Patent Publication Number: US-6907894-B1

Title: Collapsible protective shelter device having dielectric and fire-resistant properties

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates generally to collapsible shelter structures and, more particularly, to devices which provide temporary shelter to workers who are exposed to the environment. Specifically, the present invention relates to collapsible protective shelter devices which are both dielectric as well as fire-resistant to offer significant protection to workers who must work around high voltage electricity or in severe weather conditions. 
   2. Description of the Prior Art 
   Utility construction and repair workers must often work in rain, snow and hot sunny weather conditions, often without shelter or other protection from the environment. These working conditions can be on the ground surface or in utility lift buckets which are used to enable the work crews to access high wire connections or terminal boxes. Such working situations expose the workers to extreme environmental conditions which can be detrimental to the workers. 
   As a result, the present practice that is used to provide some environmental protection to such work crews is to employ a large but conventional, six-sided umbrella on a metal or wooden pole for protection from the elements. Such umbrella structures generally use a nylon or canvas canopy material held in place by metal ribs and other metal structural members which provide structural strength in harsh environmental conditions. Examples of typical general umbrella structures are illustrated in U.S. Pat. Nos. 3,692,035, 5,555,903 and 5,765,582. Alternatively, portable pop-up shelters similar to conventional tents for use on utility lift buckets or directly on the ground surface may also be used. These umbrellas or pop-up shelters generally provide sufficient shelter for a single person, although a work crew of two is somewhat cramped. To address the size problem, an alternate shelter assembly is suggested in U.S. Pat. No. 4,766,919 wherein several umbrella-type assemblies are secured together to provide a substantially larger size conventional environmental shelter for use on the ground surface. 
   Regardless of the size or shape of the shelters provided by the various prior art schemes, there is a definite deficiency in protection for the workers in certain working situations. Utility workers frequently work in severe weather situations where power has been interrupted by storms and the like. Such situations should include protection and shelter from not only the environment in general but also the presence of electricity in the form of lightning strikes or from high voltage sources. In the cases where utility workers must work out-of-doors during such severe thunderstorms, lightning strikes offer significant risk which has not yet been addressed by the prior art shelter devices. Moreover, such utility workers are constantly being exposed to high wire voltage sources. Finally, sparks and flying embers are a significant fire hazard to which utility workers are also exposed when working outside. Such sparks and embers can originate from lightning strikes, high wire shorts, residential or industrial fires, and the like. While prior shelter devices have been devised to provide general protection from the sun and the rain, there is still a need for protective shelter devices that not only provide such general environmental protection, but will also provide protection to workers from electrical sources and fire hazards. 
   SUMMARY OF THE INVENTION 
   Accordingly, it is one object of the present invention to provide a collapsible temporary shelter. 
   It is another object of the present invention to provide a protective cover device that is dielectric and affords protection from lightning and high voltage power lines. 
   Yet another object of the present invention is to provide a protective shelter that is also fire-resistant in the event of sparks or embers from high voltage wires or other sources. 
   Still another object of the present invention is to provide such a dielectric and fire-resistant protective shelter device that can be used in any number of varied working situations from utility lift buckets to use directly on the ground surface. 
   To achieve the foregoing and other objects and in accordance with the purpose of the present invention, as embodied and broadly described herein, a dielectric, fire-resistant shelter apparatus is disclosed. This shelter apparatus is designed to afford temporary protection to individuals exposed to the open environment. The shelter apparatus includes a protective canopy which is movable between an open position for providing temporary cover and protection to individuals exposed to the environment, and a closed collapsed position for storage. The canopy is substantially dielectric and resistant to fire. A plurality of ribs interconnect with each other to support the canopy in its open position. Moreover, a plurality of struts are secured for supporting the ribs and canopy in the open position and for enabling the ribs and canopy to move to the closed collapsed position. Finally, at least one support element is provided for maintaining the relative positions of the struts, ribs and canopy when in the open position above a ground surface, the support element also being dielectric. 
   In one preferred aspect of the invention, the ribs, struts and support element are all dielectric. Moreover, the canopy, which is both dielectric and fire-resistant, may be in the form of a single layer of flexible material which is both dielectric and fire-resistant, or it may be in the form of at least a double layer of flexible material having an outer layer of fire-resistant material and an inner layer of dielectric material. In a more preferred form, the canopy outer layer is siliconized rubber and the inner layer is woven fiberglass fabric. 
   In one preferred structure of the invention, the canopy is a tent-like structure sized and shaped for placement on a ground surface. This structure includes an upper cover portion which is maintained in an open spread-out position by the ribs, and a pair of side portions which depend from the cover portion and are secured thereto by the struts. The side portions are maintained in position on the ground surface by at least a pair of the support elements. Moreover, each side portion may be attached to the ribs and cover portion by a plurality of the struts and maintained in an upright position above the ground surface by a pair of the support elements. 
   In another structure of the invention, the canopy includes a cover member which is adapted for covering an industrial utility lift bucket. This structure of the invention includes a plurality of ribs which are adapted to maintain the cover member in an open, substantially flat condition. A plurality of struts are secured to hold the ribs in position, and a plurality of the support elements secure the ribs and struts to the bucket. 
   In yet another preferred structure of the invention, the protective canopy is in the form of an umbrella cover attached to the ribs. The apparatus further includes a hub member which is mounted on a single support element for longitudinal movement therealong. The hub member is secured to the struts for moving the umbrella cover between an open position, wherein the canopy is extended radially outwardly from the support element with the cover being supported by the ribs, and a closed position wherein the umbrella cover resides in a collapsed folded position substantially alongside the support element. 
   A further structure of the invention is in the form of a collapsible protective cover device offering temporary shelter to individuals while working in the outside environment. The device includes a flexible canopy covering which is movable between an open position wherein the canopy is expanded to provide temporary cover and protection to individuals exposed to the environment, and a closed, collapsed position for storage. The canopy covering is made from a material which is substantially dielectric and fire-resistant. A plurality of ribs are disposed to support and maintain the canopy covering in an open expanded position. In addition, a plurality of struts are secured to the ribs for supporting the canopy covering in its open position and are adapted to enable the ribs and canopy covering to move to a closed collapsed position. Finally, at least one base support element maintains the relative positions between the struts and ribs and the canopy covering when the canopy covering is in an open position above a ground surface. The base support element is made from a substantially dielectric material. 
   In still another structure of the invention, a foldable industrial umbrella is provided for use as a protective shelter for temporary protection by individuals working in the out-of-doors environment. The umbrella includes an elongate support element in the form of a pole having an upper end and a lower end. A flexible canopy sheet is movable between an open position wherein the canopy sheet is extended radially outwardly from proximate the upper end of the support element pole to provide temporary cover and protection to individuals exposed to the environment, and a closed, collapsed position folded substantially alongside the support element pole for storage. The canopy sheet is made from a material which is substantially dielectric and fire-resistant. A plurality of ribs are attached to the canopy sheet and disposed to support and maintain the canopy sheet in its open expanded position and in its closed folded position. A plurality of struts are secured to the ribs for supporting the canopy sheet in its open position and are adapted to move the ribs and canopy sheet to a closed collapsed position. Finally, the support element pole is made from dielectric material to electrically insulate the lower end of the support element pole from the struts, ribs and canopy sheet. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The accompanying drawings which are incorporated in and form a part of the specification illustrate preferred embodiments of the present invention and, together with a description, serve to explain the principles of the invention. In the drawings: 
       FIG. 1  is a front perspective view of one umbrella embodiment of the present invention installed onto a utility lift bucket and in its open position; 
       FIG. 2  is a side sectional view of the umbrella embodiment of  FIG. 1  and taken substantially along line  2 — 2  of  FIG. 4 ; 
       FIG. 3  is an enlarged perspective view of the hub member for attachment of the ribs of the umbrella embodiment illustrated in  FIG. 2 ; 
       FIG. 4  is a top plan view of the umbrella embodiment illustrated in  FIG. 1 ; 
       FIG. 5  is an enlarged cross-sectional view of one umbrella cover sheet embodiment of the invention as taken substantially along line  5 — 5  of  FIG. 2 ; 
       FIG. 6  is a cross-sectional view substantially similar to that illustrated in  FIG. 5  but showing a one-layer cover sheet embodiment; 
       FIG. 7  is a front perspective view of another umbrella embodiment of the present invention installed for use on the ground surface; 
       FIG. 8  is a perspective view of another cover device embodiment constructed in accordance with the present invention and illustrating its use on a utility lift bucket; and 
       FIG. 9  is a perspective view of yet another embodiment of the invention constructed in the form of a tent-like structure for use on the ground surface. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   As previously described, the present invention is directed to a collapsible, protective shelter device which is primarily designed to provide temporary protection to people, and in particular utility workers, while they are working in the out-of-doors. Utility workers are particularly emphasized because they must work in the open environment under all sorts of good as well as bad weather conditions. However, it should be understood that the present invention may be used as a protective shelter or covering device for anyone under any type of circumstances. Moreover, the present invention is specifically designed to provide protection from electric shock and fire, two dangers that are very real in the lives of utility workers. Electric shock can come from touching a utility lift bucket or a protective umbrella or other shelter to a high voltage wire or from being struck by lightning during a storm. Fire can originate from sparks or embers arising from damaged high voltage wires, from lightning strikes, or from nearby structural fires. In any event, the device of the present invention not only offers protection from the typical environmental concerns such as rain, snow and hot sunny weather conditions, but even more importantly it offers protection from electric shock and fire. 
   Referring particularly now to  FIGS. 1–5 , a shelter apparatus  10  is illustrated. In one preferred form, the apparatus  10  is in the form of an umbrella  12  having a flexible covering member  14  which is adapted to provide the cover or shelter for the device  12 . The protective cover member or canopy  14  is preferably a flexible material and is made from material which is both dielectric as well as fire-resistant as described in greater detail below. In this manner, should the cover member or sheet  14  come into contact with a high voltage wire or other electrical source, the cover sheet  14  will not conduct the electricity through the remaining portions of the device  12  and to a worker standing beneath the device  12  as described further below. 
   The umbrella cover sheet or canopy  14  is supported by a plurality of ribs  16  which are preferably arranged in a radially extending, fan-like manner along the underside  18  of the cover member  14 . In this manner, the cover sheet  14 , although flexible, is maintained in a fully extended position when the device  12  is in its open position as illustrated in  FIGS. 1–4 . In preferred form, the ribs  16  may be attached to the underside surface  18  of the cover sheet  14  in any known manner in the art. The ribs  16  are attached at their outer distal ends to the outer edge  20  of the cover member  14 , while the inner ends  22  of the ribs  16  are secured to a central attachment bracket  24 . The inner end  22  is preferably attached to the bracket  24  in a manner so that the ends  22  may pivot to enable the umbrella  12  to be moved between an open position and a closed position as described below. In preferred form, the ribs  16  and the bracket  24  are substantially nonconductive or dielectric, with the ribs  16  being made from wood, aluminum or fiberglass, and preferably fiberglass, while the bracket  24  is preferably made from a polycarbonate material. 
   A plurality of struts  26  are provided to control the movement of the ribs  16  and the cover member  14  when the device  12  is moved between its open position and its closed position. The outer distal end  28  of each strut  26  is preferably secured to a rib  16  at proximately the mid-portion of its length. The inner end  30  of each strut  26  is secured to a central hub  32  for movement therewith. In preferred form, the struts  26  and the central hub  32  are substantially nonconductive or dielectric, with the struts  26  being made from wood, aluminum or fiberglass, and preferably fiberglass, while the hub  32  is preferably made from a polycarbonate material similar to the bracket  24 . 
   In preferred form, a support element  34  in the form of a pole is provided for supporting the umbrella device  12  is its desired position. The hub  32  is positioned to move along the length of the pole element  34 , thereby moving the inner ends  30  of the struts  26  upwardly and downwardly along the length of the pole element  34 . When the hub  32  is moved upwardly toward the attachment member  24 , the outer ends  28  of the struts  26  are moved away from the pole element  34  and in turn push the ribs  16  and the cover member  14  away from the pole element  34  until the cover member  14  is substantially taut. The hub  32  is held in this open position by a release catch  35 . Likewise, when the hub  32  is released from the catch  35  and moved downwardly along the pole element  34 , the ribs  16  and the cover member  14  are folded in toward the pole element  34  until the ribs  16  and the struts  26  reside substantially alongside the pole element  34  for folding and storage. A stop member  37  limits the downward movement of the hub  32  along the pole  34 . This is typical of general umbrella construction and behavior. 
   In preferred form, the support element or pole  34  is made from dielectric material so as to not to conduct electricity along its length. While any type of appropriate dielectric material may be used in the present invention, the preferred materials for the support element include wood, fiberglass or aluminum, which are strong yet electrically substantially nonconductive. More preferably, the support element  34  is made from fiberglass, which is virtually completely electrically nonconductive. Moreover, the struts  26  are likewise preferably dielectric and preferably made from fiberglass. In the more preferred form, the support element  34  and the struts  26  are both made from non-conducting fiberglass. In this manner, the primary support structure of the apparatus  10 , i.e. the pole  34  and the struts  26 , is preferably entirely dielectric and therefore electrically nonconductive. Furthermore, as previously mentioned, it is also preferred that the ribs  16  be made from dielectric material the same as that of the struts  26 . 
   The cover sheet  14  of the device  12  is preferably both dielectric as well as fire-resistant. To accomplish this task, the cover sheet  14  is preferably made from appropriate materials. Referring particularly to  FIGS. 5 and 6 , the one embodiment of  FIG. 5  illustrates two layers  36 ,  38  of material for the cover member  14 . The outer layer  36  is preferably made from a fire resistant or retardant material such as siliconized rubber, although any type of appropriate fire-resistant fabric material known to the art may be used. The inner layer  38  is preferably made from an electrically nonconductive, dielectric fabric such as woven fiberglass, although any type of appropriate dielectric fabric material known to the art may be used. In this manner, the two materials will provide a synergistic effect of being both electrically nonconductive as well as resisting fire when exposed directly thereto. It should also be understood that the inner layer may be the fire-resistant layer while the outer layer may be the dielectric material. In an alternative from, a single layer  40  may be used as a cover sheet  14  provided the material  40  is a combination of a fire-resistant material which is also substantially dielectric. In this manner, should the cover sheet  14  come into contact with an electrical source, the electricity will not be passed therealong to the pole  34  and the workers  52  positioned beneath the device  12 . Moreover, should sparks or embers strike the cover sheet  14 , a fire will be prevented due to the fire resistant qualities of the cover member. 
   In the preferred structure of the invention, the two-layer form for the cover sheet  14  illustrated in  FIG. 5  is preferred. In this embodiment, the material  36  is preferably siliconized rubber. More preferably, the material  36  is cured vinyl rubber which is layered or coated over a layer  38  of woven fiberglass fabric. One preferred source of this combination layered material is known as Aramatex SF7, a trademarked product distributed by Mid-Mountain Materials of Seattle, Wash. Another specific product which may be used in this capacity is No-MEX, a trademarked product of the 3M Company. An umbrella structure constructed in accordance with the invention described above was tested by Sturgeon Electric Company of Colorado. This test was performed on the structure of a wet umbrella device  12  using a Chance hot stick tester rated at 100,000 volts per foot. The results of these tests indicated that the structure of the invention did not conduct electricity therethrough and withstood any fire problems as well. 
   Referring to  FIG. 1 , the umbrella device  12  is preferably attached in one form to a receptacle  42  which is removably bolted to a leg  44  of a utility lift bucket  46 . The receptacle  42  includes a tubular receiver  48  which is sized and shaped to removably receive either the lower end  50  ( FIG. 2 ) of the support element or pole  34 , or an extension  49  which in turn holds end  50 . In this manner, the device  12  is firmly implaced during its use yet it can be readily removed when desired. Thus, an operator  52  of the bucket lift  46  is free to use his hands as necessary yet he is protected from the general elements of the environment such as rain, snow and sun. In addition, the operator  52  is protected from electric shock should any part of the umbrella device  12  come into contact with a high voltage wire or lightning. Finally, should the device  12  be exposed to sparks or embers, the device  12  will not only protect the operator  52  from being struck by these items, but it will also keep from being set afire due to its fire resistance. 
   Referring now to  FIG. 7 , an alternate embodiment for using the umbrella device  12  of  FIG. 1  is illustrated. In this particular embodiment, the umbrella device  12  is as described in the previous  FIGS. 1–5 . However, the lower end  50  of the support element  34  is placed into a receptacle  56  which in turn is pivotally secured to a tripod device  58 . The tripod device  58  preferably includes a length adjustable shaft member  60  and three collapsible tripod legs  62  extending from the lower end portion  63  of the shaft member  60 . In this manner, the umbrella device  12  can be positioned on a ground surface  64  to provide environmental, electrical and fire protection to a worker  66  who must work on the ground as opposed to in the air in a utility bucket as in the prior embodiment. 
   Referring now to  FIG. 8 , an alternate structure for the present invention is illustrated. In this embodiment, a shelter device  70  is provided for a utility lift bucket  36  as in the prior embodiment of  FIG. 1 . However, in this embodiment the device  70  includes a cover member or canopy  72  in the form of a substantially flat sheet made from the dielectric and fire-resistant material as previously described and specifically illustrated in  FIGS. 5 and 6 . The cover sheet  72  is maintained in its extended flat position over the bucket  36  and the worker  52  therein by a plurality of ribs  74  similar in construction and function to the ribs  16  of the previous embodiment. The ribs  74  are secured to the cover sheet  72  to hold it in its open position, and the ribs  74  are in turn maintained in place by a plurality of struts  76  similar to the struts  26  of the prior embodiment. The struts  76  are secured at one end to the ribs  74  and at their opposite ends, in turn, to a plurality of support elements  78 . The support elements  78  are attached to the bucket  36  as illustrated. The support elements  78  are similar in material construction to the support element  34  of the previous embodiment in that the support elements  78  are preferably dielectric and made from fiberglass. Likewise, the struts  76  are preferably dielectric and made from the same material as the support elements  78 , and the ribs  74  may also be made from the same dielectric material. In this manner, an alternate form of structure may be utilized to provide environmental protection to the worker  52  in the bucket  36  as well as electrical and fire resistant protection. 
   Referring now to  FIG. 9 , a further embodiment of the invention is illustrated herein. In this embodiment, the dielectric and fire-resistant device  80  is in the form of a tent-like structure for placement on a ground surface  64 . In this embodiment, the device  80  includes a cover portion or canopy  82  which is made from dielectric and fire-resistant material similar to the canopies  14  and  72  and as specifically illustrated in  FIGS. 5 and 6 . The cover portion  82  provides the primary protection for any worker positioned thereunder and is maintained in its spread-out or extended position by a plurality of ribs  84  placed under the edges of the cover portion  82 . The ribs  84  are constructed similar to the ribs  16  and  74  of the prior embodiments, are attached to the cover portion  82 , and serve in the same capacity of maintaining the cover portion  82  in its extended and open position. The ribs  84  are in turn attached to a plurality of struts  86  which, similar to the struts  26  and  78  of the prior embodiments, are preferably made from dielectric material such as fiberglass. 
   In this embodiment, the device  80  includes a pair of side portions  88 ,  90  which depend from the cover portion  82  and are secured to the ground surface  64 . The side portions  88 ,  90  are preferably made from the same dielectric and fire-resistant material as the cover portion  82  and provide enhanced protection for individuals positioned within the device  80 . The struts  86  assist in holding the side portions  88 ,  90  in position tautly beneath the cover portion  82 . The struts  86  are in turn secured to a plurality of support elements  92  which attach the device  80  to the ground surface  64 . In preferred form, the support elements  92  are similar to the support elements  34  and  78  of the prior embodiments in that they are preferably made from dielectric material such as fiberglass. In this manner, the electrical insulating capability of the device  80  is primarily provided by the cover portion  82 , the side portions  88 ,  90 , the struts  86  and the support elements  92 . In one preferred form, each side portion  88 ,  90  is supported by a pair of support elements  92  foldably secured to the struts  86  with a connector device  94  of known design. Rear door flaps  96  and front door flaps (not illustrated) can also be incorporated into the design of this embodiment. 
   As can be seen from the above, utility workers frequently work in severe weather situations where power has been interrupted by storms, and the presence of electricity in the form of lightning strikes or from high voltage sources is an ever present danger. In the cases where utility workers must work out-of-doors during such severe thunderstorms, lightning strikes offer significant risk. Moreover, such utility workers are constantly being exposed to high wire voltage sources. In addition, sparks and embers are a significant fire hazard to which utility workers are also exposed when working outside in emergency situations. As can be seen, the present invention is a shelter device that provides workers, and in particular utility repair or construction workers, general protection from the environment such as from the sun, snow and rain. However, the present invention more importantly provides protection to workers from electrical sources and fire hazards due to the fact that it is dielectric and fire-resistant. As previously detailed, utility workers are frequently exposed to electrical and fire dangers while performing important repair or construction work, and the present invention not only provides environmental protection and comfort, but it also protects workers against exposure to such dangers. Finally, the present invention with its electrical and fire protection capabilities can be formed in a variety of structural configurations to permit its use on a utility lift bucket or on the ground surface in a number of different situations. 
   The foregoing description and the illustrative embodiments of the present invention have been described in detail in varying modifications and alternate embodiments. It should be understood, however, that the foregoing description of the present invention is exemplary only, and that the scope of the present invention is to be limited to the claims as interpreted in view of the prior art. Moreover, the invention illustratively disclosed herein suitably may be practiced in the absence of any element which is not specifically disclosed herein.