GB1593143A

GB1593143A - Drill bit attachments

Info

Publication number: GB1593143A
Application number: GB22618/78A
Authority: GB
Original assignee: Jacobs Manufacturing Co Ltd; Jacobs Manufacturing Co
Current assignee: Jacobs Manufacturing Co Ltd; Jacobs Vehicle Systems Inc
Priority date: 1978-05-25
Filing date: 1978-05-25
Publication date: 1981-07-15

Description

(54) AN IMPROVEMENT IN OR RELATING TO DRILL BIT ATTACHMENTS (71) We, THE JACOBS MANUFACTUR ING COMPANY LIMITED, a British Company, of Archer Tool Works, Archer Road, Sheffield, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The invention relates to drill bit attachments and has for its object to provide an improvement in or modification of the invention claimed in our prior patent No.

1,444,538.

It has been found that in certain conditions, and especially when used with a percussive drill, the drill bit attachments described and illustrated in Figs. 1 and 2 of our prior patent specification No. 1,444,538 tend to work their way back down the drill bits on which they are fitted so that in moving further away from the work surface they fail to receive all of the dust or swarf falling from the work surface, thereby detracting from their usefulness.

According to the invention, there is provided an improvement in or modification of the invention claimed in our prior patent No.

1,444,538, that is to say an attachment for fitment to a drill bit, the attachment having an annular member to receive dust or swarf during drilling, the annular member having at least a central part made of a resilient material with a central hole through which the drill bit is to extend so as to be gripped resiliently thereby, the hole being capable of accommodating a range of drill bit sizes. and the annular member having an inturned lip forming part of the boundary of a containing space to hold dust or swarf received by the attachment during drilling. the improvement or modification residing in the fact that the annular member is rotatable within a collar fitment which can be hand held by the user to retain the attachment in close proximity to the work surface so that it can receive substantially all the dust or swarf falling therefrom.

The annular member may be largely of moulded rubber construction. On the other hand, the annular member may define a container of which the base is a disc normal to the axis of the hole and the inturned lip will in this case be formed on a circumferential rim member which is a snap fit on the disc. In this case, the central part may be constituted by a central support bush made of rubber and engaged in a central aperture of the disc, the central support bush having been moulded integrally with a flexible gaiter defining the central hole through which the drill bit is to extend.

The collar fitment within which the annular member is rotatable may be of composite construction and include an outer casing element and a circlip accommodated in a internal groove in the outer casing. The axial length of the collar fitment will preferably be such that it can be held in abutment with the work surface whilst the "spinner" part of the attachment remains free to rotate with it with the drill bit on which it is fitted. The collar fitment may be formed with a flange portion which can be held against the work surface and will preferably be provided with a knurled or serrated portion on its exterior surface to facilitate it being held against rotation by the user.

In order that the invention may be fully understood and readily carried into effect, the same will now be described, with reference to the accompanying drawings, of which: Fig. I is an axial section through one form of attachment embodying the invention, Fig. 2 is a view similar to Fig. I of another form of such attachment, and Fig. 3 is an exploded view of the attachment shown in Fig. 2.

Referring now to Fig. I of the drawings, the attachment there illustrated includes a moulded rubber annular element generally indicated 10 having the form of a flat circular container with an undercut, i.e. inturned circumferential lip 12. At its centre the attachment has a flexible gaiter 14 surrounding and defining a central hole 16, the arrangement being such that the attachment can be fitted to any one of a range ofdrill bits by being made to slide onto the drill bit, the flexible gaiter expanding to accommodate the drill bit and gripping the latter resiliently.

A thin metal cage 11 with inturned lips top and bottom contains the moulded rubber element 10 (the latter having been able to be sprung into the cage by virtue of its flexible nature). The arrangement is such that when drilling in an overhead location, dust or swarf which falls from the work surface into the attachment is swept by centrifugal force beneath the circumferential lip 12. Consequently, it cannot fall into the drill chuck or onto the user.

Associated with the annular element 10 is a collar fitment 24 within which the annular element is rotatable when the collar fitment is hand held by the user, as shown in the drawing, to retain the attachment in close proximity to the work surface. In this way, the attachment can be prevented from working its way back down the drill bit on which it is fitted, which especially when percussive drilling it might otherwise have a tendency to do, and it can be ensured that the attachment will receive substantially all the dust or swarf falling from the work surface. The collar fitment includes an outer casing element 26 and a circlip 28 which can be accommodated in an internal groove 30 in the outer casing.

The arrangement is such that the "spinner" part of the attachment can be entered into the outer casing of the collar fitment and can be retained therein by the fitment of the circlip in its groove. The outer casing element is formed with a serrated portion 32 on its exterior surface to facilitate it being held against rotation by the user. It is also formed with an inturned flange portion 34 which partly overlies the "spinner" part of the attachment and which can be held against the work surface. The "spinner" part is freely rotatable within the collar fitment and is very slightly spaced from the work surface when the collar fitment is held in abutment with said surface. (It will be understood that the cage II, being made of metal, can spin freely within the outer casing element of the collar).

Referring now to Figs. 2 and 3. the attachment there illustrated is similar in operation to that described above but is of composite construction, the "spinner" part of the device comprising a flat annular disc 18 made of a synthetic plastics material, a central support bush 20 made of rubber, and a circumferential rim member 22 also made of a synthetic plastics material and having an inturned circumferential lip 12, so that together with the annular disc 18 it constitutes a container for dust and swarf. The disc 18 is normal to the axis of the hole 16 and forms the base of the container. The rim member is a snap fit on the disc 18 and the support bush is engaged in the central aperture of the annular disc. The support bush has been moulded integrally with a flexible gaiter 14 defining the central hole 16 which is to receive the drill bit on which the attachment is to be fitted.

As in the case of the previously described embodiment, the "spinner" part of the attachment is associated with a collar fitment generally indicated 24 which can be hand held, as shown in Fig. 2, to retain the "spinner" part in close proximity to the work surface. The collar fitment is of the same construction as that previously described, except that it is somewhat longer to accommodate the composite construction of "spin ner". In addition, the outer casing element is in this case shown to be provided with a number of slots 36 through which the user can see that the "spinner" part of the attachment is rotating with the drill bit on which it is fitted. In addition, these slots allow for the escape, by centrifugal action of any minute particles of dust which may have fallen onto the top flat face of the "spinner" part.

Thus there is provided an improvement in or modification of the drilling attachment described and illustrated in Figs. 1 and 2 of our prior patent specification No. 1,444,538.

Various modifications may be made without departing from the scope of the invention defined by the appended claims. For example, the casing part of the collar fitment could be made either of plastics or of metal (that is to say, as a die-casting). It will also be understood that the cage surrounding the "spinner" part of the embodiment of Fig. I could be made of plastics instead of metal and that the collar fitment could be a one piece element.

WHAT WE CLAIM IS: 1. An improvement in or modification of the invention claimed in our prior patent No.

1,444,538, that is to say an attachment for fitment to a drill bit, the attachment having an annular member to receive dust or swarf during drilling, the annular member having at least a central part made of a resilient material with a central hole through which the drill bit is to extend so as to be gripped resiliently thereby, the hole being capable of accommodating a range of drill bit sizes, and the annular member having an inturned lip forming part of the boundary of a containing space to hold dust or swarf received by the attachment during drilling, the improvement or modification residing in the fact that the annular member is rotatable within a collar fitment which can be hand held by the user to retain the attachment in close proximity to the work surface so that it can receive substantially all the dust or swarf falling therefrom.

2. An attachment according to claim I, in which the annular member is of one piece moulded rubber construction.

3. An attachment according to claim I,

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. the drill bit and gripping the latter resiliently. A thin metal cage 11 with inturned lips top and bottom contains the moulded rubber element 10 (the latter having been able to be sprung into the cage by virtue of its flexible nature). The arrangement is such that when drilling in an overhead location, dust or swarf which falls from the work surface into the attachment is swept by centrifugal force beneath the circumferential lip 12. Consequently, it cannot fall into the drill chuck or onto the user. Associated with the annular element 10 is a collar fitment 24 within which the annular element is rotatable when the collar fitment is hand held by the user, as shown in the drawing, to retain the attachment in close proximity to the work surface. In this way, the attachment can be prevented from working its way back down the drill bit on which it is fitted, which especially when percussive drilling it might otherwise have a tendency to do, and it can be ensured that the attachment will receive substantially all the dust or swarf falling from the work surface. The collar fitment includes an outer casing element 26 and a circlip 28 which can be accommodated in an internal groove 30 in the outer casing. The arrangement is such that the "spinner" part of the attachment can be entered into the outer casing of the collar fitment and can be retained therein by the fitment of the circlip in its groove. The outer casing element is formed with a serrated portion 32 on its exterior surface to facilitate it being held against rotation by the user. It is also formed with an inturned flange portion 34 which partly overlies the "spinner" part of the attachment and which can be held against the work surface. The "spinner" part is freely rotatable within the collar fitment and is very slightly spaced from the work surface when the collar fitment is held in abutment with said surface. (It will be understood that the cage II, being made of metal, can spin freely within the outer casing element of the collar). Referring now to Figs. 2 and 3. the attachment there illustrated is similar in operation to that described above but is of composite construction, the "spinner" part of the device comprising a flat annular disc 18 made of a synthetic plastics material, a central support bush 20 made of rubber, and a circumferential rim member 22 also made of a synthetic plastics material and having an inturned circumferential lip 12, so that together with the annular disc 18 it constitutes a container for dust and swarf. The disc 18 is normal to the axis of the hole 16 and forms the base of the container. The rim member is a snap fit on the disc 18 and the support bush is engaged in the central aperture of the annular disc. The support bush has been moulded integrally with a flexible gaiter 14 defining the central hole 16 which is to receive the drill bit on which the attachment is to be fitted. As in the case of the previously described embodiment, the "spinner" part of the attachment is associated with a collar fitment generally indicated 24 which can be hand held, as shown in Fig. 2, to retain the "spinner" part in close proximity to the work surface. The collar fitment is of the same construction as that previously described, except that it is somewhat longer to accommodate the composite construction of "spin ner". In addition, the outer casing element is in this case shown to be provided with a number of slots 36 through which the user can see that the "spinner" part of the attachment is rotating with the drill bit on which it is fitted. In addition, these slots allow for the escape, by centrifugal action of any minute particles of dust which may have fallen onto the top flat face of the "spinner" part. Thus there is provided an improvement in or modification of the drilling attachment described and illustrated in Figs. 1 and 2 of our prior patent specification No. 1,444,538. Various modifications may be made without departing from the scope of the invention defined by the appended claims. For example, the casing part of the collar fitment could be made either of plastics or of metal (that is to say, as a die-casting). It will also be understood that the cage surrounding the "spinner" part of the embodiment of Fig. I could be made of plastics instead of metal and that the collar fitment could be a one piece element. WHAT WE CLAIM IS: 1. An improvement in or modification of the invention claimed in our prior patent No.

3. An attachment according to claim I,

in which the annular member defines a container of which the base is a disc normal to the axis of the hole and the inturned lip is formed on a circumferential rim member which is a snap fit on the disc.

4. An attachment according to claim 3, in which the central part is constituted by a central support bush made of rubber and engaged in a central aperture of the disc, the central support bush having been moulded integrally with a flexible gaiter defining the central hole through which the drill bit is to extend.

5. An attachment according to any one of the preceding claims, in which the collar fitment within which the annular member is rotatable is a one piece element.

6. An attachment according to any one of claims 1 to 4, in which the collar fitment is of composite construction and includes an outer casing element and a circlip accommodated in an internal groove in the outer casing.

7. An attachment according to any one of the preceding claims, in which the axial length of the collar fitment is such that it can be held in abutment with the work surface whilst the "spinner" part of the attachment remains free to rotate within it with the drill bit on which it is fitted.

8. An attachment according to claim 7, in which the collar fitment is formed with a flange portion which can be held against the work surface.

9. An attachment according to any one of the preceding claims, in which the collar element is provided with a knurled or serrated portion on its exterior surface to facilitate it being held against rotation by the user.

10. An attachment for fitment to a drill bit, constructed, arranged and adapted to be used substantially as hereinbefore described, with reference to and as illustrated by Fig. I or Figs. 2 and 3 of the accompanying drawings.