Patent Application
20170266471
The present relates most generally to a descent control device to facilitate rapid descent and abseil (rappelling) maneuvers, and more particularly to a descent control device for use in either recreational or emergency abseil use, and still more particularly to a descent device specifically adapted for emergency rapid escape from a dangerous environment encountered by emergency first responders, firefighters, and military or law enforcement personnel.
Emergency rescue personnel (principally firefighters, and military and law enforcement personnel) may encounter conditions requiring a very rapid egress from a building or other structure at height. When trapped in a structure above ground level and in urgent need of getting to ground, but when having no reasonable means to descend to ground level in a customary manner (stairs, elevators, and the like), it is desirable to have equipment that provides for a safe descent in a non-customary manner-13 such as by jumping from a window. To be able to do so safely in urgent circumstances is an answer to prayer; to have those prayers answered in advance is the object of the present invention.
In principle, all descent control devices (aka “descenders”) use friction in one or another manner to control the rate of descent when using a rope to lower equipment or people. Broadly, there are two categories of descenders, namely variable friction and fixed friction, and three types: (1) figure eights, a fixed friction device commonly used for short drops and use in bottom belays, but prone to put kinks and twists in rope; (2) racks, which are variable friction devices which resemble a miniature ladder, most useful for very long descents but significantly bulkier and heavier than figure eights and thus not well suited for emergency use by first responders; and (3) bobbins, almost universally associated with popularized by its French caving gear producer, Petzl. Bobbins are constant friction descenders using bollards over which rope is threaded in a sinuous pattern to create a friction angle of about 480° . Newer models may include a rope brake that can be actuated to apply stopping force friction during a descent. Belay plates and Munter hitches are also popular. There are basically three types of descent devices:
Type 1—Hand Brake/Hand Control Descent: User must hold onto the rope with this device to brake and to control their decent. If not, they will fall to the ground.
Type 2—Auto Brake/Hand Control Descent: User does not need to hold onto the device when exiting a window, the device will auto brake for them. When the device is manipulated in some fashion via a lever or motion, the rope will be free to move depending on the user controlling the rope release.
Type 3—Auto Brake/Auto Control Descent: User does not need to hold onto device when exiting a window, the device will break for them. The device can be also set to descend at a set rate of speed, no need for the user to control the rope.
The present invention (which bears the proprietary name of the “Core”) is a Type 2 Auto Brake/Hand Control Device. It is an auto braking descent device that brakes without any help from the user. The unique feature of the Core is that it does not use any moving parts to make the auto breaking work. The absence of moving parts prevents damage and operational failure in the presence of debris, dirt, sand, or other potential impediments are present, such as are commonly found in firefighter and military activities and environments. It is the first to use gravity alone—i.e., the user's weight and threading of the rope into the device—to accomplish the auto breaking.
Auto Brake/Hand Control Devices are popular among firefighters because firefighters were heavy protective firefighter gloves and are often unable to feel and locate the free end of the rope during an emergency exit. This is because firefighter gloves are bulky and lack flexibility, and dramatically decrease tactile awareness. Also, the inability to see clearly through a safety facemask, such as those worn by firefighters, limits the ability the see and to easily find and use the free end of the rope. Time is short in emergency situations, and just getting an anchor established is the only action one can accomplish prior to making an emergency jump from a window or roof. The Core catches the firefighter (stops freefall) once out the window, and the firefighter can then locate the handle and control the descent. Once out of the hazardous environment, the firefighter can locate the free end of the rope and manipulate the Core to complete a descent.
Military personnel encounter similar problems, particularly when lowering from a helicopter and under fire. The Core will not allow a user to fall to the ground if wounded and disabled, and the user can thus be flown to a safer location. Again, the absence of failure-prone moving parts allows for a higher degree of safety. In contrast, when using a Type 1 descent device, the user would simply fall to the ground. And Type 3 devices are simply large, costly, and have several failure-prone moving parts that jam with debris.
Existing descenders work sufficiently well in most commercial and recreational applications. But for the emergency first responder, an extremely high quality descent control device is required. This is particularly true because when intended for use by firefighters, descent control devices must meet extremely stringent standards set by the National Fire Protection Association (“NFPA”). Specifically, the NFPA 1983 (amended 2012) Escape “E” standards for Descent Control Device Performance Requirements of 3 σ MBS of not less than 13.5 kN (3,034 lbf). Under a load test, the descent control device must not allow rope to slide through the device when locked off under a load of 300+lbs. However, when the user wishes for rope to be paid out, when rope is released for free payout, the payout must occur at less than 20 lbs of applied force. NFPA 1983 standards also require that ropes must have strength, static, and stretch characteristics that will not allow them to break under a tensile load of 3,000 lbs, and many descent control devices will actually cause rope failure under such tensile loads.
The present invention is a descent control device that meets and exceeds all NFPA 1983 standards for descent control hardware. It is lightweight, simple to use, self-righting, absolutely reliable, and perfectly adapted for firefighters, rescuers, and military and law enforcement personnel. Importantly, the descender is exceedingly simple to use, intuitive in every respect, and as a critical safety component is configured to immediately lock upon release when under load. When not under load, rope properly threaded through the hole configuration easily pays out horizontally, when, for instance, a firefighter is mapping a path through a smoke-filled structure using a tethered safety line.
The descent device (descender) of the present invention 10 includes a body 12 having an outer side 14 (which faces away from user when in use, meaning when bearing a load) and an inner side 16 (which faces a user when in use). The body further includes an upper (superior) side 18 (generally oriented in a superior position when in use), a lower (inferior) side 20 (generally oriented in an inferior position when in use), a left side 22, and a right side 24.
Integrally affixed to and extending from an inner portion 26 of the upper side 18 of the body 12 is a handle (or bar) 28 for gripping by a user. A rope clearance space for creating a gap or clearance between a climbing rope and the handle when a load is suspended is created by the distance D from the upper edge 30 of the upper portion 32 of the body 12 to the outer side 34 of the handle. The inner side 36 of the handle may be flat and is generally coplanar with the surface 14a of the inner side 14 of the body 12.
The body next includes an attachment lug 40 integral with an outer portion of the lower side 20 of the body 12. The upper surface 42 of the attachment lug may be coplanar with the outer surface 14a of the outer side 14 of the body 12. The attachment lug 42 includes a slot or hole 44 for passing a rope or lanyard, which is then employed to couple the descender to a user's climbing harness or belt.
The body next includes a set of through holes, each passing from the upper side to the lower side of the descender body with the respective axes of the holes each oriented generally normal to the inner and outer sides, and thus parallel to one another. The holes include a payout hole 50 having a diameter 52 and a central axis 54 located on the longitudinal axis 56 of the descender. Conjoined to an upper portion 58 of the payout hole is an anchor hole 60 having a diameter 62 smaller than that of the payout hole and a central axis 64 also located on the longitudinal axis of the descender. Looked at from the top and bottom plan views (
Surrounding the payout hole on the outer side 14 of the descender body 12 is a chamfered opening 66 that provides a surface for inducing a gentle bend in rope disposed through the payout hole. Similarly, the upper end of the anchor hole includes a chamfered opening 68 that terminates in an arcuate shelf 70 formed at a depth from the surface 14a of the outer side 14 of the descender body 12, such that rope sized for use in the descender will bend proud across the shelf in relation to the surface 14a of the outer side 14. These features are described in more detail below and may be appreciated by reference also to
Right and left holes 80, 90, respectively, are disposed through the descender body, each having a central axis 82, 92 normal to the longitudinal axis 56 of the body. Right and left holes each include a chamfered upper opening 84, 94 to induce gentle bends in rope.
Right and left holes 80, 90, have chamfered lower openings 86, 96, at the outer side 16 of the descender body 12. Disposed between each of the left and right holes and the anchor hole 60 on the inner side of the descender body are shallow channels 88, 98 to accept and constrain a rope segment bent proud between one or the other side holes and the anchor/payout hole. The shallow channels are, respectively, longitudinally aligned with a line 80d, 90d, drawn between the center of the right and left holes 80c, 90c, and the center of the anchor hole 60c. Payout hole 50 and anchor hole 60 each have chamfered outer openings, 100, 102, respectively.
Referring next at
Referring now to
When so configured, (see
The present application claims the benefit of U.S. Provisional Patent Application Ser. No. 62/310,580 filed Mar. 18, 2016, which is incorporated in its entirety by reference herein.
| Number | Date | Country | |
|---|---|---|---|
| 62310580 | Mar 2016 | US |
