US2107495A

US2107495A - Core drill

Info

Publication number: US2107495A
Application number: US73222A
Authority: US
Inventors: Otto William; Scott Francis Elmer
Original assignee: Individual
Current assignee: Individual
Priority date: 1936-04-08
Filing date: 1936-04-08
Publication date: 1938-02-08
Anticipated expiration: 1955-02-08

Description

Feb. 8, 1938. w. OTTO ET AL CORE DRILL Filed April 8, 1956 3 mumoaao, Erancdslijcoii.

Patented Feb. 8, 1938 UNITED STATES PATENT OFFICE CORE DRILL Application April 8, 1936, Serial No. 73,222

3 Claims.

This invention relates to improvements in drilling apparatus, more especially in core drills, and its objects are as follow;

First, to provide a core drill to be used in drilling for oil, gas and water, and which is of such a construction that it can be attended by one man.

Second, to provide a drill of the character described which when used for any of the foregoing purposes or for the drilling of test and shot holes in mining and tunnel work, is adapted to pumping out the core cuttings and removing the same to the surface of the ground so that the kind of earth formation through which the bit is passing can be inspected at any and all times without ceasing drilling operations.

Third, to provide a drilling apparatus which is made so light that it can be moved in a small trailer by any ordinary kind of automobile.

Other objects and advantages will appear in the following specification, reference being had to the accompanying drawing in which Figure 1 is a central vertical section of the bitcarrying body which functions as a pump.

Figure 2 is a detail side elevation of the drill bit which screws on to the bit body.

Figure 3 is an elevation of the framework of the drill rig, showing the drill in position.

Attention is first directed to Figure 1 which illustrates the previously mentioned bit body or so called pump. This body has chambers l, 2 and 3 through which core cuttings pass. A transversely situated pin 4 limits the upward movement of a ball valve 5. This ball valve is 3 displaced to the dotted line position 5 from its normally occupied seat 6 in order to allow core cuttings to pass on their way to the surface.

Holes, such as I, 8 and 9 (Fig. 1) and In (Fig. 3) are bored into the bit body so that they communicate with the chamber 2. These holes are situated on sharp angles. They are directed upwardly toward the ball valve 5 and thus facili tate the passage of the cuttings toward and past the ball valve.

The bit body, or pump as it has been called, is now designated ll. At its upper end it has a standard left-hand pipe thread l2. At its lower end it has a heavy left-hand thread I3 to match the correspondingly threaded socket in a known type of drill bit M. This is known as an air hammer bit. It has cutting edges IS. A hole [6 beginning at the internally threaded socket and going through the bit admits core cuttings from the bottom of the hole to the pump II to be pumped out to the surface through the drill stem as will be understood.

Reference is now made to Figure 3. A rubber hose 25, of which only a small portion is shown, disposes of the core cuttings. This hose is attached by means of a swivel joint 26 to a heavy 1 A" drill stem 21. This drill stem is made up of heavy pipe sections with screw joints on the inside. This arrangement leaves the stem smooth on the outside.

A support 28 carries a screw 29. This screw is in the form of a. sleeve through which the drill stem 21 passes, the function of the screw sleeve being to regulate the working of the bit H on the bottom of the hole, this being accomplished by turning the handle 29 as cutting proceeds.

A heavy steel spring 30 imparts a quick and added force to the down stroke of the drill. This insures fast cutting. A clamp 3| on the drill stem 21 provides a rest for the bottom of the spring 30, the other end of the spring abutting the screw sleeve 29. A guide 32 of any appropriate type guides the drill stem 21 in its reciprocation.

A lift is generally designated 33. The showing is to be considered as conventional. Actually the lift can be made in a number of ways in order to raise the drill stem 21 anywhere from 3 to 6" as may be desired. This lift will be timed to raise the drill stem about two hundred times per minute. It will take hold of the drill stem when the bit I4 is on the bottom of the hole, raising the drill stem and releasing it when the lift is completed. It is then that the spring 30 imparts a powerful down thrust.

What we claim is:-

1. A core drill comprising a hollow stem having a cutting bit attached to the lower end thereof, lift means applied to the stem medially of its ends and so operable as to periodically lift the stem, a rig which has means to guide the stem, a spring carried by the stem, said stem having an abutment with which one end of the spring is in engagement to resist the lifting effort of said lifting means, and a screw sleeve against which the other end of the spring abuts, said sleeve slidably carrying the stem, said rig having a support in which said sleeveis screwed for adjustment to vary the tension of the spring.

2. A core drill comprising a hollow drill stem, composed of pipe sections having inside joints which provide the stem with a smooth exterior, a cutting bit and means connecting the cutting bit to the lower end of the stem, a rig which has guide means for the stem and which has a screw support, a spring coiled around the stem and having one of its ends in engagement with a clamp on the;stem, an externally threaded sleeve screwed throigh said screw support, slidably' carrying and guiding the stem in addition to said guide means, and being abutted at one of its ends by the otheriiend of the spring, said stem being adjustable in'the screw support to vary the tension of the spring, and means to periodically lift the stem against the tension oi the spring.

3. A core drill colnprising a. hollow stem, a hose and means by which to connect said hose to the uppepend of the stem to carry away cuttings, a cutting bit and means connecting said bit to the lower end of the stem, said means cemprising a body with openings to admit the cuttings and a valve to control the passage of;said cuttings into the stem, a spring which exercises only a. downward pressure so as to drive the bit to its work, a rig on which the stem is guided, a pair of abutment means respectively on the stem and on the rig with which the opposite ends of the spring; contact to force the cutting bit down as stated, and lift means operating on the stem medially of its ends to produce lifting movements of the stem against the tension of the spring. 7 WILLIAM O'I'IG.

F. ELMljR sco'r'r.