US2539664A - Collapsible safety guard for derrick ladders - Google Patents

Description

Jan. 30, 1951 L. E. HAY 2,539,664

COLLAPSIBLE SAFETY GUARD FOR DERRICK LADDERS Filed Nov. 7, 1946' 2 Sheets-Sheet 1 INVEN TOR.

Lg htman EHa M MW;

A TORNEY5 Jan. 30, 1951 I HAY 2,539,564

Filed Nov. 7, 1946 2 Sheets-Sheet 2 INVENTOR L 13 11 man E. Ha

A TTOHNEYS Patented Jan. 30, 1951 .COLLAPSIBLE SAFETY GUARD FOR DERRICK LADDERS Lehman E. Hay, Beaumont, Tex assignor to The Sun Oil Company, Philadelphia, Pa., a corporation of New Jersey Application November 7, 1946, Serial No. 708,383

4 Claims. 3

In the rotary process of drilling, it is necessary to erect a derrick of considerable height, provided with suitable hoisting equipment for manipulating the. drill pipe in the bore hole. At frequent intervals, it is necessary to withdraw the pipe from" the hole in order to replace the bit. During this operation, it is required that a man, known as the derrickman, be at a point near the top of the derrick, where he can connect, or disconnect, the drill pipe from the elevating equipment.

While thederrickmanv is sometimes permitted to ride the elevators in order to reach his working -position, this is generally considered to be dangerous practice and is prohibited by a great many operators of drilling equipment. A ladder is provided in order that the derrickman may climb to his Work position. This ladder is exposed to the weather, and often becomes coated with mud or fee, so that there is considerable danger of his slipping and perhaps falling from the ladder. Consequently, it is desirable that the ladder be enclosed in a chute or guard.

The safety guards now in general use consist of an angle llOll'flSJIIlE work of U-shaped cross section covered with an extruded metal sheathing. There are numerous disadvantages to this construction. For example, the sections of the guard chute are constructed of relatively light material. The become bent and distorted in dismantling and moving the derrick, so that the reassembling operation is dangerous and time-consuming. Furthermore, the chute frequently becomes so badly damaged after a few such moves that reassembly is impossible. In this event, a few sections of the chute are occasionally left out, which leaves the derrickman without protection on this portion of the ladder. An additional disadvantage is that the extruded metal sheathing is relatively smooth, and does not permit the derrickman to grab the safety chute and stop his fall in the event that he should slip.

I have devised a safety guard construction which eliminates the disadvantages inherent in safety chutes now or heretofore in use. A preferred embodiment of the invention is shown in the drawings, in which- Fig. l is a perspective showing my improved safety guard applied to a derrick, only a part of the height or length of each being shown.

Fig. 2 is a view in front elevation of a short length of the safety guard.

Fig. 3 is a plan view of one of the brackets forming one element of the safety guard.

Fig. 4 is a plan view of one of the end brackets of a section if the safety guard is made in sections.

To the derrick a is so secured the ends of a series of spaced-apart U shaped angle-iron brackets d as to surround the ladder E2 on all sides thereof except the derrick side; The brackets are provided with spaced-apart slots or openings (see Fig. 3) through which a series of chains 0' are threaded. Each opening has preferably a keyhole shape. Each c is'securely anchored in place by inserting links thereof in the narrowportions 2 of vertical aligning openings in the series of brackets and locking the chain to the brackets by means of bolts g inserted into the larger round portions-f ofthe openings.

The safety guard may be made in sections to facilitate handling. In such case each section should preferably be of a length equal to some even multiple of the girt spacing of the derrick. If made in sections, the upper and lower (or end) brackets of section should have openings hav ing an additional narrow portion 6 diametrically opposite to the opening e, as-shown in Fig; i; that is, each opening has a central circular portion f and oppositely located narrow portions e, e. The end links of each two aligning chains spanning adjacent sections are in-serted,.one in one narrow portion and the other in the other narrow portion, of an opening; after which one bolt g serves to lock both chains in place. The link of each of the two chains inserted into the opening should be at least one link removed from the end of such chain in order to permit locking in this manner.

The vertical distance a between successive brackets 11 (see Fig. 2) and the distance y between bracket openings (see Fig, 3) and'therefore between parallel chains 0 are so determined as to prevent the derrickman from falling through the guard. In practice a bracket spacing m of 3 /2 feet and a chain spacing y of 9 inches is satisfactory. Obviously both dimensions might be reduced considerably, or either or both might be slightly increased without rendering the device unsafe.

Once assembled, it is unnecessary to completely dismantle the safety guard preparatory to the removal of the derrick from one location to an other and the reinstallation thereon of the safety guard. t is necessary only to disconnect the brackets d from the derrick. The guard may then be collapsed into'a relatively small space for moving.

The brackets d, which are the only rigid elements of the guard, may be constructed of relatively heavy angle iron, in order to resist the ordinary stresses of dismantling and moving without increasing the weight of the complete structure above that of safety guards now or heretofore in use.

A safety guard embodying my invention provides many surfaces which the derrickman may catch, or which will necessarily arrest his fall,

"in the event that he should slip off the ladder; yet there are no sharp projections likely, if

sharpl contacted, to cause injury,

The advantages of the invention may be summarized as follows:

Maximum degree of safety to the derrickman.

Ease and simplicity of attachment to the derrick, dismantling, and re-attachment.

Substantial insurance against damage during attachment, dismantling and transportation.

What I claim and desire to protect by Letters Patent is:

l. A safety guard for a ladder, which is applied to a building structure, comprising a plurality of spaced-apart horizontal brackets, each bracket having a series of apertures therein so spaced that the apertures of adjacent brackets are in general vertical alignment providing in the brackets sets of Vertically aligned apertures,

a plurality of cables, one of said cables extending through each set of vertically aligned apertures, means for securing each cable in the aligned apertures of each set, said brackets having side and rear portions and being supported by the building structure, and said side and rear portions forming with said cables and the building structure an enclosure for the ladder.

2. A safety guard for a building structure having a ladder applied thereto, said guard comprising a series of protective brackets spaced apart in'vertical relation and certain of which are supported by the building structure, which, with said brackets, enclose the ladder, each of a number of successive brackets being provided with spaced apart openings each having a wider portion communicating with a narrower slotted portion, a series of protective vertically extending cables engaging a number of successive brackets at spaced apart points along each bracket, each cable comprising a chain one link of which eX- tends into the narrower slotted portion of an opening and bolts-extending through the wider portions of the openings and securing the chains to the brackets.

3. A safety guard for a building structure having a ladder applied thereto, said guard comprising a plurality of sections, one above another, each of which sections is composed of two spaced apart protective brackets, the upper bracket of one section constituting the lower end bracket of an adjacent section, each of said brackets having spaced apart openings each of which has a relatively wide central portion and two oppositely disposed relatively narrow end portions, said guard also comprising cables each of which comprises a series of protective chain sections extending between brackets, the lower link of a chain section of an upper guard section extending into one of said narrower slotted portions and the upper link of a chain section of a lower guard section extending into the other of said narrower slotted portions, and a bolt extending through the wider portion of each opening and anchoring both chain sections to the bracket.

4. A safety guard as defined in claim 1 comprising also other brackets constructed and arranged as therein specified and with which the cables are connected as therein specified and which are arranged between the brackets therein specified but which are supported solely by the cables.

LEHMAN E. HAY.

REFERENCES CITED 'The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 77,587 Colborn May 5, 1868 334,230 Jeffers Jan. 12, 1886 1,141,919 Auchu June 8, 1915 1,432,561 Johnson, Jr Oct. 17, 1922 1,507,651 Young Sept. 9, 1924 1,683,138 Kautz Sept. 4, 1928 FOREIGN PATENTS Number Country Date 7,751 Great Britain 1911 1 12,635 Great Britain l895 Certificate of Correction Patent No. 2,539,664 January 30, 1951 LEHMAN E. HAY

It is hereby certified that the name of the assignee in the above numbered patent was erroneously described and specified as The Sun Oil Company Whereas said name should have been described and specified as S'ZML Oil Company; and that the said Letters Patent should be read as corrected above, so that the same may conform to the record of the case in the Patent Ofiice.

Signed and sealed this 10th day of April, A. D. 1951.

[SEAL] THOMAS F. MURPHY,

Assistant Commissioner of Patents.

Images