GB2179593A

GB2179593A - Saw blade

Info

Publication number: GB2179593A
Application number: GB08620843A
Authority: GB
Inventors: Tai-Her Yang
Original assignee: Individual
Current assignee: Individual
Priority date: 1985-08-28
Filing date: 1986-08-28
Publication date: 1987-03-11
Also published as: GB8620843D0; GB8521368D0

Abstract

A saw blade for use in e.g. a hand saw, band saw or circular saw has spaced side faces and a toothed edge and is characterised in that the faces have means to remove debris from the sides of a kerf cut by the blade. These means may comprise spaced, straight or curved ribs 11. The blade may have a tapered cross-section such that it is thicker adjacent the toothed edge than an opposite, untoothed edge. <IMAGE>

Description

SPECIFICATION Saw blades This invention relates to saw blades for use in various saws such as hand saws, circular saws etc.

In general, saw blades comprise a substantiallyflat plage having spaced parallel faces and atoothed edge. In use, the toothed edge cuts into the surface of a workpiece, removing waste material from the workpiece to create a slot or kerf. In the case of a wooden workpiece, for example, that waste material is in the form of sawdust and splinters. As the blade sinks further into the workpiece, the kerf is deepened and the faces of the blade tend to rub againstthe sides of the kerf.

The frictional resistance between the faces of the blade and the kerf is disadvantageous in that it hinders the passage of the blade through the workpiece, thus, increasing the amount of work required to cut through theworkpiece and also causing the blade to heat up. Furthermore, the frictional resistance is increased when the waste material becomes trapped between the faces of the blade and the sides of the kerf.

It is an object of the present invention to overcome the foregoing disadvantages.

Hitherto, attempts at overcoming the foregoing disadvantages have included providing slots through thethickness of the saw blade to minimisethesurface areaofthebladewhich might rub againstthe sides of the kerf. For example, British Patent 727,227 to Establishment C.D. discloses a tensioned band saw blade provided with a series of circular holes along the middie of the blade, The holes assist in removal of waste material from the kerf and facilitate cooling of the blade. However, such attempts have only been partially successful.

According to one aspect ofthe invention there is provided a saw blade having spaced side faces and a toothed edge characterised in that the faces have scraping means to remove debris from the sides of a kerfcutbythe blade.

The scraping means may comprise spaced ribs.

The ribs may be curved. The ribs may extend substantially completely across the faces of the blade. The blade may be circular. According to a further aspect of the invention there is provided a saw blade compris- ing spaced faces and a toothed edge characterised in that a portion of a face is located out of a plane containing the remainder of said face. Said portion may comprise an elongate rib proud of said plane.

Alternatively, said portion may comprise an elongate groove formed in said face. Said rib or groove may be parallel with said cutting edge.

Alternatively, the blade may be circular. According to a still further aspect of the invention there is pro- vided a saw blade comprising spaced faces, a toothed first edge and a second edge spaced therefrom char acterised in that the distance between said faces adjacent the second edge is less than the distance between the faces adjacent the toothed edge, the blade may have a substantially triangular cross section.

Alternatively, the blade may have a substantially trapezoidal cross-section. The blade may be circular.

The blade may have a spiral-like formation on a side face thereof. The spiral-like formation may comprise a rib or grooves in the blade. There is also provided a saw blade constructed and arranged substantially as described herein with reference to the accompanying drawings.

The invention will now be described by way of example with reference to the accompanying drawings: Figure 1 is an elevation of a portion of a saw blade in accordance with one aspect of the invention.

Figure la is a plan ofthe blade of Figure 1.

Figure 2-1 is an elevation of a portion of a saw blade in accordance with the invention.

Figure 2-2 is an elevation of a portion of a sawblade in accordance with the invention.

Figures 3,4 and 5 a re elevations of portions of sawblades in accordance with the invention.

Figures 3-1,41 and 5-1 fand IAJ are cross sec- tions through the saw blades shown in Figures 3,4 and 5 respectively.

Figure 5-2 is an elevation of a portion of a hand sawblade in accordance with the invention.

Figures 5-2A and 5-2B are cross sections through the saw blade shown in Figure 5-2.

Figure 5-3 is an elevation of a circular saw blade in accordance with the invention.

Figures 5-3A and 5-38 are cross sections through the saw blade shown in Figure 5-3.

Figures 6-A and 6-B are cross sections and partial elevations of further saw blades in accordance with the invention.

The blade 1 shown in Figure 1 has a toothed edge 2 and parallel faces 3 and 4 (not shown). Scraping means comprising curved ribs, eg 5, stand proud of faces 3 and 4 and extend towards the toothed edge 2.

In use, the curved ribs scrape waste material from the sides of the kerf.

The blade 10 shown in Figure 2-1 has scraping means comprising scale-like ribs e.g. 11 on both faces 12 and 13 (not shown). In use, the ribs 11 scrape waste material from the sides of the kerf.

The blade 20 shown in Figure 2-2 has ribs 21 arranged in a criss-cross pattern on faces 22 and 23 (notshown) ofthe blade 21. In use, the ribs 21 have a filing action on the sides of the kerf, thus smoothing those sides and reducing the frictional resistance between the faces 22 and 23 of the blade and the sides of the kerf.

The blade 30 shown in elevation in Figure 3, and in cross section in Figure 3-1, has grooves 31 extending parallel to toothed edge 32 oftheblade. By reducing the area of contact between the faces of the blade and the sides ofthe kerfthegrooves 31 minimisethe friction between the faces blade and the sides ofthe kerf.

The blade 35 shown in elevation in Figure 4, and in cross-section in Figure 4-1, has ribs 36 extending parallel to the toothed edge 37 ofthe blade. The height of the ribs 36 above the surface of the blade 35 is equal to the set S of the toothed edge. In use, onlythe ribs 36 rib against the side of the kerf. By reducing the area of contact between the faces of the blade and the side of the kerf the ribs 36 minimisethefriction between the faces of blade and the sides of the kerf.

The gaps 38 between the ribs 36 assist in there moval of the waste material from the kerf.

For certain applications, it may be desirable to have such ribs or grooves angled towards the cutting edge.

The blade 40 shown in elevation in Figure 5 and in cross section in Figures 5-1 and 5-1A has ribs 41 or grooves 42 angles towards atoothed cutting edge 43.

In use, during the forward cutting stroke ofthe blade, the friction between the ribs 41 and the sides of the kerf produces a force having downward component which urges the toothed edge 43 down into the kerf thus enhancing the cutting action of the blade.

The gaps between the ribs 41 and the grooves 42 assist in removal of waste material from the kerf.

The blade 50 shown in elevation in Figure 5-2, and in cross-section in Figures 5-2A and 5-2B, is adapted for use in a band saw, has ribs 51 or grooves 52 angled towards toothed cutting edge 53. In use, the friction between ribs 51 and the sides of the kerf results in a force on the blade having a component in the direction thetoothed edge 53 which urges the toothed edge 53 towards the workpiece thus assisting the cutting action of the blade.

The circular saw blade 60 shown in elevation in Figure 5-3 and in cross-section in Figures 5-3A and 5-3B has curved ribs 61 or grooves 62 on faces 63 and 64.

The blade 70 shown in Figure 6-A has a tapered cross section such that the blade is thicker adjacent the toothed edge 71 than adjacent the spine ofthe blade 72.

This tapered cross-section reduces the contact between the faces of blade 70 and the sides ofthe kerf without substantially reducing the strength of the blade.

The blade 80 has toothed edge 81 and spine 82. The lateral section 83 ofthe blade 80 adjacent the spine 82 of the blade is of reduced thickness compared to the lateral section 84 adjacent the toothed edge 81. In use, the reduced thickness of the section 83 minimises the friction between the faces ofthe blade and the sides ofthe kerf.

Because ofthe slight loss in lateral strength, blades 70 and 80 find particularapplication in saws, such as hacksaws, in which the blade is kept under tension.

Claims

1. A saw blade having spaced side faces and a toothed edge characterised in that the faces have scraping means to remove debris from the sides of a kerficut by the blade.

2. A saw blade according to Claim 1 characterised in that the scraping means comprise spaced ribs.

3. A saw blade according to Claim 2 characterised in thatthe ribs are curved.

4. A saw blade according to Claim 2 or3 characterised in that the ribs extend substantially completely acrossthefaces ofthe blade.

5. A saw blade comprising spaced faces and a toothed edge characterised in that a portion of a face is located out of a plane containing the remainder of said face.

6. A saw blade according to Claim characterised in that said portion comprises an elongate rib proud of said plane.

7. A saw blade according to Claim 5 characterised in that said poriton comprises an elongage groove formed in said face.

8. A saw blade according to Claim 6 or 7 characterised in that said rib or groove is parallel with said cutting edge.

9. A saw blade according to Claim 6 or 7 characterised in that said rib or groove extends towards said cutting edge.

10. A saw blade comprising spaced faces, a tooth ed first edge and a second edge spaced therefrom characterised in that the distance between said faces adjacent the second edge is less than the distance betweenthefacesadjacentthetoothed edge.

11. A saw blade according to claim 10characterised in that the blade has a substantially triangular cross section.

12. A saw blade according to Claim 11 characterised in thatthe blade has a substantiallytrapezodial cross-section.

13. A saw blade according to any preceding claim characterised in thatthe blade is circular.

14. A saw blade according to Claim 13 characterised in that the blade has a spiral-like formation on a side face thereof.

15. A saw blade according to Claim 14 characterised in that the spiral-like formation comprises a rib or grooves in the blade.

16. A saw blade constructed and arranged sub stantiallyas described herein with referencetothe accompanying drawings.