TIMBER REAMER

Abstract: A timber reamer comprising a shaft (2), a cutting blade (10) projecting traversely from the shaft and collar means (16) adjustably mounted on the shaft, the collar means being adjustable in axial position thereby adjusting the effective depth of cut of the cutting edge.

Description: TIMBER REAMER This invention relates to a reamer. More particularly, the invention relates to a reamer which can be used to ream holes in timber. A problem which exists in reaming holes in timber is that different reamers need to be used in soft wood and hardwood for efficient cutting. The problem arises because a reamer with a given set and depth of cut may not function efficien in both soft and hard woods. The object of the invention is to provide a reamer which can be used to cut efficiently in both soft and hard woods. According to the present invention there is provided a reamer comprising a shaft, a cutting blade projecting transversely from the shaft and collar means adjustably mounted on the shaft, the collar means being adjustable in axial position thereby adjusting the effective depth of cut of the cutting edge. The invention will now be further described with reference to the accompanying drawings, in which: Figure 1 is a side view of a reamer of the invention. Figure 2 is another side view of the reamer. Figure 3 is an end view from one end of the reamer. Figure 4 is an end view from the forward end of the reamer, Figure 5 is a longitudinal cross-section through the reamer and Figures 6 and 7 show schematic cross sectional views through cutting blades at lines 6-6 and 7-7 respectively. The reamer illustrated in Figure 1 comprises a cylindrical shaft 2 having an integral stem portion 4 of narrower diameter which is suitable for insertion in the chuck of a drill (not shown). Integrally formed with the shaft 2 is a hollow guide shaft 6 having a transverse hole 8 therethrough within which is located a blade 10. As best seen in Figure 5, the blade 10 is held in position by means of a screw 12 having an alien key head 14. The reamer includes a collar 16 which is slidably mounted on the shaft 2. The position of the collar 16 can be adjusted and fixed by means of a grub screw 18, as seen in Figure 5. The collar 16 includes a pair of flats 20 to permit shavings from the blade 10 to pass in the axial direction past the collar 16. The collar includes two forwardly projecting fingers 22 on opposite sides thereof. Each of the fingers has a curved foot portion 24 at its free end. As best seen in Figure 1, the curved foot portions 24 are curved in planes which are transverse to the axis of the reamer. In use of the reamer, a hole is drilled in the wood or timber using an auger (not shown) or the like approximately the same or slightly larger diameter as the guideshaft 6. The auger is then used to increase the diameter of the hole to a diameter which is the same as the length of - 3 - the blade 10. The collar 16 is adjusted in its axial position on the shaft 2 so that the foot portion 24 lies a predetermined distance D behind the cutting edges 26 of the blade thereby adjusting the depth of cut of the blade. The curved feet 24 bear against and slide over the uncut wood adjacent to the edges 26 and thereby prevent jamming and efficient cutting of the timber. It has been found that the performance of the auger of the invention can be improved by using blades having cutting edges 26 which vary from a fine pitch adjacent to the shaft 6 to a relatively coarse pitch near the free ends of the blade, as shown by the typical cross-sections of Figures 6 and 7. The variation of pitch along the length of the blade (on both sides thereof) has been found to improve greatly the clearing of shavings and chips of wood towards the end of the reamer. The reamer of the invention can be used efficiently in both soft and hard woods which are dry or wet. Thus it is possible to use a single tool in a wide variety of applications. The shaft 2 includes a bore 30 for receipt of a crossbar (not shown) to assist in removal of the reamer from the workpiece. Many modifications will be apparent to those skilled in the art without departing from the spirit and scope of the invention.

Claims: Q -AΪMS 1. A reamer comprising a shaft (2), a cutting blade (10) projecting transversely from the shaft and collar means (16) adjustably mounted on the shaft, the collar means being adjustable in axial position thereby adjusting the effective depth of cut of the cutting edge. 2. A reamer as claimed in claim 1 wherein the collar means includes a generally annular body and fingers (22) which extend axially of the shaft and are disposed on opposite sides of the shaft. 3. A reamer as claimed in claim 2 wherein a foot member (24) is located at the free end of each finger, each foot member having a curved surface which, in use, bears against a transverse face of the material being reamed by the reamer. 4. A reamer as claimed in claim 3 wherein each curved surface includes a leading edge and a trailing edge, the leading edge being further spaced from said generally annular body than the trailing edge. 5. A reamer a claimed in claim 3 or 4 wherein the radially outer edges of the foot members have the same spacing from the axis of the shaft as the radially outer edges of said body. 6. A reamer as claimed in any one of claims 2 to 5 wherein the body includes a radial bore in which is threadably received a grub screw (18) which bears against the shaft and fixes the position of the body on the shaft. 7. A reamer as claimed in any one of claims 2 to 6 wherein said body includes flats (20) which permit shavings of material removed by the blade to pass axially of the shaft. 8. A reamer as claimed in any preceding claim wherein the blade is elongate and extends through a diametral bore (8) through the shaft. 9. A reamer as claimed in claim 8 wherein the blade is held in porition by a mounting screw (12) which is threadably received in a bore which extends axially from the forward end of the shaft.

Inventors: KNIGHT JOHN KEITH, KNIGHT, JOHN, KEITH
Applicants: ELTEK HOLDINGS PTY LTD, ELTEK HOLDINGS PTY. LTD.
Application year: 1987
Main classification: B27G15
IPC codes: B27G15