CA2313514A1 - Fall restrict device - Google Patents
Fall restrict device Download PDFInfo
- Publication number
- CA2313514A1 CA2313514A1 CA 2313514 CA2313514A CA2313514A1 CA 2313514 A1 CA2313514 A1 CA 2313514A1 CA 2313514 CA2313514 CA 2313514 CA 2313514 A CA2313514 A CA 2313514A CA 2313514 A1 CA2313514 A1 CA 2313514A1
- Authority
- CA
- Canada
- Prior art keywords
- pole
- strap
- piercing
- support portion
- loop
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 239000002023 wood Substances 0.000 claims abstract description 7
- 230000000712 assembly Effects 0.000 claims description 23
- 238000000429 assembly Methods 0.000 claims description 23
- 239000000463 material Substances 0.000 claims description 12
- 230000035515 penetration Effects 0.000 claims 1
- 230000007246 mechanism Effects 0.000 description 8
- 238000010276 construction Methods 0.000 description 5
- 230000008901 benefit Effects 0.000 description 3
- 230000037396 body weight Effects 0.000 description 2
- 230000009194 climbing Effects 0.000 description 2
- 230000003578 releasing effect Effects 0.000 description 2
- 230000004044 response Effects 0.000 description 2
- 208000027418 Wounds and injury Diseases 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 230000006378 damage Effects 0.000 description 1
- 208000014674 injury Diseases 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000009419 refurbishment Methods 0.000 description 1
- 230000008439 repair process Effects 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
Classifications
-
- A—HUMAN NECESSITIES
- A62—LIFE-SAVING; FIRE-FIGHTING
- A62B—DEVICES, APPARATUS OR METHODS FOR LIFE-SAVING
- A62B35/00—Safety belts or body harnesses; Similar equipment for limiting displacement of the human body, especially in case of sudden changes of motion
- A62B35/0006—Harnesses; Accessories therefor
- A62B35/0025—Details and accessories
- A62B35/0031—Belt sorting accessories, e.g. devices keeping the belts in comfortable positions
-
- A—HUMAN NECESSITIES
- A62—LIFE-SAVING; FIRE-FIGHTING
- A62B—DEVICES, APPARATUS OR METHODS FOR LIFE-SAVING
- A62B35/00—Safety belts or body harnesses; Similar equipment for limiting displacement of the human body, especially in case of sudden changes of motion
- A62B35/0043—Lifelines, lanyards, and anchors therefore
- A62B35/0068—Anchors
Landscapes
- Health & Medical Sciences (AREA)
- General Health & Medical Sciences (AREA)
- Business, Economics & Management (AREA)
- Emergency Management (AREA)
- Emergency Lowering Means (AREA)
Abstract
A fall restrict device for use by a lineworker on a wood electric utility pole includes a flexible strap that can be formed into a loop around the pole. A free end of the strap loop is fastened to a body harness worn by the worker. A pair of pole piercing assembly are secured to the strap, each assembly including a planar plastic paddle formed with slots through which the strap is interleaved. The paddles are positioned so as to locate on diametrically opposite sides of the pole when the loop is formed around the pole, and each paddle carries piercing elements oriented to penetrate the pole as the loop is tightened. Tension on the free strap end automatically causes the piercing elements to penetrate the pole. To permit the device to be released from the pole, each paddle defines a fulcrum to one side of its piercing elements that bears against the pole, and a lever to an opposite side of the piercing elements.
The paddles can be manually rotated by means of their levers to pry their piercing elements from the pole.
The paddles can be manually rotated by means of their levers to pry their piercing elements from the pole.
Description
FALL RESTRICT DEVICE
FIELD OF THE INVENTION
The invention relates generally to fall restrict devices used by lineworkers when working on wood poles.
DESCRIPTION OF THE PRIOR ART
Lineworkers often climb wood poles that support electric power lines in order to perform construction, maintenance or refurbishment work. To climb such a pole, a lineworker normally wears boots fitted with gaffs that penetrate the pole. The lineworker may also use a pole strap that locates about the pole and fastens to a safety belt worn at the waist. Once positioned to perform work, the lineworker relies on the gaffs to support his or her weight, and relies on the pole strap to be able to lean away from the pole and free his or her arms. A fall restrict device is used to prevent serious injury if footing is lost while climbing the pole, moving around the pole, or supporting oneself in order to perform repairs.
Various fall restrict devices have been proposed. Three commercially available devices are described in U.S. patent no. 4,595,078 which issued on June 17, 1986 to Greenway; U.S. patent no. 5,137,113 which issued on August 11, 1992 to Lortie; and U.S. patent no. 5,141,074 which issued on August 25, 1992 to Sulowoski et al. The Greenway device includes a yoke assembly that locates partially around a pole. The yoke has a tubular main body, and a pair of arms hinged to the main body and carrying sharp projections. Coil springs urge the arms to close about the pole and engage their projections with the pole. Handles on the arms allow the lineworker to disengage the device when moving along the pole. A safety strap extends through eyelets on the handles and has opposite ends fastened to the lineworker's waist belt or harness. This arrangement ensures that the device automatically engages the pole to stop a fall.
The Sulowoski et al device has a main strap that is partially wrapped about a pole with two runs of strap extending back to the lineworker and fastened to a waist belt. A pair of connectors mount an adjustable cross-strap between the two runs of the main strap, to complete a loop around the pole, and a coil spring, which extends circumferentially along the main strap, is fastened to the connectors. The cross-strap can be adjusted to tension the coil spring and form a tight loop around the pole.
The Lortie device is somewhat similar to the Sulowoski et al device. It uses a pair of straps that extend from the lineworker's waist belt.
One strap is wrapped partially around a pole and fastened with a special connector to the other strap. Part of the other strap serves as a cross-belt to complete a loop encircling the pole.
Such prior art fall arrest devices have several shortcomings. The rigid components of the Greenway device make it difficult to manipulate, particularly if work space is limited by an adjacent pole or structure. The device is also difficult, if not impossible, to use on many poles that have multiple lengthwise conduits. The Sulowoski et al and Lortie devices require repeated adjustment if used while climbing a pole, and their performance on iced or multiple conduit poles is also inadequate.
BRIEF SUMMARY OF THE INVENTION
In one aspect, the invention provides a fall restrict device which comprises flexible strap material, preferably a single continuous strap, and connector means for forming the strap material into a flexible loop which tightens and loosens as a free end portion of the loop is pulled respectively away from and toward the pole. Fastener means are provided to secure the free end portion of the loop to a body harness worn by the lineworker. The fastening means preferably comprise a mechanism for automatically retracting and paying out the free strap end portion to accommodate natural movement of the worker while performing required services, but the free end portion may be secured directly to the body harness. A pole-piercing assembly is attached to the strap material. The assembly includes a piercing element positioned to penetrate the pole as the loop tightens, a fulcrum portion positioned to one side of the piercing element, and an elongate lever portion positioned to an opposite side of the piercing element so that the assembly can be manually rotated about its fulcrum portion to disengage the piercing element from the pole. Ideally, a similar pole-piercing assembly is secured to the strap material so that the assemblies engage diametrically opposing sides of the pole.
The fall restrict device of the invention is simple to use. To engage the fall restrict device, the lineworker simply leans away from the pole, and the resulting tension on the free end of the loop engages the piercing assemblies with the pole. To release the fall restrict device, the lineworker simply leans toward the pole to release tension, and then rotates the lever portions to disengage the piercing assemblies from the pole. Should the lineworker slip, his or her weight on the free end of the loop quickly tightens the loop, if otherwise loose, and engages the piercing assemblies to resist his or her fall.
For purposes of this specification, the term "body harness"
should be understood as encompassing a waist belt or more elaborate rigging intended to support the weight of the wearer. The "free end" or "free end portion" of a strap or strap loop should be understood as an end of a strap, or section of strap adjacent to such an end, that extends away from the loop and move freely relative to the loop, particularly toward or away from the loop when the loop is fastened around a pole.
Various advantages and other aspects of the invention will be more apparent from a description below of a preferred embodiment, and will be more specifically defined in the appended claims.
DESCRIPTION OF THE DRAWINGS
The invention will be better understood with reference to drawings in which:
fig. 1 is a fragmented perspective view showing a lineworker using a pole strap together with a fall restrict device;
fig. 2 is an enlarged perspective view of the fall restrict device itself;
fig. 3 is a view of outer surfaces of a pole-piercing assembly associated with the fall restrict device;
fig. 4 is a partially exploded view of inner surfaces of the pole-piercing assembly;
fig. 5 is a horizontal cross-section about the pole showing how the fall restrict device engages the pole; and, fig. 6 is an enlarged horizontal cross-section about the pole showing a pole-piercing assembly can be manually pivoted to pry pole piercing element from the pole, to release the fall restrict device.
DESCRIPTION OF PREFERRED EMBODIMENT
Reference is made to fig. 1 which shows a lineworker 10 on a wood pole 12. The worker 10 is shown leaning away from the pole 12, which is commonly done to free the hands to perform required work. His body weight is supported by gaffs (not shown) attached to his boots and by a conventional pole strap 14 that fastens to a body harness 16 worn by the worker 10. A fall restrict device 18 is mounted about the pole 12. The device 18 is normally oriented substantially coplanar with the pole strap 14, and is fastened to the same body harness 16.
The construction of the fall restrict device 18 is more apparent in the view of fig. 2. The key components are two pole-piercing assemblies 20, 22 which have been used in this application of the invention to convert a conventional retractable lanyard into a reliable fall restrict device. The lanyard includes a flexible synthetic strap 24 and a conventional carabiner 26 which is fastened to one end portion 28 of the strap 24 and adapted to receive the opposing end portion 30 of the strap 24 to form a loop. The lanyard is equipped with a conventional strap tensioning mechanism, mounted to the body harness 16, that pays out and automatically retracts the free end portion 30 of the strap 24. Only a reel 32 associated with the mechanism has been illustrated (in fig. 2), and the free end portion 30 of the strap 24 is wound about and retained on the reel 32. The tensioning mechanism is comparable to those associated with automotive seat belts, allowing the free end portion 30 of the strap 24 to pay out freely under moderate tension, but halting paying out if the strap 24 is suddenly tensioned. Fastening of the free strap end portion 30 to the body harness 16 with such a tensioning mechanism allows the worker 10 considerable freedom of movement, the length of the free strap end portion 30 adjusting automatically to accommodate his movement. However, in other implementations of the invention, the automatic retraction feature may be eliminated, and fastening means may be substituted for the tensioning mechanism that secure the free strap end portion 30 more directly to a body harness.
The pole-piercing assembly 20 detailed in figs. 3 and 4 is typical of both assemblies 20, 22, and components common to the two assemblies 20, 22 have consequently been labeled with like reference numerals in the drawings. The main component of the assembly 20 is a unitary, planar plastic paddle 38. When viewed in an operative orientation fastened to the strap 24, the paddle 38 has an inner face 40 that faces toward and bears against the strap 24 and the pole 12, and an opposing outer face 42. The paddle 38 defines a central support portion 44 whose purpose is to support three piercing elements 46; a fulcrum portion 48 to one side of the support portion 44 and piercing elements 46; and an elongate lever portion 50 to an opposite side of the support portion 44 and piercing elements 46. The piercing elements 46 are conventional bolts whose free ends are machined to sharp points. The piercing elements 46 are inserted through clearance holes 52 in the support portion 44, above and below the strap 24. The piercing elements 46 are extended through an aligned set of clearance holes 54 in a planar, rectangular plastic block 56. The piercing elements 46 are secured to the support portion 44 with nuts, such as the exemplary nut 58 shown in fig. 4, that fit flush within the block 56. The points of the piercing elements 46 consequently protrude from the inner face 40 of the paddle 38, positioned to penetrate the pole 12 when the strap 24 is formed into a loop around the pole 12.
The support portion 44 is formed with a pair of slots 60 through which the strap 24 is interleaved. The term "interleaved" as used in this specification in respect of a strap and pairs of openings may be understood with reference to the relative orientation of the strap 24 and slots 60 shown in figs. 3 and 4. The slots 60 are formed transverse to and spaced apart along a lengthwise axis of the paddle 38. A lengthwise slot 62 (apparent in fig. 4) intersects the transverse slots 60 and facilitates such interleaving of the strap 24.
To attach the assembly 20 to the strap 24, the nuts associated with the piercing elements 46 are removed to expose the lengthwise strap 62, and a side edge of a section 64 of the strap 24 is introduced into the lengthwise slot 62 and worked into the transverse slots 60 so that it bears centrally against the outer face 42 at the support portion 44. The block 56 is then re-attached to the paddle 38, closing the lengthwise slot 62 to prevent the strap section 64 from accidentally releasing from the paddle 38. The assembly 20 can still be positioned along the strap 24 by drawing the section 64 away from the outer surface 42 of the paddle 38, and sliding the paddle 38 relative to the strap 24.
The mounting arrangement permits each of the pole-piercing assemblies 20, 22 to be positioned at any desired location along the strap 24.
In practice, the assemblies 20, 22 should be positioned to accommodate the diameter of a particular pole, and more specifically, to locate the assemblies 20, 22 substantially at diametrically opposite sides of the pole, as shown in fig.
with respect to the pole 12. It should be noted that one piercing assembly 22 is attached to the strap 24 with its lever portion 50 extending in one direction (toward free end portion 30 of the strap 24), and that the other piercing assembly 20, with its lever portion 50 extending in an opposite direction (toward the other end portion 30 of the strap 24). Thus, when the fall restrict device 18 is located around the pole 12, both lever portions 50 extend toward the lineworker 10.
Fig. 4 shows the device in its operative orientation around the pole 12. To achieve that orientation, the worker 10 wraps the strap 24 partially about the pole 12, and locates the carabiner 26 about the free end portion 30 of the strap 24 to form a loop completely encircling the pole 12. The tensioning mechanism to which the free end portion 30 is attached takes up excess slack.
As the free end portion 30 of the loop is pulled radially away from the pole 12, as by leaning quickly away from the pole 12, the loop tightens, drawing the pole-piercing assemblies 20, 22 into firm engagement with the pole 12. The strap 24 bears centrally against the support portion 44 of each paddle 38, ensuring that the piercing elements 46 are drawn forcefully toward and penetrate the pole 12.
The device 18 is very easily disengaged from the pole 12 when the lineworker 10 wishes to climb up or down. The lever portions 50 tend to align with the pole strap 14, and the lineworker 10 can accordingly grip both the pole strap 14 and the lever portions 50 of the device 18 simultaneously. To release the device 18, the lineworker 10 simply leans forward toward the pole 12 to release tension on the strap 24, and pivots the lever portions 50 away from the pole 12. This releasing action is illustrated in greater detail in the view of fig. 6. As the lever portion 50 of the assembly 20 is displaced away from the pole 12, the fulcrum portion 48 of the assembly 20 bears against the pole 12, and the lever portion 50 pivots the entire assembly 20 about the fulcrum portion 48. A significant mechanical advantage is obtained that allows the piercing elements 46 to be easily pried from the pole 12. The lineworker 10 can then climb up or down the pole 12, leaving the fall arrest device 18 loosely looped about the pole 12. Should the lineworker 10 lose his footing, his body weight on the free end portion 30 of the strap 24 re-engages the piercing assemblies 20, 22 with the pole 12, and, in this particular embodiment, the tensioning mechanism associated with strap 24 locks to prevent paying out.
The advantages of the invention relative to the prior art devices discussed above should now be more apparent. The invention lends itself to a very simple construction, which requires no rigid components or biasing springs. Repeated adjustment is not required, as the piercing assemblies 20, immediately position and engage when the loop is tightened by tension on the free end portion 30 of the strap 24. In tests on iced poles and also on multiple conduit poles, the fall arrest device 18 has proven to grip far more reliably than the prior art devices.
It will be appreciated that a particular embodiment of the invention has been described and that modifications may be made therein without departing from the spirit of the invention or necessarily departing from the scope of the appended claims. The embodiment of the invention illustrated involves use of pole piercing assemblies 20, 22 to adapt a conventional retractable lanyard for use as a fall restrict device. This permits the free end _g_ portion 30 of the strap 24 to be payed out and automatically retracted in response to the user's movement. The invention can, however, be practised with a strap loop that fastens directly to a body harness, as by securing a releasable hook-like fastener to the free end of the strap. In alternative devices, various connectors, include simply eyelets, can be substituted for the carabiner 26, and such connectors must simply allow the free end of the strap to displace for purposes of tightening and loosening the loop. The exact nature and number of piercing elements is not critical. The planar slotted paddles 38 described and illustrated are preferred for ease of construction and mounting;
however, the broader aspects of the invention can be practised with pole-piercing assemblies of other shapes and having other fasteners for attachment to a strap. Technically the invention can be practised with only a single pole piercing assembly; however, paired assemblies adapted to locate on diametrically opposite sides of a pole are strongly preferred in order to reduce the forces which each assembly must react and to allow the assemblies to be positioned for easy access to their lever portions. A single strap with a single free end for fastening to a harness is preferred for reasons of simplicity and reliability of action. However, for broader aspects of the invention, separate lengths of strap material may be joined with connectors to form more complex loops with one or more free ends fastened to a body harness, but at least one free end that tightens and loosens the strap in response to tension applied through that end. For example, a loop might have a construction somewhat comparable to that described in the Lortie patent except for a fixed connection between the end of the cross-strap and the main strap, and an eyelet or other connector fixed to an end of the main strap that allows the cross-strap to pay through the connector to tighten the loop. Once again, the simple single strap version shown and described is strongly preferred.
FIELD OF THE INVENTION
The invention relates generally to fall restrict devices used by lineworkers when working on wood poles.
DESCRIPTION OF THE PRIOR ART
Lineworkers often climb wood poles that support electric power lines in order to perform construction, maintenance or refurbishment work. To climb such a pole, a lineworker normally wears boots fitted with gaffs that penetrate the pole. The lineworker may also use a pole strap that locates about the pole and fastens to a safety belt worn at the waist. Once positioned to perform work, the lineworker relies on the gaffs to support his or her weight, and relies on the pole strap to be able to lean away from the pole and free his or her arms. A fall restrict device is used to prevent serious injury if footing is lost while climbing the pole, moving around the pole, or supporting oneself in order to perform repairs.
Various fall restrict devices have been proposed. Three commercially available devices are described in U.S. patent no. 4,595,078 which issued on June 17, 1986 to Greenway; U.S. patent no. 5,137,113 which issued on August 11, 1992 to Lortie; and U.S. patent no. 5,141,074 which issued on August 25, 1992 to Sulowoski et al. The Greenway device includes a yoke assembly that locates partially around a pole. The yoke has a tubular main body, and a pair of arms hinged to the main body and carrying sharp projections. Coil springs urge the arms to close about the pole and engage their projections with the pole. Handles on the arms allow the lineworker to disengage the device when moving along the pole. A safety strap extends through eyelets on the handles and has opposite ends fastened to the lineworker's waist belt or harness. This arrangement ensures that the device automatically engages the pole to stop a fall.
The Sulowoski et al device has a main strap that is partially wrapped about a pole with two runs of strap extending back to the lineworker and fastened to a waist belt. A pair of connectors mount an adjustable cross-strap between the two runs of the main strap, to complete a loop around the pole, and a coil spring, which extends circumferentially along the main strap, is fastened to the connectors. The cross-strap can be adjusted to tension the coil spring and form a tight loop around the pole.
The Lortie device is somewhat similar to the Sulowoski et al device. It uses a pair of straps that extend from the lineworker's waist belt.
One strap is wrapped partially around a pole and fastened with a special connector to the other strap. Part of the other strap serves as a cross-belt to complete a loop encircling the pole.
Such prior art fall arrest devices have several shortcomings. The rigid components of the Greenway device make it difficult to manipulate, particularly if work space is limited by an adjacent pole or structure. The device is also difficult, if not impossible, to use on many poles that have multiple lengthwise conduits. The Sulowoski et al and Lortie devices require repeated adjustment if used while climbing a pole, and their performance on iced or multiple conduit poles is also inadequate.
BRIEF SUMMARY OF THE INVENTION
In one aspect, the invention provides a fall restrict device which comprises flexible strap material, preferably a single continuous strap, and connector means for forming the strap material into a flexible loop which tightens and loosens as a free end portion of the loop is pulled respectively away from and toward the pole. Fastener means are provided to secure the free end portion of the loop to a body harness worn by the lineworker. The fastening means preferably comprise a mechanism for automatically retracting and paying out the free strap end portion to accommodate natural movement of the worker while performing required services, but the free end portion may be secured directly to the body harness. A pole-piercing assembly is attached to the strap material. The assembly includes a piercing element positioned to penetrate the pole as the loop tightens, a fulcrum portion positioned to one side of the piercing element, and an elongate lever portion positioned to an opposite side of the piercing element so that the assembly can be manually rotated about its fulcrum portion to disengage the piercing element from the pole. Ideally, a similar pole-piercing assembly is secured to the strap material so that the assemblies engage diametrically opposing sides of the pole.
The fall restrict device of the invention is simple to use. To engage the fall restrict device, the lineworker simply leans away from the pole, and the resulting tension on the free end of the loop engages the piercing assemblies with the pole. To release the fall restrict device, the lineworker simply leans toward the pole to release tension, and then rotates the lever portions to disengage the piercing assemblies from the pole. Should the lineworker slip, his or her weight on the free end of the loop quickly tightens the loop, if otherwise loose, and engages the piercing assemblies to resist his or her fall.
For purposes of this specification, the term "body harness"
should be understood as encompassing a waist belt or more elaborate rigging intended to support the weight of the wearer. The "free end" or "free end portion" of a strap or strap loop should be understood as an end of a strap, or section of strap adjacent to such an end, that extends away from the loop and move freely relative to the loop, particularly toward or away from the loop when the loop is fastened around a pole.
Various advantages and other aspects of the invention will be more apparent from a description below of a preferred embodiment, and will be more specifically defined in the appended claims.
DESCRIPTION OF THE DRAWINGS
The invention will be better understood with reference to drawings in which:
fig. 1 is a fragmented perspective view showing a lineworker using a pole strap together with a fall restrict device;
fig. 2 is an enlarged perspective view of the fall restrict device itself;
fig. 3 is a view of outer surfaces of a pole-piercing assembly associated with the fall restrict device;
fig. 4 is a partially exploded view of inner surfaces of the pole-piercing assembly;
fig. 5 is a horizontal cross-section about the pole showing how the fall restrict device engages the pole; and, fig. 6 is an enlarged horizontal cross-section about the pole showing a pole-piercing assembly can be manually pivoted to pry pole piercing element from the pole, to release the fall restrict device.
DESCRIPTION OF PREFERRED EMBODIMENT
Reference is made to fig. 1 which shows a lineworker 10 on a wood pole 12. The worker 10 is shown leaning away from the pole 12, which is commonly done to free the hands to perform required work. His body weight is supported by gaffs (not shown) attached to his boots and by a conventional pole strap 14 that fastens to a body harness 16 worn by the worker 10. A fall restrict device 18 is mounted about the pole 12. The device 18 is normally oriented substantially coplanar with the pole strap 14, and is fastened to the same body harness 16.
The construction of the fall restrict device 18 is more apparent in the view of fig. 2. The key components are two pole-piercing assemblies 20, 22 which have been used in this application of the invention to convert a conventional retractable lanyard into a reliable fall restrict device. The lanyard includes a flexible synthetic strap 24 and a conventional carabiner 26 which is fastened to one end portion 28 of the strap 24 and adapted to receive the opposing end portion 30 of the strap 24 to form a loop. The lanyard is equipped with a conventional strap tensioning mechanism, mounted to the body harness 16, that pays out and automatically retracts the free end portion 30 of the strap 24. Only a reel 32 associated with the mechanism has been illustrated (in fig. 2), and the free end portion 30 of the strap 24 is wound about and retained on the reel 32. The tensioning mechanism is comparable to those associated with automotive seat belts, allowing the free end portion 30 of the strap 24 to pay out freely under moderate tension, but halting paying out if the strap 24 is suddenly tensioned. Fastening of the free strap end portion 30 to the body harness 16 with such a tensioning mechanism allows the worker 10 considerable freedom of movement, the length of the free strap end portion 30 adjusting automatically to accommodate his movement. However, in other implementations of the invention, the automatic retraction feature may be eliminated, and fastening means may be substituted for the tensioning mechanism that secure the free strap end portion 30 more directly to a body harness.
The pole-piercing assembly 20 detailed in figs. 3 and 4 is typical of both assemblies 20, 22, and components common to the two assemblies 20, 22 have consequently been labeled with like reference numerals in the drawings. The main component of the assembly 20 is a unitary, planar plastic paddle 38. When viewed in an operative orientation fastened to the strap 24, the paddle 38 has an inner face 40 that faces toward and bears against the strap 24 and the pole 12, and an opposing outer face 42. The paddle 38 defines a central support portion 44 whose purpose is to support three piercing elements 46; a fulcrum portion 48 to one side of the support portion 44 and piercing elements 46; and an elongate lever portion 50 to an opposite side of the support portion 44 and piercing elements 46. The piercing elements 46 are conventional bolts whose free ends are machined to sharp points. The piercing elements 46 are inserted through clearance holes 52 in the support portion 44, above and below the strap 24. The piercing elements 46 are extended through an aligned set of clearance holes 54 in a planar, rectangular plastic block 56. The piercing elements 46 are secured to the support portion 44 with nuts, such as the exemplary nut 58 shown in fig. 4, that fit flush within the block 56. The points of the piercing elements 46 consequently protrude from the inner face 40 of the paddle 38, positioned to penetrate the pole 12 when the strap 24 is formed into a loop around the pole 12.
The support portion 44 is formed with a pair of slots 60 through which the strap 24 is interleaved. The term "interleaved" as used in this specification in respect of a strap and pairs of openings may be understood with reference to the relative orientation of the strap 24 and slots 60 shown in figs. 3 and 4. The slots 60 are formed transverse to and spaced apart along a lengthwise axis of the paddle 38. A lengthwise slot 62 (apparent in fig. 4) intersects the transverse slots 60 and facilitates such interleaving of the strap 24.
To attach the assembly 20 to the strap 24, the nuts associated with the piercing elements 46 are removed to expose the lengthwise strap 62, and a side edge of a section 64 of the strap 24 is introduced into the lengthwise slot 62 and worked into the transverse slots 60 so that it bears centrally against the outer face 42 at the support portion 44. The block 56 is then re-attached to the paddle 38, closing the lengthwise slot 62 to prevent the strap section 64 from accidentally releasing from the paddle 38. The assembly 20 can still be positioned along the strap 24 by drawing the section 64 away from the outer surface 42 of the paddle 38, and sliding the paddle 38 relative to the strap 24.
The mounting arrangement permits each of the pole-piercing assemblies 20, 22 to be positioned at any desired location along the strap 24.
In practice, the assemblies 20, 22 should be positioned to accommodate the diameter of a particular pole, and more specifically, to locate the assemblies 20, 22 substantially at diametrically opposite sides of the pole, as shown in fig.
with respect to the pole 12. It should be noted that one piercing assembly 22 is attached to the strap 24 with its lever portion 50 extending in one direction (toward free end portion 30 of the strap 24), and that the other piercing assembly 20, with its lever portion 50 extending in an opposite direction (toward the other end portion 30 of the strap 24). Thus, when the fall restrict device 18 is located around the pole 12, both lever portions 50 extend toward the lineworker 10.
Fig. 4 shows the device in its operative orientation around the pole 12. To achieve that orientation, the worker 10 wraps the strap 24 partially about the pole 12, and locates the carabiner 26 about the free end portion 30 of the strap 24 to form a loop completely encircling the pole 12. The tensioning mechanism to which the free end portion 30 is attached takes up excess slack.
As the free end portion 30 of the loop is pulled radially away from the pole 12, as by leaning quickly away from the pole 12, the loop tightens, drawing the pole-piercing assemblies 20, 22 into firm engagement with the pole 12. The strap 24 bears centrally against the support portion 44 of each paddle 38, ensuring that the piercing elements 46 are drawn forcefully toward and penetrate the pole 12.
The device 18 is very easily disengaged from the pole 12 when the lineworker 10 wishes to climb up or down. The lever portions 50 tend to align with the pole strap 14, and the lineworker 10 can accordingly grip both the pole strap 14 and the lever portions 50 of the device 18 simultaneously. To release the device 18, the lineworker 10 simply leans forward toward the pole 12 to release tension on the strap 24, and pivots the lever portions 50 away from the pole 12. This releasing action is illustrated in greater detail in the view of fig. 6. As the lever portion 50 of the assembly 20 is displaced away from the pole 12, the fulcrum portion 48 of the assembly 20 bears against the pole 12, and the lever portion 50 pivots the entire assembly 20 about the fulcrum portion 48. A significant mechanical advantage is obtained that allows the piercing elements 46 to be easily pried from the pole 12. The lineworker 10 can then climb up or down the pole 12, leaving the fall arrest device 18 loosely looped about the pole 12. Should the lineworker 10 lose his footing, his body weight on the free end portion 30 of the strap 24 re-engages the piercing assemblies 20, 22 with the pole 12, and, in this particular embodiment, the tensioning mechanism associated with strap 24 locks to prevent paying out.
The advantages of the invention relative to the prior art devices discussed above should now be more apparent. The invention lends itself to a very simple construction, which requires no rigid components or biasing springs. Repeated adjustment is not required, as the piercing assemblies 20, immediately position and engage when the loop is tightened by tension on the free end portion 30 of the strap 24. In tests on iced poles and also on multiple conduit poles, the fall arrest device 18 has proven to grip far more reliably than the prior art devices.
It will be appreciated that a particular embodiment of the invention has been described and that modifications may be made therein without departing from the spirit of the invention or necessarily departing from the scope of the appended claims. The embodiment of the invention illustrated involves use of pole piercing assemblies 20, 22 to adapt a conventional retractable lanyard for use as a fall restrict device. This permits the free end _g_ portion 30 of the strap 24 to be payed out and automatically retracted in response to the user's movement. The invention can, however, be practised with a strap loop that fastens directly to a body harness, as by securing a releasable hook-like fastener to the free end of the strap. In alternative devices, various connectors, include simply eyelets, can be substituted for the carabiner 26, and such connectors must simply allow the free end of the strap to displace for purposes of tightening and loosening the loop. The exact nature and number of piercing elements is not critical. The planar slotted paddles 38 described and illustrated are preferred for ease of construction and mounting;
however, the broader aspects of the invention can be practised with pole-piercing assemblies of other shapes and having other fasteners for attachment to a strap. Technically the invention can be practised with only a single pole piercing assembly; however, paired assemblies adapted to locate on diametrically opposite sides of a pole are strongly preferred in order to reduce the forces which each assembly must react and to allow the assemblies to be positioned for easy access to their lever portions. A single strap with a single free end for fastening to a harness is preferred for reasons of simplicity and reliability of action. However, for broader aspects of the invention, separate lengths of strap material may be joined with connectors to form more complex loops with one or more free ends fastened to a body harness, but at least one free end that tightens and loosens the strap in response to tension applied through that end. For example, a loop might have a construction somewhat comparable to that described in the Lortie patent except for a fixed connection between the end of the cross-strap and the main strap, and an eyelet or other connector fixed to an end of the main strap that allows the cross-strap to pay through the connector to tighten the loop. Once again, the simple single strap version shown and described is strongly preferred.
Claims (10)
1. A fall restrict device for use by a lineworker wearing a body harness while working on a wood pole, comprising:
flexible strap material;
means for forming the strap material into a flexible loop that tightens and loosens about the pole as a free end portion of the strap material is pulled respectively away from and toward the pole;
fastener means for fastening the free end portion of the strap material to the body harness; and, a pole-piercing assembly attached to the strap material, the assembly comprising:
(a) a piercing element positioned to penetrate the pole as the loop tightens about the pole; and, (b) a fulcrum portion located to on one side of the piercing element;
(c) an elongate lever portion located to an opposing side of the piercing element such that the assembly can be manually rotated about its fulcrum portion to disengage the piercing element from the pole.
flexible strap material;
means for forming the strap material into a flexible loop that tightens and loosens about the pole as a free end portion of the strap material is pulled respectively away from and toward the pole;
fastener means for fastening the free end portion of the strap material to the body harness; and, a pole-piercing assembly attached to the strap material, the assembly comprising:
(a) a piercing element positioned to penetrate the pole as the loop tightens about the pole; and, (b) a fulcrum portion located to on one side of the piercing element;
(c) an elongate lever portion located to an opposing side of the piercing element such that the assembly can be manually rotated about its fulcrum portion to disengage the piercing element from the pole.
2. The fall restrict device of claim 1 in which the pole-piercing assemblies comprises means for fastening the assembly at various selectable positions along the loop.
3 . The fall restrict device of claim 2 in which the fastening means comprise a pair of openings through which the strap material is interleaved.
4. The fall restrict device of claim 1 in which the pole-piercing assembly comprises:
a generally planar body member with a lengthwise axis, the body member defining the fulcrum portion, the lever portion, and a support portion between the fulcrum and lever portions to which the piercing element is attached; and, a pair of slots spaced apart along and oriented transverse to the lengthwise axis through which the strap material is interleaved.
a generally planar body member with a lengthwise axis, the body member defining the fulcrum portion, the lever portion, and a support portion between the fulcrum and lever portions to which the piercing element is attached; and, a pair of slots spaced apart along and oriented transverse to the lengthwise axis through which the strap material is interleaved.
5. A fall restrict device for use by a lineworker wearing a body harness while working on a wood pole, comprising:
a flexible strap;
connector means attached to one end portion of the strap for receiving the other end portion of the strap thereby to form a loop about the pole which tightens and loosens as the other end portion of the strap is displaced respectively away from and toward the pole;
fastener means attached to the other end portion of the strap for fastening the strap to the body harness; and, a pair of pole-piercing assemblies attached to the strap at spaced-apart locations, each of the pole-piercing assemblies comprising:
(a) a support portion;
(b) a piercing element mounted to the support portion and oriented to penetrate the pole as the loop tightens about the pole; and, (c) a fulcrum portion positioned to on one side of support portion;
and, (d) an elongate lever portion positioned to an opposing side of the support portion such that the assembly can be manually rotated about its fulcrum portion to disengage the piercing element from the pole; and, the lever portions of the assemblies extending in opposite directions relative to the strap such that both of the lever portions extend toward the lineworker when the strap is looped about the pole.
a flexible strap;
connector means attached to one end portion of the strap for receiving the other end portion of the strap thereby to form a loop about the pole which tightens and loosens as the other end portion of the strap is displaced respectively away from and toward the pole;
fastener means attached to the other end portion of the strap for fastening the strap to the body harness; and, a pair of pole-piercing assemblies attached to the strap at spaced-apart locations, each of the pole-piercing assemblies comprising:
(a) a support portion;
(b) a piercing element mounted to the support portion and oriented to penetrate the pole as the loop tightens about the pole; and, (c) a fulcrum portion positioned to on one side of support portion;
and, (d) an elongate lever portion positioned to an opposing side of the support portion such that the assembly can be manually rotated about its fulcrum portion to disengage the piercing element from the pole; and, the lever portions of the assemblies extending in opposite directions relative to the strap such that both of the lever portions extend toward the lineworker when the strap is looped about the pole.
6. The fall restrict device of claim 5 in which each of the assemblies comprises a lengthwise axis and in which, in each of the assemblies:
the support portion comprises an inner face bearing against the strap, an opposing outer face, and a pair of slots;
the piercing element protrudes from the inner face of the support portion; and, the strap is interleaved through the slots such that a section of the strap bears against the outer face of the support portion.
the support portion comprises an inner face bearing against the strap, an opposing outer face, and a pair of slots;
the piercing element protrudes from the inner face of the support portion; and, the strap is interleaved through the slots such that a section of the strap bears against the outer face of the support portion.
7. A pole-piercing assembly for a fall restrict device that employs a loop of strap adapted to tighten and loosen from around a wood pole, comprising:
a rigid body comprising a support portion, a fulcrum portion located to one side of the support portion, and an elongate lever portion located to an opposing side of the support portion;
a piercing element fixed to the support portion; and, securing means for securing the body member to the strap with the piercing element positioned for penetration of the pole as the loop is tightened about the pole.
a rigid body comprising a support portion, a fulcrum portion located to one side of the support portion, and an elongate lever portion located to an opposing side of the support portion;
a piercing element fixed to the support portion; and, securing means for securing the body member to the strap with the piercing element positioned for penetration of the pole as the loop is tightened about the pole.
8. The pole-piercing assembly of claim 7 in which:
the support portion has opposing faces;
the piercing element extends from one of the opposing faces;
and, the securing means are mounted to the support portion and locate the one face of the support portion against the strap.
the support portion has opposing faces;
the piercing element extends from one of the opposing faces;
and, the securing means are mounted to the support portion and locate the one face of the support portion against the strap.
9. The pole-piercing assembly of claim 8 in which the securing means comprise a pair of slots formed in the support portion, the slots shaped and oriented such that the belt can be interleaved through the slots with a section of the belt bearing against the outer face of the support portion.
10. The pole-piercing assembly of claim 9 in which:
the pair of slots are oriented substantially parallel and transverse to a lengthwise axis; and, the securing means comprise a lengthwise slot extending between the pair of slots and intersecting each of the pair of slots such that the strap be inserted edgewise through the lengthwise slot into the pair of slots.
the pair of slots are oriented substantially parallel and transverse to a lengthwise axis; and, the securing means comprise a lengthwise slot extending between the pair of slots and intersecting each of the pair of slots such that the strap be inserted edgewise through the lengthwise slot into the pair of slots.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2313514 CA2313514A1 (en) | 2000-07-06 | 2000-07-06 | Fall restrict device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2313514 CA2313514A1 (en) | 2000-07-06 | 2000-07-06 | Fall restrict device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2313514A1 true CA2313514A1 (en) | 2002-01-06 |
Family
ID=4166662
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2313514 Abandoned CA2313514A1 (en) | 2000-07-06 | 2000-07-06 | Fall restrict device |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2313514A1 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102836538A (en) * | 2012-07-30 | 2012-12-26 | 河南省电力公司信阳供电公司 | Special device for climbing telegraph pole |
| US20150360062A1 (en) * | 2014-06-11 | 2015-12-17 | Edward Anthony Oliver | Personal Positioning Strap System |
-
2000
- 2000-07-06 CA CA 2313514 patent/CA2313514A1/en not_active Abandoned
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102836538A (en) * | 2012-07-30 | 2012-12-26 | 河南省电力公司信阳供电公司 | Special device for climbing telegraph pole |
| CN102836538B (en) * | 2012-07-30 | 2015-09-30 | 国家电网公司 | Electric pole climbs special purpose device |
| US20150360062A1 (en) * | 2014-06-11 | 2015-12-17 | Edward Anthony Oliver | Personal Positioning Strap System |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5141074A (en) | Lineman's pole strap assembly | |
| US7600660B2 (en) | Harness tightening system | |
| US5184696A (en) | Fall arrest belt assembly | |
| EP2544773B1 (en) | Pole climbing fall prevention assembly | |
| CA1269077A (en) | Lineman's safety strap assembly | |
| US8210406B2 (en) | Tool lanyard wrist cuff | |
| US4243350A (en) | Winch load fastening apparatus | |
| CA1231359A (en) | Lineman's safety strap | |
| US7306241B2 (en) | Strap for snowboard boots or bindings | |
| US20100089694A1 (en) | Pole climbing and fall restraint device and kit | |
| US5165499A (en) | Anchor system for use with fall prevention safety devices | |
| US7516976B2 (en) | Strap for snowboard boots or bindings | |
| US9155376B2 (en) | Tool lanyard wrist cuff | |
| US9232849B2 (en) | Tool lanyard wrist cuff | |
| EP1759741A2 (en) | Strap for snowboard boots or bindings | |
| CA2768585C (en) | Fall protection device for use in climbing poles | |
| CA1268504A (en) | Pole climbing aid | |
| US20120292129A1 (en) | Lineman's Pole Strap Assembly | |
| US6752242B1 (en) | Wood pole fall protection device | |
| CA2123517C (en) | Adjustable rope lock | |
| US20070114095A1 (en) | Positioning and safety lanyard device and associated method of use | |
| CA2032399C (en) | Lineman's safety strap assembly | |
| CA2681870C (en) | A pole climbing and fall restraint device and kit | |
| CA2313514A1 (en) | Fall restrict device | |
| CN209828143U (en) | Pole climbing climber capable of quickly fastening foot |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Dead |