US1031628A - Underreamer. - Google Patents

Description

J. M. DELMORE.

UNDERREAMEB..

4 APPLICATION lFILED AUG. 1, 1911. 1,031,628. Patented July 2,1912.

? d@ )gf/95% JOSEPH M. DELMORE, 0F LOS ANGELES, CALIFORNIA.

UNDERREAMER.

Specification of Letters Patent.

Application led August 1, 1911. Serial No. 641,783.

' cutters will expand to cut around a complete circle or a very large proportion thereof. In its preferred form I utilize three cutters; but it will be seen that any number may be used.

The gist of the invention is contained in the construction which allows the use of three or more cutters. And one of the prime advantages of my underreamer is its provision for three or more cutters; but the' construction which allows of this 1s of such 'simple and practical nature that it may be used to advantage in a two cutter construction if desired.

Heretofore, so far as I am aware, most underreamers have been provided with only two cutters and have been able to cut over only about half of the circle of the well hole. IVith my underreamer nearly the whole circle is cut over at each stroke; thus insuring a uniformly cylindrical hole.

In the drawings I have shown a preferred form of my construction, illustrating an underreamer with three cutters.

In these drawings: Figure 1 is a longitudinal section showing my underreamer in.

position for insertion in a well. Fig. 2 is a longitudinal section showing the underreamer with its cutters expanded ready yfor drilling operations. Fig. 3-is across section taken on lines 3 3 of Figs. 2 and 5. Fig. 4 is a cross sectiontaken on line 4.-4 of Fig. 2. Fig. 5 is an enlargedfragmentary longitudinal section taken as indicated Fig. 3. Fig. 6 is a longitudinal section taken on line 6-6 of Fig. 5. Fig. 7 is a bottom view of the underreamer as shown in Fig.

In' thel drawings 10 designates a mandrel having a suit-able connecting means 11 on its a longitudinal bore 12 therein. This longitudinal bore 12 is enlarged into a conical opening 13 of any suiti upper end and havin able shape at the lower end of the mandrel. A longitudinal rod 14 is secured in the mandrel at lts upper end, as at 15, and itslower end has an enlargement 16 thereon. This enlargement 16 is typicall below the lower end of the mandrel and 1s held stationary from the stationary rod 14. Mounted around rod 14 and sliding within the bore 12 Patented July 2, 1912.

of the mandrel is a barrel 20. Rod 14carries a collar 21 upon which a compression spring 22 is supported, the upper end of this spring pressing upwardly against a collar 23 in the upper end ofthe barrel 20, thus tending to raise the barrel to its uppermost position. The lower portion lof the barrel 20 is reduced, as shown at 20a, and this reduced portion carries on its lower end an enlargement 25. The movement of barrel 20 is sufficient to move the enlarged portion 25 from the position shown in Fig 1 to the position shown in Fig. 2. Enlargement 25 provides a means for connecting the barrel 20 with the cut-ters of the underreamer; and is typical of other methods of connection which may be used. l

Cutters 30 are preferably three in number and are each provided with upper portions 30a which t into the conical opening 13 in the lower end of the mandrel and which fit around the reduced portie-n 20al of barrel 20.

This is perhaps best shown in Figs. 2 and 3.

In this posit-ion of the cutters vthe lower ends SObare expanded to the posit-ion shown in Fig. 2. IThe upper ends of the cutters bed solidly against the mandrel and against the portion 20a of the barrel and t-he cutters are thereby held solidly in position. In this position inwardly'projecting portions 30c of the cutters bear against enlargement- 16, and the lower ends of the vcutters are thus solidly held in their expanded position. Shoulders 30d of the cutters rest'upon enlargement 25; and the cut-ters are thus supported by the spring 22 which supports barrel 20. When the barrel 20 is lowered, as when the underreamer is passing through the casing 50, the cutters are lowered to the position shown in Fig. 1, so that the recesses 30e in each of the cutters directly above portions 30c will then be opposite enlargement 16 and will allow the cutters to contract to the position shown in Fig. 1. When the underreamer is in this condition, both enlargements 16 and 25 will v be surrounded by the recesses 80. The up A perl ends of thefcutters do not then touch each other but hang comparatively loosely in the conical opening 13 and around the portion 20a of barrel 20. Immediately the underreamer passes out of the casing the spring 9.2 raises `the barrel 20 and raises the cnt-ters, forcing their upper ends into solid engagement with the mandrel and with the portion 20a of barrel 20 and forcing the portions 30c of the cutters into engagement with enlargement 16. This causes, as before eX- plained, the positioning of the cutters as shown in Fig. 2; and it will be. seen thatin this position t-he cutters are solidly supported against inward transverse thrust at their lower ends and against. longitudinal upward thrust.

Although the cutters are held within the mandrel by being connected with the barrel.

20, I additionally provide for retaining them within the mandrel by means of the device shown in Figs. 3, 5 and G. This device is intended to act as a safety appliance in case spring QQ-should break and allow the barrel 20 to lower; or in case the rod-14 should break and otherwise allow the barrel and the cutters to fall completely out of the mandrel. In each of the upper ends 30aL of the cutters 30.1 have provided a slot G0 which is wider at its lower end than at its upper end. Shoulders G1 are thus `formed against which the enlarged end portion G2 of link 63 may engage. Link 63 is placed in the position shownand has an enlarged upper end 64 which engages in a, slot 65 in barrel 9.0, this slot being of such configuration as to afford shoulders 6G against which the enlarged portion (Se may bear. Slots 60 and enlarged portions G2 allow'the cutters 30 their proper' vertical movement; but

should the cutters have a tendency to drop farther, the links 63 will prevent this.

From the foregoing it will be seen that my invention consists broadly in the provision of certain mechanism whereby a multiple cutter underreamer may be constructed; and specifically in the combination of the concentric vertically moving parts'which support andcontrol the action of the cutters. It is to these parts that I wish to particularly direct the following claims; desiring to cover broadly the combinations described. For this purpose Ithe exact conformation Vof the several parts is of n'o great importance; and particularly is this true of the central rod and its surrounding barrel.

The barrel may be 'considered broadly asa resiliently supported cutter supporting member, while the main function 'of the rod is to expandl the cutters which engage its lower end. Although I have adopted and shown a practical form for the working combination of the rod, barrel and cutters, the exact designs described are not essential.

Other arrangements may be substituted for VV'those specifically and preferably described without exceeding the scope of my invention.

Having described my invention, I claim: 1. In an underreamer comprising a tubular body having an attaching end, said body having a bore with a reduced upper portionv and an enlarged mouth portion, a rod, a barrel mounted upon the rod, said rod being secured in the reduced portion of the bore against movement,enlarged portions formed .at the lower ends of the rod and barrel, expansible means around t-he rod and within the barrel for 'holding said enlarged portions normally separated and the barrel in an upward position, and cutter' members having link connections with the barrel above the enlarged portions and having inwardly projecting portions engageable with said enlarged portions.

2. An underreamer comprising a tubular `mandrel having an Venlarged conical opening at its lower end, a vertical rod secured to the mandrel atyits upper end and passing down through its interior, an enlarged portion on the lower end of the rod near thc enlarged conical opening, a vertically. movable barrel on the rod and within the mandrel, an en- 'larged portion on the lower end of the barrel above the enlarged portion on the rod, a coiled spring around the rod within the barrel and acting to raise the barrel, and cutters supported on the barrel enlargedportion and having portions engageable with the rod enlarged portion, the upper ends of the cut-ters fitting into the conical opening in the lower end of the mandrel..

3.' An underreamer comprising a hollow -mandrel having a conical opening at its lower end, a longitudinal rod allixed at its upper end to the mandrel and extending through the mandrel to a point near its lower end, a barrel within the hollow mandrel and surrounding the rod, resilient means for supporting the barrel, cutters having upper ends adapted to fit within the conical lower opening of the mandrel andl having portions engaging the lower end of the longitudinal rod, and connectingl means between the cutters and the barrel.

4. An' underreamer, comprising a hollow mandrel having an upwardly tapering opening at its lower end, a' vertical rod secured at its upper end to the mandrel and projecting down through the tapering opening, a barrel slidable on said rod within the mandrel, resilient means to move the barrel upwardly on t-he rod, and a set of cutters supported by the barrel and having portions adapted to lit within the mandrel opening and portions adapted to engage the lower end of said rod'.

5. An underreamer, comprising a mandrel having an upwardly tapering opening at its lower end, a vertical rod secured at its upper end -to4 the mandrel and projecting down In Witness that I claim the foregoing I through said tapered opening, a. cutter suphave hereuntoisubscribed my name this 25 10 porting member slidable on th?) rod, resiliday of July 1911.

ent means to su ort said mem er, and cutters supported lfiythe said member and hav- JOSEPH'M' DLLMORE' ing portions engaging Wit-hin said tapered Witnesses:

opening and portions engaging the lower JAMES T. BARKELEW,

end of said rod. JAS. H. BALLAGH.

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