Abstract:
A low profile latch mechanism for use in existing and new parachute quick release couplings of the type having two nested members. The mechanism uses a U shaped latch connected to a lever. In an overlying position of the lever, the members are retained in the nested condition, preventing release of the coupling. A W-shaped spring biases tabs into engagement with apertures in one of the members. The lever is retained in the overlying position by connection with the W-shaped spring. Disengaging the W-shaped spring allows the lever to be pivoted, moving the U shaped latch to a position whereby the members are free to separate.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates generally to couplings having notable utility for connecting and quickly releasing a parachute canopy to a harness. More particularly, the invention relates to a new and improved latch mechanism for retaining the quick release coupling in a coupled condition. 
     A parachute canopy release comprises three major subassemblies: the base coupling member, the outer coupling member, and a latch mechanism which includes a cover. The outer coupling member is sewn permanently to the parachute risers and can not be changed. Consequently, there are large numbers of existing parachutes with these permanently attached outer coupling members. The base member is attached to the parachute harness. The base member is shaped to properly receive and nest or couple with the outer coupling member and therefore can not be changed without also changing the outer coupling member. During use, the outer coupling member is releasably nested with the base member so that the forces generated by the parachute can be transferred through the nested members to the harness. The latch mechanism and cover serves dual functions. In the overlying position it holds the members in the nested position, preventing accidental separation. In the release position, the mechanism allows quick and positive separation of the base and outer members. 
     The latch mechanism and cover is a significant concern in the design of parachute canopy releases. Previous latch mechanisms have extended above the outer member due to the design of their internal parts. Due to the position of the canopy release on the harness, prior latch mechanisms and their covers created a potential for impact with the wearer&#39;s chin during use. In addition, prior canopy releases have used latch mechanisms which contained a number of complex parts, requiring difficult and time consuming manufacturing and assembling steps. As in any life support equipment, reliability of the release coupling is a paramount concern. Finally, as is typical of aerospace applications, weight reduction is a serious consideration. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a parachute canopy release with a lower profile in the coupled position. 
     It is another object of the present invention to provide a parachute canopy latch mechanism and cover, which is simple to manufacture and assemble while still meeting the exacting reliability and actuation force requirements of previous latch mechanisms. 
     It is a further object of the present invention to provide a new and improved low profile parachute canopy latch mechanism and cover which can be retrofitted into existing parachute canopy releases. 
     The canopy release comprises a base coupling member secured to the parachute harness and an outer coupling member secured to the parachute riser. The coupling members are held in the nested position by a “U” shaped latch slide. The latch slide moves within grooves in the base member between a withdrawn position and a position overlying the outer member. In the overlying position the latch slide retains both members in the nested relationship. The latch slide is connected to an operating lever. When the operating lever overlies the outer coupling member, the latch slide is moved to its overlying position. When the operating lever is pivoted outwardly and downwardly, the latch slide is moved to the withdrawn position. 
     The lever is mounted to a “W” shaped spring. The outside arms of the W-shaped spring include tabs. When the operating lever is in the overlying position, the W-shaped spring fits within an outer member cavity and the tabs are biased into apertures within the cavity walls. With the operating lever in the overlying position and the spring tabs biased into the apertures, the canopy release is thereby latched together as a single unit. 
     A lock release fits between the W-shaped spring and the operating lever. When the lock release is moved, the outside arms of the W-shaped spring are compressed, thereby freeing the tabs from the apertures. Continued pulling of the lock release pivots the operating lever outwardly and downwardly, moving the U shaped latch slide to the withdrawn position. 
     Preferably the W-shaped spring is connected to the operating lever by a positioning block. The positioning block extends through a slot in the lock release, thereby slidably capturing the lock release between the positioning block and the operating lever. Also, the lock release may include a lanyard to ease actuation of the mechanism. The latch mechanism also includes a safety cover which snaps over the lanyard and operating lever to prevent accidental release. 
     In the preferred configuration, pulling on the lanyard moves the lock release, compressing the outside arms of the W-shaped spring, and freeing the tabs from the outer member apertures. Continued pulling on the lanyard causes the operating lever to pivot outwardly and downwardly, moving the latch slide to the withdrawn position. With the latch slide withdrawn, the coupling members are free to separate, thereby allowing separation of the parachute and harness. 
     Since the W-shaped spring fits within the outer coupling member and the positioning block extends only slightly above it, the height of the present latch mechanism is reduced when compared to prior assemblies. Since the height of the latch mechanism is reduced, the height of the safety cover which overlies this assembly may similarly be reduced. In addition, the parts of the present mechanism are simple in configuration and easily manufactured and assembled. These advantages are attained with the low profile latch mechanism meeting the same exacting reliability and actuation force requirements of previous latch mechanisms. Finally, the inventive latch mechanism and cover can be retrofitted into previously manufactured coupling members, thereby enhancing existing parachute canopy releases at minimal cost. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other objects and advantages of the invention will be evident to one of ordinary skill in the art from the following detailed description made with reference to the accompanying drawings, in which: 
     FIG. 1 is an enlarged side view of a parachute low profile canopy release in a typical use orientation showing the nested coupling members interconnecting a parachute harness and parachute canopy riser; 
     FIG. 2 is an exploded view of the low profile canopy release of FIG. 1; 
     FIGS. 3 a  and  3   b  are enlarged top plan and side elevational views, respectively, of the positioning block and W-shaped spring lock of a low profile canopy release prior to assembly, while FIGS. 3 c  and  3   d  are corresponding views after assembly; 
     FIG. 4 is a perspective view of the underside of an operating lever of the canopy release showing the assembled W-shaped spring and positioning block mounted thereon, and also showing parts of the lock release with attached lanyard; 
     FIG. 5 is a perspective view of the mechanism of FIG. 4 taken from the opposite end; 
     FIG. 6 a  is a side view, partly in phantom, of the low profile canopy release, with the outer coupling member deleted for clarity, showing the latch mechanism in its closed position and FIG. 6 b  is a side view of the low profile canopy release of FIG. 6 a  showing the latch mechanism in the withdrawn or release position; and 
     FIG. 7 a  is an exploded end view showing the positioning of the lock release over the W-shaped spring and positioning block combination, and FIG. 7 b  is a top plan view of the assembly of FIG. 7 a.   
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The low profile canopy release of the present invention constitutes an improvement over the canopy release structures disclosed in U.S. Pat. Nos. 3,200,463 and 4,684,083. Except as described otherwise herein, the quick release coupling may be identical to the coupling disclosed in the above patents and therefore the disclosures of U.S. Pat. Nos. 3,200,463 and 4,684,083 are incorporated herein by reference. 
     Referring now to the drawings wherein like reference numerals indicate like parts throughout the figures, a canopy release, generally designated as the numeral  10 , is shown as comprising an underlying or base coupling member  12 , an overlying or outer coupling member  14  and a releasable latch mechanism  16  (shown best in FIG. 6 b ) and cover  18  pivotally mounted to the base member  12 . FIG. 1 shows the base and outer members  12 ,  14  in their nested position with the latch mechanism  16  and cover  18  overlying those members. Although only one canopy release  10  is shown and described herein, a parachute harness typically has a canopy release  10  at each side of the harness and both must be released to separate the parachute canopy. In a conventional manner, the underlying member  12  is secured to the straps  20  of the parachute harness and the overlying member  14  is secured to a canopy riser  22  of the parachute canopy (not shown). FIG. 1 is a side view of the low profile canopy release in a typical use position. Thus, the nested members form a link for connecting the canopy riser  22  to the parachute harness. Upon actuation of the latch mechanism  16  of each coupling  10  outwardly and downwardly, with reference to the in use position shown in FIG. 1, its outer member  14  is quickly released from its base member  12  to thereby separate the parachute canopy from the harness. 
     As shown in FIG.  2  and described more particularly in the incorporated patents, the base member  12  has an upper, outwardly and downwardly projecting end flange  24  providing a downwardly opening, concave bearing or groove  26  extending transversely substantially the full width of the base member  12 . The groove  26  is effective for cooperatively retaining the overlying member  14 . At the opposite or lower end  28  of the base member  12 , an upstanding central lug  30  is provided and is spaced from the bearing  26  by an elongated recess  32 . The base member upstanding lug  30  has a generally T-shaped cross-section forming parallel guide slots  34 . 
     The outer member  14  has an upper lip  36  adapted to releasably engage the bearing  26  of the base member  12  and a lower end  38  received within the recess  32  in the base member  12  immediately adjacent the lower upstanding lug  30 . The lower end  38  of the outer member  14  also has an upstanding generally T-shaped lug  40  forming shallow slots  42  aligned with the guide slots  34  when in the nested condition. 
     The members are held in the nested position by a “U” shaped latch slide  44 . The latch slide  44  is slidable in the base member guide slots  34  between an overlying or latching position shown in FIG. 6 a  and a withdrawn position or release position as shown in FIG. 6 b.    
     In the latching position, the free ends of the latch slide  44  extend beyond guide slots  34 , engage slots  42  and overlie the lower end  38  of the outer member  14 , thereby securing the members in the nested position. Upon movement of the latch slide  44  to its withdrawn position and out of engagement with the outer member  14 , the outer member  14  is released to pivot freely about the bearing  26  and separate from the base member  12 . 
     The latch slide  44  is loosely trapped between the parallel arms  48  of an operating lever  46 . The operating lever  46  is part of a releasable latch mechanism  16  which pivots with the operating lever  46 . The latch mechanism  16  also includes a positioning block  50 , a lock release  52  and a W-shaped spring lock  54 . The latch slide  44  is thereby operably connected to be shifted between its upper overlying position and lower withdrawn position by operation of the releasable latch mechanism  16 . 
     The operating lever  46  is mounted to the base member  12  for pivotal movement. The parallel arms  48  of the lever  46  are interconnected to spaced transverse apertures  56  in the lower end  28  of the base member  12  by a pivot pin  58 . The lever  46  can pivot, from a position overlying the outer member  14 , shown in FIG. 6 a , to a withdrawn position disposed generally outwardly and downwardly, with reference to the use position of the canopy release, from the base member  12 . 
     The outer coupling member  14  has an internal central cavity  60  intermediate upper lip  36  and lower end  38 . The cavity has opposing slots  62  provided in the cavity wall  64 . A “W” shaped spring lock  54  is positionable within the cavity  60 . The outside arms  66  of the W-shaped spring lock  54  each include an outwardly bent tab support  68  and a tab  70  (best shown in FIGS. 3 and 7) which is biased into a cavity slot  62 , thereby securing the W-shaped spring lock  54  to the outer member  14 . Preferably, the tabs  70  are angled outwardly as shown in FIG. 7, to further secure the W-shaped spring lock  54  to the outer member  14 . The inner arms  72  of the W-shaped spring lock  54  are provided with apertures  74  (see FIGS.  4  and  5 ). 
     A positioning block  50  has opposing bottom and top ends  76 ,  78  and opposing side projections  80  adjacent the bottom end  76 . The block fits between the inner arms  72  of the W-shaped spring lock  54 , (as shown in FIG. 3) with the projections  80  received within the inner arm apertures  74 , thereby joining the positioning block  50  to the W-shaped spring lock  54 . The positioning block top end  78  includes an upstanding boss portion  82  and a top sliding surface  84  generally orthogonal to the upstanding boss portion  82 . The planar upper end  86  of the operating lever  46  is attached to the upstanding portion  82  as shown in FIG.  2 . The attachment may be, for example, with threaded fasteners  88 . 
     A lock release  52 , shown best in FIGS. 2 or  7   b , is generally tongue shaped with a lower end  90  and an upper end  92 . The lower end  90  securely anchors a lanyard  94 . The upper end  92  of the lock release  52  contains an elongated slot  96  extending along the longitudinal axis of the lock release, and a pair of depending flanges  98  projecting at an angle to the longitudinal axis of the lock release. Preferably, the angle of the depending flanges  98  is complementary to the angle of the outwardly bent tab supports  68  so that a camming relationship is established. As shown in FIGS. 7 a  and  7   b , the elongated slot  96  of the lock release  52  receives the upstanding portion  82  of the positioning block  50 . The lock release  52  is thereby trapped between the sliding surface  84  of the positioning block  50  and the overlying operating lever  46 , and restricted to longitudinal movement relative to a first lock position and a second release position by the upstanding portion  82  within the slot. 
     In the lock release first or lock position, shown in FIG. 7 b , the depending flanges  98  are positioned outwardly of and are adjacent to the W-shaped spring outwardly bent tab support  68 . As the lock release  52  is moved from the first position downwardly toward the second position, the depending flanges  98  cammingly engage the outwardly bent surfaces of the tab support  68  and compress the exterior arms  66  of the W-shaped spring lock  54 , driving inwardly the tabs  70 , whereby the tabs are released from the slots  62  defined within the outer coupling member cavity  60 . Continued tension on the lock release  52  outwardly and downwardly pivots the latch operating lever  46  outwardly and downwardly to the withdrawn position, thereby simultaneously moving the latch slide  44  to the withdrawn position and releasing the nested members  12 , 14 . 
     To facilitate sliding of the lock release  52  and pivoting of the operating lever  46 , a “pop-up” lanyard  94  is fixed to the lower end  90  of the lock release  52 . The lanyard  94  provides an easily gripped attachment for sliding the lock release  52  and pivoting the operating lever  46  outwardly and downwardly. 
     It should be noted that the W-shaped spring lock  54  is substantially, and may be completely, contained within the outer member cavity  60 . Further, the positioning block  50  allows attachment of the operating lever  46  to the W-shaped spring lock  54  in a compact yet effective manner. The lock release  52 , with its depending cam flanges  98 , its positioning between the position block  50  and operating lever  46  and its longitudinal, sliding movement works in synergism with the other elements in the latch assembly  16  to keep the assembly  10  as compact as possible. The net result of this unique arrangement is the creation of a low profile latch assembly which is more compact than previous latch assemblies while retaining functionality with pre-existing coupling members. 
     As seen in FIGS. 1 and 6 a , the safety cover  18  in the overlying position covers the lanyard  94  and operating lever  46  so as to preclude accidental release of the coupling. Referring to FIG. 2, the safety cover  18  is connected to the pivot pin  58  via an interconnecting resilient link or strap  100 . The upper end  102  of the strap  100  is pivotally connected to the cover  18  above a lower pivotal edge  104  of the cover. The strap  100  is formed with a generally cylindrical lower end  106 . The base member lower end  28  is formed with a pair of spaced transverse apertures  56  for engagement by the pivot pin  58 . The generally cylindrical lower end  106  of the strap  100  fits between the spaced apertures  56  and encircles the pivot pin  58 . 
     For mounting the cover  18  in its closed position, the lower edge  104  of the cover  18  is positioned in a transverse groove  108  in the outer face of the upstanding lug  30  and the safety cover  18  is pivoted upwardly and inwardly into an overlying relationship with the operating lever  46  and lanyard  94 . In the overlying position, the cover  18  is held by an over center bias provided by the resilient strap  100 . The safety cover  18  can be manually withdrawn from its closed position by pivoting outwardly and downwardly, as shown in FIG. 6 b . The lanyard  94  will then “pop up” to an upright position where it can be easily grasped. 
     To separate the members  12 ,  14  in use, the safety cover  18  is pivoted outwardly and downwardly around the transverse groove  108  so that it is away from the canopy release  10 . The lanyard  94  will then “pop up” to an upright position where it can be easily grasped. The lanyard  94  is pulled downwardly, which slides the lock release  52  toward the second or release position. As the lock release  52  slides toward the second position, the depending flanges  98  engage and compress the outwardly bent tab supports  68  of the W-shaped lock  54 , freeing the tabs  70  from the slots  62  defined in the outer member cavity  60 . Continued pulling of the lanyard  94  pivots the operating lever  46  outwardly and downwardly to the withdrawn position, simultaneously retracting the latch slide  44 . With the latch slide  44  retracted, the outer member  14  can rotate around the base member bearing  26  and separate from the base member  12 . 
     Accordingly, a canopy release is provided which affords a simple and quick uncoupling operation with reduced height, weight and complexity while retaining the exacting reliability and actuation force characteristics of previous designs. The safety and convenience of the user are thereby enhanced. Further, these improvements may be retrofitted to existing canopy releases. 
     As will be apparent to persons skilled in the art, various modifications and adaptations of the structure above described will become readily apparent without departure from the spirit and scope of the invention, the scope of which is defined in the appended claims.