GB2189287A - Connecting means for scaffolding components and the like - Google Patents

Abstract

A hook (1)which can be attached to one end of a first scaffolding component (2) defines a recess (9) in which a second scaffolding component (2) can be releasably held. A spring biased catch (5) pivotally mounted in the mouth (12) of the hook (1) can be placed in a retaining position in which it allows the second component (2) to be introduced into the recess (9) and then retains it there. The catch (5) can be manually urged to a release position, and retained there by retainer means (6), in which the second component (2) can be removed from the recess. An obstruction part (17) of the catch prevents or hinders the introduction of the second component (2) whilst the catch is in the release position.The obstruction part (17) may be a handle. <IMAGE>

Description

SPECIFICATION Connecting means for scaffolding components and the like This invention relates two connecting means for detachably connecting two components of scaffolding and the like at an angle to one another, and more particularlyto connecting means ofthe kind comprising a hook member adapted to be attached to an end of a first one of the components to hookoverthe other, second, component, and which includes a catch operable to secure the hook member against accidental disengagement from the second component. Such connecting means will be hereinafter referred to as "of the kind described .

It is known in connecting means ofthe kind described forthe catch to be spring urged into its operative position for securing the hook memberto the second component. The spring-loaded catches provided hitherto have required maintained manual action to be applied to the catch to hold it in the inoperative position for engaging the hook member with, and disengaging it from, the second component. Having to hold the catch manually in the inoperative position can make it awkward forthe operator to manipulate the first component into and out of an in use position relative to the second component.

Afurther problem with some known connecting means of the kind described is that the hook member may be unintentionally engaged with and secured by the catch to the second componentwhilstthe operator is trying to manoeuvre the first component into a required position of use relative to the second component, thus making the process of positioning the first component more difficult.

The present invention consists in connecting means of the kind described in which the hook member has a mouthed recess which in use engages partially around the second component, the catch is mounted on the hook member adjacent to the mouth ofthe recess for movement between a retaining position and a release position and has a retention part and an obstruction part, and retainer means is provided on the hook memberreleasably engageable with the catch to hold it in the release position, the retention part ofthe catch protruding into the mouth of the recess when the catch is in the retaining position such that ifthe second component is in the recess the retention part retains it there and if the second component is not in the recess the retention part allows the second component to be introduced into, and then retained in, the recess, and when the catch is in the release position the retention part is withdrawn from the mouth such that ifthe second component is in the recess it can be released from the recess but the obstruction part obstructs the mouth and prevents, or at least hinders, introduction of the second component into the recess whilst the catch is in the release position.

It will be appreciated that the connecting means now provided has the advantage thatthe catch does not have to be held manually whilst the hook member is applied to and removed from the second component, and furthermorethatwhen the catch is in the release position the obstructing of the mouth ofthe recess by the obstruction part prevents, or reduces the likelihood of, accidental reception of the second component into the recess. The operator, therefore, has both hands free for manoeuvring the first component relative to the second component and the hook member will not, or is unlikelyto, connectthe first componentto the second component until the operator is readyforthe connection to be made.

Preferablythecatch is pivoted to the hook member and is spring loaded to the retaining position, and has a part which can be engaged by hand to move the catch against the spring loading from the retaining position to the release position. Preferably the partto be engaged by hand and the obstruction part are one and the same part. Thus the catch may have a projecting handle or lever which extends across the mouth of the recess to obstruct the mouth when the catch is in the release position, and is moved away from the mouth as it is operated by handto pivot the catch to the release position.

The retention part is preferably adapted to bear on the second component when in the recess so that together the hook member and catch clampthe second component in the recess. The retention part may have a surface shaped to follow the contour of the second componentwhen the part bears on the second component.

The retainer means may comprise a spring or spring-urged element which co-operates with the catch as the catch is moved into the release position.

There may be a projection or recess on or in the catch with which the spring or spring-urged element engages with snap-action to retain the catch in the release position. The spring or spring-urged element may be caused to be deflected out of operative engagement with the projection or recess by initial manual movement ofthe catch towards the retaining position. There may be provision separate from the catch for disengaging the spring or spring-urged elementfrom the catch.

For attachment to a tubular first component, such as a tubular scaffolding member, the hook member of the connecting means preferably has a shank which is adapted to be secured co-axiallyto one end of the first component.

An embodiment ofthe invention will now be described by way of example only, with reference to the accompanying drawings ofwhich: Figure lisa longitudinal cross-section of a scaffolding hook embodying the invention, being shown in a retaining condition of use; Figure2 is a transverse cross-section on the line ll-ll of Figure 1; Figure3isa perspective view of a partofthe scaffolding hook; and Figures 4and 5are simplified longitudinal cross-sections showing the scaffolding hook in a second condition respectively immediately priorto de-coupling the hook from a scaffolding member and immediately priorto introducing a scaffolding membertothe hook.

In this embodiment the invention is applied to a scaffolding hook adapted to secure a first tubular scaffolding mem ber 2 to a second tubular scaffolding member 2' at 90 . The scaffolding hook 1 comprises a hook portion 3 from which extends an integral hollow cylindrical shank 4, a catch 5 pivoted with respect to the hook portion 3, a retention spring 6, and an engagement spring 7. A circumferential flange 8, extending radially outwardsfromthe shank 4 is provided where the shank4 meets the hook portion 3.

The hook portion 3 is of substantially U-shaped channel section, as best seen in Figure 2, and defines a mouthed recess 9 which is adapted to receive the second scaffolding member 2'. The recess 9 is defined in part bythe projecting limbs ofthe U-shaped channel section of a forwardly projecting portion 10 of the hook, in part by the portion 11 ofthe hook 3 opposite a mouth 12 to the recess 9, and in part by edges of substantially flat cheeks 13 which extend from the flange 8towards the recess 9 and are contiguous one with each ofthe limbs of the U-shaped channel section of the hook portion 3. The surfaces which define the recess are shaped so as in useto engage the second scaffolding member 2' over substantially 1 80" of the circumference of the scaffolding member.A reinforcing ridge or spine 14 extends centrally longitudinally along the exterior of the hook portion 3from the forwardly projecting portion lOto the flange 8.

The catch 5 is positioned between the two cheeks 13 and is pivotally supported for movement between a retaining position and a release position by pivot pin 15 which extends between and is anchored at its end to the two cheeks 13. The catch 5, most clearly shown in Figure 3, comprises a head 16, and a handle 17. When the catch is in the retaining position (as shown in Figure 1) the head 16 isableto engagewith the second scaffolding member 2'to secure it in the recess 9. An engagement face 18 of the head 16 is shaped to followthe contour of and bear on the second scaffolding member 2' over a portion ofthe circumference ofthe member extending beyond a region wherethe scaffolding member2 is engaged bythecheeks 13.The head 16 is pivotable away from the recess 9 to its release position in which it is received between the cheeks 13 and partially enters the hollowshank4, as described below.

Acavity 19 is provided inthe head 16 and is in part defined by side walls 19a,in partbya base surface 19b, and end surfaces 19c. The cavity 19 receives the engagement spring 7, which is a torsion coil spring mounted on the pivot pin 15 and having two legs. A first leg 20 of spring 7 bears on the base surface 1 9b ofthe head 16 to urge the head towards recess 9, that is to its retaining position. A second leg 21 ofthe spring 7 bears against the inner surface of the shank 4which provides leverage forthe spring.

The catch 5 is moved manually from its retaining position to the release position, as shown in Figures 4and 5, by the handle 17 which projects away from the recess radially of the pivot pin 15. The handle has an abutment surface 22 which co-operates with a complementary abutment surface 23 of the shank4 adjacentthe flange 8 to limitthe angular movement ofthe catch towards the recess.

The retention spring 6 is secured by a screw 24 in a hollow 25 formed in the inside of the base ofthe U-shaped channel section of the hook members 3 adjacent to the shank 4 and diametrically opposite to the abutment surface 23. The spring 6 has a tongue portion 26 which projects into the space between the cheeks 13 for co-operation with a cam surface 27 of the head 16 and a nose 28 of the head 16. The nose 28 is remote from the handle 17 and is defined between the cam surface 27 and the engagementface 18.As the catch 5 is pivoted againstthe action ofthe engagement spring 7, in the direction which moves the head 16 away from the recess 9, the tongue 26 engages with, and is deflected away from its normal position by, the cam surface 27 until the nose 28 passes the tip of the tongue whereupon the tongue snaps backtowards its normal position and exerts sufficientforce on the nose to overcomethe load exerted on the catch by the engagement spring 7, and so hold the head 1 6 away from the recess 9,that is in the release position of the catch. In orderto free the catch from that position the catch has initially to be moved manually, by operation of the handle 17, towards its retaining position until the nose 28 is clearofthetipofthetongue.Theengagementspring then comes into effect and urges the catch into the retaining position.

Shank4 is adapted to be co-axially received, as a push fit, into the bore at one end of the firsttubular scaffolding member 2. It is inserted until the circumferential flange 8 abuts againstthe annular end face of the scaffolding member and the flange is then welded or riveted to the scaffolding memberto secure the scaffolding hookto the scaffolding member. The shank may alternatively be adapted to serve as a sleeve to co-axially receive the end of the first scaffolding member.

The portion of the head 16 which defines cam surface 27 and which is furtherfrom the recess 9than the nose 28 is of narrower width than the engagement face 18 and the nose 28 of the head 16.

Sloping shoulders 29 extend outwards from this portion of narrowerwidthtothefull width ofthe nose of the head. The inside faces of cheeks 13 each carry an inwardly projecting abutment lug 30 spaced from the recess 9. Each lug 30 defines an abutment surface 30' facing the recess 9.

When the catch 5 is moved to its release position the catch pivots about pivot 15, the head 16 moving awayfrom the recess 9 and the handle 17 moving to obstruct the mouth 12 of the recess 9. The narrower portion ofthe head is received between the lugs 30 and partially enters the hollowshank4. Abutment surfaces 30' of the lugs co-operate with complementary shoulders 29 of the head to limit the angular movement of the head away from the recess 9. This in turn limits the degree to which the handle obstructs the mouth 12. The lugs 30 and shoulders 29 prevent excessive manual movement of the catch 5. The slope of the shoulders 29 is arranged such that the shoulders co-operate with respective engagementfaces 30' when the catch isfully withdrawn from the recess.

The operation of the connecting means will now be described. When the catch is in its retaining position a scaffolding component 2' which may be in the recess 9 is held there by the action of spring 7 urging the head 16 of the catch into engagementwith the component 2' and clamping the component in the recess. If there is no component 2' in the recess then, when the catch 5 is in its retaining position, a component 2' may readily be introduced into the recess since handle 17 does not obstruct the mouth 12. A component so introduced to the recess will be held there as described above.

When the catch 5 is in its retaining position and no component 2' is in the recess 9 the catch is prevented from protruding too far into the recess by the engagement of abutment surfaces 22 and 23.

When the catch 5 is in its release position the handle 17 partially obstructs the mouth 12 of the recess. If there is is a component 2' in the recess 9 (as shown in Figure 4) this component 2' may be readily removed from the recess. The act of removing the component 2' from the recess automatically leaves the catch in its retaining position. This is achieved by thecomponent2' engagingthe handle 17asthe component is removed from the recess and this engagement causing the catch to pivot to its retention position, removing the obstruction to the mouth 12 and so enabling the component 2' to leave the recess 9. When the catch 5 is in its release position and no scaffolding component 2' is in the recess 9 (as shown in Figure 5) a component 2' positioned outside of the recess is prevented from entering the recess.However, such a component 2' may be introduced into the recess if sufficient force urging it into the recess is applied, since the force will tend to urge the catch from its release position towards its retaining position. In so moving the catch 5the handle 17 ofthecatch moves to a position in which itleavesthe mouth 12 unobstructed.

It is possible in other embodiments of the invention to arrange that the moment produced by urging the component 2' into the recess acts on the handle to urge the catch furthertowards its release position and thereby arrange that the component 2' cannot be introduced merely by pressing it towards the recess. This necessitates manual movement of the catch to its release position beforethe introduction of component 2' to the recess, and can be achieved by altering the length and/or angle ofthe handle 17 so that the normal force on the handle (shown as F in Figure 5) acts to produce a suitable moment.

Claims (14)

1. Connecting means of the kind described in which the hook member has a mouthed recess which in use engages partially around the second component, the catch is mounted on the hook member adjacentto the mouth of the recessfor movement between a retaining position and a release position and has a retention part and an obstruction part, and retainer means is provided on the hook member releasably engageable with the catch to hold it in the release position, the retention part of the catch protruding into the mouth ofthe recess when the catch is in the retaining position such that if the second component is in the recess the retention part retains it there and if the second component is not in the recess the retention part allows the second component to be introduced into, and then retained in, the recess, and when the catch is in the release position the retention part is withdrawn from the mouth such that if the second component is in the recess it can be released from the recess but the obstruction part obstructs the mouth and prevents, or at least hinders, introduction of the second component into the recess whilst the catch is in the release position.

2. Connecting means according to Claim 1 in which the catch has means whereby it is automaticaily placed in the retaining position as a second component which the connecting means is adapted to engage in use is removed from the recess.

3. Connecting means according to Claim 2 in which said means of the catch and the obstruction part are one and the same element.

4. Connecting means according to any preceding claim in which the catch is pivotally connected to the hook member.

5. Connecting means according to Claim 4 in which the pivotal connection of the catch to the hook member is intermediate the retention part and the obstruction part of the catch.

6. Connecting means according to any preceding claim in which the catch is acted upon by spring means which continually urges the catch towards the retaining position.

7. Connecting means according to Claim 6 in which the spring means is a torsion spring coiled around the axis of the pivotal connection and having a first leg which bears on the catch and a second leg which bears on the hook member.

8. Connecting means according to any preceding claim in which the catch is provided with a handle to assist manipulation of the catch.

9. Connecting means according to Claim 8 in which the handle and the obstruction part are one and the same structure.

10. Connecting means according to any preceding claim in which the catch and the hook member are provided with complementary abutments which limit the range of movement ofthe catch.

11. Connecting means according to any preceding claims in which the retainer means comprises a spring orspring-urged element which co-operates with the catch as the catch is moved into the release position.

12. Connecting means according to Claim 11 in which the catch is provided with a projecting nose with which the spring retainer means engages with snap-action to retain the catch in the release position.

13. Connecting means according to Claim 11 or Claim 12 in which the catch hasacammingsurface with which the spring or spring-urged retainer means co-operates such that during initial movement ofthe catch from the retaining position to the release position the retention part of the catch is urged by the spring orspring-urged retainer means towards the recess, but during final movement ofthe catch from the retaining to the release position the spring orspring-urged retainer means urgesthe retention part of the catch away from the recess.

14. Connecting meanssubstantially as herein described with reference to the accompanying drawings.