Line retraction device having a damper assembly

A line retraction device includes a rotatable drum having a line associated therewith, with the line including a first end directly or indirectly attached to the drum and a second end opposite the first end, and at least one retraction member biasing the drum in a first rotational direction of the drum opposite a second rotational direction of the drum, where the drum is configured to: (i) retract the line when the drum moves in the first rotational direction; and (ii) payout the line when the drum moves in the second rotational direction. The device further including a damper assembly configured to provide rotational resistance to the drum in: (i) the first rotational direction of the drum as the line is being retracted; and (ii) the second rotational direction as the line is being paid out.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates generally to safety systems and arrangements and, in particular, to a line retraction device, such as a fall arrest or controlled descent device, including self-retracting lanyards and the like, which may be used in connection with a harness to protect the wearer from a sudden, accelerated fall arrest event, as well as a line retraction device having a damper assembly.

Description of the Related Art

A line retraction device may be used in a variety of situations and applications. For example, one type of line retraction device is in the form of a lanyard, such as a self; retracting lanyard (SRL), which are commonly used for fall protection in industrial environments, as well as in connection with recreational activities. Self-retracting lanyards have numerous industrial end uses, including, but not limited to, construction, manufacturing, hazardous materials/remediation, asbestos abatement, spray painting, sand blasting, welding, mining, numerous oil and gas industry applications, electric and utility, nuclear energy, paper and pulp, sanding, grinding, stage rigging, roofing, scaffolding, telecommunications, automotive repair and assembly, warehousing, and railroading.

SRLs frequently include a housing that includes a rotatable drum or hub around which a line, typically made of webbing, cable, rope, and/or synthetic material is wound. The hub rotates to unwind (or “payout”) the line from its housing when a certain level of tension is purposefully applied. When that degree of tension is reduced or released, the hub can slowly rotate in a reverse direction causing the line to retract or rewind about itself in a desired manner. Certain housings further include a braking mechanism or assembly for resisting hub rotation when an inelastic line (e.g., a steel cable) unwinds too rapidly, i.e., faster than its predetermined maximum velocity for normal payout. A sudden line payout is an indication that the lanyard wearer/user has experienced a fall that needs to be stopped or arrested.

During an unintentional, accidental fall, an engagement and braking arrangement in the housing of the SRL engages, which prevents the SRL wearer from falling too far. In addition, SRLs typically connect at one end to an anchorage point, often on the support structure at or near where a user is performing certain assigned tasks. The line from the SRL housing is clamped (or otherwise attached) to a harness worn by the user. The maximum allowable stopping forces and distances are defined by known industry standards. The stopping force provided by a brake is inversely proportional to the stopping distance, i.e., the higher the force, the shorter the distance, and vice versa. As a result, the force cannot exceed the maximum allowed by standards, and yet it must also be large enough so that the extension distance does not exceed the maximum, also regulated by these standards.

The drum of the SRL is biased to retract the line back into the housing of the SRL. As noted above, the line will payout from the drum as the user walks away from the SRL and will also retract back into the housing as the user walks toward the SRL. When a user disconnects the line from their harness and releases the line, “freewheeling” can occur, which is the unrestrained retraction of the line back into the housing of the SRL. When the end of the line reaches the SRL, an end connector on the line can impact the housing of the SRL and damage the housing, the end connector, and/or the internal components of the SRL. Such an impact may also jam the SRL requiring the repair of the SRL and, in some circumstances, injure the user. The issues caused by the impact of the end connection against the housing may create a dangerous condition where the SRL may not function properly the next time it is used. Proper line retraction is typically controlled by the user either directly by hand or indirectly with a tag line secured to the main line of the SRL.

SUMMARY OF THE INVENTION

Accordingly and generally, provided is an improved line retraction device having a damper assembly.

In one preferred and non-limiting embodiment or aspect, provided is a line retraction device, comprising: a rotatable drum having a line associated therewith, the line including a first end directly or indirectly attached to the drum and a second end opposite the first end; at least one retraction member biasing the drum in a first rotational direction of the drum opposite a second rotational direction of the drum, wherein the drum is configured to: (i) retract the line when the drum moves in the first rotational direction; and (ii) payout the line when the drum moves in the second rotational direction; and a damper assembly configured to provide rotational resistance to the drum in: (i) the first rotational direction of the drum as the line is being retracted; and (ii) the second rotational direction as the line is being paid out.

In one preferred and non-limiting embodiment or aspect, the damper assembly comprises at least one fixed element and at least one moveable element, the at least one moveable element moving in conjunction with the drum. In another preferred and non-limiting embodiment or aspect, the line retraction device comprises a shaft having a first end and a second end, the shaft connected to and rotatable with the drum, the at least one moveable element connected to the shaft. In another preferred and non-limiting embodiment or aspect, the damper assembly further comprises a damper housing receiving the at least one fixed element and the at least one moveable element, and wherein the damper housing contains a fluid in fluid communication with at least a portion of the at least one fixed element and at least a portion of the at least one moveable element. In another preferred and non-limiting embodiment or aspect, the fluid comprises a silicone fluid.

In another preferred and non-limiting embodiment or aspect, the at least one fixed element comprises a first set of arcuate-shaped vanes radially spaced from a second set of arcuate-shaped vanes, the first set of vanes and the second set of vanes each arranged in a circular shape. In another preferred and non-limiting embodiment or aspect, the at least one moveable element comprises a first annular vane radially spaced from a second annular vane, the first and second annular vanes of the at least one moveable element intermeshed with the first and second sets of vanes of the at least one fixed element.

In one preferred and non-limiting embodiment or aspect, the line retraction device comprises a housing assembly that receives the drum and the retraction member, the retraction member comprising a power spring having a first end fixed relative to the housing assembly and a second end secured directly or indirectly to the drum, e.g., to a shaft. In another preferred and non-limiting embodiment or aspect, the housing assembly comprises a main housing and a cover, the cover defining an opening that receives a first end of the shaft, and wherein the damper assembly is secured to at least one of the following: a side of the cover, a shaft, the drum, or any combination thereof. In another preferred and non-limiting embodiment or aspect, the line retraction device comprises a brake assembly configured to prevent rotation of the drum upon activation of the brake assembly. In another preferred and non-limiting embodiment or aspect, the brake assembly comprises a speed-sensitive mechanism having an activated position and a non-activated position, the speed-sensitive mechanism rotatable in conjunction with the drum and configured to transition from the non-activated position to the activated position upon a predetermined rotation speed of the drum.

In one preferred and non-limiting embodiment or aspect, the retraction member comprises a power spring. In one preferred and non-limiting embodiment or aspect, an end connector is secured to the second end of the line, the end connector configured to be releasably connected to a user of the line retraction device.

In one preferred and non-limiting embodiment or aspect, provided is a line retraction device, comprising: a housing; a rotatable drum received at least partially within the housing and having a line associated therewith, the line including a first end directly or indirectly attached to the drum and a second end opposite the first end; at least one retraction member biasing the drum in a first rotational direction of the drum opposite a second rotational direction of the drum, wherein the drum is configured to: (i) retract the line when the drum moves in the first rotational direction; and (ii) payout the line when the drum moves in the second rotational direction; a damper assembly configured to provide rotational resistance to the drum in: (i) the first rotational direction of the drum as the line is being retracted; and (ii) the second rotational direction as the line is being paid out.

In one preferred and non-limiting embodiment or aspect, the damper assembly comprises at least one fixed element, at least one moveable element, and a damper housing receiving the at least one fixed element and the at least one moveable element. In another preferred and non-limiting embodiment or aspect, the damper housing contains a fluid in fluid communication with at least a portion of the at least one fixed element and at least a portion of the at least one moveable element. In another preferred and non-limiting embodiment or aspect, the at least one fixed element comprises a first set of arcuate-shaped vanes radially spaced from a second set of arcuate-shaped vanes, the first set of vanes and the second set of vanes each arranged in a substantially circular shape, and wherein the at least one moveable element comprises a first annular vane radially spaced from a second annular vane, the first and second annular vanes of the at least one moveable element intermeshed with the first and second sets of vanes of the at least one fixed element.

In one preferred and non-limiting embodiment or aspect, the housing receives the drum and the retraction member, the retraction member comprising a power spring having a first end fixed relative to the housing assembly and a second end secured directly or indirectly to the drum.

In one preferred and non-limiting embodiment or aspect, provided is a fall protection device, comprising: a rotatable drum having a line associated therewith, the line including a first end directly or indirectly attached to the drum and a second end opposite the first end; at least one retraction member biasing the drum in a first rotational direction of the drum opposite a second rotational direction of the drum, wherein the drum is configured to: (i) retract the line when the drum moves in the first rotational direction; and (ii) payout the line when the drum moves in the second rotational direction; and a damper assembly configured to provide rotational resistance to the drum in: (i) the first rotational direction of the drum as the line is being retracted; and (ii) the second rotational direction as the line is being paid out.

In one preferred and non-limiting embodiment or aspect, the damper assembly comprises at least one fixed element, at least one moveable element, and a damper housing receiving the at least one fixed element and the at least one moveable element.

Further preferred and non-limiting embodiments or aspects will now be described in the following numbered clauses.

Clause 1: A line retraction device, comprising: a rotatable drum having a line associated therewith, the line including a first end directly or indirectly attached to the drum and a second end opposite the first end; at least one retraction member biasing the drum in a first rotational direction of the drum opposite a second rotational direction of the drum, wherein the drum is configured to: (i) retract the line when the drum moves in the first rotational direction; and (ii) payout the line when the drum moves in the second rotational direction; and a damper assembly configured to provide rotational resistance to the drum in: (i) the first rotational direction of the drum as the line is being retracted; and (ii) the second rotational direction as the line is being paid out.

Clause 2: The line retraction device of clause 1, wherein the damper assembly comprises at least one fixed element and at least one moveable element, the at least one moveable element moving in conjunction with the drum.

Clause 3: The line retraction device of clauses 1 or 2, further comprising a shaft having a first end and a second end, the shaft connected to and rotatable with the drum, the at least one moveable element connected to the shaft.

Clause 4: The line retraction device of any of clauses 1-3, wherein the damper assembly further comprises a damper housing receiving the at least one fixed element and the at least one moveable element, and wherein the damper housing contains a fluid in fluid communication with at least a portion of the at least one fixed element and at least a portion of the at least one moveable element.

Clause 5: The line retraction device of any of clauses 1-4, wherein the fluid comprises a silicone fluid.

Clause 6: The line retraction device of any of clauses 1-5, wherein the at least one fixed element comprises a first set of arcuate-shaped vanes radially spaced from a second set of arcuate-shaped vanes, the first set of vanes and the second set of vanes each arranged in a circular shape.

Clause 7: The line retraction device of any of clauses 1-6, wherein the at least one moveable element comprises a first annular vane radially spaced from a second annular vane, the first and second annular vanes of the at least one moveable element intermeshed with the first and second sets of vanes of the at least one fixed element.

Clause 8: The line retraction device of any of clauses 1-7, further comprising a housing assembly that receives the drum and the retraction member, the retraction member comprising a power spring having a first end fixed relative to the housing assembly and a second end secured directly or indirectly to the drum.

Clause 9: The line retraction device of any of clauses 1-8, wherein the housing assembly comprises a main housing and a cover, and wherein the damper assembly is secured to at least one of the following: a side of the cover, a shaft, the drum, or any combination thereof.

Clause 10: The line retraction device of any of clauses 1-9, further comprising a brake assembly configured to prevent rotation of the drum upon activation of the brake assembly.

Clause 11: The line retraction device of any of clauses 1-10, wherein the brake assembly comprises a speed-sensitive mechanism having an activated position and a non-activated position, the speed-sensitive mechanism rotatable in conjunction with the drum and configured to transition from the non-activated position to the activated position upon a predetermined rotation speed of the drum.

Clause 12: The line retraction device of any of clauses 1-11, wherein the retraction member comprises a power spring.

Clause 13: The line retraction device of any of clauses 1-12, wherein an end connector is secured to the second end of the line, the end connector configured to be releasably connected to a user of the line retraction device.

Clause 14: A line retraction device, comprising: a housing; a rotatable drum received at least partially within the housing and having a line associated therewith, the line including a first end directly or indirectly attached to the drum and a second end opposite the first end; at least one retraction member biasing the drum in a first rotational direction of the drum opposite a second rotational direction of the drum, wherein the drum is configured to: (i) retract the line when the drum moves in the first rotational direction; and (ii) payout the line when the drum moves in the second rotational direction; and a damper assembly configured to provide rotational resistance to the drum in: (i) the first rotational direction of the drum as the line is being retracted; and (ii) the second rotational direction as the line is being paid out.

Clause 15: The fall protection device of clause 14, wherein the damper assembly comprises at least one fixed element, at least one moveable element, and a damper housing receiving the at least one fixed element and the at least one moveable element.

Clause 16: The fall protection device of clauses 14 or 15, wherein the damper housing contains a fluid in fluid communication with at least a portion of the at least one fixed element and at least a portion of the at least one moveable element.

Clause 17: The fall protection device of any of clauses 14-16, wherein the at least one fixed element comprises a first set of arcuate-shaped vanes radially spaced from a second set of arcuate-shaped vanes, the first set of vanes and the second set of vanes each arranged in a substantially circular shape, and wherein the at least one moveable element comprises a first annular vane radially spaced from a second annular vane, the first and second annular vanes of the at least one moveable element intermeshed with the first and second sets of vanes of the at least one fixed element.

Clause 18: The line retraction device of any of clauses 14-17, wherein the housing receives the drum and the retraction member, the retraction member comprising a power spring having a first end fixed relative to the housing assembly and a second end secured directly or indirectly to the drum.

Clause 19: A fall protection device, comprising: a rotatable drum having a line associated therewith, the line including a first end directly or indirectly attached to the drum and a second end opposite the first end; at least one retraction member biasing the drum in a first rotational direction of the drum opposite a second rotational direction of the drum, wherein the drum is configured to: (i) retract the line when the drum moves in the first rotational direction; and (ii) payout the line when the drum moves in the second rotational direction; and a damper assembly configured to provide rotational resistance to the drum in: (i) the first rotational direction of the drum as the line is being retracted; and (ii) the second rotational direction as the line is being paid out.

Clause 20: The fall protection device of clause 19, wherein the damper assembly comprises at least one fixed element, at least one moveable element, and a damper housing receiving the at least one fixed element and the at least one moveable element.

DETAILED DESCRIPTION OF THE INVENTION

As illustrated inFIGS. 1-22, certain preferred and non-limiting embodiments or aspects of a line retraction device10for use in industrial environments and recreational activities is provided. The line retraction device10can be implemented in any appropriate application or environment where a user or worker engages in activities in an elevated position and requires some protection in the event of a fall. Further, in one preferred and non-limiting embodiment or aspect, the line retraction device10of the present invention is in the form of a fall protection device or lanyard, such as a self-retracting lanyard. The line retraction device10protects the user should an unintentional, accidental fall commence. The line retraction device10is configured to prevent the user from falling too far or stopping too quickly as discussed in more detail below.

Referring toFIGS. 1-5, and in one preferred and non-limiting embodiment or aspect, the line retraction device10includes a drum14having a line46, such as a lifeline, a retraction member20biasing the drum14in a first rotational direction of the drum14, and a damper assembly22. The drum14is configured to (i) retract the line46when the drum14moves in the first rotational direction and (ii) payout the line46when the drum14moves in the second rotational direction. The damper assembly22is configured to provide rotational resistance to the drum14in (i) the first rotational direction of the drum14as the line46is being retracted and (ii) the second rotational direction as the line46is being paid out.

In one preferred and non-limiting embodiment or aspect, and referring again toFIGS. 1-5, the line retraction device includes a housing assembly12, the drum14, a shaft16, a brake assembly18, the retraction member20, and the damper assembly22. The housing assembly12includes a main housing28that at least partially receives the brake assembly18and a spring cover30that receives the retraction member20. The spring cover30is secured to the main housing28via bolts32, although any suitable fastening arrangement may be utilized. The shaft16is received by the housing assembly12and extends from a first end34of the housing assembly12to a second end36of the housing assembly12positioned opposite the first end34. The second end36of the main housing28includes a housing cover38adjacent to the shaft16. In another preferred and non-limiting embodiment or aspect, the brake assembly18may be in the form of or replaced by a leading edge energy absorbing arrangement, such as a tear-tape arrangement connecting the end connector52to the line46.

In one preferred and non-limiting embodiment or aspect, and referring toFIGS. 4, 5, 16, and17, the drum14, includes a body42defining a recessed portion44that receives the line46. The line46is wound about the drum14and includes a first end50attached to the drum14and a second end48positioned opposite the first end50. An end connector52is secured to the second end48of the line46and is configured to be releasably secured to a user of the line retraction device10. The body42of the drum14includes a hub54that receives the shaft16. The drum14is rotatable within the housing assembly12and is configured to payout or retract the line46from and to the housing assembly12.

In one preferred and non-limiting embodiment or aspect, and referring toFIGS. 4, 5, and14-17, the shaft16has a first end60and a second end62positioned opposite the first end60. The first end60of the shaft16includes an engagement surface64that is configured to mate with the damper assembly22as discussed in more detail below. In one preferred and non-limiting embodiment or aspect, the engagement surface64is a square drive surface, although other suitable engagement surfaces may be utilized. In one preferred and non-limiting embodiment or aspect, the shaft16is rotatable within the housing assembly12and is received by first and second bushings66,68provided within the spring cover30and the main housing28, respectively. The shaft16is connected to and rotatable with the drum14. In particular, the shaft16includes a key70received within a recess72defined by the shaft16. The key70cooperates with a corresponding recess74in the hub54of the drum14such that the shaft16rotates in conjunction with drum14. Accordingly, paying out the line46from the drum14or retracting line46into the drum14will rotate the drum14and the shaft16. In one preferred and non-limiting embodiment or aspect, axial movement of the shaft16within the housing assembly12is restricted by the bushing68with the drum14being restricted axially by a plurality of retaining rings76, although any other suitable arrangement for restricting axial movement may be provided. In another preferred and non-limiting embodiment or aspect, the shaft16is not rotatable, and instead is fixed with respect to the housing assembly12, such that the drum14rotates around the shaft16. In another preferred and non-limiting embodiment or aspect, the damper assembly22is secured to at least one of the following: a side of the cover30, the shaft16, the drum14, or any combination thereof.

In one preferred and non-limiting embodiment or aspect, and referring toFIGS. 5 and 18-22, the brake assembly18is configured to prevent rotation of the drum14upon activation of the brake assembly18. The brake assembly18includes a speed-sensitive mechanism80having an activated position and a non-activated position. The speed-sensitive mechanism80is secured to the shaft16and rotatable in conjunction with the drum14. The speed-sensitive mechanism80is configured to transition from the non-activated position to the activated position upon a predetermined rotation speed of the drum14. The predetermined rotation speed of the drum14to transition the speed-sensitive mechanism80from the non-activated position to the activation position is a known range of rotation speed that is indicative of a fall event. More specifically, the line46will payout from the drum14during a fall event and cause the drum14and speed-sensitive device80to rotate at the predetermined rotation speed via their connection to the shaft16.

In one preferred and non-limiting embodiment or aspect, and as shown inFIG. 18, the brake assembly18further includes a brake case82secured to the main housing28of the housing assembly12. The brake case82includes a ratchet member84having a plurality of teeth86spaced apart from each other. The speed-sensitive mechanism80includes first and second pawls88,90that are moveable radially outward into engagement with the teeth86of the ratchet member84when the speed-sensitive mechanism80transitions from the non-activated position to the activated position. The first and second pawls88,90are biased radially inward via springs92, although any other suitable biasing arrangement may be provided. The biasing force needs to be overcome in order for the first and second pawls88,90to move radially outward and into engagement with the ratchet member84. In particular, when the drum14, shaft16, and speed-sensitive mechanism80are rotating at the predetermined rotation speed indicative of a fall event, the centripetal force provided by the springs92is not sufficient to keep the first and second pawls88,90from engaging the ratchet member84thereby allowing the pawls88,90to move radially outward into engagement with the ratchet member84, which is fixed relative to the housing assembly12.

Accordingly, the brake assembly18is configured to slow and stop rotation of the drum14through the engagement of the speed-sensitive mechanism80with the brake case82. However, additional line46will continue to extend from the housing assembly12based upon the forces of the fall and the weight of the user attached to the end connector52through the use of the brake assembly18. In particular, a sudden stopping of rotation would exert unsafe force on the user, possibly causing bodily harm. The brake assembly18is configured to ensure a more gradual slowing process, thereby reducing the fall forces exerted on the user as discussed below.

In one preferred and non-limiting embodiment or aspect, and referring toFIGS. 4 and 18-22, the speed-sensitive mechanism80is connected to the shaft16via a friction assembly94to provide the gradual slowing and stopping process of the drum14during a fall event. The friction assembly94includes a brake washer96, a plurality of spacers98, and friction members102, which transfer rotation of the speed-sensitive mechanism80to the shaft16. In particular, as shown inFIGS. 20-22with the shaft16omitted for clarity, the speed-sensitive mechanism80is secured to the shaft16via engagement between a hub104and the plurality of spacers98. The hub104receives the shaft16and is rotationally fixed relative to the shaft16via corresponding flat portions106,108of the hub104and the shaft16. Similarly, flat portions110of the plurality of spacers98engage the flat portion106of the hub104to rotationally fix the plurality of spacers98relative to the hub104. The brake washer96, plurality of spacers98, and friction members102are forced together via a Belleville washer112and a nut114such that the plurality of spacers98and the brake washer96each engage one of the friction members102. Although the Belleville washer112and the nut114are provided, other suitable arrangements for facilitating the engagement between the brake washer96, spacers98, and friction members102may be utilized. The friction members102may be annular brake pads, although other suitable friction members may be utilized.

During normal operation of the line retraction device10, there is no relative rotational movement between the shaft16and the speed-sensitive mechanism80due to the engagement and friction between the plurality of spacers98, the brake washer96, and the friction members102. However, during a fall event, the speed-sensitive mechanism80will be positioned in the activated position with the pawls88,90engaging the ratchet member84and the shaft16and the plurality of spacers98will move relative to the friction members102based upon the forces of the fall and the weight of the user attached to the end connector52. In this manner, the forces acting on the shaft16caused by a fall event will be sufficient to overcome the frictional forces between the friction members102and the plurality of spacers98. The engagement between the friction members102and the plurality of spacers98will gradually slow the shaft16and the plurality of spacers98; thereby gradually slowing the descent of a user attached to the end connector52during a fall event.

Referring toFIGS. 4 and 5, the retraction member20is received by the spring cover30of the housing assembly12. The retraction member20is connected to the drum14and configured to bias the drum14in a first rotational direction that retracts the line46back onto the drum14and opposite to a second rotational direction of the drum14where the line46is paid out from the drum14. In one preferred and non-limiting embodiment or aspect, the retraction member20is embodied as a power spring, although any other suitable retraction members to bias the drum in the first rotational direction may be utilized. The power spring may have a first end fixed relative to the housing assembly12and a second end secured directly or indirectly to the drum14, such as directly or indirectly to the shaft16. The retraction member20includes a first end120fixed relative to the housing assembly12and a second end122secured to the shaft16. In particular, the first end120of the retraction member20is secured to the spring cover30. A disc plate124may cover the retraction member20within the spring cover30.

Referring toFIGS. 5-13, and in one preferred and non-limiting embodiment or aspect, the damper assembly22includes a damper main housing126that receives at least one fixed element128(which, in one preferred and non-limiting embodiment or aspect, may be in the form of at least one fixed vane) and at least one moveable element130(which, in one preferred and non-limiting embodiment or aspect, may be in the form of at least one moveable vane), as well as a damper cover132to enclose the damper main housing126. The damper main housing126may be secured to the damper cover132via any suitable arrangement, including a friction fit over the at least one fixed element128, a fastener, adhesive, and the like. The damper main housing126also may receive or contain a damping fluid that is in fluid communication with the at least one fixed element128and the at least one moveable element130. In one preferred and non-limiting embodiment or aspect, the damping fluid is a silicone fluid, although other suitable damping fluids, e.g., viscous fluids, may be utilized.

In this embodiment or aspect, the damper assembly22also includes a front seal134, a rear seal136, and a housing seal138to seal the damping fluid within the damper main housing126. The at least one moveable element130moves in conjunction with the drum14via connection of the at least one moveable element130to the shaft16. In particular, the engagement surface64at the first end60of the shaft16is received by a corresponding recess140defined by or associated with the at least one moveable element130, such that the shaft16is rotationally fixed relative to the at least one moveable element130. The damper assembly22provides a rotational resistance to the drum14through the movement of the at least one moveable element130relative to the at least one fixed element128in the damping fluid.

In one preferred and non-limiting embodiment or aspect, the damper assembly22is secured to an outer surface of the spring cover30via bolts148, although any other suitable securing arrangement may be utilized. An outer cover144and pad146are positioned over the damper assembly22and secured to the spring cover30with bolts148. In another preferred and non-limiting embodiment or aspect, the damper assembly22is directly or indirectly secured or mounted to the drum14, such as in an embodiment where the shaft16does not rotate. Although the damper assembly22is shown as a fluid-type damper arrangement, other suitable damper arrangements, such as a friction-type damper, may be utilized, which includes contacting frictional surfaces. In particular, in friction-type damper arrangements, a moveable element engages a fixed element during relative rotation to provide rotational resistance.

Referring toFIGS. 6-13, and in one preferred and non-limiting embodiment or aspect, the at least one fixed element128includes a first set of arcuate-shaped vanes154radially spaced from a second set of arcuate-shaped vanes156. The first set of vanes154and the second set of vanes156are each arranged in a substantially circular shape. The at least one moveable element130includes a first annular vane158radially spaced from a second annular vane160. The first and second annular vanes158,160of the at least one moveable element130are intermeshed with the first and second sets of vanes154,156of the at least one fixed element128. In one preferred and non-limiting embodiment or aspect, the at least one moveable element130also includes a first set of openings162radially spaced from a second set of openings164. The first set of openings162are positioned radially outward from the first annular vane158and the second set of openings164are positioned between the first and second annular vanes158,160. In this embodiment or aspect, the first set of openings162are larger than the second set of openings164, although other suitable arrangements and sizes may be utilized. A gap166is defined between the at least one moveable element130and the damper cover132such that the first set of openings162are in fluid communication with the second set of openings164, thereby allowing damping fluid to pass between the first and second annular vanes158,160.

The shearing resistance of the damping fluid between the vanes154,156,158,160of the at least one moveable element130and the at least one fixed element128provides the rotational resistance to the drum14during retraction and payout of the line46. The retraction velocity of the line46is controlled at a desired level via the geometry of the at least one fixed element128and the at least one moveable element130, as well as the viscosity of the damping fluid. The damper assembly22prevents freewheeling of the line46and the end connector52(and the associated damage caused by impacts of the end connector52against the housing assembly12). The torque provided by the damper assembly22increases as the rotational speed of the shaft16increases. As the drum14accelerates during retraction of the line46, the at least one moveable element130also accelerates via the shaft16until the torque from the damper assembly22counters the torque generated by the retraction member20. At this point, the retraction velocity remains constant due to the torque of the retraction member20being countered by the damper assembly22. As the line46continues to be retracted, the torque generated by the retraction member20will decrease with the torque from the damper assembly22also decreasing, thereby resulting in a reduced retraction velocity, which will continue until the line46is fully retracted into the housing assembly12. Accordingly, the damper assembly22provides a controlled and smooth retraction of the line46back into the housing assembly12and prevents damage to the housing assembly12, end connector52, and internal components, impact of the end connector52with the user, and also prevents jamming of the line retraction device10.

The damper assembly22also provides resisting torque when the drum14pays out the line46. Although the payout torque from the damper assembly22may provide resistance to a user walking away from the housing assembly12, the torque is low enough that any additional effort required of the user will likely not be noticeable by the user. In particular, the force provided by the retraction member20is great enough that the effect of the additional torque from the damper assembly22on the line46as it pays out will not be noticed by the user. Further, the line retraction device10will perform in the same manner during a fall event with or without the damper assembly22. Accordingly, providing a damper assembly22that provides resistance in both rotational directions of the drum14eliminates the need for a one-way engagement mechanism or clutch, which reduces the complexity and cost and increases the reliability of the line retraction device10.