Unlock instant, AI-driven research and patent intelligence for your innovation.

Integral bit retention system

a retention system and integrated technology, applied in the field of percussion bits, can solve the problems of difficult installation of bits, system cannot be used, and difficult removal of percussion bits, and achieve the effect of simple, without the risk of thread fouling

Inactive Publication Date: 2005-04-07
NUMA TOOL CO
View PDF0 Cites 11 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

[0005] With the present invention, a novel percussion bit assembly, and associated novel bit retainer, can be simply achieved without the requirement for rotating the bit relative to the retainer, and without the risk of thread fouling.
[0007] The upper portion of the percussion bit axial bore forms a circumferential shelf. In one embodiment, the bit retainer includes a pair of retainer bars, with each of the retainer bars having a longitudinal portion and a lateral portion defining the longitudinal and lateral members. A radially outer end portion of each lateral portion is received in one of a pair of circumferentially spaced receptacles. The upper end portion of each longitudinal portion has a tab extending radially outward therefrom which are supported on the shelf of the percussion bit axial bore. The bit retainer also includes upper and lower spacers. The upper spacer is positioned proximate to the upper end portions of the retainer bars and the lower spacer is positioned proximate to the lower end portions of the retainer bars, such that the upper and lower spacers prevent radial movement of the tabs and the lateral portion of the retainer bars.
[0011] In one variation of this embodiment, the first end portion of the pin includes outer and inner segments. The outer segment extends from the outer surface of the first side of the bit skirt to an intermediate position between the outer surface of the first side of the bit skirt and the axial bore, with the inner segment extending from the intermediate position to the axial bore. The second end and middle portions of the pin and the inner segment of the first end portion of the pin have a substantially uniform outside diameter which is smaller than the inside diameters of the transverse bore and the openings of the retainer tube, to facilitate insertion of the pin into the transverse bore. The outer segment of the first end portion of the pin has an outside diameter selected such that the outer segment frictionally engages the transverse bore after the pin is inserted.

Problems solved by technology

The threaded section of such retainers may become fouled during drilling operations, making removal of the percussion bit difficult.
Bits may be difficult to install due to corrosion and wear induced degradation of the threaded section of the retainer.
Accordingly, the system cannot be used until a modified chuck is installed on the drill string.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Integral bit retention system
  • Integral bit retention system
  • Integral bit retention system

Examples

Experimental program
Comparison scheme
Effect test

first embodiment

[0036] A bit retention system 58, 106, 118, 126, 138, 140, 198 in accordance with the invention is integral with the bit 60. Accordingly, such a bit 60 may be used with any standard drill without requiring modification of the drill. With reference to FIGS. 2-5, a bit retention system 58 in accordance with the invention includes a pair of retainer bars 62 and upper and lower spacers 64, 66.

[0037] Each retainer bar 62 has an upper end portion 68 including a radially extending tab 70, an intermediate portion 72 extending downwardly from upper end portion 68, and a radial retainer portion 74 extending perpendicularly from the intermediate portion 72. The bottom end of intermediate portion 72 includes a radially extending protrusion 76. The retainer bars 62 are inserted longitudinally into the upper end 78 of the bit axial bore 80, retainer portion 74 first, until the lower surface 82 of each tab 70 is positioned just above the location of a shelf 84 formed in bore 80 and each retainer p...

embodiment 138

[0045] In the embodiment 138 shown in FIGS. 9 and 11, the second end portion 162, the middle portion 166 and an inner segment 172 of the first end portion 168 have a uniform diameter 174 which is sufficiently smaller than the inside diameter 176 of blind bore 152 and openings 158 to allow easy passage therethrough. An outer segment 178 of the first end portion 168 has an outside diameter 180 which is greater than outside diameter 174. Diameter 180 is selected such that the outer surface 182 of outer segment 178 will frictionally engage the inner surface 184 of blind bore segment 170 to lock an installed pin 160 within blind bore 152. To install the pin 160, the bit skirt 104 is heated sufficiently to increase inside diameter 176, the pin 160 is inserted into blind bore 152, and the bit skirt 104 is allowed to cool. As the bit skirt cools, inside diameter 176 returns to its original size, thereby clamping the outer segment 178 of the pin 160 within blind bore segment 170. Any part of...

embodiment 140

[0046] In the embodiment 140 shown in FIGS. 10 and 12, the entire pin 160′ has a uniform diameter 186 which is sufficiently smaller than the inside diameter 188 of blind bore 152 and openings 158 to allow easy passage therethrough. The pin 160′ has a length 190 that is less than the length 192 of blind bore 152. Accordingly, an outer portion 194 of bore segment 170 remains empty after the pin 160′ is fully inserted into blind bore 152. A plug or a plug weld 196 is installed in this outer portion 194 to lock the pin 160′ in blind bore 152.

[0047] The embodiment 198 shown in FIG. 13 is a variation of embodiment 138, with two pins 160″ and two bores 200 in place of the single pin 160 and blind bore 152 of embodiment 138. Preferably the bores 200 are positioned substantially 180° apart. Each pin 160″ has a first end portion 168 having an inner segment 172 and an outer segment 178, similar to pin 160. However, the middle portion 166″ of each pin 160″ only extends through one of the openin...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

A percussion bit assembly includes a percussion bit having an upper, elongated bit shank, a lower bit head, and a bit skirt disposed intermediate the bit shank and the bit head. The percussion bit has an axial bore extending longitudinally through at least the bit shank and the bit skirt and at least one receptacle extending radially outward from the lower portion of the axial bore. A bit retainer includes at least one longitudinal member and at least one lateral member. The longitudinal member extends longitudinally within the axial bore of the percussion bit from an upper end portion, mounted within the upper portion of the axial bore, to a lower end portion disposed in the lower portion of the axial bore. The lateral member extends laterally from a radially inner end portion connected to the lower end portion of the longitudinal member to a radially outer end portion mounted in the receptacle.

Description

BACKGROUND OF THE INVENTION [0001] This invention relates generally to earth boring percussion bits. More particularly, the invention relates to retention systems for ensuring that even when broken during use, the percussion bit remains connected to the drill string. [0002] U.S. Pat. No. 5,065,827 discloses a conventional hammer and percussion bit assembly having a percussion bit retention system. The percussion bit retention system includes a retainer which is mounted on the drive sub of the percussion bit assembly. The retainer includes a lower section having an inner chamber and a thread-shaped, inwardly extending projection. The bottom portion of the percussion bit includes a head section, a threaded section and a recess disposed intermediate the head section and the threaded section. The percussion bit is installed by inserting the upper portion of the percussion bit into the retainer until the threaded section of the lower portion abuts the thread-shaped projection of the reta...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
IPC IPC(8): E21B10/36E21B17/046
CPCE21B17/046E21B10/36
Inventor PASCALE, JACK H.VINCENT, ROBERT F.PELLETIER, GARY R.
Owner NUMA TOOL CO