GB2044650A - Removing slugs from flow drills - Google Patents

Abstract

A flowdrilling machine comprising a tubular spindle carrying a hollow flow drill a motor for rotating the spindle, a pneumatic cylinder for feeding the spindle and a rod or tube 17 passing through the spindle to project beyond the end of the drill when the drill is retracted to remove a slug C therefrom as the drill is retracted. <IMAGE>

Description

SPECIFICATION Improvements in slug removal from flow drills This invention relates to improvements in drilling machines, and more particularly to flowdrilling machines.

Flowdrilling is the process of forming a sleeve opening in a thin metal wall consisting of passing a rapidly rotating spinning drill tool through the wall for simultaneously frictionally generating red heat in the metal adjacent to the tool, thus causing the metal to became plastic and displacing it in both directions along a tool known as a flowdrill. A process is described in U.S. Patent 1,906953 (Enghauser) dated May 2, 1933 for forming a sleeve opening in thin wall malleable iron pipe consisting of passing a rapidly rotating spinning tool through the wall thereof for simultaneously frictionally generating red heat in the metal of the pipe adjacent the tool, thereby causing the metal to become plastic, and displacing the metal in both directions along the tool.

In recent years improved tools have been developed to perform this process, and its application to thin walls of a variety of metals is gaining ground.

The U.S. Specification 1906953 also describes a flowdrilling process consisting of initially forming an aperture in the wall and thereafter flowdrilling by passing a flowdrill of a greater diameter through the aperture and the wall. This method is applied where reduced length of the sleeve opening is required or where the available space requires the use of a shorter flowdrill.

A flowdrill which forms the initial aperture in the wall and subsequently flowdrills through this aperture in the wall in one end the same operation has recently been developed.

The flowdrill is formed with a cylindrical hollow core along its axis and a ground annular edges at its front and equal in size to the desired initial aperture.

In use this edge forms the initial aperture while leaving a central slug or disc of the wall material intact.

This slug can lodge inside the core of the self predrilling nose of the flowdrill which must be removed therefrom before the next operation commences.

According to the invention a flowdrilling machine comprises a tubular spindle carrying a hollow flowdrill, a motor for rotating the spindle, means for moving the spindle longitudinally and a rod or tube passing through the spindle to project beyond the end of the drill when the drill is retracted to remove a slug therefrom as the drill is retracted.

The invention will be described with reference to the accompanying drawings:- Fig. 1 is a vertical section through a flowdrilling machine incorporating the invention; Fig. 2 is a similar section to a larger scale of the rotating spindle in the fully retracted position.

Figs. 3-6 show detail sections of the flowdrill in progressive positions during operation.

A flowdrilling machine A comprises a rotating spindle 1 having a lower end la formed to carry a drill holding a collet chuck 3 and drill 4. The spindle 1 is driven by a motor 2 through a driving pulley 5, belt 6 and driven pulley 7. The spindle 1 rotates in bearings 8, 8a which are housed in a quill 9 mounted to slide longitudinally in the machine body 10 thus moving the rotating spindle 1 with the flowdrill 4 towards the work piece to perform the piercing operation and retracting again thereafter.

The feeding and retracting movement of the flowdrill 4 is shown diagrammatically, by the piston 11 attached to the quill 9 and reciprocating in a cylinder chamber 12 in the body 10, compressed air from a pneumatic circuit (Not shown) being alternately fed to the opposite ends of the cylinder chamber 12 through ports 13, 14. The machine body 10 is mounted on a pedestal 15 which is supported bathe drilling table 16 on which the work piece (not shown) is clamped.

A rod or tube 17 of relatively small diameter is mounted concentrically with the spindle 1 and passes through a bore therein and is adjustably clamped by a screw 19 to an arm 18 mounted on the upper end of the pedestal 15 and extends through the bore in the spindle 1 to project below the end of the tool 4 when this latter is in the retracted position. Alterna timely the rod 17 may be affixed to an arm carried by the body 10.

The rod or tube 17 passes through bearings 20, 21 in the spindle 1.

Figs. 3-6 show successive position of the rod or tube 17 during the piercing operation. Fig. 3 shows the tool 4 piercing the work piece B, Fig. 4, shows the tool 4 after passing through the work piece with a slug C removed from the work piece and lodged in the tool, Fig. 5 shows the tool at the end of the piercing stroke with the slug still lodged therein and a shoulder 4' on the tool in engagement with the metal which has flowed upwards during the piercing operation to form a bead D, Fig. 6 shows the tool being retracted and the rod or tube 17 removing the slug C from the tool.

1. Aflowdrilling machine comprising a tubular spindle carrying a hollowflowdrill, a motorforrotat- ing the spindle, means for moving the spindle longitudinally and a rod or tube passing through the spindle to project beyond the end of the drill when the drill is retracted to remove a slug therefrom as the drill is retracted.

2. A flowdrilling machine as in Claim 1, in which the rod or tube is adjustably mounted concentrically with the spindle on an arm extending from a stationary part of the machine.

3. A flowdrilling machine as in Claims 1 or 2 in which the rod or tu be is mounted in bearings in the spindle.

4. A flowdrilling machine substantially as described with reference to the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (4)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Improvements in slug removal from flow drills This invention relates to improvements in drilling machines, and more particularly to flowdrilling machines. Flowdrilling is the process of forming a sleeve opening in a thin metal wall consisting of passing a rapidly rotating spinning drill tool through the wall for simultaneously frictionally generating red heat in the metal adjacent to the tool, thus causing the metal to became plastic and displacing it in both directions along a tool known as a flowdrill. A process is described in U.S. Patent 1,906953 (Enghauser) dated May 2, 1933 for forming a sleeve opening in thin wall malleable iron pipe consisting of passing a rapidly rotating spinning tool through the wall thereof for simultaneously frictionally generating red heat in the metal of the pipe adjacent the tool, thereby causing the metal to become plastic, and displacing the metal in both directions along the tool. In recent years improved tools have been developed to perform this process, and its application to thin walls of a variety of metals is gaining ground. The U.S. Specification 1906953 also describes a flowdrilling process consisting of initially forming an aperture in the wall and thereafter flowdrilling by passing a flowdrill of a greater diameter through the aperture and the wall. This method is applied where reduced length of the sleeve opening is required or where the available space requires the use of a shorter flowdrill. A flowdrill which forms the initial aperture in the wall and subsequently flowdrills through this aperture in the wall in one end the same operation has recently been developed. The flowdrill is formed with a cylindrical hollow core along its axis and a ground annular edges at its front and equal in size to the desired initial aperture. In use this edge forms the initial aperture while leaving a central slug or disc of the wall material intact. This slug can lodge inside the core of the self predrilling nose of the flowdrill which must be removed therefrom before the next operation commences. According to the invention a flowdrilling machine comprises a tubular spindle carrying a hollow flowdrill, a motor for rotating the spindle, means for moving the spindle longitudinally and a rod or tube passing through the spindle to project beyond the end of the drill when the drill is retracted to remove a slug therefrom as the drill is retracted. The invention will be described with reference to the accompanying drawings:- Fig. 1 is a vertical section through a flowdrilling machine incorporating the invention; Fig. 2 is a similar section to a larger scale of the rotating spindle in the fully retracted position. Figs. 3-6 show detail sections of the flowdrill in progressive positions during operation. A flowdrilling machine A comprises a rotating spindle 1 having a lower end la formed to carry a drill holding a collet chuck 3 and drill 4. The spindle 1 is driven by a motor 2 through a driving pulley 5, belt 6 and driven pulley 7. The spindle 1 rotates in bearings 8, 8a which are housed in a quill 9 mounted to slide longitudinally in the machine body 10 thus moving the rotating spindle 1 with the flowdrill 4 towards the work piece to perform the piercing operation and retracting again thereafter. The feeding and retracting movement of the flowdrill 4 is shown diagrammatically, by the piston 11 attached to the quill 9 and reciprocating in a cylinder chamber 12 in the body 10, compressed air from a pneumatic circuit (Not shown) being alternately fed to the opposite ends of the cylinder chamber 12 through ports 13, 14. The machine body 10 is mounted on a pedestal 15 which is supported bathe drilling table 16 on which the work piece (not shown) is clamped. A rod or tube 17 of relatively small diameter is mounted concentrically with the spindle 1 and passes through a bore therein and is adjustably clamped by a screw 19 to an arm 18 mounted on the upper end of the pedestal 15 and extends through the bore in the spindle 1 to project below the end of the tool 4 when this latter is in the retracted position. Alterna timely the rod 17 may be affixed to an arm carried by the body 10. The rod or tube 17 passes through bearings 20, 21 in the spindle 1. Figs. 3-6 show successive position of the rod or tube 17 during the piercing operation. Fig. 3 shows the tool 4 piercing the work piece B, Fig. 4, shows the tool 4 after passing through the work piece with a slug C removed from the work piece and lodged in the tool, Fig. 5 shows the tool at the end of the piercing stroke with the slug still lodged therein and a shoulder 4' on the tool in engagement with the metal which has flowed upwards during the piercing operation to form a bead D, Fig. 6 shows the tool being retracted and the rod or tube 17 removing the slug C from the tool. CLAIMS

1. Aflowdrilling machine comprising a tubular spindle carrying a hollowflowdrill, a motorforrotat- ing the spindle, means for moving the spindle longitudinally and a rod or tube passing through the spindle to project beyond the end of the drill when the drill is retracted to remove a slug therefrom as the drill is retracted.

2. A flowdrilling machine as in Claim 1, in which the rod or tube is adjustably mounted concentrically with the spindle on an arm extending from a stationary part of the machine.

3. A flowdrilling machine as in Claims 1 or 2 in which the rod or tu be is mounted in bearings in the spindle.

4. A flowdrilling machine substantially as described with reference to the accompanying drawings.