Abstract:
An apparatus for releasably attaching all stands or risers of a parachute canopy to a parachutist includes two interlocking plates. The plates incorporate a fulcrum, lever, and alignment tabs, which decrease the amount of force required by the parachutist to release the canopy and hold the plates in position.

Description:
This application claims the benefit of provisional application Ser. No. 60/264,527, filed Jan. 26, 2001. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to a parachute canopy quick release device. 
     Releasing an entangled main canopy from a person or package in free fall is the first step in the sequence of deploying a reserve canopy. If the entangled main canopy is not released, the possibility that the reserve canopy will become entangled with the main canopy is significant. A main canopy may also have to be released after a person/package has landed, in order to prevent the canopy from inflating, due to wind, and dragging the person along the ground. This scenario is particularly important if high winds exist in the landing area. 
     When used by a person, a canopy is attached at the person&#39;s right and left shoulders. 
     Several devices exist in an attempt to release the main canopy. Some prior art devices require the user to separately release a mechanism at each shoulder. These devices require a relatively long period to release, a disadvantage when an individual is falling at terminal velocity at low altitudes. 
     Other devices automatically release the canopy at both shoulders when a person pulls a cord; however these devices are easily assembled in an improper manner and thus prone to failure. 
     Some prior art devices fail in use and only release one side of the canopy and not the other. The user is thus faced with the unpleasant option of trying to clear the malfunction and running out of altitude, or releasing the reserve into the main, with the increased chance of reserve failure. 
     Some prior art devices require lubrication and are thus prone to failure if the lubricant is lacking. An overly lubricated device may stain the canopy&#39;s risers or the user&#39;s clothing. 
     Other prior art devices require a relatively force to activate. Other prior art devices are large, bulky, relatively heavy, or easily fouled by dirt. 
     Multiple problems have been identified with one of the most popular systems, commonly called a three-ring release. The rings may deform under high loads. The rings must have metal-to-metal contact: if the large ring is not in contact with the second ring, but is touching the riser webbing, the load transferred to the small ring and loop is drastically increased. Rings also sometimes deform when the parachutist opens the canopy while falling in an unstable attitude, thereby placing a high load on the rings. Rings must be rotated periodically to prevent elongation or deformation. 
     SUMMARY OF THE INVENTION 
     The invention is a secure and release mechanism that detachably connects two objects together, and includes a male plate with means to attach said plate to attach to a first object; and a female plate with means to attach to a second object, wherein said female plate has means for accepting said male plate. A pocket located at one end of the female plate accepts a lip located on the corresponding end of the male plate; together these form a lever and fulcrum. 
     A means for securing said male and female plates to one another is provided. Said means is constructed in such a manner that when a force is applied to the secured plates by the attached objects, a force is also applied to the means for securing by cooperation of the plates and the fulcrum. The means for securing the said male and female plates also provides a means for releasing said male and female plates from one another by operating the means for securing said male and female plates. 
     Said female plate also incorporates means to prevent lateral movement between said male and female plates, wherein means to prevent lateral movement consists of tabs, and a hole distal to the tabs, wherein said tabs protrude from surface or edges of said female plate and engage with said male plate; the hole distal to the tabs engages with a protrusion in the male plate. 
     The mechanism recited has a means to attach to a parachute canopy and also a means to attach to a parachute harness. When used to link a parachute and parachute harness, two of the mechanisms recited can be used together and the means for release can be combined, whereby a single pull releases both sets of harness or webbing. 
     A secondary means for release, on each apparatus, are combined whereby a single pull on the secondary means releases both sets of harness or webbing. 
     The mechanism then, detachably connects a parachutist to a parachute, and is comprised of a) a female plate with a pocket forming part of a fulcrum; b) a male plate with a lip forming part of a fulcrum; c) said male plate having a protrusion on the end distal to the lip; d) said male plate protrusion having a hole or other means to accept a locking pin or other locking method; e) said locking pin having a primary cord, which when pulled causes release of said pin; f) said locking pin having a secondary cord or other means to cause release of said pin should said primary cord fail to cause release; g) said male plate having holes to accept a strap or straps of a parachute; h) said female plate having tabs along its sides designed to prevent lateral movement of said female plate; i) said female plate having scallops or indentations to provide clearance from straps attached to said male plate; j) said female plate having holes to accept a strap or straps of a parachute harness; k) said female plate having a hole designed to accept protrusion of said male plate. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a front view of a parachutist with the main canopy deployed, showing the canopy, canopy lines, canopy risers, canopy quick release device, pull handle, bifurcated cord, chest strap, parachute harness webbing, and parachutist. 
     FIG. 2 is an enlarged, detailed view of a parachutist with the main canopy deployed, showing the canopy risers, canopy quick release device, pull handle, bifurcated cord, secondary activation means, parachute harness webbing, and parachutist. The chest strap has been omitted for clarity. 
     FIG. 3 is a perspective view of the canopy quick release device of the present invention comprising a female base having a fulcrum, side tabs, oblong hole for parachute harness webbing, and a male removable plate with multiple oblong holes for canopy risers. 
     FIG. 4 is a front view of the male removable plate, showing multiple oblong holes for canopy risers, the hidden male protrusion that fits through the female plate, and the hole for the locking pin. 
     FIG. 5 is a front view of the female base, showing upper lip, multiple scallops for canopy risers, side tabs, hole for male protrusion, and oblong hole for parachute harness webbing. 
     FIG. 6 is the side view of the female base showing the upper lip, side tabs, hole for male protrusion, and hole for parachute harness webbing. 
     FIG. 7 is a side view of the male removable plate, showing a lip, multiple oblong holes for canopy risers, the male protrusion that fits through the female plate, and the hole for the locking pin. 
     FIG. 8 is a side view of the assembled canopy quick release device showing the female base having a fulcrum, side tabs, parachute harness webbing, and a male removable plate with locking pin through protrusion, secondary activation means, and two canopy risers. 
     FIG. 9 is a side view of the assembled canopy quick release device showing the forces acting on the device. 
     FIG. 10 is a front view of the male plate showing an alternative construction method, wherein the tabs are located on the male plate. 
     FIG. 11 is a front view of the male plate showing an alternative construction method, wherein inboard holes are provided for tabs. 
     FIG. 12 is a front view of female base, showing an alternative method of construction. A protruding tab extends from surface of female base. 
     FIG. 13 is a side view of female base, shown an alternative method of construction and alternative profile. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     As required, detailed embodiments of the present invention are disclosed here. However, it is 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 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. 
     This invention includes a male plate and female base and relates to attachment methods of parachute canopies and harness to people and objects. The invention provides a method to quickly detach two objects that are linked together with the invention, and while the example of parachute canopies and related harnesses is used, the invention has other uses as well. For example, people using rappelling gear can use the invention in order to provide a quick release from such gear. As another example, the invention can be used to secure and release the ends of a restraining wire or wires. 
     The means of construction of the device depends on the application and forces placed on it in that application. In critical applications such as parachuting, the device is preferably constructed of a metal such as steel, aluminum, or titanium and is forged. In less critical applications such as fastening the ends of a packing wire together, the device may be stamped steel or molded plastic. 
     The device includes a female half with integrated guides, fulcrum, and holes, and a male half with corresponding mating parts. In the example of a parachutist, the female half is attached to the parachute&#39;s webbing; the male half to the canopy risers. In use, the female half stays attached to the parachutist or package, while the male half separates from it and remains attached to the canopy risers. 
     The top of the female half uses a fulcrum, tabs and holes to align the male half. The female half may have indentations or scallops to provide room for the canopy risers looped through the male half. The bottom of the female half is designed to accept, and hold in place, the corresponding male portion. 
     The male half consists of a plate with attachment points for the canopy risers. The male half has a tongue at its top, which engages the female fulcrum when the two halves are coupled. The male half also has a portion designed to provide interlocking engagement with the female half. This portion, which may be in the form of a protrusion or finger, is held in place by a pin or other mechanical means. When the pin is removed, the male portion disengages from the female portion, and the canopy is released from the parachutist or package. The pin is typically removed by pulling on a bifurcated cord or wire connected to the pin. Should the bifurcated cord become separated from the pin, a secondary means of pulling the pin is provided for. 
     The fulcrum is formed by a lip or pocket on the female half and a lip on the male half fitting into the lip or pocket on the female half. 
     The male and female pieces may be flat, curved or hinged to provide better fit to the user or package. 
     While the drawings include the exemplary embodiments, the drawings are merely meant to be representative of the invention and not absolute with regard to particular profiles, angles, curves, and sizes. 
     Referring to FIG. 1 there is a parachutist  1 , suspended under a canopy  2 . Canopy lines  3  come to a confluence at risers  4 . The risers  4  are linked through assembled canopy quick release device  5  to the parachute harness webbing  6 . Chest strap  7  links parachute harness webbing  6  to prevent parachutist  1  from falling out of parachute harness webbing  6  when canopy  2  inflates. Leg straps  10  support lower body of parachutist  1  during canopy  2  inflation. Pull ring  8  is used to activate canopy quick release device  5 , and is linked to canopy quick release device  5  through bifurcated cord  9 . 
     FIG. 2 shows an enlarged, detailed view of a parachutist  1 , with chest strap  7 , omitted for clarity. Risers  4  are looped through upper oblong hole  13   a , in assembled canopy quick release device  5 . Parachute harness webbing  6  is also fed through lower oblong hole  13   b  of assembled canopy quick release device  5 . To release main canopy  2 , parachutist  1  pulls on pull ring  8 . Pull ring  8  acts on assembled canopy quick release device  5  through bifurcated cord  9 . Should pull ring  8  fail to activate assembled canopy quick release device  5 , parachutist  1  may pull secondary activation device  22  to activate assembled canopy quick release device  5 . 
     FIG. 3 shows an assembled canopy quick release device  5  with tabs  14  protruding from the female base  11 . Upper oblong holes  13   a  in the female base  11  provide a means for connecting parachute harness webbing  6 . The male plate  12  has protrusion  15 , which passes through female base  11 . Lower oblong holes  13   b  in male plate  12  provide connection point for canopy risers  4 . Tabs  14  on female base  11  help align and hold male plate  12  in place. Profile of female base  11  may be curved or flat. Profile of male plate  12  may be curved or flat. Tabs  14  may extend from edges of female plate  11  or extend from edges of male plate  12 . 
     FIG. 4 is a frontal view of the male plate  12  showing upper oblong holes  13   a  for canopy risers  4 . Protrusion  15  contains hole  16 . Locking pin  21  fits in hole  16 . 
     FIG. 5 is a frontal view of the female base  11  showing tabs  14  and scallop  18 . Scallop  18  prevents canopy risers  4  from rubbing female base  11  and becoming abraded. Hole  17  in female base  11  accepts male protrusion  15 . Lower oblong hole  13   b  accepts parachute harness webbing  6 . 
     FIG. 6 is a side view of female base  11 , showing fulcrum pocket  19 , tab  14 , hole  17 , and lower oblong hole  13   b . Alternative profiles of female base  11  are possible. 
     FIG. 7 is a side view of male plate  12  showing fulcrum lip  20 , upper oblong hole  13   a , protrusion  15 , and hole  16 . Hole  16  is for locking pin  21 . Alternative profiles of male plate  12  are possible. 
     FIG. 8 is a side view of the assembled canopy quick release device  5  showing female base  11 , locking pin  21 , upper portion of bifurcated pull cord  9  for locking pin  21 , parachute harness webbing  6 , male base plate  12 , and canopy riser  4 . Secondary activation device  22  can be pulled to remove locking pin  21  should bifurcated cord fail. 
     FIG. 9 is a side view of the assembled canopy quick release device  5  showing the forces acting on the device. Bifurcated pull cord  9 , and secondary activation device  22 , have been omitted for clarity. Female base  11 , male base plate  12 , locking pin  21 , canopy riser  4  and parachute harness webbing  6 , protrusion  15 , and fulcrum lip  20 , are shown. L 1  is the distance between the fulcrum lip  20  and the canopy riser  4 . L 2  is the distance between the fulcrum lip  20  and the top of the protrusion  15 . F c  is the force exerted up by the canopy  2  and also the force exerted down by the parachutist  1 . P is the force required to pull the locking pin  21 . The coefficient of friction μ is between the locking pin  21  and hole  16  in protrusion  15 . F 1  is the force normal to the locking pin  21 , produced by F c . 
     When the parachutist  1  wishes to release the main canopy  2 , he pulls on the pull ring  8 . Pull ring  8  disengages locking pin  21  by action of bifurcated cord  9 . Force F c  causes male base plate  12  to pivot on fulcrum lip  20 . Protrusion  15  passes through hole  17  in female base  11 . Parachutist  1  now falls away from canopy  2 . 
     The force P required to pull locking pin  21  can be calculated as follows. 
     
       
           P=μ×F   1 .  (Equation 1) 
       
     
     F 1  is calculated by taking the summation of moments around the fulcrum lip  20 , or 
     
       
           F   1   ×L   2   =F   c   ×L   1 =summation of torque moments=0.  (Equation 2) 
       
     
     Rearranging equation 2: 
     
       
           F   1   =F   c ×( L   1   /L   2 )  (Equation 3) 
       
     
     Combining equations 3 and 1, we find; 
     
       
           P=μ×F   c ( L   1   /L   2 )  (Equation 4) 
       
     
     Typically, μ=0.1 or less. 
     If L 1 /L 2 =0.25/3=0.0833 and F c =500 lbs, then P=4.166 lbs. 
     FIG. 10 is a front view of male plate  12   a , showing an alternative method of construction. Male plate tabs  14   a  extend down from top surface of male plate  12   a . Upper oblong hole  13   a , protrusion  15 , and hole  16  are shown. Fulcrum lip  20  fits fulcrum pocket  19 . 
     FIG. 11 is a front view of male plate  12   b , showing an alternative method of construction. Tab hole  23  is for protruding tab  24 . Upper oblong hole  13   a , protrusion  15 , and hole  16  are shown. Protrusion  15  helps limit lateral movement. Hole  16  is for pin  21 . Male plate  12   b  constructed in this fashion can be used with either female base  11  or female base  11   a . Fulcrum lip  20  fits fulcrum pocket  19 . 
     FIG. 12 is a front view of female base  11   a , showing an alternative method of construction. Protruding tab  24  extends from surface of female base  11   a . Protruding tab  24  engages tab hole  23  in male plate  12   b . Scallop  18 , hole  17 , and lower oblong hole  13   b , are shown. Hole  17  engages protrusion  15  in male base  12   b.    
     FIG. 13 is a side view of female base  11 , shown an alternative method of construction and alternative profile. Protruding tab  24  extends from surface of female base  11 . Fulcrum pocket  19  engages fulcrum lip  20 . Scallop  18 , hole  17 , and lower oblong hole  13   b , are shown.