Patent Application
20180236274
Not Applicable.
This disclosure relates to a retrieval tower that can be readily erected on a sloped (or on a flat) roof of a grain bin or other storage structure over an opening in the roof such that rescue ropes or a winch and cable may be attached or mounted to the tower over the opening so that rescue team members can be lowered into the storage structure and so that a person entrapped in grain or the like or otherwise incapacitated in the storage structure may be retrieved.
Grain bins, tower dryers, silos and other structures hold large quantities of fluent, granular material, such as grain (e.g., corn, soy beans, wheat, or the like) or other fluent products, such as plastic pellets. In addition, such storage structures include petroleum tanks and the like. Grain stored within such storage structures is often unloaded by means of an unloading conveyor (e.g., an auger conveyor) located at the bottom of the storage structure. Upon actuation of the unloading conveyor, grain or other fluent, granular material will be unloaded from the bottom of the storage structure. As grain is unloaded from the bottom of the storage structure, grain in the storage structure will flow in a conical-shaped column of grain moving downwardly toward the unloading conveyor. At times, a farmer or grain handling personnel will enter the storage structure and walk on the top surface of the grain to inspect the grain or to break up grain bridges or the like that inhibit the downward flow of grain toward the auger or conveyor. If the unloading conveyor is turned on to unload grain while a person is walking on the top surface of the grain, the downward flow of grain will entrap the person's feet and legs. Once a person's legs become entrapped, the weight of the grain around the legs prevents the person from moving. If the unloading conveyor is not turned off, the person will continue to sink into the grain until the person is buried in the grain, which often leads to suffocation and death. Many persons will think that they can escape from the moving grain column by climbing up out of the grain, but entrapment can happen quite quickly, within about 10 seconds or so, depending on the type of grain, the unloading capacity of the unloading conveyor, the diameter of the grain storage structure, and the depth of grain in the storage structure.
The best chance that an entrapped person has to escape is to shout to someone outside of the storage structure to shut off the auger. Oftentimes the person in the bin is alone, but even if someone hears the entrapped person shout, it can take some time for the unloading conveyor to be turned off, during which time the person will become further entrapped or even buried as more grain is conveyed from the storage structure. Even if the unloading conveyor is turned off before the person is fully buried in the grain, it is virtually impossible for an entrapped person who is buried up to the waist to free himself or for a rescuer to pull the person free of the grain.
It will be appreciated that if a rescuer attempts to remove grain from around the legs or body of the entrapped person, other grain will immediately flow into the void created by the grain removal. Coffer dams, such as shown in U.S. Pat. No. 9,139,372, are often used by a rescue team to stabilize the grain in which a person is entrapped and to prevent other grain from flowing toward the person as grain from around the person is removed. Once the coffer dam is in place, grain between the entrapped person and the inside of the coffer dam may be removed by the rescue team to free the person. Small portable auger conveyors, such as shown in U.S. Pat. No. 9,139,372, are known that will quickly remove grain from within a coffer dam once the coffer dam is in place so that the entrapped person may be freed from the grain.
In such storage structure rescues, the rescued person or victim is often overly fatigued, injured, incapacitated, or unconscious such that it is difficult for the rescue team to remove the victim from the storage structure. It is common for the rescue team to fit a harness to the victim or to place the victim in a rescue litter so that the victim can be hoisted from the bin through an opening in the bin roof using a retrieval tower and rescue ropes or the like supported by the retrieval tower.
However, existing prior art towers are difficult to use on a sloped storage structure roof that are often sloped at a relatively high slope angle, e.g., up to about 35°. Moreover, many prior art rescue towers must be guy wired or roped to the storage structure to prevent the tower from tipping over as rescue team members are lowered into the storage structure or as the victim is hoisted from within the storage structure. Many storage structures, such as farm grain bins, do not have many, if any, places on their sloped roof to which guy wires or ropes can be readily attached. Also, it is often difficult for a rescue team to lower a victim from the sloped roof to ground level, especially if the victim is incapacitated or is in a rescue litter. Access is often gained to the roof of the storage structure by means of ladders leaning against the storage structure or by a ladder system or circular staircase attached to the sidewall of the storage structure such that it is difficult for a rescue team to get a retrieval tower or other rescue equipment to the roof or to lower a victim or the rescue equipment.
There has been a long-standing need for a retrieval tower that can be readily installed on the sloped roof of a grain bin or other storage structure over an opening (either an existing roof opening or an opening cut in the roof by the rescue team), so that rescue ropes or a powered/hand winch supported by the retrieval tower (or supported by other structure) can be used to hoist the person from within the grain bin. Further, once the rescued person or victim has been removed from the bin and is on the sloped roof, there has been a long-standing need for a system and method that can be readily employed by a rescue team to lower the victim from the sloped roof to ground level.
In accord with the present disclosure and as shown in the drawings, a rescue retrieval tower is disclosed that may be readily secured to a sloped roof of a grain bin or other storage structure over an opening in the sloped roof, where rescue ropes or a cable and winch may be supported by the top of the tower over the opening so that rescue ropes or a cable extends down through the opening, which then may be used to lower rescuers into the bin and to hoist the victim and the rescuers from the bin;
The provision of such a retrieval tower that extends above the roof a sufficient distance such that a person, even if unconscious and in a rescue harness or strapped in a rescue litter, may be swung out of the of the tower to be clear of the roof opening;
The provision of such a retrieval tower that may be rapidly clamped to the roof over the opening, and that may be readily removed from the roof;
The provision of such a retrieval tower that can be used on flat roofs and on sloped roofs having a slope angle of up to about 35° or more;
The provision of such a retrieval tower that may be readily adjusted such that the rescue ropes or cable will extend substantially vertically from the top of the tower through the opening with sufficient clearance between the sides of the opening so that a person may readily clear the opening;
The provision of such a retrieval tower that is sufficiently light that a rescue team member may readily carry the tower to the roof of a grain bin or other storage facility using a ladder leaning against the storage structure or carried up a circular staircase affixed to the storage structure;
The provision of such a retrieval tower that may be readily erected and secured (e.g., clamped) to the roof without the use of even simple hand tools and without the need to stabilize the tower with guy wires or the like so long as the top of the tower is substantially over the opening;
The provision of such a retrieval tower that is sufficiently strong so as to support the weight of a heavy adult person, along with any equipment carried or attached to the person being lowered or hoisted into or from the storage structure with an appropriate safety factor to be man-rated;
The provision of such a retrieval tower that may readily be rotated with respect to its base from a first position in which the tower is positioned over a roof opening positioned proximate (e.g., up to about 18 or more inches) from the edge of the roof to a lowering position in which the top of the tower is proximate or extends beyond the edge of the roof so that rescue ropes supported by the top of the tower may be used to lower the person from the roof to ground level; and
The provision of such a retrieval tower that may be used on other storage structures, such as petroleum tanks and the like that need to be periodically inspected or cleaned, where persons entering such storage structures may be overcome by fumes or the like and need to be rescued.
A retrieval tower is disclosed for rescues from a grain bin or other storage structure containing, for example, a supply of fluent granular material, such as grain or the like, that may entrap a person or containing fumes that may incapacitate a person or victim. The storage structure has a sloped roof whose slope ranges between about 0° to about 35°, where the roof has an outer edge (e. g., an eave) and a peak. The tower comprises a base configured to surround an opening in the roof of such storage structure, where the base has a pair of side rails adapted to be disposed on opposite sides of the opening and extending substantially along the slope of the roof and a pair of cross members extending between the ends of the side rails proximate the upper and lower margins of the opening. At least one clamp member is adapted to be inserted into the opening and to be positioned under a respective the cross member with a portion of the roof proximate the opening therebetween. The clamp member has a clamp adapted to clamp a portion of the roof between the clamp member and its respective cross member so as to securely mount the base to the roof. A pair of spaced legs (e.g., front legs) is adapted to be attached to one of the cross members, preferably attached to the cross member toward the edge of the roof. A head is supported by the upper ends of the spaced legs, at least one other leg (e.g., a back leg) is pivotally attached to the head and extends downwardly and is adapted to be attached to the other of the cross members. The other or back leg includes means for adjusting the length of the back leg.
A method of effecting a rescue of a victim from within a storage structure, such as a grain bin, is described in which the victim has become entrapped in grain or the like, or has otherwise been overcome in the storage structure, where the storage structure has a roof whose slope ranges between about 0° to about 35°, and were the roof has an outer edge or eave. This method uses a retrieval tower comprising a base configured to surround an opening in the roof of such storage structure. The base has a pair of side rails adapted to be disposed on opposite sides of the opening and a pair of cross members configured to extend between the end portions of the side rails and to be disposed proximate the opening. At least one clamp member adapted to be inserted into the opening and to be positioned under a respective cross member with a portion of the roof proximate the opening therebetween. The clamp member has a clamp for clamping a portion of the roof between the clamp member and its respective cross member so as to securely mount the base to the roof. The tower further comprises a pair of spaced legs attached to one of the cross members, preferable attached to the cross member toward the edge of the roof. A head is supported by the upper ends of the front legs. The tower comprises at least one other leg (e.g., a back leg) attached to the head that extends downwardly to be attached to the other of the cross members. The method of the present disclosure comprises positioning the base on the roof surrounding the opening with the side rails extending generally perpendicular to the edge of the roof and extending along the slope of the roof with the cross members being positioned to extend between the side rails. At least one of the clamping members is installed on the inside of the roof substantially under a respective cross member with a portion of the roof proximate the opening disposed therebetween. The clamp member and its respective cross member are clamped to the roof such that the portion of the roof between the clamp member and the cross member is securely clamped so as to secure the base to the roof. The pair of legs is secured to one of the cross members, preferably the cross member toward the roof edge, such that the pair of legs constitute the front legs of the tower. The other leg constituting the rear leg of the tower is attached to the other of the cross members with the head positioned substantially over the opening so that rescue ropes or a cable from a winch attached to the tower or other suitable structure is supported by the head will pass through the opening thus allowing rescuers to be lowered into the storage structure and to enable the victim to be hoisted from within the storage structure.
Other objects and features of this disclosure will be in part described herein and will be apparent to one of ordinary skill in the art.
Corresponding reference characters represent corresponding parts throughout the several views of the drawings.
Referring now to the drawings, a retrieval tower, in accord with a preferred embodiment of the present disclosure, is generally indicated at 1 and is shown in
Grain bin roofs are generally conical-shaped and typically are comprised of a series of pie-shaped triangular roof panels 3 extending upwardly from the outer edge or eave E of the roof to a center ring (not shown) at the apex or peak of the roof. The roof panels 3 have raised seams or ribs 5 that that extend from the roof edge to the peak of the roof and are sealed to keep rain out of the bin. Conventionally, the roof panels 3 are made of sheet metal and the seams or ribs 5 strengthen the roof such that personnel can walk on the roof. The opening O may be an existing opening in the roof that is provided for access to the interior of the bin, or it may be an emergency hole cut in the roof by rescue personnel. In many commercially available grain bins, the opening O may be a man hole or access portal that is typically spaced 12-18 inches from the roof eave E so that a farmer or other bin personnel may access the opening from a ladder or a staircase affixed to the side wall of the storage structure. The opening is typically reinforced by a collar or coaming C (as shown in
Retrieval tower 1 comprises a base 7 that is adapted to be removably clamped or otherwise secured to the roof so as to surround opening O and a raised tower 9 secured to the base. More specifically, base 7 comprises a pair of spaced side rails 11a, 11b configured to extend generally parallel to the roof ribs 5 and to be spaced outside of opening O when the tower is installed on the roof R. The base further comprises a pair of spaced cross members 13a, 13b adapted to be removably secured to the end portions of side rails 11a, 11b by quick release pins 31 (as will be described hereinafter). The side rails are preferably spaced apart somewhat wider than the diameter or width of opening O, and the cross members are preferably spaced in close proximity above the upper and lower edges of the opening. The side rails and the cross members are somewhat longer than the diameter of the opening so as to give rescuers full access to the opening. Each of the side rails 11a, 11b has a respective extension 14a, 14b that is telescopically received in a respective main portion 15a, 15b of each side rail so that the length of the side rails may be adjusted to fit the size of opening O. As shown best in
As shown best in
With base 7 firmly clamped in place on roof R around opening O, as above described, tower 9 may be installed on the base. The tower 9 is preferably, but not necessarily, a three legged unit having a pair of spaced front legs 23a, 23b configured to be removably and pivotally secured to the lower cross member 13b. More specifically, the lower end of each of the front legs is received in a clevis fitting 25 secured on the upper surface of the lower cross member 13b and is pivotally attached to the clevis fittings by a quick release pin 31. The tower preferably has a single back leg 29 secured to its cross-member 13a. However, in certain instances, two spaced back legs 29 may be desirable. The lower end of back leg 29 is preferably received in a clevis 25 secured to the upper cross-member 13a by means of a quick release pin 31. The upper end of back leg 29 is pivotally connected by another pin 31 to an upper head member 33 which is carried on the upper ends of front legs 23a, 23b.
In accord with the present disclosure, upper head 33 may be used to attach different rescue roping systems to the tower, where such roping systems are well known to those skilled in the rescue field. With such roping systems attached to head 33, when the head is positioned over opening O rescue personnel and rescue equipment may be lowered into or raised from the storage structure and a victim may be hoisted from within the storage structure. Preferably, head 33 is pivotally connected to the upper ends of front legs 23a, 23b so that upon the head supporting a load on a rescue rope or cable supported by the head, the head will pivot to be in line with the load on a rescue rope attached to the head. Additionally, a winch and cable (or rope) assembly, as generally indicated at 34, may be mounted to one of the legs (e.g., leg 29, as shown in the drawings) such that a cable or rope 36 (or other flexible tension member) extending from the winch may be entrained through a suitable pulley 38 attached to the head and will extend downwardly opening O preferably near the center of the opening such that the rope may be used to lower and raise rescue personnel and equipment into and out of the storage structure and to hoist a victim from within the storage structure. The winch may either be manually operated by a hand crank winch, or it may be powered by an electric motor. One such winch that is commercially available is from Pelsue of Englewood, Colo. As shown, a single pulley 38 is attached to head 33 and the rope or cable 36 is passed around this pulley. However, as those skilled in the art will know, that instead of a simple pulley, a block and tackle system may also be used. Quick release pins 31, as described in this disclosure, are preferably used to secure lock side rails 11a, 11b at their desired length, to secure tower 9 to base 7 and to lock the leg extensions to the main portions of the front legs 23a, 23b and back leg 29. These quick release pins are also known as ball lock pins and are commercially available from Carr Lane Mfg. Co., of St. Louis, Mo. Such pins may be attached to surrounding structure by a cable lanyard (not shown) so that they are not separated from the legs when disengaged to prevent them from being lost during use or storage of tower 1. Further, it is preferable that base 7 and tower 9 are made of a suitable aluminum alloy to minimize the weight of those components thus making it easier for rescue personnel to carry or hoist the rescue tower to the roof of a storage structure.
As previously mentioned, roof R is typically a sloped roof having a slope angle ranging between about 0° and about 35° or more. In order to accommodate roofs of different slopes, including flat roofs, and to insure that a rescue rope or a cable 36 supported by head 33 is appropriately positioned within the opening O, the lower portions of the front tower legs 23a, 23b and the back tower leg 29 may preferably be lengthened or shorted so that when the tower 9 is in its first position, head 33 is substantially directly above opening O. However, it is not necessary (only preferable) that the length of the front legs be adjustable. As shown in the drawings, the upper or main portion 35 of each front leg 23a, 23b and of back leg 29 is a hollow tube. The lower portion of each leg is an extension 37 having a somewhat smaller cross section than the opening in hollow tube forming the main portion 35 such that the extensions are telescopically received in their respective main portions 35. Each of the extensions 37 has a series of spaced holes 39 therein spaced at, for example, two inch increments (as best shown in
While shortening or lengthening of back leg 29 may be accomplished by pulling its quick release pin 31 and extending or retracting its extension 37 according to the spacing of holes 39 and then re-inserting the pin, it is preferred that a screw jack arrangement, as generally indicated at 45, be utilized so that the length of the back leg may be adjusted without disconnecting the back leg from base 7. Screw jack 45 includes a first screw collar 47 pivotally mounted by a quick release pin 31 received in a clevis 25 that is secured to the center of upper cross member 13a. Screw jack 45 has a lower screw portion 49, which is threadably received in base collar 47, and an upper screw portion 51, which is threadably received in a second screw collar (not shown) housed within the lower end of leg extension 37 of back leg 29. The screw threads on the lower and upper screw portions 49 and 51 of screw jack 45 are threaded opposite one another (i.e., one portion has right-hand threads and the other has left-hand threads) so that upon turning the screw jack in one direction or the other by means of a handle 53, the length of back leg 29 may be adjustably extended or shortened. It will be appreciated that screw jack 45 is constructed such that the screw portions 49 and 51 cannot be fully unscrewed from their respective screw collars thus preventing the screw jack from becoming uncoupled from base collar 47 and from leg 29 so that the back leg 29 is connected to its cross member 13a at all times as the length of the back leg is adjusted. More particularly, a screw stop (not shown), such as a stop pin carried by one of the screw portions, will prevent the one screw portion from being fully unthreaded from its respective screw collar. Also, the other screw portion is preferably somewhat longer that the other such that when the one screw portion with the stop pin comes against its stop, the other screw portion is fully threadably engaged with its respective screw collar. It will also be appreciated that the screw jack 45 may be used to more finely adjust the length of back leg 29 to adjust the position of a rescue rope 36 as it extends through opening O or as it extends beyond eave E, as best shown in
The height of tower 9 and the slope of roof R may be such that when tower 1 is spaced appropriately close (e.g., within about 10-12 inches) to roof edge E, screw jack 45 has sufficient extension (up to about 24 inches) such that the tower may be repositioned from its first position (as shown in
As mentioned above, screw jack 45 is preferably used to move tower 9 from its first position to its second position so that back leg 29 remains securely attached to its cross member 13a. However, in other instances, particularly where the opening O is farther from the roof edge E or where the slope of the roof is low, screw jack 45 may not have sufficient adjustment capability to fully move the tower to its second position. In those instances, it may be necessary to remove the load supported by head 33 and to pull the quick release pin 31 coupling extension 37 from the main portion 35 of the back leg 29 to lengthen the back leg and to re-insert the pin to lock the back leg in this lengthened position. Then, the screw jack may be used for final positioning of the tower in its second position.
In a rescue attempt of a person entrapped in grain (or in other granular fluent material, such as plastic pellets) inside of a grain bin GB or overcome by fumes or the like in another storage structure, rescue personnel may, upon arrival at the grain bin, quickly install the retrieval tower 1 of the present disclosure to the roof R of the grain bin over an opening O in the roof. The opening may be one that has been provided in the roof for ingress and egress into and out of the bin for normal inspection and maintenance purposes, or the opening may be one that is rapidly cut in the roof by rescue personnel using a rotary abrasive saw or the like. The base 7 and the tower 9 may be readily carried or hoisted by rescue personnel from ground level to the roof. Once the rescue personnel arrive at the location of opening O, the base 7 is assembled and positioned on the exterior of the roof R to surround the opening with the side rails 11a, 11b on opposite sides of the opening and with cross members 13a, 13b positioned proximate the upper and lower edges of the opening and connected to the side rails. Rescue personnel may then insert a folded clamp bar 17a or 17b through opening O, unfold the clamp bar, and position the clamp bars below their respective upper or lower cross member 13a, 13b on the inside of the bin roof. Then, clamp screw 19 is aligned with its screw collar C, and handle 21 is manually turned to securely clamp the base 7 to the roof. With the base clamped in place on the roof, rescue personnel may then install tower 9 to the base 7 by inserting quick release pins 31 through clevises 25 on the lower cross member 13b and through holes a hole in the bottom of leg extension 37 to attach front legs 23a, 23b to cross member 13b. Back leg 29 may then be attached to its clevis 25 on the upper face of the upper cross member 13a by a quick release pin 31 in a similar manner. Legs 23a, 23b and 29 may be lengthened or shortened, as above described, so that with the tower 9 is in its first position, a rescue rope 36 or cable will extend vertically downwardly from head 33 through opening O. It will be appreciated that the legs 23a, 23b and 29 are of sufficient length that side openings SO are formed between one of the lower side legs 23a, 23b and the upper leg 29 of tower 9 of sufficient size to allow a person wearing a safety harness or the like and connected to a rescue rope attached to head 33 via pulley 38 to step through one of the side openings SO (as best shown in
As various changes could be made to the above constructions and embodiments without departing from the broad scope of this disclosure, it is intended that all matter contained in the above description or shown in the accompanying drawings be interpreted in as illustrative and not in a limiting sense.
This application claims the benefit of U.S. Provisional Application No. 62/461,935, filed Feb. 22, 2017, the disclosure of which is hereby incorporated by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 62461935 | Feb 2017 | US |
