Abstract:
A roofing worker safety device is provided that delivers a resistive force in response to a working falling from an elevated work surface such as a roof via a safety cable connecting the worker to the safety device, the cable transmitting the force of the falling worker to the device to activate an arrestor arm that is forced into the surface on which the safety device is placed thereby stopping the fall of a worker from the roof.

Description:
[0001]    This application claims benefit of U.S. Provisional Application, Ser. No. 60/814,121 filed Jun. 16, 2006. 
     
     FIELD OF THE INVENTION  
       [0002]    The present invention relates to fall arresting safety devices generally, and in particular, to a safety device which may be used adjacent a precipice such as a flat roof surface or an upper story of a multi-story building being constructed that has no exterior wall or on the ground adjacent a shaft or well or other precipice. In one typical situation the present invention can be used by roofers and roof repair workers to allow the workers to attach a safety cable to the safety device to allow the workers to move freely about a building roof surface but to provide a resistance to a sudden fall from the roof by a worker to prevent the worker from falling to the ground. In this same manner the device can be used by workers during the construction of a multi-story building prior to the installation of exterior walls or by workers on the ground adjacent a shaft or well or other precipice. 
       SUMMARY OF THE INVENTION  
       [0003]    The fall arrestor assembly of the present invention comprises an arrestor arm having a first end pivotally attached to a support and a second end presenting a toothed gripping plate. A cable or tether connects the worker with the second end of the arm. During normal worker activity the arm is held above the surface, such as a roof, on which the support has been placed by a gas filled cylinder that provides just sufficient pressure to maintain the arm and gripping plate spaced from the surface. Upon a worker beginning to fall from the roof, the tether exerts a pull or a pulling force against the arm having the gripping plate connected thereto. The pulling force is directly proportional to the weight of the worker and the velocity of the worker&#39;s fall. This pulling force overcomes the pressure of the gas filled cylinder and allows the pulling force generated by the falling worker to jamb the gripping plate into the surface to provide a resistance to terminate the fall of the worker. 
         [0004]    In a typical embodiment, the arrestor arm is mounted on a wheeled cart which acts as the support. The cart is intended for use on a roof top and is provided with large rubber wheels so the cart may hold and transport a variety of roofer repair equipment about the roof work area while also providing emergency fall arresting capabilities for the workers who are atop the roof. An embodiment of simplest form, comprises a wheeled cart having the fall arrestor arm mounted thereon with tether or safety cable attachment points to allow workers to attach safety cables to the fall arrestor with the second end of the safety cable attached to the worker. 
         [0005]    It will be appreciated that the wheeled cart allows the arrestor arm to be mobile and to be situated easily and quickly wherever the workers are located. Typically, the work site will be a generally flat roof of a large building upon which the cart holding the arrestor arm can be placed. 
         [0006]    Therefore, it is an object of the present invention to provide an easily mobile fall safety arrestor which may be used by one or more roofing repair workers while at the top of a building for repairing the roof thereof. 
     
     
       DESCRIPTION OF THE DRAWINGS  
         [0007]    Preferred embodiments of the invention, illustrative of the best modes in which the applicant has contemplated applying the principles, are set forth in the following description and are shown in the drawings and are particularly and distinctly pointed out and set forth in the appended claims. 
           [0008]      FIG. 1  is a front and left side perspective view of an embodiment of the present invention mounted on a wheeled cart having a utility box on top of the cart; 
           [0009]      FIG. 2  is a cross section view taken along line  2 - 2  of  FIG. 1  and showing the arrestor arm in the supported position; 
           [0010]      FIG. 3  is a left side and rear perspective view of the arrestor arm removed from the support structure of the cart and showing the arrestor arm in the supported position; 
           [0011]      FIG. 4  shows the arrestor arm of  FIG. 3  in the lowered position for terminating a worker fall by digging into the roof or surface on which the cart of  FIG. 1  is positioned; 
           [0012]      FIG. 5  is a rear and right side perspective view of an embodiment of the present invention with a worker tethered to the fall arrestor and the fall arrestor in the raised or supported position with the fall arrestor attached to a cart on a roof top; 
           [0013]      FIG. 6  is a side view of the embodiment of  FIG. 5  showing the worker tethered to the fall arrestor after a fall from the roof and the fall arrestor in the lowered or engaged position and inserted into the roof to stop the fall or the worker; 
           [0014]      FIG. 7  is a front and side fragmentary view of the throat guide showing an alternative embodiment of the throat guide having a wide mouth to avoid any interference of the throat guide with movement of the cable when a worker is positioned at nearly a ninety degree angle to the throat guide and the arrestor arm; 
           [0015]      FIG. 8  is a top view of the throat guide showing the securing plate being pulled to nearly a ninety degree angle with respect to the throat guide as could happen when a worker is working at an angle to the arrestor; 
           [0016]      FIG. 9  is a front and left side view of a guard which may be used to surround the gripping plate to prevent objects from impeding the operation of the gripping plate; and 
           [0017]      FIG. 10  shows a wheel lock which may be used to prevent movement of a cart that is used to support the arrestor arm and showing the wheel lock in the wheel released position and showing in phantom lines the wheel lock in the engaged or wheel locked position. 
       
    
    
     DETAILED DESCRIPTION  
       [0018]    As required, detailed embodiments of the present inventions are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure. 
         [0019]    Referring now to  FIG. 1 , a perspective view of an embodiment of the present invention is shown. Safety vehicle  10  generally comprises a wheeled cart having front and rear assemblies  12 ,  14  with a steel superstructure  16  mounted therebetween and a tongue or handle  18  attached to front wheel assembly  12 . While not a requirement of the use of the present invention, additional weight may be added to the present invention to increase safety by adding devices such as a utility box  20  to the top of superstructure  16 . Also, a generator (not shown) could be added to the top of superstructure  16 . It will be appreciated by those skilled in the art that safety vehicle  10  is intended to operate without any additional material added onto superstructure  16 , and that the weight and operational features of safety vehicle  10  are sufficient in and of themselves to provide the needed fall arresting capabilities which safety vehicle  10  is intended to provide. It will further be appreciated that while the arrestor arm could operate while attached to a fixed or immobile support, having the arrestor arm attached to a mobile support such as vehicle  10  enhances the ease of use of the arrestor arm 
         [0020]    Referring to  FIG. 2 , fall arrestor assembly  22  is shown positioned between front and rear wheel assemblies  12 ,  14  with front wheel assembly and the front portion of safety vehicle  10  removed for clarity. In  FIG. 2  the general manner a affixing arrestor assembly  22  to a support structure is shown with the arrestor assembly  22  being mounted to vehicle  10  so assembly  22  is clear of wheel assemblies  12 ,  14  and is provided with a clear and unobstructed downward path to allow engagement or gripping plate  36  to contact the surface upon which the cart or vehicle  10  is positioned. In general, the attachment of fall arrestor  22  to superstructure  16  is by welding with the intent being to make arrestor assembly  22  an integral part of vehicle  10 . 
         [0021]    Referring now to  FIG. 3 , the construction arrestor assembly  22  will be described. Arrestor assembly  22 , in its most basic form, is comprised of an arm which pivots at a first end and which is provided with a means for gripping or gouging into or securing itself to a roof or other resilient structure upon which arrestor assembly  22  is positioned above. A cable from the worker is connected to the end of the arm adjacent to the gripping plate to thereby cause a response of the arrestor assembly  22  if the worker exerts a sudden velocity on the cable such as occurs in a fall, the response is the rapid pivoting of the arm downwardly in response to the force of the falling worker. The force of the worker&#39;s fall is transmitted through the cable and causes the gripping plate to pivot downwardly and be thrust into the surface above which arrestor assembly  22  is mounted thereby providing a resistance to further falling of the worker. Specifically, as shown in  FIG. 3 , arrestor assembly  22  is comprised of arrestor arm  34  having a first end  34   a  which is pivotally mounted by pivot pin  38  on securing plate  40  which extends from horizontal member  26 . A second end  34   b  of arm  34  is provided with gripping plate or engagement plate  36  having teeth  36   a  extending on a lower edge of engagement plate  36 . It will be appreciated that engagement plate  36  may, alternatively, be comprised of a generally blunt edge or blunt engagement projection surface in a substitute embodiment with respect to teeth  36   a . Depending on the type of surface on which the arrestor assembly  22  is used, alternative surface engaging portions on engagement plate  36  may be preferred to teeth  36   a . Such a substitution is a matter of choice for those skilled in the art. 
         [0022]    It will be generally appreciated that arm  34  is held in an upward position which is out of contact with any surface, such as a roof, upon which vehicle  10  is positioned. Hereinafter, this upward position in which arm  34  is spaced away from a roof or other support surface will be referred to as the “disengaged position” of arrestor assembly  22 . 
         [0023]    Arrestor arm  34  is held in the disengaged position by arm support  44 . Arm support  44  may be comprised of a hydraulic cylinder or a pneumatic cylinder or a spring to bias arm support  44  into the disengaged position. It will be appreciated that arm support  44  connects between arm  34  and any other conveniently located structure to retain arm  34  in the disengaged position. It also will be appreciated that arm  34  could be maintained in place using a sheer pin to retain arm  34  in the disengaged position until the applied force of a falling worker causes the pin to break thereby allowing the arm to move into the engaged position. 
         [0024]    As shown in  FIG. 3 , arm support  44  connects between arm  34  and cable tunnel or cable throat  28 . The movement of arm  34  between the upward, or disengaged position, and the downward or engaged position ( FIGS. 3 and 4 ) is effected by cable  42 . Cable  42  is connected to an area of arm  34  that is adjacent arm second end  34   b . This connection may be or on or adjacent to engagement plate  36 . A second end of cable  42  is attached to connector plate  30 . On an opposite side of connector plate  30  from the point of attachment of cable  42  are connection eyes  32  to which a worker can affix the safety line which is attached to the worker. While the operation of arrestor assembly  22  will be described in greater detail hereinafter, it will be appreciated that, generally, the force of a falling worker or falling body which is exerted against connection eye  32  is transmitted via connector plate  30  to cable  42  and this force overcomes the resistance of arm support  44  and causes arm  34  to pivot toward the engaged position to force engagement plate teeth  36   a  into the surface upon which vehicle  10  and arrestor assembly  22  are positioned. The gripping of engagement plate  36  in the surface terminates the pivotal movement of arm  34  and provides a resistance against further falling of the worker connected to arrestor assembly  22  by connection eye  32 . 
         [0025]    Referring now to  FIGS. 3 and 4 , the attachment of fall arrestor assembly  22  and the parts making up fall arrestor assembly  22  will be described. First referring to  FIG. 3 , it may be seen that fall arrestor assembly  22  is connected to a vertical member  24  and horizontal member  26 . Vertical member  24  and horizontal member  26  are used to mount the fall arrestor assembly  22  onto vehicle  10 . It will be appreciated by those skilled in the art that vertical member  24  and horizontal member  26  can be a part of vehicle  10  or, where arrestor assembly  22  is manufactured as a separate unit for mounting on a structure supplied by another, vertical member  24  and horizontal member  26  can be incorporated into the construction of arrestor assembly  22  to permit manufacture of a complete arrestor assembly that can be integrated into a pre-existing vehicle of a consumer. 
         [0026]    Attached to horizontal member  26  is arrestor arm  34  having engagement plate  36  attached thereto. Arrestor arm  34  is pivotally connected to horizontal member  26  by pivot pin or attachment pin  38  which connects arrestor arm  34  to securing plate  40  which is attached to horizontal member  26 . Vertical member  24  has a first end connected to horizontal member  26  and has an opposite end connected to cable tunnel  28  or throat. Connector cable  42  passes to connect engagement plate  36  with cable connector plate  30  which is positioned against the opposite end of cable tunnel  28  from the entrance end for connector cable  42 . It will be appreciated by those skilled in the art that it is necessary that arrestor arm  34  having engagement plate  36  thereon be retained in an upward position to avoid dragging and to provide a spaced relation to a roof top or other surface. This spacing is accomplished by the use of arm support  44  which, in one embodiment of the present invention, is a gas cylinder. Arm support  44  provides sufficient resistance to maintain arrestor arm  34  and roof engagement plate  36  in an upward, unengaged position with respect to a roof surface. Attached to cable connector plate  30  is eye  32  which allows convenient attachment of worker safety cables to fall arrestor assembly  22 . 
         [0027]    The two operational positions of fall arrestor assembly  22 , unengaged and engaged, are shown in  FIGS. 3 and 4  respectively. In  FIG. 3 , fall arrestor assembly  22  is in the upward or unengaged position. In  FIG. 4 , fall arrestor assembly  22  is in the engaged position in which arm  34  has pivoted to bring engagement plate  36  forcefully into contact with a roof surface so that teeth  36   a  bite into the roof surface. Typically, arrestor assembly  22  will be in the position shown in  FIG. 3  as it does not engage with the roof or building surface at any time other than when a worker has fallen from the roof of a building. 
         [0028]    Now referring to  FIGS. 5 and 6 , an embodiment of the present invention  10  is shown having a worker safety cable  50  attached to eye  32  of cable connection plate  30 . In  FIG. 5 , arrestor arm assembly  22  is shown in the upward or unengaged position as a worker  60  walks about on a roof  62  of a structure. It will be appreciated that roof  62  will typically be a large work area and that the mounting of arrestor arm assembly  22  on vehicle  10  provides a great benefit to its use in both mobility of the arrestor arm assembly  22  about the roof  62  and in ease of use of the device. The present arrestor assembly is very easy for workers to use as it only require repositioning of vehicle  10  from one work area to another on roof  62 . The present arrestor assembly does not require any lengthy setup or break down for it use. A worker  60  need only position vehicle  10  near the work site and attach the safety cable  50  to eye  32 . This ease of operation is substantially different from prior art devices requiring use of counter weight structures that must be assembled and disassembled. 
         [0029]    Again, referring to  FIG. 5 , the fall arrestor assembly  22 , having roof engagement plate  36  thereon. Arm support  44  holds arm  34  in the upward position during normal work conditions as fall arrestor assembly  22  has not been activated by the fall of an employee  60  from the roof  62  which would cause a forceful downward pull on arrestor arm  34  by safety cable  50  connected to connector cable  42 . 
         [0030]    Referring now to  FIG. 6 , the engagement of fall arrestor assembly  22  during the course of stopping or arresting the fall of a worker  60  from the roof  62  of a building is shown. In  FIG. 6 , after a worker  60  has fallen from the roof  62 , worker safety cable  50  has transmitted the force of the worker&#39;s fall and has pulled arm  34  of fall arrestor assembly  22  downwardly due to the weight of the fallen worker pulling on worker safety cable  50 . This force from the fall of the worker is transmitted to eye  32  to which worker safety cable  50  is attached. Eye  32 , being attached to cable connector plate  30 , transmits the load of the worker&#39;s fall through worker safety cable  50  to connector cable  42  which is attached to cable connector plate  30 . Connector plate  30  then passes this force through cable tunnel  28  to transmit the force of the worker&#39;s fall to arrestor arm  34 . The force transmitted along worker safety cable  50  through eye  32  and to cable plate  30  and then to connector cable  42  reaches arrestor arm  34  and causes a downward force on arrestor arm  34  which pivots downwardly and causes engagement plate  36  to strike roof  62 . It will be appreciated that prongs  36   a  on roof engagement plate  36  are forced into roof  62  thereby adding additional resistance, beyond the weight of vehicle  10  and arrestor assembly  22 , against the pulling force of the worker&#39;s weight on worker safety cable  50 . It further will be appreciated that the previously described force traveling along worker safety cable  50  to arrestor arm  34  overcomes the upward supporting force of arm support  44  to allow arrestor arm  34  to pivot downwardly about attachment pin  38  which secures arrestor arm  34  to securing plate  40  of horizontal member  26 . 
         [0031]    Still referring now to  FIG. 6 , the various operational connections that are employed to bring fall arrestor assembly  22  into action to prevent a complete fall of a worker to the ground will be described. Superstructure  16  is shown supporting fall arrestor assembly  22  thereon with horizontal member  26  placed laterally across superstructure  16  and with vertical member  24  extending from horizontal member  26  and with cable tunnel  28  attached to vertical member  24 . As previously described, worker safety cable  50  is attached to eye  32  which is connected to cable connection plate  30  to which is attached cable connector  42  which extends through cable tunnel  28  to connect with arrestor arm  34  having roof engagement plate thereon. As a result of the weight and force provided by the falling worker on worker safety cable  50 , this force is transmitted through the connections previously described to arrestor arm  34  which is forced downwardly and into roof  62  as arrestor arm  34  pivots on attachment pin  38  which connects arm  34  to securing plate  40  which is attached to horizontal member  26 . In this manner, arrestor arm assembly  22  of safety vehicle  10  becomes securely attached to roof  62  to prevent the fall of the worker for any greater distance than it is allowed by the length of worker safety cable  50 . 
         [0032]    Still referring to  FIG. 6 , it will be further appreciated that a plurality of eyes  32  may be provided on cable connector plate  30  to permit multiple worker safety cables  50  to be attached to safety vehicle  10 . 
         [0033]    Referring now to  FIG. 7 , a variation in the configuration of cable tunnel or cable throat  28  will be described. An examination of the cable throat  28  of  FIG. 3  shows an embodiment of the cable throat in which the cable throat is essentially a rectangular tube which is squared off on either end. In  FIG. 7 , a variation of the cable throat is shown in which the end of the cable throat  28  which contacts connector plate  30  is widened into a mouth-like structure having side walls which are angled outwardly at approximately 45 degrees to the side wall of cable throat  28 . The benefit of the addition of a mouth  64  to cable throat  28  is that an impediment to free cable movement is eliminated. Such an impediment to free cable movement can occur when a worker positions himself at an angle of 45 degrees or greater angle with respect to the side wall of cable throat  28 . In a configuration such as is shown in  FIG. 3  wherein cable throat  28  alone carries connector cable  42 , it is possible for a worker who has improperly moved to an angle of greater than 45 degrees with respect to cable throat  48  to cause a slight slowing down of response of arrestor arm  34  due to this improper positioning of the worker on the rooftop with respect to cable throat  28 . The inclusion of mouth  64  at the end of cable throat  28  reduces or eliminates any potential for slowing of the response through friction of arrestor arm  34 . In  FIG. 8 , it is shown that as connector plate  30  is pulled to one side of cable throat  28  that mouth  64  allows connector plate  30  to be positioned at nearly a ninety degree angle while maintaining connector cable  42  within mouth  64  and cable tunnel  28  and in an unimpeded position to allow an immediate response by arrestor arm  34  to any sudden force that is placed on connector cable  42  by the force of the fall of a worker being transmitted to eye  32  and connector plate  30 . 
         [0034]    Referring now to  FIG. 9 , a guard for engagement plate  36  is shown. Guard  66  spaces workers and equipment from engagement plate  36  thereby avoiding a circumstance in which materials or equipment or body parts of a person come in contact with engagement plate  36  or arm  34  thereby encumbering the efficient operation of arm  34  and engagement plate  36 . It will be appreciated that guard  66  need not extend fully to the ground as engagement plate  36  will travel in an arc which moves inwardly toward the center of vehicle  10 . Therefore, if the foot of a worker, for example, were to extend slightly underneath guard  66 , the movement of engagement plate  36  in an inwardly directed arc would not contact the worker&#39;s foot. 
         [0035]    Referring now to  FIG. 10 , a wheel lock device for use on vehicle  10  is shown. Wheel lock  70  is comprised of handle  72  which is pivotally connected to mounting bracket  74 . Arm  76  extends from handle  72  at generally a right angle, and arm  76  is pivotally mounted to handle  72 . On the unmounted end of arm  76  is clamp  78  which can be fixed and locked against wheel  80  by pressing handle  72  in the direction of arrow A to bring clamp  78  into contact with wheel  80 . The pressure of arm  72  against clamp  78  and wheel  80  causes arm  76  to pivot on shaft  82  and to lock arm  76  into a fixed position holding clamp  78  against wheel  80  thereby preventing movement of wheel  80 . It will be appreciated by those skilled in the art that these clamping wheel locks are quickly accessible and easily released or locked into position thereby, when locked, eliminating any movement of vehicle  10  along a roof top. 
         [0036]    In the foregoing description, certain terms have been used for brevity, clearness and understanding; but no unnecessary limitations are to be implied therefrom beyond the requirements of the prior art, because such terms are used for descriptive purposes and are intended to be broadly construed. Moreover, the description and illustration of the inventions is by way of example, and the scope of the inventions is not limited to the exact details shown or described. 
         [0037]    Certain changes may be made in embodying the above invention, and in the construction thereof, without departing from the spirit and scope of the invention. It is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not meant in a limiting sense. 
         [0038]    Having now described the features, discoveries and principles of the invention, the manner in which the inventive [method or apparatus and method etc] for [doing whatever] are constructed and used, the characteristics of the construction, and advantageous, new and useful results obtained; the new and useful structures, devices, elements, arrangements, parts and combinations, are set forth in the appended claims. It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.