Patent Application
20180147428
The following information is provided to assist the reader to understand the devices, systems and methods disclosed below and the environment in which they will typically be used. The terms used herein are not intended to be limited to any particular narrow interpretation unless clearly stated otherwise in this document. References set forth herein may facilitate understanding of the devices, systems and method or the background thereof. The disclosures of all references cited herein are incorporated by reference.
Many devices have been developed in an attempt to prevent or minimize injury to a worker falling from a substantial height. For example, a number of devices (known alternatively as self-retracting or retracting lifelines, retracting lanyards, fall arrest blocks, etc.) have been developed that limit a worker's free fall distance to a specified distance and limit fall arresting forces to a specified value.
In general, most currently available retracting lifeline safety devices or systems include a number of common components. Typically, a housing or cover provides enclosure/protection for the internally housed components. The housing includes attached thereto a connector for anchoring the retracting lifeline to either the user or to a fixed anchor point. The connector must be capable of withstanding forces required to stop a falling body of a given mass in a given distance. Components of retracting lifeline system such as the lifeline and connectors can, for example, have an ultimate tensile load or minimum breaking strength of at least 4500 pounds.
A drum or spool around which a lifeline is coiled or spooled rotates within the housing. The drum is typically under adequate rotational tension to reel up excess extended lifeline without hindering the mobility of the user. Like the anchor connector and the other operative components of the retractable lifeline safety device, the drum is formed to withstand forces necessary to stop a falling body of a given mass in a given distance. The lanyard or lifeline is attached at one end thereof to the drum to allow the drum to reel in excess lifeline. The lifeline is attached at the other end thereof to either the user or to an anchorage point, whichever is not already attached to the housing.
Retracting lifeline systems also include a mechanism which locks (that is, prevents rotation of) the drum assembly of the retracting lifeline upon indication that a fall is occurring. For example, when the rope, cable or web being pulled from the retracting lifeline system causes the drum assembly to rotate above a certain angular velocity or experience an angular acceleration above a certain level, a brake mechanism can cause the drum assembly to suddenly lock.
Given the forces experienced by retracting lifeline systems upon sudden locking of drum rotation, the operational components of retracting lifeline system are typically manufactured from high-strength materials such as stainless steel to ensure locking, while withstanding the stresses associated therewith. In that regard, though the fall may be stopped upon actuation of the braking mechanism of a retracting lifeline system, the suddenness of the stop may cause injury to the user or produce higher than desirable stresses in one more components of the safety system. Energy or shock absorbing devices or systems are typically used to absorb energy experienced by the retracting lifeline system and the user.
In a tie-back application, a lifeline of a retracting lifeline system is wrapped around an acceptable anchorage structure and is connected back onto itself (via an end connector), creating a secure anchorage for the user. In currently available retracting lifeline systems, a substantial length of a strengthened or reinforced portion of the lifeline over which tie-back is permitted is maintained outside of the housing. For example, a sleeve of a durable and/or sacrificial material can be used to encase a length of lifeline extending from the housing to enable tie-back over the length of the sleeve. The thickness and stiffness of the sleeve and/or a stitched portion in the webbing prevents the sleeve from being drawn within the housing. Although it is safe to tie back over the length of the sleeved or reinforced portion of the lifeline, there is no guarantee that a user will not tie back up-line from that portion of the lifeline over which it is safe to tie back. Moreover, the substantial length of lifeline maintained outside of the housing (for example, 36 inches or more) creates a catching, snagging and/or tripping hazard. Further, the substantial length of lifeline maintained outside of the housing can result in an undesirable length of free fall in the case that a significant portion of the length outside the housing is unused in tie back to an anchor (for example, in the case of tie back to an anchor having a relatively small circumference).
In one aspect, a retracting lifeline system, includes: a housing, a first connector attached to the housing, a lifeline, and a hub to which the lifeline is attached at a first end of the lifeline and around which the lifeline is coiled within the housing. The housing includes an opening through which the lifeline exits the housing. The hub is tensioned to rotate in a first direction to cause retracting of the lifeline and coiling of the lifeline around the hub. The retracting lifeline system further includes a second connector attached to a second end of the lifeline. At least a section of the lifeline has an initial ultimate tensile load of at least 8000 pounds and is abrasion resistant such that the section of the lifeline is available for tie-back anchoring using the second connector. The section of the lifeline is at least partially retractable within the housing. As used herein, the phrase “abrasion resistant” refers to a line or lifeline that satisfies the abrasion test requirement set forth in the ANSI/ASSE Z359.13 2009 standard.
The section of the lifeline can, for example, have an initial ultimate tensile load of at least 9,000 pounds, at least 10,000 pounds or at least 12,000 pounds.
The entire length of the lifeline that is extendible from the housing (or the entire length of the lifeline) can, for example, have an initial ultimate tensile load of at least 8,000 pounds, at least 9,000 pounds, at least 10,000 pounds or at least 12,000 pounds and be abrasion resistant (that is, satisfying the abrasion test requirement set forth in the ANSI/ASSE Z359.13 2009 standard) such that the entire length of the lifeline that is extendible from the housing is available for tie-back anchoring.
In a number of embodiments, the lifeline can, for example, be formed as a continuous length of woven webbing. The webbing can, for example, have a thickness less than 0.1 inches and a width of not greater than 1.25 inches. No protective sleeve or reinforced section is required to enable tie back on the webbing.
The retractable lifeline system can, for example, further include an energy absorbing system positioned at least partially within the housing. The energy absorbing system includes a first retaining member and a second retaining member. The first retaining member can, for example, be connected to a connector extending from the housing so that the connector is rotatable relative to the first retaining member. The connector extending form the housing can be connected to the first connector such that the first connector is rotatable relative to the housing. The second retaining member is operatively connected to the hub. The first retaining member is connected to the second retaining member by at least one energy absorbing member that increases in effective length upon activation thereof so that the distance between the first retaining member and the second retaining member increases upon activation of the energy absorbing system.
The energy absorbing member can, for example, include at least a first length of material connected to a second length of material via tear elements which tear to absorb energy upon activation of the energy absorbing system.
The retractable lifeline system can, for example, further include at least one breakable connector connecting the first retaining member to the second retaining member. The breakable connector breaks or disconnects upon experiencing a first load such that first retaining member separates from the second retaining member by an observable distance to provide an observable indication that the first load has been experienced.
The energy absorbing member can, for example, be activated upon or after breaking of the breakable connector. As used herein, the terms “break”, “breakable” and like terms as used in connection with the breakable connector indicated that the connection formed by the breakable connector disconnects upon the first load such that first retaining member separates from the second retaining member.
Upon activation, the energy absorbing member can, for example, absorb energy to maintain a load experienced by the lifeline during activation of the energy absorbing member no greater than a predetermined magnitude.
The retractable lifeline system can further include an abutment member or a stop connected to the lifeline. In a number of embodiments, the stop includes at least a first member extending from at least a first surface of the lifeline to abut the opening upon retraction of the lifeline and prevent further retraction of the lifeline. The distance the first member extends from the first surface can, for example, vary to increase from a perimeter of the first member to an inward portion of the first member.
The stop can further include at least a second member extending from at least a second surface of the lifeline to abut the opening upon retraction and prevent further retraction of the lifeline. The distance the second member extends from the second surface can, for example, vary to increase from a perimeter of the second member to an inward portion of the second member. The first member can, for example, be connected to the second member by a connecting member passing through the lifeline. The lifeline can, for example, include or be formed as webbing. In a number of embodiments, the first member has a generally frusto-conical shape and the second member has a generally frusto-conical shape. The connecting member can, for example, include a rivet. The distance the first member extends from the first surface can, for example, be at a minimum at the perimeter of the first member, and the distance the second member extends from the second surface can, for example, be at a minimum at the perimeter of the second member. In a number of embodiments, the distance that each of the first member and the second member extends from the first and second surfaces, respectively, increases linearly from the perimeters thereof toward an inward portion thereof.
In another aspect, a retracting lifeline system includes a housing, a first connector attached to the housing, a lifeline, and a hub to which the lifeline is attached at a first end of the lifeline and around which the lifeline is coiled within the housing. The housing includes an opening through which the lifeline exits the housing. The hub is tensioned to rotate in a first direction to cause retracting of the lifeline and coiling of the lifeline around the hub. The retracting lifeline system further includes an energy absorbing system positioned at least partially within the housing. The energy absorbing system includes a first retaining member and a second retaining member. The first retaining is connected to a connector extending from the housing so that the connector is rotatable relative to the first retaining member. The connector extending form the housing can be connected to the first connector such that the first connector is rotatable relative to the housing. The second retaining member is operatively connected to the hub. The first retaining member is connected to the second retaining member by at least one energy absorbing member that increases in effective length upon activation thereof so that the distance between the first retaining member and the second retaining member increases upon activation of the energy absorbing system.
The energy absorbing member can, for example, include at least a first length of material connected to a second length of material via tear elements which tear to absorb energy upon activation of the energy absorbing system.
The retractable lifeline system can, for example, further include at least one breakable connector connecting the first retaining member to the second retaining member. The breakable connector breaks or disconnects upon a first load such that first retaining member separates from the second retaining member by an observable distance to provide an observable indication that the first load has been experienced.
The energy absorbing member can, for example, be activated upon or after breaking of the breakable connector.
Upon activation, the energy absorbing member can, for example, absorb energy to maintain a load experienced by the lifeline (and the end user) during activation of the energy absorbing member no greater than a predetermined magnitude.
At least a section of the lifeline can, for example, have an initial ultimate tensile load of at least 8000 pounds and be abrasion resistant (that is, satisfying the abrasion test requirement set forth in the ANSI/ASSE Z359.13 2009 standard) such that the section of the lifeline is available for tie-back anchoring using the second connector. The section of the lifeline can, for example, be at least partially retractable within the housing.
In a further aspect, a retracting lifeline system includes a housing, a connector attached to the housing, the connector (which can, for example, be rotatable relative to the housing), a lifeline, and a hub around which the lifeline is coiled within the housing. The housing includes an opening through which the lifeline exits the housing. The hub is tensioned to rotate in a first direction to cause coiling of the lifeline around the hub and retraction of the lifeline. The retracting lifeline system further includes a stop connected to the lifeline. The stop includes at least a first member extending from at least a first surface of the lifeline to abut the opening upon retraction and prevent further retraction of the lifeline. The distance the first member extends from the first surface can, for example, vary to increase from a perimeter of the first member to an inward portion of the first member.
The stop can also include at least a second member extending from at least a second surface of the lifeline to abut the opening upon retraction and prevent further retraction of the lifeline. The distance the second member extends from the second surface can, for example, vary to increase from a perimeter of the second member to an inward portion of the second member. The first member can, for example, be connected to the second member by a connecting member passing through the lifeline. The lifeline can, for example, include or be formed from webbing. The first member can, for example, have a generally frusto-conical shape, and the second member can, for example, have a generally frusto-conical shape. The connecting member can, for example, include a rivet. The stop can, for example, be formed from a metal such as stainless steel.
The distance the first member extends from the first surface can, for example, be at a minimum at the perimeter of the first member, and the distance the second member extends from the second surface can, for example, be at a minimum at the perimeter of the second member. In a number of embodiments, the distance that each of the first member and the second member extends from the first and second surfaces, respectively, increases linearly from the perimeters thereof toward an inward portion thereof.
At least a section of the lifeline can, for example, have an initial ultimate tensile load of at least 8000 pounds and be abrasion resistant (that is, satisfying the abrasion test requirement set forth in the ANSI/ASSE Z359.13 2009 standard) such that the section of the lifeline is available for tie-back anchoring using the second connector. The section of the lifeline can, for example, be at least partially retractable within the housing.
In another aspect, a retracting lifeline system includes a housing, a first connector attached to the housing, a lifeline, and a hub to which the lifeline is attached at a first end of the lifeline and around which the lifeline is coiled within the housing. The housing includes an opening through which the lifeline exits the housing. The hub is tensioned to rotate in a first direction to cause retracting of the lifeline and coiling of the lifeline around the hub. The retracting lifeline system further includes a first retaining member and a second retaining member. The first retaining is connected to a connector extending from the housing, which is connected to the first connector. The second retaining member is operatively connected to the hub. At least one breakable connector connects the first retaining member to the second retaining member. The breakable connector breaks or disconnects upon experiencing a first load such that first retaining member separates from the second retaining member by an observable distance to provide an observable indication that the first load has been experienced.
In a number of embodiments, the first retaining member is further connected to the second retaining member by at least one energy absorbing system that increases in effective length upon activation thereof so that the distance between the first retaining member and the second retaining member increases upon activation of the energy absorbing system.
In a number of embodiment, the connector extending from the housing can, for example, be rotatable relative to the first retaining member. The connector extending form the housing can, for example, be connected to the first connector such that the first connector is rotatable relative to the housing.
In a further aspect, a method of protecting a person in the case of a fall from a height, includes: providing a retractable lifeline system as set forth above. The retractable lifeline system can, for example, include at least a section of lifeline that has an initial ultimate tensile load of at least 8000 pounds and be abrasion resistant (that is, satisfying the abrasion test requirement set forth in the ANSI/ASSE Z359.13 2009 standard) such that the section of the lifeline is available for tie-back anchoring using the second connector. The section of the lifeline available for tie-back anchoring can, for example, be at least partially retractable within the housing.
In a further aspect, a method of operating a retractable lifeline system includes at least partially retracting a section of a lifeline within a housing of the retractable lifeline system, wherein the section of the lifeline has an initial ultimate tensile load of at least 8000 pounds and is abrasion resistant (that is, satisfying the abrasion test requirement set forth in the ANSI/ASSE Z359.13 2009 standard) such that the section of the lifeline is available for tie-back anchoring using a first connector attached to the lifeline. In a number of embodiments, the retractable lifeline system includes the housing; a second connector attached to the housing, the lifeline; and a hub to which the lifeline is attached at a first end of the lifeline and around which the lifeline is coiled within the housing. The housing includes an opening through which the lifeline exits the housing. The hub can, for example, be tensioned to rotate in a first direction to cause retracting of the lifeline and coiling of the lifeline around the hub.
The devices, systems and/or methods, along with the attributes and attendant advantages thereof, will best be appreciated and understood in view of the following detailed description taken in conjunction with the accompanying drawings.
As used herein and in the appended claims, the singular forms “a,” “an”, and “the” include plural references unless the content clearly dictates otherwise. Thus, for example, reference to “a connector” includes a plurality of such connectors and equivalents thereof known to those skilled in the art, and so forth, and reference to “the connector” is a reference to one or more such connectors and equivalents thereof known to those skilled in the art, and so forth.
As illustrated, for example, in
Overhead anchorage is typically recommended. However, in certain circumstances, lifeline 40 can be anchored below the harness back D-ring 410. Fall clearance should be calculated from the anchor point when anchoring below the harness back D-ring 410 and the distance between the anchor and harness D-ring 410 must be added into the calculation as known in the art. See, for example, Calculating Fall Clearance Distance in the Miller Self-Retracting Lifelines & Fall Limiters instruction manual available from Sperian Fall Protection, Inc. of Franklin, Pa.
Unlike currently available retracting lifeline systems, a user can tie back at generally any position along lifeline 40. Also unlike such currently available retracting lifeline systems, at least a portion of lifeline 40 over which tie-back can occur is retractable onto drum assembly 100 (see
Suitable initial ultimate tensile load and cut-resistance and/or abrasion resistance in lifeline 40 enables connection or tying back directly to lifeline 40 at any position thereon in a choking fashion, eliminating the need of a thick protective sleeve or extension that cannot be wound around a drum assembly and/or drawn within a housing. As discussed above, as used herein, “abrasion resistant” is defined as being in compliance with the abrasion test requirement set forth in the ANSI/ASSE Z359.13 2009 standard (see, for example, sections 3.2.6 and 4.1.9 through 4.1.12). The ANSI/ASSE Z359.13 2009 standard incorporates Federal Test Method STD. No. 191A, Method 5309, Abrasion Resistance of Textile Webbing. Those standards are provided as appendices to U.S. Provisional Patent Application Ser. No. 61/321,491.
Lifeline 40 provides the strength, abrasion and cut resistance necessary for tie-back applications, and yet is sufficiently flexible to retract back into a properly sized housing 20 using standard tensioning mechanisms such as a steel coil spring. In a number of embodiments, in addition to the retraction tension required to retract the weight of lifeline 40 (including the attached connector), the retraction tension on lifeline 40 is not less than 1.25 pounds (0.6 kg) nor more than 25 pounds (11.4 kg) at any point in the range of motion provided by the line. ANSI/ASSE Z359.1 1992 Section 3.2.8.6. In several embodiments, the retraction tension was not less than 1.5 and not more than 8 pounds or not less than 1.5 pounds and not more than 5 pounds.
In a number of embodiments, webbing lifelines developed for use in retracting lifeline system 10 were woven from at least two fiber materials to include an interior (referring to the general position in the woven webbing) of a high strength or high tenacity fiber material and an exterior of an abrasion resistant material. The high strength or high tenacity fibers can, for example, have a breaking tenacity of at least 20 grams per denier (g/den). In a number of embodiments, the high strength or high tenacity fibers have a breaking tenacity between approximately 20 g/den and approximately 35 g/den. Examples of suitable high strength or high tenacity fiber materials include VECTRAN™ fibers (high strength, liquid crystalline aromatic polyesters), available from Kuraray America, Inc. of Houston, Texas, SPECTRA® fibers (ultra-high molecular weight polyethylene material) available from Honeywell of Virginia, USA, KEVLAR® fibers (para-aramid synthetic fibers) available from E. I. du Pont de Nemours and Company of Wilmington, Del. USA (or other aramid fiber material) or DYNEEMA® fibers (an ultrahigh molecular weight polyethylene material) available from DSM Dyneema of Geleen, The Netherlands. In a number of embodiments, the high strength or high tenacity material also exhibits relatively low elongation. In a number of embodiments, the elongation at break of the high strength or high tenacity fibers was in the range of 2.4 to 3.7%. Use of denser high strength or high tenacity fibers (for example, KEVLAR® and VECTRAN® fibers are denser than SPECTRA® and DYNEEMA® fibers) results in a thinner webbing.
As described above, in a number of such embodiments, the webbing lifeline further includes an exterior (referring once again, to the general position in the woven webbing) of an abrasion resistant material such as spun yarns or spun polymeric fibers. Many different abrasion resistant spun yarns can be used. The abrasion resistant yarns or fibers can also provide cut resistance. In a number of embodiments, spun polyester fibers were used as the abrasion resistant material. The material forming the exterior of the webbing can also, for example, provide UV protection for the inner, high strength material. An example of a material developed for use herein is webbing product no. K2197 available from Technical Textiles of Charlotte, N.C., which includes a weave of high-strength VECTRAN fibers and spun polyester fibers as described above to produce a lifeline having an initial ultimate tensile load of at least 8000 pounds and abrasion resistance as defined above.
The interior, high strength fiber can, for example, be of a first color and at least a portion the exterior, abrasion resistant fiber can be of a second, different color. The interior, high strength fiber can, for example, be chosen or formed to be white, and at least a portion of the exterior, abrasion resistant fiber can be black. In this manner, abrasion resulting in damage of the exterior portion can be apparent as the differently colored interior portion will become visible.
In the case of a number of materials, some abrasion on the outside edges of lifeline 40 will not significantly adversely affect the performance of lifeline 40. As, for example, illustrated in
The size and weight of retracting lifeline housing 20 are considerations in designing retracting lifeline system 10. Users can, for example, wear one or more of retracting lifeline systems 10 for eight hours or more. Excessive fatigue or discomfort associated with overly large or heavy retracting lifeline systems can lead to injury or to lack of compliance in usage retracting lifeline systems. The width, thickness and length of lifeline 40 affect the size and weight of drum assembly 100 and thereby other components of retracting lifeline system 10, including housing 20.
In a number of embodiments, lifeline webbing has a width W (see
The length of lifeline 40 can, for example, be in the range of 4 to 12 feet. Other lengths are also possible. In several embodiments, the length of lifeline 40 was between approximately 4.5 feet and 8 feet. Such ranges of length of lifeline 40 provide length for tie-back around a wide range of anchorages, for movement and for fall arrest, while providing a reasonable size and weight for housing 20 and the components therein.
Although tie-back can be effected at any position along lifeline 40, and lifeline 40 can be fully retracted within housing 20, a length or portion of lifeline 40 can, for example, be provided or maintained exterior to housing 20. Maintaining a length of lifeline 40 exterior to housing 20 enables the user to, for example, readily connect snap hook 600 (or other connector) to a connector 610 (see
As illustrated, for example, in
A connector such as rivet 49 (which can, for example, form central section 48) passes through each section 45 and lifeline 40, sandwiching lifeline 40 between each section 45 to retain stop 44 in connection with lifeline 40. To prevent excessive damage to lifeline 40, in forming an opening to enable passage of rivet 49 therethrough, an awl A (see
Unlike prior stops (for example, a section of lifeline stitched back on itself to create an area of increased width), the low profile and/or sloped surfaces of stop 44, prevent catching or interference of stop 44 with anchors such as I beams or other anchors, which can interfere with, for example, tie-back installation. Stop 44 can, for example, be formed from a durable material such as a metal.
A hub or drum assembly 100 of system 10 includes a first hub flange or hub plate 110, a hub or drum 120 around which lifeline 40 (for example, webbing) is coiled, a second hub flange 140, and connectors such as screws 150. In several embodiments, hub plate 110 and hub flange 140 were formed from a metal such as aluminum or stainless steel, while hub 120 was formed from a deformable polymeric material as described in U.S. Patent Application Publication No. 2009/0211847. When assembled, hub plate 110, hub 120, hub flange 140, and screws 150 form hub or drum assembly 100 which rotates on shaft 70. A loop end of lifeline 40 is positioned with a passage 123 formed within hub 120 around shaft 70 to anchor the loop end of lifeline 40 securely within drum assembly 100. The loop end extends through a slot 121 formed in hub 120 and a portion of lifeline 40 is coiled around hub 120, leaving a free end which extends from housing 20.
Shaft 70 is rotationally locked to hub plate 110 via a catch or braking base 112 (formed, for example, from a metal such as case stainless steel) that is connected to hub plate 110 by screws 150. In that regard, braking base 112 includes a passage 113 formed therein through which shaft 70 passes and a radially inward projecting member 114 which engages a radially outward portion of slot 76 of shaft 70. Tension is applied to drum assembly 100 to retract lifeline 40 after extension thereof via a power spring assembly 160 including coiled strap of spring steel inside a plastic housing formed by housing members 168. A radially outward end 163 of spring steel strap can be anchored to frame 50. A radially inward end 163′ can engage a radially inward, narrow portion of slot 76 in shaft 70. One housing member 168 of power spring assembly 160 can, for example, be rotationally locked to frame member 50 by a projecting member or stud 164 on housing member 168 which engages frame 50. As described above, lifeline web 40 is anchored to and coiled around hub 120 of drum assembly 100. At assembly, power spring 162 is “wound up” to provide torque to shaft 70 and thus to drum assembly 100. The torque applied to shaft 70 pre-tensions lifeline 40 and causes lifeline 40 to coil up or retract around hub 120 after it has been uncoiled therefrom.
Retracting lifeline system 10 also includes a braking mechanism 105. Retracting lifeline system 10 can, for example, include a braking mechanism as described in U.S. Patent Application Publication No. 2009/0211848. In that regard, a catch 190 (formed, for example, from a metal such as cast stainless steel) is pivotably or rotatably mounted (eccentric to the axis of shaft 70) to catch base 112 via a partially threaded pivot member 180 which passes through a passage 192 formed in catch 190 to connect to a threaded passage 116 on catch base 112. The axis of threaded pivot member 180 (and passage 192) preferably corresponds approximately or generally to the center of mass of catch 190. In that regard, pivot member 180 is preferably positioned in the vicinity of the center of mass of catch 190 and preferably as close to the center of mass as possible. Braking mechanism 105 can also include a catch spring 200 having one end which engages a connector 117 (for example, a loop or passage) of catch base 112 and another end which engages a connector 194 (for example, a loop or passage) of catch 190. The force exerted by the catch spring 200 is generally balanced against the rotational inertia of catch 190 so that catch 190 actuates (via centrifugal force) to effect braking only when lifeline web 40 is being pulled from retracting lifeline system 10 at an acceleration rate corresponding, for example, to the beginning of a fall (as described in U.S. Patent Application Publication No. 2009/0211848). For example, catch 190 and catch spring 200 can be readily designed (using engineering principles known to those skilled in the art) to actuate when lifeline 40 is being pulled out at a certain determined acceleration (for example, ½ or ¾ times the acceleration of gravity). For lower accelerations or when the user is extending the web at a constant rate, such as when walking, catch 190 will not actuate and hub assembly 100 will turn freely.
The center of mass of catch 190 is located generally where it pivots or rotates on pivot member 180. Catch 190 will thus maintain its position relative to hub assembly 100, while hub assembly 100 is rotating at a constant angular velocity as when lifeline 40 is being pulled out of retracting lifeline system 10 at a constant rate. That is, catch 190 and catch base 112/hub assembly 100 will rotate as a unit and centrifugal force will not cause catch 190 to rotate about pivot member 180 relative to catch base 112/hub assembly 100. However, if hub assembly 100 experiences a clockwise (in the orientation of
When catch 190 is rotated counterclockwise about pivot member 180 relative to hub assembly 100, an abutment section, stop section or corner 195 of catch 190 extends radially outward (because catch pivot 180 is not concentric with shaft 70). In this case, abutment section 195 of catch 190 will abut or catch an abutment member of a stop or abutment member 51 of frame 50. Catch 190 cannot rotate in a counterclockwise direction because of abutment of shaft 70 with an end of curved slot or opening 193 of catch 190. As a result the contact of abutment section 195 with frame 50 and the abutment of slot 193 with shaft 70, the rotation of hub assembly 100 is brought to a halt.
When the user has relaxed the tension on lifeline 40 to allow hub assembly 100 to retract lifeline 40 a short distance, hub assembly 100 rotates counterclockwise (as a result of the tensioning force of tensioning mechanism 160), and abutment section 195 of catch 190 moves away from abutment with frame 50. Catch 190 then rotates (as a result of the biasing force of catch spring 200) about the axis of pivot member 180 clockwise relative to hub assembly 100. At this point, hub assembly 100 is now free to rotate again.
In the illustrated embodiment, screws 150 are passed through passages 118 in catch base 112, passages 111 in hub plate 110, through passages 122 in hub 120 and through passages 142 in hub flange 140 to retain drum assembly 100 and catch base 112 in operative connection.
Hub 120 can, for example, be molded from an integral piece of a polymeric material such as, for example, copolymer polypropylene. As described in U.S. Patent Application Publication No. 2009/0211847, hub 120 includes a peripheral or perimeter member 124 which forms the outer surface or perimeter of hub 120. Lifeline 40 is coiled around peripheral or perimeter member 124 which facilitates smooth coiling and uncoiling of lifeline 40 therearound when lifeline 40 extends and retracts during normal, non-locked use. As also described U.S. Patent Application Publication No. 2009/0211847, hub 120 also included an intermediate connector such as a septum 126 extending between peripheral member 124 and a radially inward or generally central portion 128 of hub 120. The thickness and/or other properties of septum 126 enable adjusting or determining the energy absorption afforded by hub 120 using defined engineering principles as described in U.S. Patent Application Publication No. 2009/0211847.
In the case of a fall, at the instant that drum assembly 100 has locked and tension in lifeline 40 is rapidly increasing, coils of lifeline 40 constrict around hub 120. At a certain tension level, determined, for example, in large part by the thickness of septum 126, hub 120 will begin to crush as a result of the radial forces acting upon it. Deformation of hub 120 absorbs energy. Generally central portion or flange connecting portion 128 of hub 120 (around passage 123) remains substantially or completely undeformed to facilitate rotation of hub or drum assembly 100 after energy absorbing deformation of at least a portion of hub 120.
Retracting lifeline system 10 further includes a shock or energy absorbing system 800 to further absorb energy in the case of a fall. In many cases, lifelines of retracting lifeline system include an energy absorbing system at a distal end of the lifeline thereof. However, because lifeline 40 is used in tie-back applications, an energy absorbing system positioned at the distal end thereof can become isolated from the remainder of system 10 upon tie-back and thus become inoperative to absorb energy.
Energy absorbing system 800 is in operative connection with housing 20. In a number of embodiments, energy absorbing system 800 includes, for example, at least one element which effectively lengthens (for example, via deformation, breakage, tearing etc.) while absorbing energy during a fall by the user of retracting lifeline system 10. In the illustrated embodiment (see, for example,
In the illustrated embodiment, extending, energy absorbing section or webbing 810 is connected to (or forms a part of) a first retaining member or bracket 820, which is in operative connection with and provides a base for connector 30, and to a second retaining member or bracket 840 which is connected to (or forms a part of), for example, frame 50 to be operatively connected to hub assembly 100 and lifeline 40. In the illustrated embodiment, webbing 810 is formed in a loop which extends around a first shaft 822 connected to first retaining member 820 and around a second shaft 842 connected to second retaining member 820 (see, for example,
As, for example, illustrated in
In the illustrated embodiment, first retaining member 820 and second retaining member 840 are connected or attached in a manner to provide a load indicator. That is, an observable change, associated with disconnection of first retaining member 820 from second retaining member 840 and relevant movement thereof, occurs when retracting lifeline system 10 experiences a first load, which can be less than or equal to a second load experienced in a fall situation, but is nonetheless of sufficient magnitude that retracting lifeline system 10 should undergo at least a thorough inspection. In the illustrated embodiment, extending members 826 of first retaining member 820 are spaced slightly wider than extending members 844 of second retaining member 840 to extend therearound. Extending members 826 include holes or passages 828 which are aligned with holes or passages 848 formed in extending members 844 so that shear pins 850 or other breakable or disconnectible connectors can be passed therethrough to connect extending members 826 with extending members 844. In the illustrated embodiment, two shear pins 850 are illustrated. However, a single shear pin which extends to pass through passages 828 and passages 848 on both sides of first retaining member 820 and second retaining member 840 can be used.
During use of retracting lanyard system 10, forces on lifeline 40 are passed via drum assembly 100, shaft 70 and frame 50 to pins 850. Under a load of a magnitude of the first load described above, pins 850 will shear, and first retaining member 820 will separate from second retaining member 840. First load can, for example, be in the range of approximately 450 to approximately 650 lbs. In a number of embodiments, first load was approximately 600 lbs. The load indicator can, for example, actuate under a load of sufficient magnitude that damage to system 10 can occur (such that system 10 should be taken out of surface for at least inspection). However, the magnitude of value of the first load should not be so low that the load indicator activates under normal loads experienced in normal use. The state of activation of the load indicator after system 10 experiences the first load is illustrated in
Each housing section 20a of housing 20 can, for example, be formed (for example, molded) monolithically from a polymeric material such as a high-impact nylon. Housing section 26 can, for example, be formed (for example, molded) from the same or similar polymeric material as housing section 20a of housing 20 and can, for example, for a snap fit with housing sections 20a when assembled. In general, the load indicator operates independently of housing 20. Although housing section 26 separates with retaining member 820 upon the occurrence of the first load, the magnitude of the first load is determined by pins 850 in connection with first retaining member 820 and second retaining member 840. In that regard, loads required to deform and/or break polymeric materials are typically too low or too unpredictable. Use of breaking or shearing members such as metallic shear pins 850 provides substantial control over and tuning of the load required to activate the load indicator.
After breaking of shear pins 850, weaving or stitching 812 can tear, absorbing energy, and the loop of webbing 810 will expand or extend to the state illustrated in
As second loop of a webbing 816 or other material (having an ultimate load greater than webbing 810) can also extend around shafts 822 and 842 to ensure that connector 30 remains connected to frame 50 and lifeline 40. Webbing 815 can, for example, have an ultimate tensile load of at least 4500 pound or at least 5000 pounds. Other types of energy absorbing systems in which, for example, a length of a material such as a metal is uncoiled and/or torn (see, for example, U.S. Patent Publication No. 2009/1094366) or one or more friction elements is/are pulled through a constriction can be used.
First retaining member 820 includes a passage 830 in an upper (in the orientation of
A spacer 868 (for example, a polymeric annular member) can be provided at the lower (in the orientation of
As illustrated in
The operative connection of connector 30 with first retaining member 820 facilitates the attachment of one or more retracting lifeline systems into the support systems disclosed in U.S. Patent Application Publication No. 2009/0211849.
Frame 220 further includes a space or slot 222 formed in an upper surface 220c thereof, which is in communicative connection with the space between front frame member 220a and rear frame member 220b. As illustrated, for example, in
In several embodiments, at least two independent actions are required of a user to remove connector 214 from operative connection with D ring 410. In the illustrated embodiment, one must first rotate an abutment element or catch lever 260 about a pivot element 262 (for example, a rivet) to remove catch lever 260 from abutting contact with a forward end of an attachment element such as a pin, shaft or rod 240. Abutment element 260 can, for example, be rotated approximately 45 degrees to move it out of abutment with attachment element or pin 240 and to allow clearance for attachment pin 240 to slide, move or retract within the space between front frame member 220a and rear frame member 220b of frame 220. In the illustrated embodiment, attachment pin 240 is movably or slidably retained within a passage or hole 224 formed in forward frame member 220a of frame 220. Contact elements such as pins 226 (positioned within passages 228 formed in front frame member 220a) extend into passage 224 to cooperate with slots 244 formed along a portion of the length of attachment pin 240. Cooperation of pins 226 with slots 244 prevents attachment pin 240 from being removed from operative connection with frame member 240 and prevents rotation of attachment pin 240 relative to (and between) front frame member 220a and rear frame member 220b, while allowing attachment pin 240 to slide between front frame member 220a and rear frame member 220b.
In the illustrated embodiment, attachment pin 240 is formed generally as a cylinder having a generally central passage 246. The inner wall of passage 246 includes threading (not shown) over at least a portion thereof to form a threaded engagement with threading 248 of a rod, shaft or bolt 250. Bolt 250 passes through a passage or hole 230 formed in front frame member 220a to enter the space between front frame member 220a and rear frame member 220b and engage attachment pin 240. A grasping member, such as a knurled knob 252, can be provided to facilitate grasping and rotation of bolt 250. In that regard, after moving catch lever 260 out of contact with attachment pin 240, knob 252 is rotated (for example, counterclockwise) until threading 248 of bolt 250 disengages cooperating threading of attachment pin 240 and attachment pin 240 is free to move independently of bolt 250. At this point, attachment pin 240 can be slid forward (for example, under the force of gravity upon tilting of connector 214) until it is suitably clear of connection with D Ring 410 so that D ring 410 can be removed from slot 222.
The process described above for removal of D ring 410 is reversed to connect D ring 410 to connector 214. In that regard, D-Ring 410 in inserted into slot 222 until D-Ring moves past or clear of attachment pin 240. Attachment pin 240 is then slid rearward to pass through the center hole in D-Ring 410. While holding attachment pin 240 to both maintain its position through the center hole of D-Ring 410 and abut bolt 250, knob 252 is rotated (for example, clockwise) so that threading 248 engages the threading in passage 246 of attachment pin 240. Upon hand tightening, attachment pin 240 is fully engaged. After engaging attachment pin 240, catch lever 260 is rotated into engagement with attachment pin 240. In several embodiments, the distal end of catch lever 260 includes a U shaped bracket 264 that contact frame 220 to provide an indication to the user that catch lever 260 is in the engaged position. Bracket 264 can be dimensioned so that the legs thereof must be forced outward to engage frame 220, thereby reducing the likelihood that catch lever will be accidentally disengaged from abutting contact with attachment pin 240. A detent element 266 can also be provided to assist in maintaining catch lever in an engaged state. Once catch lever 260 is in abutting contact with attachment pin 240, attachment pin 240 cannot slide forward to a disengaged position.
To attach or remove retracting lifeline systems 10 (and/or other elements such as safety devices) to connector 214 in the embodiment illustrated in
Connector 214 further includes a retainer such as a sliding retainer or bracket 270 that is slidably positioned on frame 220. In the illustrated embodiment, bracket 270 is generally U shaped including a front member 270a and a rear member 270b connected over a central portion thereof by a lower member 270c. Bracket 270 further includes tabs 272 extending from the top of front member 270a and rear member 270b thereof to at least partially encompass frame 220. Tabs 272 can include downward extending sections 272a that form a detent engagement with seatings or passages to assist in maintaining bracket 270 in a first or detent position as further described below. During assembly, shaft or bolt 250 passes through a passage 274 formed in rear surface 270b of bracket 270 before knob 252 is attached thereto. The attachment of shaft or bolt 250 and knob 252 assists in retaining bracket 270 in operative connection with frame 220. As, for example, illustrated in
Once attachment pin 240 is disengaged form bolt 250 and slid forward to be generally clear of slot 222 (and out of engagement with passage 230 of retainer bracket 270) as described above, bracket 270 can be slid to one side out of the first, detent position and to a second position (for example, to the right as illustrated in
Once bracket 270 is slid to the second position illustrated in
To attach another retracting lifeline system 10 (or other elements) to connector 214, the above process is repeated, but device attachment or retainer bracket 270 is slid in the opposite direction (that is, to the left) to a third position as illustrated in
As illustrated, for example, in
In the embodiments set forth above, lateral pivoting of retracting lifeline systems 10 occurs about the axes of extending members or attachment pins 280 and 284. As clear to one skilled in the art, however, lateral pivoting or rotation of the retracting lifeline housing can be provided by or inherent in a connector of the retracting lifeline system (similar to the rotation provided about axes A1 and A), and such a connector can be fixed or immovably attached to a connector similar to connector 214.
By encompassing a portion of D ring 410 within connector 214, the fall clearance is reduced as compared to, for example, embodiments in which such a connector is attached to a D ring via an intervening connector or attachment element. The vertical (in, for example, the orientation of
Uninterrupted tie off (where by a tie-back operation or otherwise) is provided with a wide range of movement for a worker either using both retracting lifeline system 10 during a transition from one anchor point to another, or when using a single retracting lifeline or retracting lifeline system with a single anchor point. Although a wide range of motion is provided, the two devices (for example, retracting lifeline system 10) attached to connector 214 are kept separate and are somewhat restricted in their interaction to reduce the possibility of interference. In that regard, retracing lifeline systems 10 can, for example, be prevented from pivoting toward each other (about attachment pins 280 and 284) by an abutment of frame 220 with retracting lifeline system connector 30.
The foregoing description and accompanying drawings set forth the preferred embodiments of the invention at the present time. Various modifications, additions and alternative designs will, of course, become apparent to those skilled in the art in light of the foregoing teachings without departing from the scope of the invention. The scope of the invention is indicated by the following claims rather than by the foregoing description. All changes and variations that fall within the meaning and range of equivalency of the claims are to be embraced within their scope.
This application is a continuation of, and claims the benefit of the filing date of U.S. Provisional Ser. No. 61/321,491, filed Apr. 6, 2010, and U.S. Ser. No. 13/080,731, filed Apr. 6, 2011, which are hereby incorporated by reference in their entirety.
| Number | Date | Country | |
|---|---|---|---|
| 61321491 | Apr 2010 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 13080731 | Apr 2011 | US |
| Child | 15882530 | US |
