ES2312952T3 - SECURITY DEVICES - Google Patents

Abstract

A safety brake for a fall arrest system, for use with a vertical track 46 such that downward pressure on lever 50 via a carabiner through hole 53 forces, by action of a cam on lever 50, brake shoe 56 against track 46. A gravity actuated switch 80 falls as shown so that tooth 81 engages notch 82 in member 59 so that upward force on lever 50 does not actuate the brake but downward force does, and because of switch 80, the safety brake may be installed either way up.

Description

Security devices

The present invention relates to a clamp for use in a fall arrest system to protect the workers who work in high places.

It is often necessary for the worker to access elevated places, for example, in a building, a bridge or a scaffolding to perform various tasks such as maintenance or cleaning A slip or fall from such a place can produce a serious and even fatal injury and, therefore, the worker you must wear a harness that is attached through a cord to a fall arrest device mounted in the building. Is it is essential that the system be flexible and easy to use, so that workers can move from one place to another and perform their tasks without having to unhook and hook repeatedly from the fall arrest device, nor put in danger your safety with it.

A well-known fall arrest system comprises a safety guide in the form of a cable that is fixed temporarily or permanently to the building or other structure and to the which the worker hooks through a safety clamp that is connected to the free end of a cord attached to a harness worn by the worker. The worker's movements generally parallel to the cable are not limited because the clamp can slide freely along the cable as reaction to a pull on the cord. When the clamp remains attached permanently to the cable, the falls stop quickly, with which prevents bodily injury. The detention systems of falls of this type are generally well known and workers they are usually obliged to use them when they work in places elevated to meet various health and safety standards.

The safety clip to hook the cord the cable generally comprises a part of tubular hook elongated to receive the cable and a jaw that can be opened to facilitate the hooking of the clamp to the cable, and close to retain the clamp on the cable so that the cable can slide freely through the hook part. It is important to ensure that the sliding movement of the clamp along the cable is not impeded or interrupted by any support used to Fix the cable to the building. To overcome this, a space or groove between the tip of the jaw and the tip of the hook, so that the brackets, which have a neck part thin formed from a flat plate in an area adjacent to the place where they get attached to the cable, they can slide through the space without it being necessary for the worker to unhook and return to hook the clamp on both sides of the bracket.

The clamp has a loop part through the which can pass a connection element such as a ring or carabiner to hook the end of a cord to the clamp. He loop has dimensions and position such that, when passes the connecting element through the loop, blocks or substantially prevents the movement of the jaw from the closed position to open, so that the clamp cannot be unintentionally unhooking the cable while the element of connection is in place.

It will be noted that it is important to ensure that the space or groove between the end of the hook and the end of the jaw is sufficient to allow the brackets that hold the cable pass through it easily, but it is not allowed that is larger than the diameter of the cable along which the clamp will slide, otherwise the cable can pass to through space and release the cable clamp. Yes, for example, a connection element having a cross section is used with a smaller diameter to hook the cord to the clamp, the gag has greater freedom of movement between position closed and open, since it is not locked by the element of connection to the same point as a connection element that has a larger cross section. Therefore, potentially, the jaw could still open to a point that is sufficient to allow a smaller diameter cable to fit through the space and unhook the cable clamp.

Therefore, it will be noted that with the tweezers of  security of the type described above there is the problem of which are only designed to work with cables and elements connection that are within a relatively range of sizes small. The use of the clamp with cables and / or connection elements that are outside this range can be dangerous due to  which can result in the clamp being released from the cable involuntary for the reasons explained above.

An object of the present invention consists in substantially overcome or alleviate the aforementioned problems and in providing a safety clamp for use in a system of fall arrest, which not only has a more functioning simple, but also safer use than tweezers conventional.

From GB2370312, it is known that provides a safety clamp for use in a system of Fall arrest that includes a guide, and safety clip comprises a body and a jaw mounted on the body so pivoting and that can be moved between an open position, in the that the body can be hooked and uncoupled from the guide, and a closed position, to retain the clamp in the guide.

A safety clip according to this invention is characterized by a cam element mounted on the body so that it can rotate, and with the jaw deflected towards the open position, and the cam element and the jaw collaborate reacting to the rotation of the cam element to make the pivot jaw to the closed position.

The body preferably includes a part of hook to receive the guide and the cam element and the jaw They are configured so that when the jaw is in a closed position, there is a space between the tip of the jaw and the tip of the hook part.

In one embodiment, the body comprises a connection part that hangs on the hook part, and the part connection has an opening in it to receive an element of connection to hook the clamp to a cord.

Preferably, the cam element is fixed pivotally to the connecting part, and the clamp is configured so as to substantially prevent rotation of the cam element when the connection element is received at Through the opening.

Advantageously, the cam element is annular and the opening in the connecting part and in the cam element is align when the cam element is positioned such that the jaw is in a closed position, and the element of connection can be received through both openings, that of the connecting part and that of the cam element, to prevent substantially the rotation of the cam element with respect to the connection part.

In a preferred embodiment, the cam element is configured such that any limited rotation of the cam element is still possible when the cam element is received through the openings in the connection part and the cam element can be operated to make the jaw move beyond the closed position until one in which the size of the space between the jaw and the part of hook is reduced or eliminated.

The cam surface is formed preferably on the outside of the annular cam member and it comprises a first cam surface and a second surface of cam adjacent to the first cam surface.

Conveniently, the first and second cam surface are substantially flat and join in a oblique angle

Preferably, the first cam surface is coupled with the jaw when the jaw is in A closed position.

In one embodiment, an area located between the first and the second cam surface is coupled with the jaw when the cam element is rotated initially and the space between the jaw and the hook part is It reduces or is eliminated.

The jaw preferably cooperates with the second cam surface when the element of coupling and the cam element is allowed to rotate beyond said initial rotation.

In another embodiment, the element of cam includes means of diversion to divert it to a position in which the jaw has pivoted to the position closed.

The present invention also provides a fall arrest system that incorporates a clamp safety according to the invention.

Now, embodiments of the  invention, by way of example only, with reference to attached drawings, in which:

fig. 1 is a front perspective view of a safety clamp according to an embodiment of the invention;

fig. 2 is a perspective rear view of the safety clamp illustrated in figure 1;

fig. 3 is an exploded view in perspective of the safety clip shown in the figures 1 and 2;

fig. 4 is a front perspective view of the safety clip shown in figure 1 but with the rotated cam so that the jaw is in one position open

fig. 5 is a front perspective view of the safety clip shown in figure 1, mounted on a cable and with a hooked hook;

fig. 5th is a front perspective view of an alternative version of the safety clamp according to the present invention with the jaw in closed position; Y

fig. 5b is a front perspective view of an alternative version of the safety clamp according to the present invention with the jaw in the open position.

Referring now to figures 1 to 5 of the attached drawings, in figure 1 a clamp of safety 1 for use in a fall arrest system in the that the clip 1 can be hooked, so that it can slide and drop, to a guide fixed to a building, scaffolding or other structure high. The clamp 1 includes a body 2 comprising a part of hook 3 and a connection part 4. A jaw element 5 is pivotally fixed to the body 2, between the hook part 3 and the connection part 4, and a cam element 6 is fixed of pivoting shape to connection part 4.

The hook part 3 and the jaw element 5 together define an elongated tubular opening in which receive the guide, such as a cable 7 (see figure 5) of the fall arrest device when clamp 1 is hooked to it. It will be noted that the opening has a section transverse with a diameter considerably larger than the diameter of the cross section of the cable 7, so that the clamp 1 can slide freely along it.

The connection part 4 hangs on the part of hook 3 and has an opening 8 therein to receive a connecting element such as a carabiner 9 (see figure 5), that hooks to a cord that extends from a harness that He is wearing the worker who is using the system.

The cam element 6 is illustrated with greater clarity in figure 3, and is pivotally mounted on the connection part 4 to rotate about an axis "A" indicated in figure 3, and has a hole 10 therein of a diameter substantially equal to that of the opening 8 in the part of connection 4. The cam element 6 has a generally shaped annular with a smooth outer profile except in a front area 11 in which the cam element has a first cam surface 12 flattened between two second cam surfaces 13 that extend at an oblique angle from the first cam surface 12. The first cam surface 12 may have a shoulder or protruding flange (not shown) for coupling with the jaw element 5 and for reasons that will be manifest.

The jaw element 5 is fixed to the body 2  generally between the hook part 3 and the connection part 4 to rotate about an axis "B" indicated in figure 1 and it comprises a pair of legs 14 that hang from a central section 15. The inner face of the legs 14 and section 15 has a shape arched or curved in order to be part of the tubular opening to receive the cable 7. The body 2 includes a cylindrical hollow 16 to receive an axis 17 whose ends are received in some corresponding openings 18 at the distal end of each leg 14 to attach the jaw element 5 to the body 2. There is also a spiral spring 19 mounted inside a cavity 20 in the body 2, at one end of the gap 16. One end 21 of the spring is received in an extension 21a of the cavity 20 in the body 2 and the other end in a corresponding cavity (not shown) in the jaw element 5. The spring 19 deflects the element of jaw 5 to the open position, or the position illustrated in the figure 4.

The cam element 6 is fixed so pivoting to the connecting part 4 through a screw 22 that extends through a gap 23 at the edge of the element of ring cam 6 and through a corresponding hole 24 in the part connection 4. Screw 22 is threadedly coupled to a bushing 25 on the other side of the connection part 4.

The cam element 6 can rotate freely in both directions around the "A" axis reacting to the User manipulation with the fingers. However, in an alternative embodiment, the cam element 6 is you can apply a spring in a similar way to the element of jaw 5, so that it is deflected to the closed position, which is the position shown in figure 1.

The cam element 6 can be retained in the position shown in figure 1 by a mechanism catch 26 received in a threaded opening 27 in the part of connection 4. The locking mechanism includes a spring 28 and a stud 29 protruding from connection part 4 and is received in a cavity (not shown) on the back surface of the element cam 6 when cam element 6 is in position shown in figure 1. When enough is applied torque to cam element 6 to overcome deflection force provided by the pier 28, the stud 29 deviates towards inside causing it to leave the cavity and allowing the cam element 6 rotate around the "A" axis. A screw without head 29a retains the spring 28 and the stud 29 in the opening 27. It will be noted that the deflection force can be adjusted as reaction to the tightening or loosening of the headless screw 29a in the threaded opening 27.

The operation of the safety clip 1. To hook the hook part 3 to the cable 7, the jaw element 5 must be pivoted to a position open, so that a space (indicated with an X in the figures 1 and 4) between the tip of the hook part 3 and the tip of the jaw element 8 is sufficient to allow cable 7 pass through the tubular opening. The movement of jaw element 5 until the open position is achieved by turning the  cam element 6 around the "A" axis, so that the jaw element 5 can pivot, due to the deflection provided by the spring 19, to the open position shown in the Figure 4. It will be noted that, before the rotation of the element of cam 6 from the position shown in figure 1, the first cam surface 12 of cam element 6 is coupled with the outer surface of the jaw element 5, and thus, the element cam 6 prevents the jaw element 5 from rotating until the open position

Once the cable has been received in the tubular opening, jaw element 5 can be moved to the closed position to hold the cable in place. This is get by turning cam element 6 in the opposite direction until you return to the position shown in figure 1, or releasing it if cam element 6 is deflected by a spring. TO As cam element 6 is rotated, cam surfaces 12, 13 are coupled with the outer surface of the jaw element 5 and force its closure against the deflection force provided by the spring 19 so that the distance X is reduced and prevented that the cable 7 comes out. It will be observed that a small space to allow clip 1 to pass over brackets (not shown) used to secure cable 7 to the structure, as explained above.

Once the clamp 1 is hooked to the cable, at that time a connection element 9 can be attached to the clamp 1 inserting it through both openings aligned 8, 10 in the connection part 4 and the cam element 6.

It will be noted that the rotation of the element of cam 6 from the position shown in figure 1, in which the jaw element 5 is kept in a closed position, until the position shown in figure 4, in which the element of Jaw 5 can pivot freely from an open position, is prevented by the connecting element 9 that blocks the cam element 6 in place. However, the rotation of the cam element 6 is only prevented to the extent that the diameter of the opening 10 in the cam element 6 is the same as the diameter of the connecting element 9 passing through it. In In practice, the diameter of the connecting element 9 is smaller than the diameter of the opening 10 to allow the element of connection 9 hang freely from the clamp 1. Therefore, the Rotation of cam element 6 is not totally prevented.

One of the characteristics of clamp 1 is the that an initial rotation of cam element 6 serves in reality to make the space X between the tip of the element of jaw 5 and the tip of the hook part 3 is smaller than when the jaw element 5 is in the closed position normal with cam element 6 in the position shown in Figure 1. As the cam element 6 rotates, the part of the cam surface between the first and the second surface of cam 12, 13 engages with the jaw element 5 forcing it further beyond the closed position, so that space X is reduced. If then the cam element 6 is still rotated, it is achieved that the jaw element 5 engages with the second surface of cam 13 and the jaw element 5 open. Only at the moment wherein the opening 10 in the cam element 6 and the opening 8 in the connection part 4 is completely misaligned, the rotation of cam element 6 will allow the space X. Therefore, regardless of the diameter of the connection element 9, jaw element 5 cannot be moved towards the open position until the connection element 9 is remove from openings 8, 10.

In Figures 5a and 5b, a second is illustrated. embodiment of the safety clip 100 according to the invention. The safety clamp 100 is similar to the clamp security 1 of the first embodiment, except that in this modified version, cam element 6 has been replaced by another annular cam member 101 and the connection part 4 of the body has two arms 103 between which the annular cam member 101 pivotally to rotate about of an "F" axis indicated in the figures. The cam element 101 is set for rotation to the body at a 90 degree angle with regarding its position in the first embodiment.

The annular cam member 101 has a opening 104 therein to receive such a connection element as a carabiner 9. It will be noted that the annular cam element 102 cannot rotate to a position in which the element of jaw 5 can be moved to an open position, as shown in figure 5b, until the element of connection 9. As in the first embodiment, the cam element 101 has a shape such that any rotation initial of the cam member 101 due to the opening 104 being greater than the diameter of the connecting element 9 will cause the jaw 5 moves beyond the closed position, so that it reduce the space between the hook part 3 and the jaw 5, with which avoids the possibility that the safety clamp 100 will cable release. The cam member 101 is provided with a flattened area 105 to facilitate rotation of the cam element 101 around the "F" axis. The flattened part 105 is also attaches to a seat (not shown) on the back faces of arms 103 when the jaw moves to the position closed to prevent cam member 101 from continuing to rotate in the same direction.

The invention has been described with reference only to the preferred embodiments. The modifications or alterations of the embodiments that fall within the scope of the appended claims are included in the scope of protection.

Claims (15)

1. A safety clamp for use in a fall arrest system that includes a guide and the safety clamp comprises a body (2) and a jaw (5) pivotally mounted on the body (2) and which is it can move between an open position, in which the body (2) can be engaged and unhooked from the guide, and a closed position, to retain the clamp on the guide, characterized by a cam element (6) mounted on the body (2) so that it can rotate, and with the jaw (5) offset towards the open position, and the cam element (6) and the jaw (5) collaborate by reacting to the rotation of the cam element (6) to make that the jaw (5) pivots to the closed position. 2. A safety clamp according to the claim 1, wherein the body (2) includes a part of hook (3) and cam element (6) and jaw (5) are configured so that, when the jaw (5) is found in the closed position, there is a space between the tip of the jaw (5) and the tip of the hook part (3). 3. A safety clamp according to the claim 2, wherein the body (2) comprises a part of connection (4) that hangs on the hook part (3), and the part of connection (4) has an opening (8) in it to receive a connecting element to hook the clamp to a cord. 4. A safety clamp according to the claim 3, wherein the cam element (6) is fixed of pivoting shape to the connecting part (4), and the clamp is configured so as to substantially prevent rotation of the cam element (6) when the connection element is received at through the opening (8). 5. A safety clamp according to the claim 4, wherein the cam element (6) is annular and the opening (8) in the connecting part (4) and in the cam element (6) align when the cam element (6) is placed in such so that the jaw (5) is in a closed position, and the connection element can be received through both openings (8), that of the connecting part (4) and that of the cam element (6), to substantially prevent rotation of the cam element (6) with respect to the connection part (4). 6. A safety clamp according to the claim 5, wherein the cam element (6) is configured in such a way that any limited rotation of the cam element (6) is still possible when the element of cam is received through the openings (8) in the part of connection (4) and the cam element (6) can be operated to make the jaw (5) moves beyond the closed position until one in which the size of the space between the jaw (5) and the part hook (3) is reduced or eliminated. 7. A safety clamp according to the claim 6, wherein a cam surface is formed on the outside of the annular cam element (6) and comprises a first cam surface (12) and a second surface of cam (13) adjacent to the first cam surface (12). 8. A safety clamp according to the claim 7, wherein the first and second surface of Cam (12, 13) are substantially flat and join at an angle oblique. 9. A safety clamp according to the claims 7 or 8 wherein the first cam surface (12) is coupled with the jaw (5) when the jaw (5) is found in a closed position. 10. A safety clamp according to the claim 7, 8 or 9, wherein an area between the first and second cam surface (12, 13) is coupled with the jaw (5) when the cam element (6) is rotated initially and the space between the jaw (5) and the hook part (3) is reduced or eliminated. 11. A safety clamp according to any of claims 7 to 10, wherein the jaw (5) collaborates with the second cam surface (13) when the coupling element and the cam element is allowed (6) rotate beyond that initial rotation. 12. A safety clamp according to any of the preceding claims, wherein the cam element (6) includes diverting means to divert it to a position in which the jaw (5) has been pivoted to the position closed. 13. A safety clamp according to the claims 1 or 2, wherein the body (2) includes a pair of arms hanging from the hook part (3), and the cam element (6) is located between said arms and fixed thereto pivoting 14. A safety clamp according to the claim 13, wherein the cam element (6) has a opening (10) through it to receive an element of connection and arms substantially prevent the rotation of the cam element (6) when receiving a connection element to Through the opening. 15. A fall arrest system that incorporates a safety clamp according to any of the claims 1 to 14.