Patent Application
20220401765
This application claims priority to United Kingdom Patent Application No. 1916588.5 filed Nov. 14, 2019 and to United Kingdom Patent Application No. 2000291.1 filed 9 Jan. 2020, the disclosure of which are incorporated by reference herein in their entirety.
The present disclosure is directed towards an apparatus for use in a fall arrest or fall protection device for setting or restricting the maximum length of safety line that can be paid out of the device.
Fall arrest devices are used to prevent personnel working at height from suffering injury as a result of falling. Fall arrest devices are often referred to as height safety systems or fall protection devices. Fall arrest devices typically include: a drum upon which a safety line or lifeline is wound and a speed responsive mechanism arranged to inhibit the drum rotation above a predetermined rotational speed.
The fall arrest device may include an energy absorber device or ring arranged to be activated if a load above a predetermined threshold is deployed when the speed responsive mechanism is activated. Alternatively, an external energy absorber device may be provided, which is usually connected between the safety line and the user. For example, the energy absorber device may be connected to a harness worn by a user.
The energy absorber device absorbs the energy, or shock of a fall arrest event. If an energy absorber device is not used as part of a fall arrest system, a user can continue to descend even after engagement of other safety arrangements, such as a speed responsive brake, due to the loading force of the user's weight acting on the safety line. This continued descent is prevented or limited by an energy absorber device.
A self-retracting lifeline (SRL) is a type of fall arrest device which includes a rewinding mechanism configured to automatically pay out and retract the lifeline as necessary to allow the user movement while keeping the lifeline taut. The drum upon which the lifeline is wound is therefore biased to rewind the lifeline onto the drum.
Fall arrest devices, including self-retracting lifeline devices, do not prevent a user from falling. Rather, they arrest the descent of the user's fall and attempt to limit any injuries sustained as a result of the fall. However, any fall or fall arrest event is likely to result in some distress and trauma to the user, whether mental or physical. It is therefore preferable to reduce the likelihood of the user falling while wearing the fall arrest device.
Often, fall arrest devices are used on roofs, scaffolding, or other raised worksites. One option for reducing the likelihood of a user falling (without making any changes to the worksite itself) is to restrict the length of the safety line (or lifeline) so that the user cannot reach the very edge of the worksite.
An example of a fall arrest device which allows the user to set the maximum length of the safety line that can be paid out is described in U.S. Pat. No. 10,207,128. The maximum length of safety line that can be paid out is controlled by a plurality of gears and a pivot mechanism.
Another example of a fall arrest device comprising a restraint system is the Bornack® BOOT Height securing device.
There is a need for an improved fall arrest device comprising an apparatus for setting or restricting the maximum length of the safety line.
In particular, there is a need for a simple and cost-effective apparatus for setting or restricting the maximum length of the safety line that can be incorporated into an existing fall arrest device.
The present disclosure provides a fall arrest device and an apparatus for setting the length of safety line that can be paid out from a fall arrest device.
In some non-limiting embodiments or aspects, a fall arrest device may include a drum configured to have a safety line wound thereon; a speed responsive engagement assembly arranged to inhibit rotation of the drum above a predetermined rotational speed; and a traveller configured to move in response to rotation of the drum. The traveller may be configured to activate the speed responsive engagement assembly when a predetermined length of safety line has been paid out. The traveller may also be referred to as an actuator or an actuator member.
In some non-limiting embodiments or aspects, the speed responsive engagement assembly may be a mechanism that prevents further pay out of the safety line and may be activated when the rotation of the drum reaches a speed indicative of a fall arrest event.
In some non-limiting embodiments or aspects, the present disclosure provides a technical advantage of not requiring an additional locking mechanism to be incorporated into the fall arrest device. In some non-limiting embodiments or aspects, the traveller may activate or engage the speed responsive engagement assembly of the fall arrest device when a predetermined length of safety line has been paid out from the drum. Thus, the present disclosure does not require a separate load bearing locking mechanism to be incorporated into the fall arrest device, thereby reducing cost, weight and complexity of the device. The present disclosure is safer and more reliable, as no override mechanism is required.
The traveller may be configured to move transversely to the rotational axis of the drum in response to rotation of the drum to pay out and retract safety line. Thus, in some non-limiting embodiments or aspects, the traveller does not move along (or parallel to) the axis of rotation of the drum.
In some non-limiting embodiments or aspects, as the traveller engages or activates the existing speed responsive engagement assembly of the fall arrest device, the traveller is not load bearing. This means that the traveller can be made of plastic, or other light and cost-effective material.
In some non-limiting embodiments or aspects, the traveller may be configured to slide transversely to the rotational axis of the drum.
In some non-limiting embodiments or aspects, the traveller may be configured to move outwards in response to rotation of the drum to pay out safety line. In some non-limiting embodiments or aspects, the traveller may be configured to move radially outwards in response to the rotation of the drum to pay out safety line.
In some non-limiting embodiments or aspects, the traveller may be configured to move inwards in response to rotation of the drum to pay out safety line. In some non-limiting embodiments or aspects, the traveller may be configured to move radially inwards in response to the rotation of the drum to pay out safety line.
In some non-limiting embodiments or aspects, the traveller may be configured to move linearly (e.g. along a straight line or a straight path). In some non-limiting embodiments or aspects, the traveller may be moveable between a start position and an end position, wherein the end position is arranged such that the traveller engages a component of the speed responsive engagement assembly. In some non-limiting embodiments or aspects, the end position may be spaced further from the rotational axis of the fall arrest drum than the start position. Optionally, the end position is located radially outwards of the start position. In some non-limiting embodiments or aspects, the end position may be located closer to the rotational axis of the fall arrest drum than the start position. Optionally, the end position is located radially inwards of the start position. In some non-limiting embodiments or aspects, the start and end positions may be aligned along a radial path.
In some non-limiting embodiments or aspects, the start position of the traveller can be adjusted to set the predetermined length of safety line that can be paid out from the drum. It will be appreciated that there are a number of ways in which the start position of the traveller can be adjusted. Optionally, the traveller may be moved manually (by hand), or an actuator may be provided to adjust the start position of the traveller. In some non-limiting embodiments or aspects, the predetermined length of safety line that can be paid out can be adjusted to restrain the user from the edge of a worksite or other location at which a fall may occur. Therefore, this helps to reduce the risk of a fall, while still arresting the user's descent if a fall should occur. In some non-limiting embodiments or aspects, the distance of the start position of the traveller from the rotational axis of the drum may set the predetermined length of safety line that can be paid out.
If the traveller is configured to move outwards in response to rotation of the drum to pay out safety line, the closer the start position of the traveller is to the rotational axis of the drum, the longer the predetermined length of safety line is. Accordingly, to reduce the length of safety line that can be paid out from the device, the start position of the traveller may be adjusted to move towards the circumference of the drum. If the traveller is configured to move inwards in response to rotation of the drum to pay out safety line, the further away the start position of the traveller is from the rotational axis of the drum, the longer the predetermined length of safety line is. In other words, to reduce the length of safety line that can be paid out from the device, the start position of the traveller may be adjusted to move towards the center of the drum.
In some non-limiting embodiments or aspects, the speed responsive engagement assembly may include a pawl and a pawl stop formation. In the end position, the traveller may be configured to move the pawl into engagement with the pawl stop formation. In some non-limiting embodiments or aspects, the traveller may be configured to push the pawl into engagement with the pawl stop formation. In some non-limiting embodiments or aspects, the traveller may be configured to pull the pawl into engagement with the pawl stop formation. In some non-limiting embodiments or aspects, the speed responsive engagement assembly may include a plurality of pawls. The traveller may be configured to move one of the pawls into engagement with the pawl stop formation. The speed responsive engagement assembly may be as defined in WO2016/120614.
In some non-limiting embodiments or aspects, each pawl may be pivotally mounted on a pawl carrier and the pawl carrier may be mounted to rotate with the drum. Each pawl may be biased by a spring towards a home position in which the pawl does not engage the pawl stop formation. In a fall arrest event, the speed at which the drum and pawl carrier rotates causes the pawls to pivot radially outwards to an activated position, as the centrifugal force overcomes the biasing force of the springs. This causes one of the pawls to engage the pawl stop formation, thereby preventing further safety line being paid out. Thus, a centrifugal speed responsive engagement assembly may be provided. The speed responsive engagement assembly may be as defined in WO2008/007119.
In some non-limiting embodiments or aspects, the pawl stop formation may be mounted to rotate with the drum and each pawl may be mounted to a chassis or a housing of the fall arrest device. The pawl stop formation may be a locking disc, or a ratchet wheel.
As described in WO2008/007119, each pawl may be pivotably mounted to the chassis or the housing of the fall arrest device. In normal operation, the ratchet wheel teeth may contact the pawl(s) as it rotates, generating an oscillating movement of the pawl from a first position towards a second position with an amplitude dependent on the speed of rotation. In a fall arrest event, the oscillating movement may bring the pawl into an engaged position with the ratchet wheel, preventing further safety line being paid out.
In some non-limiting embodiments or aspects, the traveller may be configured to move radially inwards in response to the rotation of the drum to rewind safety line. In some non-limiting embodiments or aspects, the traveller may be configured to move radially outwards in response to the rotation of the drum to rewind safety line. In some non-limiting embodiments or aspects, the fall arrest device may be a self-retracting lifeline device (or SRL), and the drum may be biased to retract or rewind safety line onto the drum.
In some non-limiting embodiments or aspects, the traveller may move towards the start position in response to the drum rotating to rewind or retract the safety line. In some non-limiting embodiments or aspects, the fall arrest device further may include a mechanism configured to intermittently arrest movement of the traveller while allowing the drum to continue to rotate. In some non-limiting embodiments or aspects, the fall arrest device further may include a traveller plate having a curved path that extends outwards towards the circumference of the traveller plate, wherein a portion of the traveller is received in the curved path. In some non-limiting embodiments or aspects, the traveller may include a projection which is arranged to be seated within the curved path of the traveller plate. The projection may be pin or peg. In some non-limiting embodiments or aspects, the curved path may be a helical path. In some non-limiting embodiments or aspects, the helical path may include a plurality of turns extending outwards from the center of the traveller plate.
In some non-limiting embodiments or aspects, the fall arrest device may further include a carrier plate mounted to rotate with the drum, wherein the carrier plate may include a guide into which a portion of the traveller is received. In some non-limiting embodiments or aspects, the traveller plate and the carrier plate may include a central aperture through which a bolt or other mechanical fixing is received to mount the traveller plate and the carrier plate to the fall arrest device. In some non-limiting embodiments or aspects, the carrier plate may be mounted to the speed responsive engagement assembly. For example, the carrier plate may be mounted to the pawl carrier. In some non-limiting embodiments or aspects, the traveller may be slidably mounted in or to the guide of the carrier plate.
In some non-limiting embodiments or aspects, the guide may include a radial channel. The traveller may be mounted within the radial channel. Additionally or alternatively, the guide may include a runner or a rail to which the traveller is mounted. The runner or rail may extend radially. In some non-limiting embodiments or aspects, the traveller may be sandwiched between the traveller plate and the carrier plate. In some non-limiting embodiments or aspects, the traveller plate can be rotated relative to the carrier plate in order to adjust the start position of the traveller along the curved path. In some non-limiting embodiments or aspects, the traveller plate may be rotated by hand in order to adjust or set the start position of the traveller. Alternatively, an actuator may be provided in order to rotate the traveller plate relative to the carrier plate.
In some non-limiting embodiments or aspects, in response to rotation of the drum to pay out safety line, the traveller may travel outwards along the curved path in the traveller plate and move along the guide in the carrier plate in a radially outwards direction. In some non-limiting embodiments or aspects, in response to rotation of the drum to pay out safety line, the traveller may travel inwards along the curved path in the traveller plate and move along the guide in the carrier plate in a radially inwards direction. In some non-limiting embodiments or aspects, the traveller plate may be mounted within the fall arrest device such that it does not rotate in response to rotation of the carrier plate or the drum. The traveller plate may be mounted in a fixed position. In some non-limiting embodiments or aspects, the traveller plate may be mounted to rotate in response to rotation of the drum to pay out safety line.
In some non-limiting embodiments or aspects, the fall arrest device may include a mechanism configured to intermittently arrest rotation of the traveller plate while allowing the carrier plate to rotate relative to the traveller plate. This may be advantageous as it increases the maximum predetermined length of safety line without increasing the length of the curved path in the traveller plate. For example, the traveller may be configured to only move along the curved path in the traveller plate in response to relative rotation between the carrier plate and the traveller plate. If the traveller plate rotates with the carrier plate (at the same rate of rotation) then movement of the traveller may be arrested.
In some non-limiting embodiments or aspects, the mechanism may include a stopper configured to be moveable between an engaged position and a disengaged position, wherein, in the engaged position, the stopper is configured to prevent the traveller plate from rotating. In some non-limiting embodiments or aspects, the stopper may be biased towards the engaged position by one or more biasing members. In some non-limiting embodiments or aspects, one or more abutment members may be mounted to the traveller plate. The one or more abutment members may be arranged to abut the stopper when the stopper is in the engaged position. In some non-limiting embodiments or aspects, a plurality of abutment members may be mounted to the traveller plate. The abutment members may include radial spokes or rods.
In some non-limiting embodiments or aspects, the mechanism may include an offset plate or offset member mounted between the traveller plate and the carrier plate. The offset plate or offset member may be configured to offset the rate of rotation of the traveller plate from the carrier plate. In some non-limiting embodiments or aspects, the offset plate may include one or more push formations configured to engage the stopper and move it into the disengaged position. In some non-limiting embodiments or aspects, the offset plate may include a plurality of circumferentially spaced push formations. The push formations may extend from the circumference of the offset plate. In some non-limiting embodiments or aspects, the offset plate may be mounted to the carrier plate. The offset plate may be snap-fit to the carrier plate.
It will be appreciated that the apparatus for setting the predetermined length of safety line may be provided separately to the fall arrest device. The apparatus (or restraint apparatus) may be retrofitted to (or attached to) an existing fall arrest device.
In some non-limiting embodiments or aspects, an apparatus for setting a length of safety line that can be paid out from a fall arrest device may include a drum onto which the safety line is wound, a traveller plate having a curved path that extends outwards towards the circumference of the traveller plate, a carrier plate having a guide, and a traveller configured to be moveably mounted to or within the guide. A portion of the traveller may be arranged to be received in the curved path of the traveller plate. In response to rotation of the drum to pay out safety line, the traveller may move along the curved path of the traveller plate and may be urged along the guide of the carrier plate.
It will be appreciated that any feature or embodiment of the first aspect of the disclosure may form part of the second aspect of the disclosure. In particular, the traveller, traveller plate and/or carrier plate may be as defined in any embodiment of the first aspect of the disclosure.
The traveller plate, traveller and carrier plate may be made of plastic or other light-weight inexpensive material. This is possible because the apparatus is not load bearing, even in a fall arrest event. The guide may extend in a direction transverse to the rotational axis of the fall arrest drum. Optionally, the guide extends in a radial direction.
In some non-limiting embodiments or aspects, the apparatus further may include a mechanism configured to intermittently arrest rotation of the traveller plate while allowing the carrier plate to rotate relative to the traveller plate. In some non-limiting embodiments or aspects, the mechanism may include a stopper configured to be moveable between an engaged position and a disengaged position, wherein in the engaged position the stopper is configured to prevent the traveller plate from rotating. In some non-limiting embodiments or aspects, one or more biasing members may be provided. In some non-limiting embodiments or aspects, each biasing member may be configured to bias the stopper towards the engaged position.
In some non-limiting embodiments or aspects, the apparatus may further include one or more abutment members mounted to the traveller plate. The one or more abutment members may be arranged to abut the stopper in the engaged position. In some non-limiting embodiments or aspects, a plurality of abutment members may be mounted to the traveller plate. The abutment members may include radial spokes or rods. In some non-limiting embodiments or aspects, the mechanism further may include an offset plate configured to be mounted between the traveller plate and the carrier plate, wherein the offset plate may include one or more push formations configured to engage the stopper and move it into the disengaged position. In some non-limiting embodiments or aspects, the offset plate may include a plurality of circumferentially spaced push formations. In some non-limiting embodiments or aspects, the offset plate may be configured to snap-fit to the carrier plate.
In some non-limiting embodiments or aspects, the offset plate may include a projection configured to mate with a corresponding opening in the carrier plate. In some non-limiting embodiments or aspects, the offset plate may include an opening configured to mate with a corresponding projection on the carrier plate. In some non-limiting embodiments or aspects, the traveller plate, carrier plate and the offset plate may each include a central aperture for receiving a bolt or other mechanical fixing therethrough.
Further non-limiting embodiments or aspects are set forth in the following numbered clauses:
Clause 1. A fall arrest device comprising: a drum configured to have a safety line wound thereon; a speed responsive engagement assembly arranged to inhibit rotation of the drum above a predetermined rotational speed; and a traveller configured to move in response to rotation of the drum, wherein the traveller is configured to activate the speed responsive engagement assembly when a predetermined length of safety line has been paid out.
Clause 2. The fall arrest device of clause 1, wherein the traveller is configured to move transversely to the rotational axis of the drum.
Clause 3. The fall arrest device of clause 1 or 2, wherein the traveller is configured to move outwards, or radially outwards, in response to the rotation of the drum to pay out safety line.
Clause 4. The fall arrest device of any of clauses 1-3, wherein the traveller is configured to move inwards, or radially inwards, in response to the rotation of the drum to pay out safety line.
Clause 5. The fall arrest device of any of clauses 1-4, wherein the traveller is moveable between a start position and an end position, wherein the end position is arranged such that the traveller engages a component of the speed responsive engagement assembly.
Clause 6. The fall arrest device of any of clauses 1-5, wherein the start position of the traveller can be adjusted to set the predetermined length of safety line.
Clause 7. The fall arrest device of any of clauses 1-6, wherein the speed responsive engagement assembly comprises a pawl and a pawl stop formation and, in the end position, the traveller is configured to move the pawl into engagement with the pawl stop formation.
Clause 8. The fall arrest device of any of clauses 1-7, wherein the speed responsive engagement assembly comprises a plurality of pawls pivotally mounted on a pawl carrier and the pawl carrier is mounted to rotate with the drum; or wherein the pawl stop formation is a ratchet wheel mounted to rotate with the drum and the pawl is mounted to a chassis or a housing of the fall arrest device.
Clause 9. The fall arrest device of any of clauses 1-8, wherein the traveller is configured to move radially inwards, or radially outwards, in response to the rotation of the drum to rewind safety line.
Clause 10. The fall arrest device of any of clauses 1-9, comprising a mechanism configured to intermittently arrest movement of the traveller while allowing the drum to continue to rotate.
Clause 11. The fall arrest device of any of clauses 1-10, further comprising a traveller plate having a curved path that extends outwards towards the circumference of the traveller plate, wherein a portion of the traveller is received in the curved path.
Clause 12. The fall arrest device of any of clauses 1-11, wherein the traveller comprises a projection which is seated within the curved path of the traveller plate.
Clause 13. The fall arrest device of any preceding clause, wherein the curved path is a helical path.
Clause 14. The fall arrest device of any of clauses 1-13, further comprising a carrier plate mounted to rotate with the drum, wherein the carrier plate comprises a guide into which a portion of the traveller is received.
Clause 15. The fall arrest device of any of clauses 1-14, wherein the traveller is slidably mounted in or to the guide of the carrier plate.
Clause 16. The fall arrest device of any of clauses 1-15, wherein the guide comprises a radial channel.
Clause 17. The fall arrest device of any of clauses 1-16, wherein the traveller is sandwiched between the traveller plate and the carrier plate.
Clause 18. The fall arrest device of any of clauses 1-17, wherein the traveller plate can be rotated relative to the carrier plate in order to adjust the start position of the traveller along the curved path.
Clause 19. The fall arrest device of any of clauses 1-18, wherein in response to rotation of the drum to pay out safety line, the traveller travels outwards along the curved path in the traveller plate and moves along the guide in the carrier plate in a radially outwards direction.
Clause 20. The fall arrest device of any of clauses 1-19, wherein in response to rotation of the drum to pay out safety line, the traveller travels inwards along the curved path in the traveller plate and moves along the guide in the carrier plate in a radially inwards direction.
Clause 21. The fall arrest device of any of clauses 1-20, wherein the traveller plate is mounted within the fall arrest device such that it does not rotate in response to rotation of the carrier plate or the drum.
Clause 22. The fall arrest device of any of clauses 1-21, wherein the traveller plate is mounted to rotate in response to rotation of the drum to pay out safety line.
Clause 23. The fall arrest device of any of clauses 1-22, further comprising a mechanism configured to intermittently arrest rotation of the traveller plate while allowing the carrier plate to rotate relative to the traveller plate.
Clause 24. The fall arrest device of any of clauses 1-23, wherein the mechanism comprises a stopper configured to be moveable between an engaged position and a disengaged position, wherein in the engaged position the stopper is configured to prevent the traveller plate from rotating.
Clause 25. The fall arrest device of any of clauses 1-24, wherein the stopper is biased towards the engaged position by one or more biasing members.
Clause 26. The fall arrest device of any of clauses 1-25, further comprising one or more abutment members mounted to the traveller plate, wherein the one or more abutment members are arranged to abut the stopper in the engaged position.
Clause 27. The fall arrest device of any of clauses 1-26, wherein the mechanism further comprises an offset plate mounted between the traveller plate and the carrier plate, wherein the offset plate comprises one or more push formations configured to engage the stopper and move it into the disengaged position.
Clause 28. The fall arrest device of any of clauses 1-27, wherein the offset plate comprises a plurality of circumferentially spaced push formations.
Clause 29. The fall arrest device of any of clauses 1-28, wherein the offset plate is mounted to the carrier plate.
Clause 30. The fall arrest device of any of clauses 1-29, wherein the fall arrest device is a self-retracting lifeline (SRL) device.
Clause 31. An apparatus for setting the length of safety line that can be paid out from a fall arrest device, the fall arrest device comprising a drum onto which the safety line is wound, wherein the apparatus comprises: a traveller plate having a curved path that extends outwards towards the circumference of the traveller plate; a carrier plate comprising a guide; and a traveller configured to be moveably mounted to or within the guide, wherein a portion of the traveller is arranged to be received in the curved path of the traveller plate, and wherein, in response to rotation of the drum to pay out safety line, the traveller moves along the curved path of the traveller plate and is urged along the guide of the carrier plate.
Clause 32. The apparatus of clause 31, wherein the traveller is as defined in any of the preceding claims.
Clause 33. The apparatus of clause 31 or 32, wherein the traveller plate and/or the carrier plate is as defined in any preceding claim.
Clause 34. The apparatus of any of clauses 31-33, further comprising a mechanism configured to intermittently arrest rotation of the traveller plate while allowing the carrier plate to rotate relative to the traveller plate.
Clause 35. The apparatus of any of clauses 31-34, wherein the mechanism comprises a stopper configured to be moveable between an engaged position and a disengaged position, wherein in the engaged position the stopper is configured to prevent the traveller plate from rotating.
Clause 36. The apparatus of any of clauses 31-35, further comprising one or more biasing members configured to bias the stopper towards the engaged position.
Clause 37. The apparatus of any of clauses 31-36, further comprising one or more abutment members mounted to the traveller plate, wherein the one or more abutment members are arranged to abut the stopper in the engaged position.
Clause 38. The apparatus of any of any of clauses 31-37, wherein the mechanism further comprises an offset plate configured to be mounted between the traveller plate and the carrier plate, wherein the offset plate comprises one or more push formations configured to engage the stopper and move it into the disengaged position.
Clause 39. The apparatus of any of clauses 31-38, wherein the offset plate comprises a plurality of circumferentially spaced push formations.
Clause 40. The apparatus of any of clauses 31-39, wherein the offset plate comprises a projection configured to mate with a corresponding opening in the carrier plate and/or wherein the offset plate comprises an opening configured to mate with a corresponding projection on the carrier plate.
Clause 41. A fall arrest device comprising: a drum configured to have a safety line wound thereon; a speed responsive engagement assembly arranged to inhibit rotation of the drum above a predetermined rotational speed; and a traveller configured to move in response to rotation of the drum, wherein the traveller is configured to activate the speed responsive engagement assembly when a predetermined length of safety line has been paid out.
Clause 42. The fall arrest device of clause 41, wherein the traveller is configured to move transversely to the rotational axis of the drum.
Clause 43. The fall arrest device of clause 41 or 42, wherein the traveller is configured to move outwards, or radially outwards, in response to the rotation of the drum to pay out safety line.
Clause 44. The fall arrest device of any of clauses 41-43, wherein the traveller is configured to move inwards, or radially inwards, in response to the rotation of the drum to pay out safety line.
Clause 45. The fall arrest device of any of clauses 41-44, wherein the traveller is moveable between a start position and an end position, wherein the end position is arranged such that the traveller engages a component of the speed responsive engagement assembly.
Clause 46. The fall arrest device of any of clauses 41-45, wherein the start position of the traveller can be adjusted to set the predetermined length of safety line.
Clause 47. The fall arrest device of any of clauses 41-46, wherein the speed responsive engagement assembly comprises a pawl and a pawl stop formation and, in the end position, the traveller is configured to move the pawl into engagement with the pawl stop formation.
Clause 48. The fall arrest device of any of clauses 41-47, wherein the speed responsive engagement assembly comprises a plurality of pawls pivotally mounted on a pawl carrier and the pawl carrier is mounted to rotate with the drum; or wherein the pawl stop formation is a ratchet wheel mounted to rotate with the drum and the pawl is mounted to a chassis or a housing of the fall arrest device.
Clause 49. The fall arrest device of any of clauses 41-48, wherein the traveller is configured to move radially inwards, or radially outwards, in response to the rotation of the drum to rewind safety line.
Clause 50. The fall arrest device of any of clauses 41-49, comprising a mechanism configured to intermittently arrest movement of the traveller while allowing the drum to continue to rotate.
Clause 51. The fall arrest device of any of clauses 41-50, further comprising a traveller plate having a curved path that extends outwards towards the circumference of the traveller plate, wherein a portion of the traveller is received in the curved path.
Clause 52. The fall arrest device of any of clauses 41-51, wherein the traveller comprises a projection which is seated within the curved path of the traveller plate.
Clause 53. The fall arrest device of any preceding clause, wherein the curved path is a helical path.
Clause 54. The fall arrest device of any of clauses 41-53, further comprising a carrier plate mounted to rotate with the drum, wherein the carrier plate comprises a guide into which a portion of the traveller is received.
Clause 55. The fall arrest device of any of clauses 41-54, wherein the traveller is slidably mounted in or to the guide of the carrier plate.
Clause 56. The fall arrest device of any of clauses 41-55, wherein the guide comprises a radial channel.
Clause 57. The fall arrest device of any of clauses 41-56, wherein the traveller is sandwiched between the traveller plate and the carrier plate.
Clause 58. The fall arrest device of any of clauses 41-57, wherein the traveller plate can be rotated relative to the carrier plate in order to adjust the start position of the traveller along the curved path.
Clause 59. The fall arrest device of any of clauses 41-58, wherein in response to rotation of the drum to pay out safety line, the traveller travels outwards along the curved path in the traveller plate and moves along the guide in the carrier plate in a radially outwards direction.
Clause 60. The fall arrest device of any of clauses 41-59, wherein in response to rotation of the drum to pay out safety line, the traveller travels inwards along the curved path in the traveller plate and moves along the guide in the carrier plate in a radially inwards direction.
Clause 61. The fall arrest device of any of clauses 41-60, wherein the traveller plate is mounted within the fall arrest device such that it does not rotate in response to rotation of the carrier plate or the drum.
Clause 62. The fall arrest device of any of clauses 41-61, wherein the traveller plate is mounted to rotate in response to rotation of the drum to pay out safety line.
Clause 63. The fall arrest device of any of clauses 41-62, further comprising a mechanism configured to intermittently arrest rotation of the traveller plate while allowing the carrier plate to rotate relative to the traveller plate.
Clause 64. The fall arrest device of any of clauses 41-63, wherein the mechanism comprises a stopper configured to be moveable between an engaged position and a disengaged position, wherein in the engaged position the stopper is configured to prevent the traveller plate from rotating.
Clause 65. The fall arrest device of any of clauses 41-64, wherein the stopper is biased towards the engaged position by one or more biasing members.
Clause 66. The fall arrest device of any of clauses 41-65, further comprising one or more abutment members mounted to the traveller plate, wherein the one or more abutment members are arranged to abut the stopper in the engaged position.
Clause 67. The fall arrest device of any of any of clauses 41-66, wherein the mechanism further comprises an offset plate mounted between the traveller plate and the carrier plate, wherein the offset plate comprises one or more push formations configured to engage the stopper and move it into the disengaged position.
Clause 68. The fall arrest device of any of clauses 41-67, wherein the offset plate comprises a plurality of circumferentially spaced push formations.
Clause 69. The fall arrest device of any of clauses 41-68, wherein the offset plate is mounted to the carrier plate.
Clause 70. The fall arrest device of any of clauses 41-69, wherein the fall arrest device is a self-retracting lifeline (SRL) device.
Clause 71. An apparatus for setting the length of safety line that can be paid out from a fall arrest device, the fall arrest device comprising a drum onto which the safety line is wound, wherein the apparatus comprises: a traveller plate having a curved path that extends outwards towards the circumference of the traveller plate; a carrier plate comprising a guide; and a traveller configured to be moveably mounted to or within the guide, wherein a portion of the traveller is arranged to be received in the curved path of the traveller plate, and wherein, in response to rotation of the drum to pay out safety line, the traveller moves along the curved path of the traveller plate and is urged along the guide of the carrier plate.
Clause 72. The apparatus of clause 71, wherein the traveller is as defined in any of the preceding claims.
Clause 73. The apparatus of clause 71 or 72, wherein the traveller plate and/or the carrier plate is as defined in any preceding claim.
Clause 74. The apparatus of any of clauses 71-73, further comprising a mechanism configured to intermittently arrest rotation of the traveller plate while allowing the carrier plate to rotate relative to the traveller plate.
Clause 75. The apparatus of any of clauses 71-74, wherein the mechanism comprises a stopper configured to be moveable between an engaged position and a disengaged position, wherein in the engaged position the stopper is configured to prevent the traveller plate from rotating.
Clause 76. The apparatus of any of clauses 71-75, further comprising one or more biasing members configured to bias the stopper towards the engaged position.
Clause 77. The apparatus of any of clauses 71-76, further comprising one or more abutment members mounted to the traveller plate, wherein the one or more abutment members are arranged to abut the stopper in the engaged position.
Clause 78. The apparatus of any of any of clauses 71-77, wherein the mechanism further comprises an offset plate configured to be mounted between the traveller plate and the carrier plate, wherein the offset plate comprises one or more push formations configured to engage the stopper and move it into the disengaged position.
Clause 79. The apparatus of any of clauses 71-78, wherein the offset plate comprises a plurality of circumferentially spaced push formations.
Clause 80. The apparatus of any of clauses 71-79, wherein the offset plate comprises a projection configured to mate with a corresponding opening in the carrier plate and/or wherein the offset plate comprises an opening configured to mate with a corresponding projection on the carrier plate.
These and other features and characteristics of the non-limiting embodiments or aspects described herein will become more apparent upon consideration of the following description and the appended claims with reference to the accompanying drawings, all of which form a part of this specification, wherein like reference numerals designate corresponding parts in the various figures. It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only.
Illustrative embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:
As used herein, the singular form of “a”, “an”, and “the” include plural referents unless the context clearly dictates otherwise.
Spatial or directional terms, such as “left”, “right”, “inner”, “outer”, “above”, “below”, and the like, relate to the embodiments or aspects as shown in the drawing figures and are not to be considered as limiting as the embodiments or aspects can assume various alternative orientations.
All numbers used in the specification and claims are to be understood as being modified in all instances by the term “about”. By “about” is meant within plus or minus twenty-five percent of the stated value. However, this should not be considered as limiting to any analysis of the values under the doctrine of equivalents.
Unless otherwise indicated, all ranges or ratios disclosed herein are to be understood to encompass the beginning and ending values and any and all subranges or subratios subsumed therein. For example, a stated range or ratio of “1 to 10” should be considered to include any and all subranges or subratios between (and inclusive of) the minimum value of 1 and the maximum value of 10; that is, all subranges or subratios beginning with a minimum value of 1 or more and ending with a maximum value of 10 or less. The ranges and/or ratios disclosed herein represent the average values over the specified range and/or ratio.
The terms “first”, “second”, and the like are not intended to refer to any particular order or chronology, but refer to different conditions, properties, or elements.
All documents referred to herein are “incorporated by reference” in their entirety.
The term “at least” is synonymous with “greater than or equal to”.
As used herein, “at least one of” is synonymous with “one or more of”. For example, the phrase “at least one of A, B, or C” means any one of A, B, or C, or any combination of any two or more of A, B, or C. For example, “at least one of A, B, and C” includes A alone; or B alone; or C alone; or A and B; or A and C; or B and C; or all of A, B, and C.
The word “comprising” and “comprises”, and the like, does not exclude the presence of elements or steps other than those listed in any claim or the specification as a whole. In the present specification, “comprises” means “includes” and “comprising” means “including”.
As used herein, the terms “parallel” or “substantially parallel” mean a relative angle as between two objects (if extended to theoretical intersection), such as elongated objects and including reference lines, that is from 0° to 5°, or from 0° to 3°, or from 0° to 2°, or from 0° to 1°, or from 0° to 0.5°, or from 0° to 0.25°, or from 0° to 0.1°, inclusive of the recited values.
As used herein, the terms “perpendicular”, “transverse”, “substantially perpendicular”, or “substantially transverse” mean a relative angle as between two objects at their real or theoretical intersection is from 85° to 90°, or from 87° to 90° , or from 88° to 90°, or from 89° to 90°, or from 89.5° to 90°, or from 89.75° to 90°, or from 89.9° to 90°, inclusive of the recited values.
The discussion of various embodiments or aspects may describe certain features as being “particularly” or “preferably” within certain limitations (e.g., “preferably”, “more preferably”, or “even more preferably”, within certain limitations). It is to be understood that the disclosure is not limited to these particular or preferred limitations but encompasses the entire scope of the various embodiments and aspects described herein.
The disclosure comprises, consists of, or consists essentially of, the following embodiments or aspects, in any combination. Various embodiments or aspects of the disclosure are illustrated in separate drawing figures. However, it is to be understood that this is simply for ease of illustration and discussion. In the practice of the disclosure, one or more embodiments or aspects shown in one drawing figure can be combined with one or more embodiments or aspects shown in one or more of the other drawing figures.
It will be appreciated that
The fall arrest device 10 shown is a self-retracting lifeline device of the type described in WO2016/120614. However, it will be appreciated that other types of fall arrest or fall protection device could be used together with the settable length apparatus of the present disclosure.
The fall arrest device 10 includes a rotatable drum 1 with a safety line 2 wound thereon. The drum 1 is mounted to a rotatable shaft (not shown). The drum 1 is biased by a rewind mechanism (not shown) to rewind the safety line 2 onto the drum 1, thus it is a self-retracting lifeline device.
A speed responsive engagement assembly is provided which includes a pawl carrier 3, pawls 4 and a pawl stop formation 6. In the embodiment shown in
In some non-limiting embodiments or aspects, three spaced pawls 4 are pivotally mounted to the pawl carrier 3. In some embodiments or aspects, two pawls or four or more pawls may be provided. A biasing spring 4a urges each pawl 4 radially inwards towards the pawl carrier 3 into a home position, such that the pawls 4 do not engage the stop formation 6. In normal use, the safety line 2 is paid out from the device 10 causing the drum 1, shaft and pawl carrier 3 to rotate together. In a fall arrest event, the safety line 2 is paid out much more rapidly. The speed at which the drum 1, shaft and pawl carrier 3 rotate causes the pawls 4 to pivot radially outwards to an activated position, as the centrifugal force overcomes the biasing force of the springs 4a. This causes one of the pawls 4 to engage the pawl stop formation 6 which is attached to or formed integrally with the chassis frame of the device 10. Once this occurs, the pawl carrier 3 is locked against and fixed with respect to the chassis frame of the device, preventing further rotation of the pawl carrier 3 together with the drum 1 and shaft.
If the torque applied by the fall arrest event is sufficient, the drum 1 and shaft will continue rotation. This can result in further safety line 2 being paid out and the continued descent of a user. In this case, the energy absorber ring (not shown) will absorb the energy of the relative rotation between the pawl carrier 3 and the collar of the shaft until the fall is completely arrested.
It will be appreciated that in some non-limiting embodiments or aspects, an external energy absorber device may be provided rather than an internal energy absorber ring. The external energy absorber device is usually connected between the safety line 2 and the user. Examples of suitable devices are described in WO2017/078669 and WO2019/175543.
In the embodiment or aspect shown in
In some non-limiting embodiments or aspects, the carrier plate 20 includes a central aperture 21 for receiving a bolt therethrough. The back of the carrier plate (not shown) may be keyed to the pawl carrier 3. The carrier plate 20 is configured to be mounted to and rotate with the pawl carrier 3.
The carrier plate 20 includes a guide 22 extending from the circumference of the carrier plate 20 towards the central aperture 21. The guide 22 extends transversely to the rotational axis of the drum.
In this embodiment or aspect, the guide 22 is a radial channel. In some non-limiting embodiments or aspects, the guide 22 may additionally or alternatively include one or more runners or guide rails. The traveller 30 may be mounted to slide along a rail or runner of the guide 22.
In the embodiment or aspect shown in
In some non-limiting embodiments or aspects, a stop assembly 50 is provided including a stopper 54, biasing members 58, and a stopper base 51. The stopper base 51 includes a pair of mounting apertures 52 arranged to align with apertures 7 on the chassis frame of the fall arrest device 10. The stopper 54 is shaped generally V-shaped, having a point 55A and a pair of legs 55B. It will be appreciated that the stopper 54 is not limited to the shape shown in
In some non-limiting embodiments or aspects, the stopper 54 is moveable between an engaged position, in which the stopper 54 holds the traveller plate 40 in a fixed position, and a disengaged position, in which the traveller plate 40 is free to rotate. An actuator (such as a latch or button) configured to move the stopper 54 may be provided on the housing of the fall arrest device (not shown). The biasing members 58 bias the stopper 54 towards the engaged position.
The traveller plate 40 includes a plurality of radial spokes 43 mounted to the front of the traveller plate 40. The spokes 43 are evenly spaced around the traveller plate 40. In this embodiment or aspect, the traveller plate 40 includes five locking spokes 43 (abutment members 43) and five non-locking spokes 45. As shown in
The traveller plate 40 is shown in more detail in
In some non-limiting embodiments or aspects, the circumferential edge of the traveller plate 40 includes teeth 44. The teeth 44 may be configured to allow the traveller plate 40 to be conveniently rotated. For example, the teeth 44 may be configured to receive a pin or dial (not shown). In other examples, the circumference of the traveller plate 40 may be smooth.
A helical path or channel 42 extends from proximate the central aperture 41 radially outwards towards the circumference of the traveller plate 40, between a start point 42A and an end point 42B of the path. The number of turns of the helical path 42 are not limited to the embodiment or aspect shown in
In use, the projection 32 of the traveller is received (or seated) in the helical path 42. The start position of the projection 32 of the traveller along the helical path 42 dictates the length of safety line 2 that can be paid out from the device 10.
The traveller 30 is shown in more detail in
The rear of the traveller 30 includes a slot 31 that is shaped to receive the projection 5 of the pawl 4 of the speed responsive engagement assembly (see
In some non-limiting embodiments or aspects, the traveller 30 does not include a slot 31 for engaging the pawl 4. The traveller 30 may be configured to push, rather than pull, the pawl 4 into engagement with the pawl stop formation 6.
The stop assembly 50 is shown in more detail in
The stopper 54 also includes shoulder portions 57 that in the disengaged position are configured to sit (or press) against the stopper base 51 (see
As the safety line 2 is paid out of the device in direction A (under normal conditions, not in a fall arrest event), the drum 1, pawl carrier 3 and carrier plate 20 rotate together in direction B relative to the traveller plate 40 which is held in a fixed position by the stopper 54. This causes the projection 32 of the traveller 30 to move along the helical path 42 of the traveller plate 40 in the direction of arrow B. This results in the traveller 30 sliding radially outwards along the radial channel 22 in the carrier plate 20 in the linear direction shown by arrow C in
Under normal conditions, the traveller 30 will move linearly radially outwards along the radial channel 22 until a pawl 4 of the speed responsive engagement assembly is received in the slot 31 of the traveller 30 and the pawl 4 is pushed into engagement with the pawl stop formation 6. This locks the pawl carrier 3 and prevents further safety line 2 being paid out, as described above. Thus, the closer the initial position of the traveller 30 is to the start point 42A of the helical path in the traveller plate 40, the more safety line 2 can be paid out before the speed responsive engagement assembly locks the device 10. For example, the start position of the traveller 30 can be set to ensure that the user is restrained from the edge of a worksite, as the maximum amount of safety line 2 that can be paid out before the traveller 30 engages the pawl 4 is less than the distance to the edge of the worksite.
If a fall arrest event occurs before the traveller 30 reaches the position where the pawl 4 is pulled (or pushed) into engagement with the pawl stop formation 6, the speed responsive engagement mechanism engages as it would without the settable length apparatus being present.
If the force in direction A pulling (or tensioning) the safety line 2 is removed before the traveller 30 engages the pawl 4, then the drum 1 will rotate in the direction opposite to arrow B (anticlockwise) to retract the safety line 2 onto the drum 1. The traveller plate 40 remains held in the fixed position relative to the carrier plate 20. This will cause the traveller 30 to travel back along the helical path 42 towards the start position 42A, resulting in the traveller 30 sliding radially inwards along channel 22 in the opposite direction to arrow C.
Advantageously, the carrier plate 20, traveller plate 40, traveller 30, and stop assembly 50 are not load bearing, even in a fall arrest event. As such, they can be made of plastic which is cost effective and lightweight.
In
As soon as the tension or force holding the stopper 54 in the raised (disengaged) position is removed, the biasing members 58 urge the stopper 54 into the lowered (engaged) position away from the stopper base 51, as shown in
In this embodiment or aspect, the stopper 54 is only moved into the disengaged position in order to set the length of safety line that can be paid out from the device as, without relative rotation between the traveller plate 40 and the carrier plate 20, there would be no movement of the traveller 30 along the radial channel 22.
It will be appreciated that a variety of locking devices could be provided in order to lock the stopper 54 in the engaged position and prevent the locking plate 40 from rotating. For example, the circumference of the locking plate 40 could comprise a plurality of holes configured to align with a moveable pin or lock provided on the stopper 54.
In some non-limiting embodiments or aspects, the start position of the traveller 30 along the helical path 42 may not be adjustable during use of the device 10. For example, the start position of the traveller 30 may be set during assembly of the device to the length required for a particular worksite. It may be preferable that this setting cannot be adjusted (without removing the device housing/disassembling the device) to prevent any accidental adjustment of the traveller 30 position during use of the device.
Additionally or alternatively, a catch or other locking mechanism may be provided to prevent any accidental rotation of the traveller plate 40.
In this locked position, the projection 5 of a pawl 4 of the speed responsive engagement assembly is received in the slot 31 on the back of the traveller 30. The movement of the traveller along the radial channel 22 pulls (or pushes) the pawl 4 into engagement with the pawl stop formation 6, locking the pawl carrier as if a fall arrest event has occurred. This prevents further safety line from being paid out, thereby restraining the user. Until a fall arrest event does occur, there should be no further torque that results in deployment of the energy absorber device.
For example, if the fall arrest device 10 is being used by workers on a roof site, wherein the edge of the roof is 5 m from where the fall arrest device 10 is mounted, the initial position of the traveller 30 can be set to allow just less than 5 m (e.g. 4.5 m) of safety line to be paid out from the device 10. This prevents the user from falling off the edge of the roof, as the safety line 2 locks before the user reaches the edge of the roof. In the event that the user did fall off the roof edge, for example if the initial position of the traveller 30 was not set correctly, then the speed responsive engagement assembly and energy absorber would arrest the descent of the user in the usual manner to reduce the risk of injury.
The offset plate 60 is shown in more detail in
The offset plate 60 also comprises three circumferential openings 63. During assembly, the openings 63 are aligned with the corresponding projections 23′ on the carrier plate (see
It will be appreciated that the offset plate 60 could include one or more projections instead of or in addition to openings 63, wherein each projection is arranged to mate with a corresponding opening in the carrier plate.
The offset plate 60 is provided to offset the rotation of the traveller plate 40 from the rotation of the drum 1, pawl carrier 3 and carrier plate 20′. This allows a longer maximum permitted length of safety line 2 to be paid out without increasing the length of the helical path 42. This is done using the push formations 65 provided on the circumference of the offset plate 60 (described below).
As shown in
The guide 22′ includes a radial channel, but it is not a straight linear channel as in carrier plate 20. The radial channel 22′ includes a recess 25′. The recess 25′ is shaped to assist the pawl 4 to engage the pawl stop formation 6 (i.e. move to the activated position) without hitting the sides of the channel 22′. It will be appreciated that channel 20 could also include the recess 25′.
The back of the carrier plate 20′ comprises flange 27′ surrounding the central aperture 21′ configured to key the carrier plate 20′ to the pawl carrier 3. The flange 27′ is preferably configured to allow the carrier plate 20′ to only be mounted to the pawl carrier 3 in a particular orientation. In addition, ribs 26′ are provided on the rear face of projections 23′ in the carrier plate 20′. The ribs 26′ are configured to abut or engage the pawl carrier 3.
The initial position of the traveller 30 and traveller projection 32 along the helical path 42 is adjusted as described in connection with
When the safety line 2 is paid out in direction A during normal operation, in the position shown in
When one of the locking spokes 43 engages the stopper 54, the stopper 54 holds the traveller plate 40 in a fixed position. This allows the traveller projection 32 to move along the helical path 42 causing the traveller 30 to slide radially outwards along channel 22′ in the carrier plate 20′ in the direction shown by arrow C. This motion continues until one of the push formations 65 engages the stopper 54, as shown in
In
In
In
In the examples shown, the traveller plate 40 includes five radial locking spokes 43 evenly spaced around the traveller plate 40. The offset plate 60 includes four push formation 65. This means that the traveller plate 40 is offset by 30° five times for every full revolution of the traveller plate 40. In other words, in a full revolution (360°) of the traveller plate 40, the drum 1, offset plate 60 and carrier plate 20′ will each have rotated 510°. This can be altered by adjusting the number and spacing of the push formations 65 and the spokes 43.
In
As shown in
It will be appreciated that, in order to increase the maximum length of safety line that could be paid out from the fall arrest device 10, the length of the helical path 42 could be increased. This would either increase the size of the traveller plate 40 required or decrease the spacing between segments of the helical path 42. A larger traveller plate 40 would be inconvenient and increase costs, as it would not fit within the housing of the fall arrest device 10. Likewise, decreasing the spacing between segments of the helical path 42 would likely result in a fragile traveller plate.
In
The direction of the helical path 142 has been reversed compared to helical path 42 in the previous figures. The helical path 142 extends inwards from the circumference in a clockwise direction, rather than an anticlockwise direction as in
As such, when the traveller plate 140 is held in a fixed position relative to the carrier plate 20, 20′, the traveller will move inwards along the helical path 142 towards the central aperture 141.
The traveller plate 140 may be used with a self-retracting lifeline device 100 of the type described in WO2008/007119, as shown in
As shown in
The carrier plate 20 may be the same as in
The traveller 130 is shown in more detail in
The fall arrest device 100 includes a different speed responsive engagement assembly compared to the fall arrest device 10 in
Each pawl 105 has a first end 106 and a second end 107. The pivot point 105a of the pawls is located between the first end 106 and the second end 107, such that when the second end 107 tilts towards the ratchet wheel 103 the first end 106 tilts away from the ratchet wheel 103.
The pawls 105 can be pivoted (about pivot point 105a) between a disengaged position and an engaged position. In the disengaged position, the ratchet wheel 103 can rotate past the pawls 105. In the engaged position, the first end 106 of each pawl 105 engages with a tooth 104 of the ratchet wheel 103, thereby locking the ratchet wheel 103.
A leaf spring 108 urges the second end 107 of each pawl downwards, so that the pawl is in the disengaged position. The operation of the speed responsive engagement assembly is described in detail in WO2008/007119.
In this non-limiting embodiment or aspect, when the safety line 2 is paid out from the drum 1 and the stopper 54 holds the traveller plate 140 in a fixed position, the traveller 130 moves inwards along the helical path 142. This moves the traveller 130 inwards along the guide 122 of the carrier plate towards the rotational axis of the drum 1. After a predetermined length of safety line 2 has been paid out, the rear projection 134 of traveller 130 is arranged to contact the first end 106 of the pawl and push the first end 106 downwards into the engaged position with one of the teeth 104 of the ratchet wheel 103. Moving the start position of the traveller 130 closer to the start point 142A of the helical path 142, increases the predetermined length of safety 2 that can be paid out of the device 100 before the traveller 130 locks the speed responsive engagement assembly.
The start position of the traveller 130 can be adjusted by manually rotating the traveller plate 140 relative to the carrier plate 20, with the stopper 54 in the disengaged position. In some non-limiting embodiments or aspects, as explained above, an actuator may be provided to rotate the traveller plate 140.
It will be appreciated that the fall arrest device 100 could also be used with the restraint (settable length) apparatus shown in
It will also be appreciated that the traveller 30, 130 may be any type of actuator configured to move in response to rotation of the drum 1 and to activate the speed responsive engagement assembly when a predetermined length of safety line has been paid out. The traveller plate, carrier plate and offset plate need not be provided. The non-limiting embodiments or aspects of the present disclosure have been described in detail herein. However, it will be appreciated by those skilled in the art that various modifications and alternatives to the embodiments or aspects may be made without departing from the concepts disclosed in the foregoing description. Such modifications are to be considered as included within the following claims unless the claims, by their language, expressly state otherwise. Accordingly, the particular embodiments or aspects described in detail hereinabove are illustrative only and are not limiting as to the scope of the disclosure, which is to be given the full breadth of the appended claims and any and all equivalents thereof.
| Number | Date | Country | Kind |
|---|---|---|---|
| 1916588.5 | Nov 2019 | GB | national |
| 2000291.1 | Jan 2020 | GB | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/GB2020/052856 | 11/11/2020 | WO |
