GB2454596A

GB2454596A - Safety clamp

Info

Publication number: GB2454596A
Application number: GB0820678A
Authority: GB
Inventors: Ralph Griffiths
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-11-12
Filing date: 2008-11-11
Publication date: 2009-05-13
Anticipated expiration: 2028-11-11
Also published as: GB0820678D0; GB2454596B; GB0722089D0; WO2009063183A1

Abstract

A safety device for securing a safety line or harness of a person who is working at a location above ground level on a ladder, the device comprising of a first member (12 Fig. 1) which has a stem 14 with an enlarged head 16, the first member secured in position at said location. The device also comprises a second member 24 having connection means 42 to which the safety line is secured and having a slot 36 having a large width portion 38 through which the head 16 of the first member is inserted, a reduced width portion 40 to engage the stem 14 and a locking plate 50 for retaining the first member in engaged position in the reduced width portion of the slot. Also claimed is a second safety device comprising a frame (60 Fig. 5) which engages an internal surface of a wall and is designed to extend from the floor 72 to the ceiling 78 to be fixed in position, the frame having an attachment point for a safety line.

Description

* 2454596 "Improved Safety Devices" This invention relates to safety devices and more particularly to safety devices for securing safety lines for use by persons who are working above ground level on a building.

It is usual for a person who is working on the exterior of a building above ground level to carry out work which only involves working at a particular location for a limited period of time to use a ladder.

It is now deemed to be necessary under current safety regulations for a person working on a ladder to maintain * three points of contact on the ladder, ie. one hand and two feet in contact with the ladder. This makes it impossible to carry out work utilising a ladder where two hands are required. For such work, it is therefore necessary to S.. *SS * erect scaffolding to as to be able to work from a platform * S. ***** provided by the scaffolding. The use of scaffolding suffers from the disadvantage that it is not economically viable where the work to be carried out at a particular location on the exterior of a building is for a relatively short duration. In order to comply with the above safety regulations it is necessary to provide a safety device for a person working with both hands from a ladder above ground level particularly on the exterior of a building.

In addition, in order to avoid having to erect scaffolding and where the location on which work is to be carried out can be reached, it is found that a person often works from inside the building leaning out of a window opening. Where a person is working in this manner from a floor which is above ground level, the person is in danger of falling particularly where the work being carried out requires the use of both hands. It is advisable for the person to use a safety line and for the safety line to be secured within the building. However, it is found when using a safety line to be difficult to find a suitable secure anchorage point within the building for securing the safety line.

The object of the present invention is to provide safety devices for securing a person when carrying out such two handed work from a ladder or from within a building which alleviates one or more of the above described I. * difficulties and disadvantages.

S.....

* S According to one aspect of the invention, a safety * ** device for securing a safety line or a safety harness line of a person who is working at a location above ground level comprises a first member adapted to be secured in position at said location having a stem with an enlarged diameter head at the free end thereof, a second member having a connection means to which said safety line or safety harness line can be secured and said second member also having a slot closed at both ends formed therein said slot having a large width portion through which the head of the first member can be inserted and a reduced width portion adapted to engage the stem, said second member also having a retaining means for retaining the first member with the stem in engaged position with the reduced width portion of the slot and said retaining means having a locking plate which is of a corresponding shape to and is positioned within the large width portion of the slot in the locked position.

Preferably, the locking plate of the retaining means is urged by resilient means into the locked position.

Preferably, also, the locking plate of the retaining means is mounted on an arm connected to the second member said arm being formed of resilient material.

*:*::* The arm is, preferably, adapted to be manually rnoveable against the action of the resilient means to S...

disengage the locking plate from the large width portion of the slot to allow the second member to be disconnected from S.....

* the first member by passage of the head of the first member *... through the large width portion of the slot in the second member.

Preferably, the stem of the first member is circular in cross-section to allow the second member in use to be angularly rnoveable thereon.

Preferably, also, the locking plate of the retaining means in the locked position is a close fit in the large width portion of the slot so that the loading on the locking plate in any one of the angular positions of the second member on the first member is carried by the whole of the second member in which the closed slot is formed.

The second member is, preferably, of a U-shape in side elevation with the slot being formed in one of the arms of the U-shape and the connection means being formed in the other one of the arms of the U-shape.

Preferably, the arms of the U are connected together at a point spaced-apart from the base of the U-shape.

According to another aspect of the invention, a safety device for securing a safety line or a safety harness line of a person who is working above ground level in a room in a building adjacent to or through an opening in a wall of the building comprises a frame adapted to engage an *:.::* internal surface of the wall in which the opening is formed and to extend from the floor to the ceiling of said room so * * *S)* as to be restrained against movement towards said opening, wherein one or more attachment points are provided on the *a.* 0S** frame to which the safety line or safety harness line can * be secured.

Preferably, the frame comprises a front member connected to a rear member which is spaced-apart therefrom wherein the or each mounting point is provided on the rear member.

Preferably, also, the spacing between the front and the rear member of the frame is adjustable.

The rear member is, preferably, connected to upwardly extending adjustable length struts adapted to engage the ceiling and maintain the rear member in contact with the floor.

Preferably, the upwardly extending struts are provided with screw means for adjusting the lengths thereof.

Preferably, also, the or each attachment point is in the form of the first member according to said one aspect of the invention herein before described which is adapted to be releasably connected to a second member according to said one aspect of the invention hereinbefore described to which said safety line or safety harness line is secured.

Preferred embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, of which:-Figure 1 is a side elevation of a first member of a * *. * * . * S.

safety device according to said one aspect of the * S invention; *5 S Figure 2 is a side elevation of a second member of the *.S..* safety device mounted on the first member shown in Figure 1 * ** of the drawings; Figure 3 is a plan view of a blank from which the second member of the safety device shown in Figure 2 is formed; Figure 4 is a side elevation of the blank shown in Figure 3; Figure 5 is a perspective view of a safety device according to said other aspect of the invention; and Figure 6 is a side elevation of the safety device shown in Figure 5.

Referring now to Figures 1 to 4 of the drawings, in a first embodiment, a safety device indicated generally at 10 comprises a first member 12 having an externally screw-threaded stern 14 adapted to be screwed into a conventional masonry anchor (not shown) having an internally screw-threaded bore. The anchor is secured in conventional manner in a wall of a building (not shown) at a suitable location where work is to be carried out by a person working above ground level from a ladder, said person being equipped with a safety line such as a safety line from a conventional safety harness (not shown) worn by the person.

* The stem 14 is circular in cross-section has an enlarged head 16 at the free end of the stem 14 which is provided *..

with means for screwing the member 12 into the anchor such * 0 * S I * 15 as an "Allen" key socket 18 in the end face or flats 20 for S. .I*I engagement with a spanner or the like. The first member 12 I'..' is provided with a smooth circular section 22 between the head 16 and the start of the screw-thread on the stem 14 and the member is formed from a steel casting or a steel fabrication capable of carrying the load imposed thereon to arrest the fall of the person in the case of an accidental fall.

A second member 24 of the safety device 10 is formed of steel from a blank 26 by a punching operation and a bending operation along the lines 28 and 30 to form it into a U-shape in side elevation having two arms 32 and 34. A closed ended slot 36 having a large width portion 38 and a reduced width portion 40 is formed in the arm 32 by a punching operation and an aperture 42 to which the end of the safety line can be attached is formed by a punching operation in the arm 34. The two arms 32 and 34 of the U-shape are connected together at a point spaced-apart from the base of the [3-shape by two set screws 44 passing through holes 46 and secured in position by shear nuts 48.

A retaining arm 50 formed of spring steel is connected to the internal face of the arm 32 of the second member 24 by a screw 52 which is accessed through a hole 54 to tighten the screw. The arm 50 has a disc 56 of steel of corresponding shape to the large width portion 38 of the * 10 slot 36 secured thereto by a screw 58. The disc 56 is a **s close fit in the large width portion 38 of the slot 36 and ** . * *.

* 15 is urged by the arm 50 into this closed position. The free * * .*** * S end of the arm 50 extends beyond the end of the disc 56 and the slot 36 so that it can be manually disengaged to lift the disc 56 out of the slot 36.

In operation, when the safety device 10 is to be used by a person who requires to carry out two handed work at a location on a wall of a building above ground level, the first member 12 is secured in position by screwing it into a conventional masonry anchor disposed in the wall where the work is to be carried out. The second member 24 is secured to the first member 12 by inserting the enlarged head 16 at the free end of the stem 14 through the large width portion 38 of the slot 36 displacing the disc 56 on the arm 50 inwardly against the action of the spring steel arm 50 arid then sliding the smooth circular section 22 on the stem 14 into the reduced width portion 40 of the slot 36 so that the enlarged head 16 is held in place behind the edges of the reduced width portion 40 of the slot 36. The disc 56 on the arm 50 then returns under the action of the spring steel arm 50 into the closed position in which the disc 56 is a close fit in the large width portion 38 of the slot 36. The engagement of the smooth circular section 22 on the stem 14 of the first member 12 in the reduced width portion 40 of the slot 36 allows the second member 24 to be angularly moveable on the first member 12 and the positioning of the disc 56 as a close fit in the large width portion 38 of the slot 36 ensures that any load imposed on the safety device 10, for example if the person using it falls, is carried by the whole of the second member 24 and particularly by the arm 32 of the second member 24 without there being any component of the load which tends to move the disc 56 out of its closed position * ** 20 irrespective of the angular position of the second member 24 on the first member 12. The safety line, such as the *e * * S * * safety line from the harness worn by the person working S.....

S

above ground level, is connected to the aperture 42 in the * *.

arm 34 so that the person can carry out work with both hands whilst working from a ladder and still have three points of attachment, namely two feet on the ladder and the attachment to the safety device 10.

Once the work has been carried out the second member 24 is disconnected from the first member 12 by pressing the free end of the arm 50 inwardly against the spring action thereof to remove the disc 56 from the large width portion 38 of the slot 36. The enlarged head 16 of the first member 12 is moved slidably from the reduced width portion of the slot 36 into the large width portion 38 and the enlarged head 16 is withdrawn therethrough to disconnect the second member 24 from the first member 12 of the safety device 10 and the safety line can also be removed from the second member 24. The first member 12 can be removed by unscrewing it from the masonry anchor which is left in place in the wall of the building, particularly if work in this location is to be carried out again, such as by a window cleaner. In order to protect the masonry anchor from the effect of weathering which could affect the efficiency of the screw thread therein, a snap-fit plastic cover can be fitted over the anchor and said cover can be coloured to match the colour of the wall. Alternatively, * both the first member 12 and the masonry anchor can be left *** in place in the wall of the building and a snap-fit plastic ** S * * S * cover can be fitted over both the first member 12 and the *S***

S

masonry anchor. * S.

S.'.,' Referring now to Figures 5 and 6 of the drawings, in a second embodiment a safety device comprises a steel frame indicated generally at 60 for securing a safety line such as a safety harness line (not shown) worn by a person who is working above ground level in a room of a building adjacent to or even through an opening 62 in a wall 64 of the building. The frame 60 comprises a front member 66 and a rear member 68 connected thereto by two spaced-apart substantially parallel adjustable length struts 70. The front member 66 and the rear member 68 both rest on a floor 72 of the room and the front member 66 is positioned in contact with the internal surface of the wall 64 containing the opening 62. The rear member 68 is provided with anchorage points 74 in each of which the first member 12 (not shown) of the safety device 10 described in the first embodiment can be mounted so that the safety line attached to the second member 24 (not shown) of the safety device 10 can be secured by engagement of the first member 12 and the second member 24 as hereinbefore described in the first embodiment. The rear member 68 of the frame is connected to two spaced-apart adjustable length upwardly extending struts 76 whose upper ends engage in contact with a ceiling 78 of the room to maintain the rear member 68 and also the * *.

front member 66 of the frame 60 in contact with the floor * S..

72. The adjustment of the length of the struts 70 is S. * S. * effected by forming each strut 70 from two telescopic S.....

sections provided with holes 80 through which a locking pin * S. (not shown) is inserted to connect the sections together to provide the desired length of the strut 70. The adjustment of the length of the struts 76 is also effected by the same method as the struts 70 namely telescopic sections with holes 80 and in addition a conventional screw-threaded adjustment mechanism 82 is provided at the lower end of each strut 76.

In operation, the frame 60 is placed in position on the floor 72 and the length of the struts 70 are adjusted to not only provided adequate working space but also to accommodate different lengths of safety line which when formed as part of a safety harness is not normally adjustable in length so that a person working in the room can not fall out of the opening 62. The lengths of the struts 76 are adjusted in length to maintain the rear member 68 and the front member 66 securely in position in contact with the floor 72 when subjected to loading in the scenario of the person connected to the frame 60 falling through the window opening 62. The tightening of the contact of the ends of the struts 76 with the ceiling 78 and the rear member 68 on the floor 72 utilising the screw-threaded adjustment mechanisms 82 increases the force securing the frame in said position. * S. * . S

* 20 Although the above described safety devices are **S. * *

particularly suitable for use by persons working from

S

* ladders or from the interior of buildings adjacent to or *S.*S.

* through openings in a wall, it will be appreciated they can * *S be used for other purposes without departing from the scope of this invention.

Claims

Claims: 1. A safety device for securing a safety line or a safety harness line of a person who is working at a location above ground level comprising a first member adapted to be secured in position at said location having a stem with an enlarged diameter head at the free end thereof, a second member having a connection means to which said safety line or safety harness line can be secured and said second member also having a slot closed at both ends formed therein said slot having a large width portion through which the head of the first member can be inserted and a reduced width portion adapted to engage the stem, said second member also having a retaining means for retaining the first member with the stem in engaged position with the reduced width portion of the slot and said retaining means having a locking plate which is of a corresponding shape to and is positioned within the large width portion of the slot in the locked position.
2. A safety device according to claim 1, wherein the * S. locking plate of the retaining means is urged by resilient *.* means into the locked position.

S a * *

* **
3. A safety device according to claim 2, wherein the * locking plate of the retaining means is mounted on an arm * *.

connected to the second member said arm being formed of resilient material.
4. A safety device according to claim 3, wherein the arm is adapted to be manually moveable against the action of the resilient means to disengage the locking plate from the large width portion of the slot to allow the second member to be disconnected from the first member by passage of the head of the first member through the large width portion of the slot in the second member.
5. A safety device according to any one of the preceding claims, wherein the stem of the first member is circular in cross-section to allow the second member in use to be angularly moveable thereon.
6. A safety device according to claim 5, wherein the locking plate of the retaining means in the locked position is a close fit in the large width portion of the slot so that the loading on the locking plate in any one of the angular positions of the second member on the first member is carried by the whole of the second member in which the closed slot is formed.
7. A safety device according to any one of the preceding claims, wherein the second member is of a U-shape in side elevation with the slot being formed in one of the arms of the U-shape and the connection means being formed in the * S*.

other one of the arms of the U-shape.

*. :
8. A safety device according to claim 7, wherein the arms * ** of the U are connected together at a point spaced-apart from the base of the U-shape. * .1
9. A safety device for securing a safety line or a safety harness line of a person who is working above ground level in a room in a building adjacent to or through an opening in a wall of the building comprises a frame adapted to engage an internal surface of the wall in which the opening is formed and to extend from the floor to the ceiling of said room so as to be restrained against movement towards said opening, wherein one or more attachment points are provided on the frame to which the safety Line or safety harness line can be secured.
10. A safety device according to claim 9, wherein the frame comprises a front member connected to a rear member which is spaced-apart therefrom wherein the or each attachment point is provided on the rear member.
11. A safety device according to claim 10 wherein the spacing between the front and the rear member of the frame

is adjustable.
12. A safety device according to claim 10 or claim 11, wherein the rear member is connected to upwardly extending adjustable length struts adapted to engage the ceiling and maintain the rear member in contact with the floor.
13. A safety device according to claim 12, wherein the * ** * * * 20 upwardly extending struts are provided with screw means for * S... S *

adjusting the lengths thereof. *

* . *
14. A safety device according to any one of claims 9 to S. 13, wherein the or each attachment point is in the form of

S

* .* the first member according to any one of the preceding

S * S.

claims 1 to 8 which is adapted to be releasably connected to the second member according to any one of the preceding claims 1 to 8 to which said safety line or safety harness line is secured.
15. A safety device constructed, arranged arid adapted to operate substantially as hereinbefore described with reference to, and as illustrated by, Figures 1 to 4 or Figures 5 and 6 of the drawings. * *5 * S S * *. *.*S * . * S..

S

S S ** : S * * *. *S * * S.