US2948348A - Escape mechanism - Google Patents

Description

Aug. 9, 1960 w. F. BOTT 2,948,348

ESCAPE MECHANISM Filed June 11, 1956 2 Sheets-Sheet 1 W/flJ 1 00 F. .50 INVENTOR.

' BY WQPM I A ITO/P/VE Kg g- 9, "19 w. F. BOTT ESCAPE MECHANISM 2 Sheets-Sheet 2 Filed June 11, 1956 BY V-M A 05 NE )5 United States Patent ESCAPE MECHANISM Winston F. Bott, P.0 Box 1006, Alice, Tex. Filed June 11, 1956, Ser. No. 590,610

Claims. (Cl. 182-11) The present invention relates to an escape mechanism and arrangement which permits fast and safe escape from elevated stations or positions in chemical plants, refineries, oil derricks and the like.

Various devices are in use at the present time whereby workmen may escape in an emergency from elevated, isolated positions such as found in and around chemical plants, refineries, oil derricks and the like. All of such devices are adapted to move along a cable which cable is connected to the derrick, or wherever the escape arrangement is to be used, and extends downwardly to the ground. The escape mechanisms presently in use have numerous disadvantages in their function and operation.

For example, escape devices'of the type under consideration wwhich are presently being used require a relatively long flat slope of the cable on which they are to move in an endeavor to provide for the safe descent of the user of the device. This is undesirable because of the large amount of space required for operation of the mechanism and also because such space is not always available in a refinery or chemical plant or around an oil derrick, or particularly where the oil derrick is mounted on a barge for operations over the water.

Another disadvantage with devices presently used is that the braking mechanism for slowing the rate of descent is weak and uncertain and there is no satisfactory means whereby the escape mechanism may be securely and firmly latched to the man, thereby necessitating the man to hold on to the mechanism with one hand, while he endeavors to operate the braking mechanism with the other.

Also, all escape mechanisms in use at the present time require the user to climb out or expose himself dangerously over open space in order to get on the device. Men have been seriously hurt, even killed, using present day escape mechanisms.

The present invention provides a mechanism which overcomes all of the above disadvantages and other disadvantages inherent with present construction in use.

An object of the present invention is to provide an escape mechanism for use on derricks, refineries, chemical plants, or in any situation where it is desired to descend rapidly and safely from an elevated position at a desired rate of descent. 1 Still another object of the invention is to provide a mechanism whereby a man may descend from an elevated position in a minimum of time with a maximum of safety.

Yet a further object of the invention is to provide a mechanism which is adapted to slide down on a cable to provide a means of escape, wherein the mechanism is provided with a positive braking arrangement so that the rate of descent may be easily and positively controlled by the user. i

Yet a further object of the invention is to provide a construction for use in moving along a cable whereby egress may be easily-eflected from an elevated position wherein the escape mechanism may be engaged or secured to the user without requiring the party using it to step out, or expose himself dangerously over open space.

2,948,348 Fatented Aug. 9, 1960 A still further object of the invention is to provide a device including a body for receiving a cable therethrough whereby the body may move along the cable, a roller means for engaging the cable on one side, a brake drum means below and in spaced relation to said roller for engaging the cable on the other side thereof, means below said drum whereby said body may be engaged with a user of the device, an elongated handle extending above said roller and adapted upon downward movement by the user to bend the cable so as to slow the movement of the body along the cable.

Other objects and advantages of the invention will become more readily apparent from a consideration of the following description and drawings wherein:

Fig. l is a vertical elevation illustrating the present invention in use on an oil derrick;

Fig. 2 is an enlarged perspective view of the preferred embodiment of the invention shown in Fig. 1;

Fig. 3 is a vertical sectional view on the line 33 of Fig. 2 looking down on the roller and illustrating the relationship of the hook assembly and the counterweight link assembly relative to each other and to the roller and brake drum;

Fig. 4 is a schematic view, showing the device on a cable and the relative position of the components of the mechanism for free movement of the device on the cable;

Fig. '5 is a schematic view, somewhat similar to Fig. 4, showing the relative position of the components of the device when it is partially braked on the cable; and

Fig. 6 is a schematic view, similar to that shown in Fig. 5, but showing the relative position of the components of the device when it is in fully braked position on the cable.

In Fig. 1, an-oil derrick is illustrated by the numeral 2 and is shown as-being provided with the customary guy Wires or ropes 3 which are engaged at the top 5 of the derrick and extend outwardly and down to be secured to the ground to help stabilize the derrick. Normally, four wires or cables are used for this purpose, with one cable. being secured adjacent each corner of the derrick top, however, additional guy wires may be used if desired. A cable or rope 6 is also shown as being secured to the ground 7 and 8 and to the derrick at 9, above and adjacent the platform 10. The platform 1-0 is provided for use of workmen during various stages of the drilling operation. Sometimes, it is necessary for the workman on the platform to make an emergency descent from the platform. The present invention relates to a device for carrying the workman down the cable 6 in such situations.

The cable 6 receives the escape mechanism 11 of the: present invention, such mechanism 11 being secured by means of the cable 12 to the counterweights 13 which help balance the weight of the main 14 during use of the: invention. The cable 12 is connected at one end to the device 11' and is looped over the pulley 15 mounted adjacent the top of the derrick and is engaged at its other end. to the counterweights 13 by any suitable means such as a clamp or the like. The counterweights 13 are provided withaframe or carriage 16 upon which are mounted the rollers 17 whereby the counterweights 13 may move along one of the guy wires 3 as the escape mechanism 11 is movedup or down along the cable6.

The construction of the escape device is shown in more detail in Fig. 2 and includes a body 20 which may be formed in any suitable manner so that it will receive the cable 6 to accommodate movement of the body 20 on cable 6 as is more fully described hereinafter. The invention is illustrated as being formed of two spaced parallel members 21 and 22 which are spaced to form an aperture for receiving the cable 6 therebetween as shown in Figs. 4, -5 and 6. A hand grip 23 is secured at one end of the members 21 and 22 and it is to be noted that} the spaced parallel body portions 21 and 22 include portions 24 and 25 respectively which are elongated relative to the remainder of the body and form a lever 22 for positive and easier actuation of the device 11 when it is desired to slow it down or to stop it as it moves downwardly along the cable 6. Such lever also extends at an angle outwardly behind the cable 6 and is inclined relative to the portions 26 and 27 of the body members 21 and 22 to provide additional leverage in the operation of the device.

Extensions 23 and 29 are provided on the portions 26 and 27 respectively which portions extend forwardly of the device while extensions 30/ and 31 extend rearwardly from the portions 26, 27 respectively and adjacent the lower end thereof, and which provide a certain automatic braking efiect to be described later. A roller 32 and a brake drum 33 are mounted in the sections 26 and 27 and between the body portions 21 and 22. It will be noted that the roller 32 is mounted above but in spaced relation, relative to the brake drum 33, and as shown in Figs. 4, and 6 of the drawings, the roller 32 and brake 33 engage the cable 6 on opposite sides to control the rate of descent of the device on cable 6 as described hereinafter. The roller 32 may be formed of any suitable wear resistant material such as brass or the like, and a suitable manner of mounting such roller between the body sections 21 and 22 is shown in Fig. 3 of the drawings, wherein a bolt 35 extends between sections 21 and 22 and is provided with a bushing 36 upon which the roller 32 is rotatably mounted. A nut 37 is engaged upon the threaded end 36 of the bolt 35 and a cotter pin 38 is secured to the bolt to maintain the nut on the bolt.

The brake drum '33 is non-rotatably mounted on the bolt 40 which extends between sections 21 and 22. A nut and cotter pin may be used as described with regard to the roller 32 to keep the drum and bolt in position between the sections 21 and 22. The drum 33 may be non-rotatably mounted on the bolt 40 in any suitable manner and a pin 40' is shown in Fig. 2 in spaced relation to bolt 40 and as extending through the body member 21, the drum 33, and body member 22. This prevents rotation of the brake drum, but a plurality of holes may be provided in drum 33 so that as it wears, the pin 40' may be removed, the drum then rotated on bolt 40, and the pin 46' replaced through the drum to maintain it in position. In this manner, the wear on drum 33 over a period of time may be evenly distributed.

The cable 6 is adapted to be positioned in the space between members 21 and 22 and is engaged by the roller and the brake drum as illustrated in Figs. 4, 5 and 6 of the drawings. It will be noted that the roller 32 is positioned in front of or on top of the cable 6 and the drum 33 is positioned behind or below the cable 6 so that the rate of descent of the device 11 along cable 6 may be easily and positively controlled by movement of the body 20 with lever 23 to bend or kink cable 6 between roller 32 and drum 33 as shown at 50 in Fig. 5.

The cable 12 is secured to the link 41 which link is engaged between the projections 28 and29 as illustrated in Fig. 2 of the drawing, such link being secured in position by any suitable means such as a bolt 42 which extends through plates 53 welded to link 41 and the extension 28 and 29. A nut engages the end of the bolt to hold it in place.

Hook 41 is welded to the positioning plates 53 and the plates engage lugs (not shown) mounted on the inner surface 54 of the projections 28 and 29, whereby the link 41 is maintained in a desired angular relationship relative to the portions 28 and 29 of the body plates 21 and 22. If it is desired to change this angular relationship, the link may be turned side for side, so as to change the angle at which the positioning stops 53 engage the lugs. Such rearrangement may be desired where the slope of the cable 6 relative to the ground is flatter than normally encountered. However, the general situation in practical use will be that the cable 6 is at an angle of 60, or greater, relative to the horizontal so that the offset from the point of take off of the device to the point of landing will be at a minimum, thus requiring a minimum amount of space around the plant or the oil derrick for the mechanism.

A hook 43 and chain 44 are secured between the spaced projections 30 and 31 by suitable means such as a bolt 45 whereby the hook may in turn engage the ends 46 and 47 of the crotch strap belts 48 and 49 which straps are secured around the workmanas he performs his routine work in the elevated position.

In order to position the mechanism on the cable 6, the bolts 45 and 40 may be removed and the cable positioned between the arms '21 and 22 and against the roller 32 as shown in Fig. 4 of the drawings. The brake drum may then be positioned between the arms 21 and 22 and in abutting relation to the cable 6 as shown in Fig. 4 and the bolt 45 with the chain 44 and hook 43 secured in position between the arms 21 and 22. The cable 12 is secured to the hook 41 and the counterweight 13 at the other end of cable 12 serves to retain the device 11 in an elevated position adjacent the platform 10 or area in position for immediate and ready use at any time. A workman on a drilling rig on the platform 10 wears a light comfortable strap while performing his routine work in the elevated position and in some cases the strap is engaged to the drilling rig to keep the man from falling out of the derrick as he moves about and works on platform 10. Such strap generally includes the links 46 and 47 whereby they may be engaged to-the line which is connected to the drilling rig.

When the workman is ready to descend on the escape device 11, he secures links 46 and 47 to the book 43. The Workman may place one hand on the chain 44 and the other arm engaged with the lever or handle 23 so that he may regulate the speed of descent of the device 11 on cable 6 as desired.

In Fig. 4 the free moving position of the cable 6 relative to the roller 32 and the brake drum 33 is illustrated. In this position it will be noted that there is only a relatively slight kink or bend in the cable 6 whereby the mechanism and the workers weight causes the counterbalance to move up the cable 3 as the worker descends on cable 6 as shown in Fig. 1 of the drawings.

If it is desired to slow the rate of descent the operator merely exerts a downward force of pull on the handle 23, thereby forming a kink or bend 56 in the cable 6 as illustrated in Fig. 5. The cable continues to slide on the brake drum 33 while rolling along the surface 32 of the mechanism.

Should it become desired to completely stop the mechanism at any given point along the cable 6, a continued downward pull on handle 23 will position the roller 32 relative to the brake drum 33 so that the movement of the mechanism along the cable 6 is stopped.

It will be noted that the roller 32 and brake drum 33 are positioned in the portions 26 and 27 of the spaced arms 21 and 22, so that as the handle 23 is pulled downwardly, the axis of the roller 32 and the axis of the drum 33 become laterally offset more and more tending to increase the amount of kink or bending in the cable 6.

The operator is supported by chain 44 on the device 11 in a manner and offset relative to the drum 33 and roller 32 so that the weight of the operator on one side of the body 20 and the counterweight 13 on the other side of the body exert forces in opposite directions to create a turning movement on the device 20 in a counter clockwise direction as viewed in Figs. 4, 5 and 6, whereby the mechanism itself has an inherent braking tendency which is additive to the force applied to handle 23. The bolt means 45, chain 44 and hook 43 are positioned in body 20 relative to drum 33 and wheel 32 and the link means 41 for engaging with the counterweight 13 is also positioned in the body relative to support means 45, 44 and 43 and relative to lever 22 to aid in slowing down movement of the device 11 on the cable 6 when the lever 22' is pulled downwardly behind cable 6. It is to be noted that an opening 51 is provided in the lower end of the portions 26 and 27 and more in alignment with the drum 33 and roller 32 and where the cable 6 is at an angle of less than approximately 60 with respect to the horizontal or ground line, the bolt 45, chain 44 and the hook 43 may be moved to the opening 51 since less braking effect by the body of the user will be necessary. However, where the angle of cable 6 is 60 or greater relative to the horizontal, it is desirable that the cable 44 be mounted in the position as illustrated in the drawings, so as to provide a maximum amount of braking by the weight of the user.

The drum 33 and wheel 32 are spaced far enough apart so that excessive kinking of the cable will not occur when it is in the free movement position as reflected in Fig. 4 of the drawings. However, the arrangement also enables the construction 'to be used in a situation where the cable angle approximates 90. For example, in oifshore drilling rigs, it is not unusual for the takeofi point of the device 11 to be ofiset from the landing area by as little as ten or twenty feet. In such situations, it can be seen that the angle of'the cable approachw 90.

Not only do limited space conditions exist in such situations as ofishore drilling rigs, but also space is generally at a premium in refineries and chemical plants.

The device may be made of any suitable material which is strong enough to withstand the stresses and strains to which it will be put over an extended period of time. One such metal i galvanized steel; however, the roller 32 and the brake drum 33 may be made of brass which are somewhat more wear resistant and spark resistant than other metals would be.

Broadly the invention relates to an escape device which is relatively simple in construction, but which is constructed and arranged so that the speed of descent may be easily and efiectively controlled by the user of the mechanism.

What is claimed is:

1. An escape device for moving down a cable to enable rapid egress from elevated positions comprising, a body having a cable receiving aperture for mounting the body on the cable, a roller means mounted in said body to ride on top of the cable, brake drum means mounted in said body below said roller means and adapted to engage the opposite side of said cable relative to that engaged by said roller, said body including a lever extending upwardly and inclined outwardly behind the cable which receives said body, a rearward extension on said body extending in the same general direction from said body as said lever, and means on said rearward extension for engaging the operator and supporting him on said device in a position laterally spaced from said drum, said lever and last named means being cooperable to shift the application of the operators weight to increase and decrease the braking effort of said brake drum means on said cable as desired.

2. An escape device for carrying a person from an elevated position down an inclined rope, cable or the like comprising, a body, roller means therein for supporting said body as it moves along the cable, brake drum means mounted in said body below said roller means and adapted to engage the side of the cable opposite to that I engaged by said roller means, and a lever on said body extending above said roller means and inclined outwardly behind said body, and means below said rollers on said body adapted to support a person on the device, said lever and last named means cooperable to, swing said body laterally of the cable to increase and decrease the braking efiort of said brake drum means to control the speed of the downward movement of said body on the cable.

3. An escape device for carrying a person from an elevated position down an inclined rope, cable or the like comprising, a body, roller means therein for supporting said body as it moves along the cable, brake drum means mounted in said body below said roller means and adapted to engage the side of the cable opposite to that engaged by said roller means, a lever on said body extending above said roller means and inclined outwardly behind said body whereby said body may be moved laterally of the cable to form a bend therein between said roller and drum means to slow downward movement of said body on the cable, and means on said body for supporting a person, said means being mounted laterally relative to said drum so that the weight of the person aids in lateral movement of said body by said lever to slow movement of said body along the cable.

4. An escape device for carrying a person from an elevated position down an inclined rope, cable or the like comprising, a body, roller means therein for supporting said body as it moves along the cable, brake drum means mounted in said body below said roller means and adapted to engage the side of the cable opposite to that engaged by said roller means, a lever on said body extending above said roller means and inclined outwardly behind said body whereby said body' may be moved laterally of the cable to form a bend therein between said roller and drum means to slow downward movement of said body on the cable, means onsaid body for supporting a person, said means being mounted laterally relative to said drum so that the weight of the person aids in lateral movement of said body by said lever to slow movement of said body along the cable, and counterweight means secured to said body to counterbalance at least in part the weight of the person on the device and positioned laterally of said support means and thereabove to add a turning movement efiect on said body as said lever is pulled down to aid in braking the device.

5. An escape device for moving down a rope, cable and the like including a body, means supporting said body on the rope, cable and the like, means for supporting a person on the escape device, and lever means on said body and movable downwardly for moving said body' laterally to shift the application of the persons weight supported in the device-to regulate the rate of movement of the device on the rope, cable and the like. References Cited in the file of this patent UNITED STATES PATENTS 247,708 Swett Sept. 27, 1881 300,843 Burks June 24, 1884 474,155 Bower May 3, 1892 970,534 McKinney Sept. 20, 1910 1,571,096 Rambin et a1 Jan. 26, 1926 2,576,531 Mitchell Nov. 27, 1951

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