Abstract:
The present invention  10  discloses an emergency descent system for a tall building  12 . The high rise emergency descent system is comprised of at least one track  18  fixedly attached to the exterior of a building  12  and a jumpsuit  20  having an integral harness  22  and descent device  23  connected to the suit by means of a cable  36  that will allow the user  12  to don the apparel having a first preselected drag brake  52  designed for a weight class that is reflected in the size of suit, and, to attach the descent device  23  to the descent track 18  and descend to the ground at a controlled rate. A second brake control  26  is provided for allowing the user  16  more individual brake control during the descent down the building  12.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to escape systems and, more specifically, to a high rise emergency descent system. The high rise emergency descent system is comprised of at least one track fixedly attached a tall building and a device for attachment thereto whereby a person can put on a jumpsuit having an integral harness and descent assembly that will allow the user to attach to the descent track and descend to the ground. 
     The system is based on providing a descent device that considers the variations of individual weight of the users. Each descent device has a drag brake that controls the rate of descent of the user. The drag brake is comprised of a brake pad under pressure engaging the descent track as the user descends to the ground. 
     To insure the correct mating between a descent device and a user the descent device is permanently attached to a jumpsuit or other compatible apparel that is donned by the user having an integral harness and descent device attached thereto. The size of the jumpsuit correlates directly to the duty rating of the pressured descent device. Therefore a smaller suit incorporates a lesser pressured brake than a larger suit having a greater pressured brake. Therefore, the descent rate can be equalized for a mixture of individuals by providing a plurality of jumpsuits having a pressured drag brake for that size of individual. 
     At the point of departure a plurality of various sized descent apparel can be stored and as individuals arrive they would select the appropriately sized garment, don the garment, move to the point of departure, and attach the descent device to the track and under a controlled descent move to the ground. 
     The descent device also incorporates an additional braking mechanism comprised of a hydraulic piston that moves a brake pad into an engaging position with the descent track. The hydraulic piston has control means attached to the descent device that is user controlled. Therefore, users can effect the rate of descent by engaging the control mechanism for the hydraulic brake. 
     The descent device is a substantially C-shaped device having opposing channels on the backside that hold and guide the descent device along the descent track. Extending transversely from the descent device are handle grips providing means for a user to hold and steady themselves while traveling along the descent track. The handle grips can incorporate a control mechanism for the hydraulic brake providing means whereby the user can control their rate of descent along the descent track. The brake mechanism has connection means for controlling the application of the brake pads to the descent track using a hydraulic cylinder mounted on the descent device and in fluid connection with a brake pad. 
     2. Description of the Prior Art 
     There are other fire escape devices designed for evacuating a building. Typical of these is U.S. Pat. No. 489,463 issued to Coker on Jan. 10, 1893. 
     Another patent was issued to Grossmann on Apr. 4, 1905 as U.S. Pat. No. 786,641. Yet another U.S. Pat. No. 4,121,689 was issued to Bonvin on Oct. 24, 1978 and still yet another was issued on Nov. 14, 1978 to Hatala as U.S. Pat. No. 4,125,172. 
     Another patent was issued to Graham on Oct. 20, 1981 as U.S. Pat. No. 4,295,543. Yet another U.S. Pat. No. 4,350,224 was issued to Jochum et al on Sep. 21, 1982. Another was issued to Vilchek on Sep. 27, 1983 as U.S. Pat. No. 4,406,349 and still yet another was issued on Feb. 19, 1985 to Milne et al as U.S. Pat. No. 4,499,966. 
     Another patent was issued to Armstrong on Dec. 16, 1986 as U.S. Pat. No. 4,629,032. Yet another U.S. Pat. No. 4,709,782 was issued to Lipinski on Dec. 1, 1987. Another was issued to Darnell et al on Oct. 15, 1991 as U.S. Pat. No. 5,056,619 and still yet another was issued on May 26, 1992 to Chouest as U.S. Pat. No. 5,115,885. 
     A portable fire escape comprising a suitable frame, means for suspending a person therefrom, a circumferentially recessed brake wheel or drum journaled in said frame, a cable having one end secured to said brake wheel and adapted to be wound thereon with in said recess, and a flexible band partially encircling the brake-wheel and extending across the recess; said band having one end fixed and the other end secured to an operating lever for tightening the band, substantially as described. 
     The combination, with the vertical wall of a building structure, of a lift, grooved guides for the lift set into said wall, and lift-ropes connected with the lift and arranged in said guides, substantially as described. 
     An escape mechanism for enabling a person to escape at any floor of a building, the escape mechanism including a vertically disposed hollow rail and at least one rack disposed within the rail. At least one running and suspension apparatus is adapted to be introduced within the rail, where the apparatus is equipped with support members and includes an engagement portion having at least one pinion. The pinion engages the rack to allow the apparatus to move along the rail only upon rotation of the pinion. The engagement portion includes impeding assemblies having inertial escapement members for hindering the rotation and for slowing the descent of the apparatus by gravity while the engagement portion is engaged within the rail. 
     A riding emergency or fire escape apparatus mountable interior of a building for delivering an inhabitant exterior of the building for free fall descent to the ground. The apparatus of this invention exterior of the building essentially comprises plate members mounted in a recess provided in the wall of the building or spaced from the wall of the building a few inches so as not to detract from the architecture of the building. A base plate is provided with a vertically extending zigzag track. A cover plate overlaying and planularly spaced from the base plate is formed with a vertically extending lineal track. The passenger transport mechanism is provided with a chair and is mountable interior of the building. Similarly arranged base and cover plates containing zigzag tracks and lineal tracks respectively, are provided at each floor level interior of the building. The tracks of the respective plates align with the corresponding tracks in the fire escape structure exterior of the building through an openable door at each floor level. The passenger transport mechanisms stored at each floor level, comprise a chair connected to a vertically disposed roller trolley frame which is provided with rollers which ride the zigzag track for a slowed down free fall descent while a second roller rides in the vertical track so that the passenger chair is restrained to a lineal vertical descent. 
     A fire escape apparatus comprises a vertically extending channel member defining a channel into which opens a slot formed between flanges constituting a front wall of the channel member. Rows of staggered projections within the channel are formed by bolts extending between the flanges and a rear wall of the channel member. A harness for supporting a person escaping in the event of fire or other emergency is suspended from a T-shaped support including a cross-piece, and an upright. In use, the cross-piece and upright are introduced into the channel through the slot. A lug on the upright projects through the slot and limits side-side movement as the harness support descends under the weight of the person escaping, the cross-piece co-operating with the bolts to perform a stepping movement. 
     A rescue for a multi-floor building includes an upright climb rail assembled of profiled rail sections defining two lateral cooling channels and an upright tooth rack extending around the entire length of the rail; a rescue cabin includes a projecting frame insertable into a front guiding slot in the rail and supporting a driving gear engaging the upright tooth rack; the frame of the cabin overlaps safety windows provided on each floor of the building and has an entrance opening facing the windows. 
     An emergency escape apparatus includes a gear track mounted vertically on an exterior surface of a building. A carriage is provided with guide rollers which engage a guide track oriented adjacent and parallel to the gear track. A gear wheel is rotatably mounted on the carriage and is maintained in positive engagement with the gear track by the guide rollers. The carriage includes automatic brakes which serve to limit the maximum downward velocity of the carriage, and a boatswain&#39;s chair is attached to the carriage to secure one or more persons to the carriage for transport down the outside of the building. 
     A gravity operated emergency system for a multi-story building is disclosed including an elongate track having a central rack which is disposed along an outside wall of the building. A traveler is provided which moves along the track and has a pinion which rotatably engages the rack. A pair of bearing members engage opposite sides of the track and these bearing members are pivotally attached to the traveler so that as the pinion is brought into contact with the rack the bearing members clear the respective sides of the track and when the pinion is fully engaged in the rack the bearing members are resiliently urged into contact with an inside face of the track. A velocity control mechanism is provided to control the rotational speed of the pinion in the rack, and hence the speed of the traveler relative to the track. During an emergency, the user is received in a harness which is connected to the traveler and the traveler slowly lowers the user to safety along the track. 
     The present invention contemplates a descent device including a roller having an annular groove about its contact surface, a support structure to which the roller is rotatably attached, a pinion gear rotatably attached to the support structure, a rotor disk directly coupled to the pinion gear, a braking device coupled to the support structure for controlling the speed of rotation of the rotor, a hand held actuator for activating the brake device, and a sling attached to the support structure capable of supporting a person who can control his or her descent by actuating the brake device, enabling a person to escape from a building during emergency conditions. The present invention also contemplates the combination of the above-described descent device and a vertically extending rail-like support track which is fixedly secured to the exterior of a building wall. The track is shaped substantially like an I-beam in which one edge of the I-beam includes a plurality of recesses and projections to form a rack designed to correspond with the pinion gear of the descent device, while the other edge of the I-beam is straight and smooth and is designed to correspond with the roller whose contact surface contacts the smooth edge. 
     A high-rise fire escape device gravity operated and particularly adaptable for use in high-rise building and modern skyscraper structures as an escape apparatus from any floor of a building for use in the rescue of an occupant who may be trapped and prevented from using the conventional stairways or elevator due to a natural or man-made disaster such as fire, electrical or power failure, building collapse or personal injury of the occupants, etc. The apparatus or device comprises the combination of a vertical skid track member attached to the wall of a building with a skid which is inserted into a guide channel located in the track. The skid track is designed to be attached to either a new or existing building with access to the skid track being available at the outside of the building at predetermined locations, such as, building corners or a plurality of locations intermediate to the corners between the building windows so as not to impede the architecture design of the building. The skid track has a back and guide portion with a plurality of spring loaded or hinged skid track doors which allows the insertion of a skid to which the occupant of a building may be attached. The skid is so designed to allow its movement down the vertical skid track with the occupant attached, with its rate of descent being controlled by a plurality of descent retarders suitably disposed along the skid tracks entire length. The descent retarder is disposed within the back section of the skid track and partially protrudes into the guide channel of said track. As the skid moves down the guide channel of the skid track it comes into fractional contact with the biased plane frictional surface of the plurality of protruding descent retarders disposed along its vertical axis causing the descent retarder to be displaced in horizontal direction perpendicular to direction of the skid movement. The movement of the descent retarders in a horizontal direction is resisted by means just as a plurality of springs interposed between the rear of the descent retarders and the inside the back portion of the skid track. While the majority of the descent retarders are spaced uniformly along the entire length of the vertical skid track, there are some that are placed in a closer or cluster configuration near the end of the vertical skid track to more greatly impede the rate of descent or velocity of the occupant user so as to prevent forceful contact with the ground. During an emergency, a building occupant may put on a harness of any standard construction and attach it to the skid which can easily be inserted into the guide portion of the vertical skid track through any of the plurality of track doors disposed along said skid track. 
     A controlled descent device is disclosed, including an elongate guide assembly that has an upper portion, a lower portion and a generally helical track that extends from the upper portion to the lower portion. A carriage includes a primary bearing that is engaged with and movable within the track. A harness is secured to the carriage and the carriage is descendible along the track to lower a person fastened in the harness from the upper portion of the guide assembly to the lower portion thereof. 
     A fire escape device incorporated into new buildings or added on to existing buildings by which occupants of the building may quickly and safely exit from the building in the case of fire or other emergency conditions. The fire escape device includes a vertical track or guide that slidably receives a slide in the form of a backpack attached to each person using the fire escape device. The slide or backpack includes an oscillatable control member that swings back and forth about an axis perpendicular to the track or guide and engages a plurality of stationary pins oriented in staggered spaced relation on opposite side of the guide or track and control members that control the speed of descent of the slide or backpack and the individual supported thereon. An interlock device is provided to control access to the track or guide to insure proper sequential use of this fire escape device by a plurality of individuals. The lower end of the fire escape device includes an angulated discharge chute or ramp or transversely aligned control pins to stop the slide or backpack just prior to reaching a bottom support surface to enable a person to safely use the fire escape device. The arrangement of the components also will stop succeeding users until the lower most user has exited from the fire escape device. 
     While these escape systems may be suitable for the purposes for which they were designed, they would not be as suitable for the purposes of the present invention, as hereinafter described. 
     SUMMARY OF THE PRESENT INVENTION 
     The present invention is a high rise emergency descent system. The high rise emergency descent system is comprised of at least one track fixedly attached to the exterior of a building and a jumpsuit having an integral harness and descent device connected to the suit by means of a tether that will allow the user to don the apparel having a first preselected drag brake designed for a weight class that is reflected in the size of suit, and, to attach the descent device to the descent track and descend to the ground at a controlled rate. A second brake control is provided for allowing the user more individual brake control during the descent down the building. 
     A primary object of the present invention is to provide an emergency system whereby occupants of high rise building can be quickly evacuated. 
     Another object of the present invention is to provide an emergency system having one or more descent tracks fixedly attached to a building. 
     Yet another object of the present invention is to provide an emergency escape system for tall buildings having at least one descent track and a point where users can attach to said track for exiting said building. 
     Still yet another object of the present invention is to provide an emergency escape system for tall buildings having an apparel device that can be used by individuals to exit the building. 
     Another object of the present invention is to provide an emergency escape device having a plurality of available garment of various sizes. 
     Yet another object of the present invention is to provide an emergency escape device having a plurality of available garment of various sizes having a harness with a descent device attached thereto by means of a tether. 
     Still yet another object of the present invention is to provide a descent device comprised of a substantially C-shaped module that can be attached to the descent track. 
     Another object of the present invention is to provide descent device incorporating a drag brake comprised of a pressured brake pad. 
     Yet another object of the present invention is to provide a pressured brake pad wherein said pressure correlates to the size of the descent apparel which directly relates to the weight of the user. 
     Still yet another object of the present invention is to provide a descent device having a hydraulic piston engaging a brake pad that can be used to control the rate of descent of the device. 
     Another object of the present invention is to provide a descent device having control means for engaging the hydraulic brake of the descent device. 
     Yet another object of the present invention is to provide user access to the hydraulic brake pad control means whereby the user can selectively engage the control means to effect the rate of descent of the descent device. 
     Additional objects of the present invention will appear as the description proceeds. 
     The present invention overcomes the shortcomings of the prior art by providing a high rise emergency descent system comprised of at least one track fixedly attached a building and a device for attachment thereto whereby a user can descent to the ground under controlled conditions. The descent device considers the variations of individual weight of the users. Each descent device has a drag brake comprised of a brake pad under pressure that continuously engages the descent track as the user descends to the ground. 
     To insure the correct mating between a descent device and a user the descent device is permanently attached to a jumpsuit or other appropriate apparel having an integral harness and descent device attached thereto that is donned by the user. The size of the jumpsuit correlates directly to the duty rating of the pressured descent device. Therefore a smaller suit incorporates a lesser pressured brake than a larger suit having a greater pressured brake. Therefore, the descent rate can be equalized for a mixture of individuals by providing a plurality of jumpsuits having a pressured drag brake for that size of individual. The descent device also incorporates an additional braking mechanism that is under user control comprised of a hydraulic piston that moves a brake pad into an engaging position with the descent track thereby users can effect the rate of descent by engaging the control mechanism for the hydraulic brake. 
     The foregoing and other objects and advantages will appear from the description to follow. In the description reference is made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. These embodiments will be described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that structural changes may be made without departing from the scope of the invention. In the accompanying drawings, like reference characters designate the same or similar parts throughout the several views. 
     The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is best defined by the appended claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In order that the invention may be more fully understood, it will now be described, by way of example, with reference to the accompanying drawings in which: 
     FIG. 1 is an illustrative view of the present invention in use. 
     FIG. 2 is and illustrative view of the present invention in use. 
     FIG. 3 is and illustrative view of the present invention. 
     FIG. 4 is an illustrative view of the present invention. 
     FIG. 5 is a perspective view of the descent device. 
     FIG. 6 is a top view of the descent device. 
     FIG. 7 is a bottom view of the present invention. 
     FIG. 8 is a sectional view of the descent assembly attached to a descent track. 
     FIG. 9 is end view of the descent assembly attached to a descent track. 
     FIG. 10 is a bottom view of the brake release of the present invention. 
     LIST OF REFERENCE NUMERALS 
     With regard to reference numerals used, the following numbering is used throughout the drawings. 
       10  present invention 
       12  tall building 
       14  departure point 
       16  user 
       18  descent track 
       20  descent suit 
       22  harness 
       23  descent assembly 
       24  descent assembly housing 
       26  brake control 
       28  handle 
       30  master cylinder 
       32  upper piston 
       34  lower piston 
       36  harness cable 
       38  large suit 
       40  medium suit 
       42  small suit 
       44  frictionous material 
       46  attachment member 
       48  flange 
       50  brake pad for upper piston 
       51  brake pad for lower piston 
       52  coiled spring 
       54  outer face of descent track 
       56  brake release lever 
       58  brake release tab 
       60  semi-interior cavity 
       62  inner surface of top side of descent assembly housing 
       64  inner surface of flange 
       66  cylindrical housing 
       68  cylindrical housing 
       70  pivotable connection 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The following discussion describes in detail one embodiment of the invention. This discussion should not be construed, however, as limiting the invention to those particular embodiments since practitioners skilled in the art will recognize numerous other embodiments as well. For a definition of the complete scope of the invention, the reader is directed to the appended claims. 
     Turning to FIG. 1, shown therein is an illustrative view of the present invention  10  in use. The present invention  10 , a personal descent jump suit, is designed for emergency evacuation from skyscrapers or tall buildings  12 . The suit is issued to the employee or a variety of sizes are stored at the evacuation point  14  of departure where an individual  16  will select the appropriate size and after donning their suit they will attach their descent device to the descent track which will safely guide them to the ground. The suits are made in various sizes because the descent device has a preselected drag brake mechanism for controlling their rate of descent. The descent device also has a hydraulic brake that is under the user&#39;s  16  control to provide selective descent control in addition to the preselected suit designed brake mechanism. 
     Turning to FIG. 2, shown therein is an illustrative view of the present invention  10  in use. Shown is the present invention  10  being used by a user  16  in an emergency evacuation from a sky scraper or tall building  12  having a plurality of longitudinally extending I-beam shaped descent tracks  18  attached to the exterior thereof extending from top to bottom and being fabricated in a manner that allows for the attachment thereon of a personal descent assembly having a preselected first brake designed for the descent suit size and a second user controlled hydraulic brake control so that the user  16  may attach themselves to the descent track and descend to the ground by means of the first brake and user controlled second hydraulic brake to control their rate of descent down the side of the building  12 . 
     Turning to FIG. 3, shown therein is an illustrative view of the present invention  10 . Shown is the descent suit  20  of the present invention  10  being worn by a user  16  having a harness  22  forming an integral part of the suit  20  and descent assembly housing  24 . The suits  20  are made in various sizes that reflects a duty rating for the preselected drag brake control of the descent assembly  23  have a housing  24  that basically determines the descent rate of the suit wearer  16  during a descent session. The suits  20  can also be made to accommodate special needs such as the physically challenged and can be manufactured in various colors to indicate such. The descent device  23  also incorporates a second hydraulic brake that is under control of the user allowing the user  16  to stop or slow down as determined by the user. Also shown are the brake control  26 , handle  28 , master cylinder  30 , upper hydraulic piston  32 , lower preselected piston  34  and harness cable  36 . 
     Turning to FIG. 4, shown therein is an illustrative view of the present invention  10 . Shown is one possible variation in suit  20  sizes being large  38 , medium  40  and small  42 . Each suit has an integral harness  22  and descent device  23  that is attached to the suit harness by a cable  36 . Each descent device  23  has two braking mechanisms. One brake mechanism is a preselected tension loaded brake that is tensioned according to the suit  20  size. Larger Suits  38  have a greater braking pressure than medium  40  or smaller  42  suits thereby controlling the descent rate. The second braking mechanism is a hydraulic brake having control means accessible to the user whereby the user can apply the hydraulic brake as the user deems necessary. 
     Turning to FIG. 5, shown therein is a perspective view of the descent device assembly  23 . Shown is the descent assembly  23  of the descent suit of the present invention having a preselected brake associated with a lower tension piston  34  wherein the pressure is calculated to apply a predetermined braking force determined by the weight of the individual as related to suit size. To insure the correct mating of a descent device  23  to the weight of the individual, the descent device  23  is fixedly mounted to a suit that is sized for the duty weight of the descent device  23 . In addition to the preselected tension brake a second hydraulic brake associated with upper piston  32  is provided whereby the user can selectively apply the hydraulic brake as needed. Also shown are the hydraulic brake control  26 , handle  28 , master cylinder  30 , housing  24 , frictionous material  44  and harness cable  36 . 
     Turning to FIG. 6, shown therein is a top view of the descent assembly device  23 . Shown are the descent assembly  23  and descent assembly housing  24  of the present invention having two handles  28  for hand placement of the user during descent to allow for control of the user&#39;s body and easy manipulation of the brake control  26 . The brake control  26  is attached to a master cylinder  30  that when activated produces pressure in the upper piston  32  to displace the inner piston into a position that allows the brake pad to engage the descent track to slow the user&#39;s descent as they travel down the descent track. The lower tension piston  34  is associated with the preselected brake. The tension of the lower piston  34  coincides with the size of the jump suit that it is attached to. The bigger the jumpsuit harness the greater the pressure on the drag brake of the lower piston  34 . An attachment member  46  is fixedly attached to housing  24  and is for receiving the harness cable. 
     Turning to FIG. 7, shown therein is a bottom view of the present invention  10 . Shown are the bottom of the descent assembly  23  and its housing  24  having a structure whereby two opposing channels are formed by curved flanges  48  extending inwardly on the bottom side portions of the descent assembly  23 . Also shown is the opposed channels having a frictionous material  44  lining that produces a reduced free fall speed of the descent assembly. Additionally shown are a plurality of brake pads  50 ,  51  that work in correlation with the upper and lower pistons respectively, to produce larger frictional coefficients on the descent track to further slow the user&#39;s descent as desired. Also shown are handle  28 , brake control  26  and attachment member  46 . 
     Turning to FIG. 8, shown therein is a partial sectional view of the descent assembly  23  attached to a descent track  18  attached to the exterior wall of a tall building  12 . Shown is the manner whereby the descent assembly  23  and its housing  24  of the present invention engages the descent track  18  when reduced descent speed is desired. The user slows their descent speed by manipulating the brake control  26  that causes the master cylinder  30  to pump increased amounts of brake fluid into the upper piston  32  and cylindrical housing  66  causing increased pressure between the brake pad  50  and the descent track  18  of the present invention producing an increased frictional coefficient that effectively slows the user&#39;s descent. Also shown are brake pads  51 , handle  28 , coil spring  52  for the preselected brake control, lower piston  34  and cylindrical housing  68 , frictionous material  44 , flange  48 , attachment member  46  and harness cable  36 . 
     Turning to FIG. 9, shown therein is a lower end view of the descent assembly  23  and its housing  24  attached to a descent track  18 . Shown is the descent assembly  23  having a semi-interior cavity  60  therein for receiving the I-beam descent track  18  therein, wherein the descent device  23  has frictionous material  44  positioned on the underside of the descent track  18  and brake pads and frictionous material  44  engaging the outer side face or connection bar  54  of the descent track  18 . The frictionous material  44  pad engaging the face  54  of the track  18  serve as a drag brake that slows the descent of the user depending on the preselected tension brake that is sized to the suit size which is related to the weight of the descending user. The second brake is hydraulic and is under the control of the descending user. Handle  28  is also shown. The semi-interior cavity  60  is referred to as a “semi” because there is an open space between the two flanges  48 . The frictionous material  44  is disposed inside the semi-interior cavity  60  and is attached to the interior surface of the top side of the descent assembly housing  23  at  62  and the interior surface of the flanges  48  at  64 . 
     Turning to FIG. 10, shown therein is a bottom view of the drag brake release mechanism. Shown is a bottom view of the descent device  23  with the flanges  48  shown in outline. The drag brake has a preselected tensioning coil  52  designed to force the brake pad  51  to engage the descent track face  54  with a pressure determined by the suit size which has a correlation to the weight of the individual wearing the suit. The drag brake release mechanism has a lever  56 , pivotable connection  70 , and a tab  58  that is positioned over the drag brake pad  51  whereby the descent mechanism  23  can be mounted to the end of the track  18  without the end of brake pad  51  contacting the top end of the track  18  and whereby the top end of the track  18  will automatically engage the drag brake release lever  56  moving the tabs  58  off of the drag brake pad  51 . Once disengaged, the drag brake pad  51  will be free to move or be urged by tension spring  52  into engagement with the descent track face  54 . The tab  58  thickness is less than the distance moved by the drag brake pad  51  to engage the track  18 ; therefore, the tab  58  will not contact the descent track face  54  or otherwise interfere with the workings of the descent mechanism.