US1832129A

US1832129A - Expanding bit

Info

Publication number: US1832129A
Application number: US374808A
Authority: US
Inventors: Schuyler C Knaur
Original assignee: Individual
Current assignee: Individual
Priority date: 1929-06-29
Filing date: 1929-06-29
Publication date: 1931-11-17
Anticipated expiration: 1948-11-17

Description

Nov. 17, 1931. s. c. KNAUR EXPANDING BIT Filed June 29. 1929 r r Y r lgsw f will@ f V Patented Nov. 17, 1931 pasaras EXPANDING Brr Application led June 29,

My invention relates to drills for use in deep well drilling for oil, gas, water, sulphur and the like.

In deep well drilling a large item of eX- pense is incurred in withdrawing the drill from the hole to sharpen or replace the cutters. Where the hole is deep it sometimes happens that a third of the time is thus consumed. This is not only expensive in the extra amount necessary to pay the drilling crew, but also in the time wasted where production should be obtained.

It is an object of myinvention to provide a drill that may be withdrawn for sharpening or replacement in a minimum of time without the necessity of removing the drill stem.

I contemplate the removal of the drill by means of a cable which may be reeled up quickly. The drill to which the cable may be engaged is adapted to collapse within the drill stem so that it may be readily removed.

It is a iurtherobject to provide a. reaming bit, to be employed with a pilot bit, the

cutters of the reamer being easily and pos'- itively expanded, and of simple construction so that the device is cheap and economical to manufacture and'not liable to get out oi order or tail to function positively at all times. I desire to eliminate springs or levers or similar elements which might get clogged or jammed and thus fail in use.

In the drawings herewith Fig.' 1 is a central longitudinal section through a device F embodying my invention, the expanding elements being` in cutting position at the lower end of the drill stem.

Fig. 2 is a broken detail illustratinsr the cutting blades in contracted position where they may be withdrawn through the drill stem to the surface.

Fig. 3 is a broken detail in elevation illustrating the manner in which the blades-are supported during rotation.

In constructing my device I connect at the lower end of a drill stem l a shoe 2, which is of slightly heavier construction than the drill stem and is formedto cooperate with my expanding bit. The inner diameter of the shoe is decreased slightly over that of Cil 1929. serial No. 374,808.

the drilll stemy to form aV shoulder upon which a drill nipple 4 may be supported. The lower end of the shoe is formed with two approximately opposite downwardly extending arms 5..'1As seen in Fig. 3, these arms may be beveled forwardly Vat 6 although this is not 'a necessary feature.

The drill which I employ may bea fish tail bit or any common type of drill `which may be preferred. I have shown a shytail bit 7 as having the usual threaded connection with the lower end of the drill nipple 4,previously referred to. Said drill nipple is of tubular construction. It has a peripheral flange 8 spaced slightly from the upper 35 f end, said flange being adapted to engageupon the shoulder 3 in the shoe and is supported b v gravity thereon.

Spaced slightly above the pilot bit I pro- .v. vide'a plurality of expanding cutter blades 9, Said blades are approximately triangular in shape and are pivotally supported upon pins 10 extending through the upper ends of said blades' andfthrough the walls of the slots 11 in the nipple. in which said blades are 75 mounted. The slots 11 in the nipple, which accommodatev the blades, are of vsufficient width to allow free movement of the blades therein. the slots .being approximately ,opposite but slightly offset so that when the blades are moved inwardly to contracted position. as shown in Fig. 2,#thelv may nass each other and overlap to some extent. It is to be noted that the "inner si des ot' the blades. indilf cated'at 12.` are straight so that thev mav con.- tact with an inner expanding mandrel 13. y The mandrel 13 is adapted to proiect above the nipple 4 and mav be provided with a head i any preferred construction. wherebv it mav be engaged bv a setting tool or similar device so that it may be lowered into the well and released and' asrainv engaged :tor withdrawal. Setting tools adapted for this purposeare of ordinary and common construction and need not be shown. i The mandrel is of suitable outer diameter to lit slidably within the nipple Ll. The lower end of the mandrel is flattened slightly/ron each side at l5 to'abut against the inner sides l2 of the blades so as 100 and the nipple l is provided by means of a transverse pin 16, which is supported within the walls of the nipple l and extends dia.-

metrically through slots 17 formed in the opposite sides of the mandrel. Each slot 17 is accurately positioned relative to the blades so as to allow suliicient longitudinal play or sliding movement of the mandrel relative to the nipple so that when the mandrel vis drawn upwardly, so as to bring the lower end of the slot 17 in contact with the pin, as shown in Fig. 2, the lower end of the mandrel will be entirely free of the cutters so that they may be moved inwardly Vinto retracted position, the length of the-slotbeing sufficient. however, so that when theV mandrel is lowered between the cutters, as shown in Fig. 1. the pin 16 will be toward the upper limit of the slot. A

It is to be noted also that when the nipple 4 is in position with-the iiange 8 resting upon the shoulder B in the shoe, the slots '11 in which the blades are mounted, will `be sufiici'ently beyond the lower end of the shoe so as to allow the blades to be projected outwardly. When said blades are thus projected,

as into the position shown in Fig. 1, the outer edgesof the blades will come into contact with the lower beveled shoulders 18 upon the shoe, thus limit-ing the outward movement of the blades and clamping` said blades rigidly between the lower end of the mandrel and the inner wall of the shoe. Also. when the drill stem is rotated in the usual right-hand direction` the arms 5 upon the shoe will engage against the rearward sides of the blades and exert a driving action thereon and support them from the rear.

The operation of my device will now be understood. The drill stem may be introduced into the hole andmay remain there throughout the drillingof the'well. The bit.J including the pilot drill 7 andthe expanding blades 8, may be lowered into the well to cutting position. While the device is being thus lowered the nipple and the bits will be supported from the mandrel and the weight of the nipple willmove the pin 16 in the said nipple to the lower end of the slot 17 in the mandrel andthe blades will be contracted below the mandrel, as seen in Fig. 2. When the bottom of the well has been reached the bit will rest upon the bottom of theA hole and the weight of the mandrel will move said mandrel downwardly relative'to the nipple, contacting with the inner edges of the blades and forcing saidblades outwardly to the position shown in Fig. 1. The flattened sides of the mandrel will engage between the blades and form a rigid and firm support for said blades on their inner sides and the outer edges of the blades will be clamped against the shoe. ,'When the blades are thus expanded it will be seen that a downward pressure upon the drill stem will be exerted against the blades and a driving torque will be exerted against the rearward sides of the blades to move them with the drill stem to cut the wall of the hole. The pilot drill 7 will cut a hole of a size to allow the nipple to move downwardly but the blades 9 will enlarge this hole to allow the 'free downward descent of the drill stem. lVhen the blades become dulled and need repair or replacement a fishing tool vers or other similar parts which may beclogffed or broken or interfere with the positive action ot the cutting blades. The blades are projected into cutting position ina positive manner and when the device is to be with drawn there is nothing' to interfere with the ready retraction of the blades so that the cut-ters may be withdrawn to the surface for repair. The further advantages-will be obvious to those skilled in the art.

1What I claim as new is:

A well drill including a drill stein, a shoe thereon, a drill nipple slidable within said shoe, a pilot drill at the Jforward end ot said nipple, cuttingblades in said nipple above said drill, said blades being pivoted to be swung outwardly from a. normally retracted position in said nipple tocut a hole ot larger .diameter than said pilot drill, and a` mandrel in said nipple adapted to lit between said blades and irovev them into cutting position, said bladeshaving straight inner sides adapted to abut against the said mandrel. for their entire length and be thus held rigidly in expanded position, and vdownwardly projecting legs on said shoe to support said blades from their rearward sides during rotation of said drill and communicate rotation to said pilot drill.

In testimony whereof I hereunto aiiix my signature this 22d day o J une, A. D. 1929.

` SCHUYLER C. KNAUR.