush casting surface.
7. A formwork system as claimed in Claim 6 wherein the means engage the shanks of the drophead units to correctly position the beams and/or drop-heads supporting the casting panels to provide a flush casting surface.
8. A formwork system as claimed in either Claim 6 or7 wherein the distance between the supporting surface of the drop-head in the supporting position and the fixed head, is equal to the distance between the top of a beam supported by the drop-heads and its support means.
9. A formwork system as claimed in any one of Claims 6 to 8 wherein each drop-head has a plate depending therefrom extending at right angles to the shank and formed with a lower wedge surface to engage the wedge surface of the wedge member.
10. A formwork system as claimed in any one of Claims 6 to 9 wherein the wedge member is tapered so that on wedge movement from the supporting to strip position, the drop-head is lowered slightly before the ledges are withdrawn from the shoulders.
11. A formwork system as claimed in any one of Claims 6 to 10 wherein the means to hold the wedge member captive comprises two stops mounted on the wedge member.
12. Aformworksystem as claimed in any of the preceding claims in which the means to position the drop-head in its supporting position comprises a stop on the shank to engage the top of the drop-head when in its supporting position.
13. A drop-head unit substantially as herein described with reference to the accompanying drawings.
14. A formwork system substantially as herein described with reference to the accompanying drawings.
GB8214898A 1981-06-08 1982-05-21 Drop head for formwork prop Withdrawn GB2099902A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB8214898A GB2099902A (en) 1981-06-08 1982-05-21 Drop head for formwork prop

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB8117525 1981-06-08
GB8214898A GB2099902A (en) 1981-06-08 1982-05-21 Drop head for formwork prop

Publications (1)

Publication Number Publication Date
GB2099902A true GB2099902A (en) 1982-12-15

Family

ID=26279721

Family Applications (1)

Application Number Title Priority Date Filing Date
GB8214898A Withdrawn GB2099902A (en) 1981-06-08 1982-05-21 Drop head for formwork prop

Country Status (1)

Country Link
GB (1) GB2099902A (en)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0092694A2 (en) * 1982-04-22 1983-11-02 Emil Steidle GmbH. &amp; Co. Shuttering system for ceilings
EP0250630A1 (en) * 1986-07-01 1988-01-07 Emil Steidle GmbH. &amp; Co. Drop head for a ceiling form work
DE19636091A1 (en) * 1996-09-05 1998-03-12 Hollmann Niels Frame especially for a platform or a scaffold or for decking formwork used in construction
WO2005045159A1 (en) * 2003-11-03 2005-05-19 Peri Gmbh Lowering device comprising a support structure
ITPR20120022A1 (en) * 2012-04-11 2013-10-12 Tecnotelai Components S R L SUPPORT HEAD FOR THE REALIZATION OF A SUPERSTRUCTURE
WO2018053479A1 (en) * 2016-09-19 2018-03-22 Lenkin Michael L Adjustable support device and shoring system
US20190194961A1 (en) * 2017-12-22 2019-06-27 Bond Formwork Systems, LLC Pass-Through Head Assembly for a Grid Shoring System
US10982452B1 (en) 2020-07-31 2021-04-20 Bond Formwork Systems, LLC Secondary joist profile for grid systems
US11047142B1 (en) 2020-07-31 2021-06-29 Bond Formwork Systems, LLC Main beam structure and profile for formwork grid systems
US11268289B2 (en) 2020-07-31 2022-03-08 Bond Formwork Systems, LLC Drophead nut for formwork grid systems

Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0092694A2 (en) * 1982-04-22 1983-11-02 Emil Steidle GmbH. &amp; Co. Shuttering system for ceilings
EP0092694A3 (en) * 1982-04-22 1984-08-22 Emil Steidle Gmbh. & Co. Shuttering system for ceilings
EP0250630A1 (en) * 1986-07-01 1988-01-07 Emil Steidle GmbH. &amp; Co. Drop head for a ceiling form work
DE19636091A1 (en) * 1996-09-05 1998-03-12 Hollmann Niels Frame especially for a platform or a scaffold or for decking formwork used in construction
WO2005045159A1 (en) * 2003-11-03 2005-05-19 Peri Gmbh Lowering device comprising a support structure
GB2422631A (en) * 2003-11-03 2006-08-02 Peri Gmbh Lowering device comprising a support structure
GB2422631B (en) * 2003-11-03 2007-06-06 Peri Gmbh Lowering device comprising a support structure
US7472878B2 (en) * 2003-11-03 2009-01-06 Peri Gmbh Lowering device comprising a support structure
ITPR20120022A1 (en) * 2012-04-11 2013-10-12 Tecnotelai Components S R L SUPPORT HEAD FOR THE REALIZATION OF A SUPERSTRUCTURE
WO2013153478A1 (en) * 2012-04-11 2013-10-17 Tecnotelai Components S.R.L. Supporting head for the construction of a superstructure
WO2018053479A1 (en) * 2016-09-19 2018-03-22 Lenkin Michael L Adjustable support device and shoring system
US10590665B2 (en) * 2016-09-19 2020-03-17 Michael L. Lenkin Adjustable support device and shoring system
US20190194961A1 (en) * 2017-12-22 2019-06-27 Bond Formwork Systems, LLC Pass-Through Head Assembly for a Grid Shoring System
US10711472B2 (en) * 2017-12-22 2020-07-14 Bond Formwork Systems, LLC Pass-through head assembly for a grid shoring system
US10982452B1 (en) 2020-07-31 2021-04-20 Bond Formwork Systems, LLC Secondary joist profile for grid systems
US11047142B1 (en) 2020-07-31 2021-06-29 Bond Formwork Systems, LLC Main beam structure and profile for formwork grid systems
US11268289B2 (en) 2020-07-31 2022-03-08 Bond Formwork Systems, LLC Drophead nut for formwork grid systems
US11473321B2 (en) 2020-07-31 2022-10-18 Bond Formwork Systems, LLC Main beam structure and profile for formwork grid systems
US11585105B2 (en) 2020-07-31 2023-02-21 Bond Formwork Systems, LLC Secondary joist profile for grid systems

Similar Documents

Publication Publication Date Title
US3130470A (en) Concrete wall form installation
EP2267243B1 (en) Concrete slab form system
US8262056B2 (en) Prop head for ceiling formwork
EP3114292B1 (en) A formwork support structure
US3239188A (en) Shuttering system for use in building construction
GB2099902A (en) Drop head for formwork prop
US3614048A (en) Arrangements for use in the supporting of formwork for the casting of concrete slabs
CH657175A5 (en) System floor shuttering with lowering head
CA1045102A (en) Supports for concrete formwork
US4342440A (en) Concrete deck forming apparatus
US3071837A (en) Concrete forms
US4437272A (en) Insert for foldable concrete building construction with pivot connections, integral lifting bar, and building height control bar
EP3121349B1 (en) Formwork structure for the execution of horizontal castings for the provision of floor slabs
US6390438B1 (en) End latch for removable support for concrete slab construction and method
US3993282A (en) Construction form support member
US3445084A (en) Stringer-supporting bracket for a concrete floor slab form structure
US20090184230A1 (en) Concrete formwork system for forming cast in place horizontal slabs
US4348002A (en) Hanger for concrete deck forming apparatus
EP1200684A1 (en) Metal hanger for use in the building industry
CA1172057A (en) Drop-heads for concrete formwork systems
EP0094246A2 (en) Improvements in decking systems and beams therefor
US20220220753A1 (en) Prop Head For Formwork Shoring And Method Of Using Same
US4401291A (en) Concrete wall form with safety attachment
US3584825A (en) Deck form support
US4348004A (en) Ledger for concrete deck forming apparatus

Legal Events

Date Code Title Description
WAP Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1)