GB2387350A

GB2387350A - Improved saw blade

Info

Publication number: GB2387350A
Application number: GB0305255A
Authority: GB
Inventors: Howard George Osborne
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-03-07
Filing date: 2003-03-07
Publication date: 2003-10-15
Anticipated expiration: 2023-03-07
Also published as: GB2387350B; WO2004078399A1; GB0305255D0

Abstract

A saw blade 1 having a cutting edge 3 provided with cutting means 5,7, characterised in that an end region 4 of the cutting edge 3 is provided with cutting means 5 having a finer cutting characteristic than a remaining region 6 of the cutting edge 3. The saw blade 1 enables a start groove to be formed in a work piece with just the end region 4 of the cutting edge 3, the finer cutting characteristic of the cutting means 5 reducing skipping, jumping and splitting of the work piece. Once the start groove has reached a sufficient depth, the coarser cutting means 7 of the remaining region 6 are applied to the work piece for fast cutting.

Description

IMPROVED SAW BLADE

The present invention relates to a saw blade, and in particular to a saw blade having at least two distinct regions along a cutting edge thereof, the two distinct regions respectively having cutting means with distinct cutting characteristics.

Traditional saw blades have a cutting edge provided with a plurality of teeth. The teeth have the same pitch and/or profile along the entire length of the cutting edge. It can be difficult to start off a saw cut with such a saw, especially if the teeth have a 10 large pitch, since the cutting edge of the saw blade will tend to jump until a reasonably deep guide cut has been formed.

It is known, for example from US 4,265,285, to provide a combination cross- and rip-cut handsaw in which teeth having different profiles and/or pitches are provided 15 along the cutting edge, the teeth being arranged in repeating groups of four, the pitch of the teeth decreasing in a forward direction within each group.

It is also known, for example from US 2002/0194975 A, to provide a handsaw having a cutting edge with multiple tiers of teeth, such that a first tier to engage a 20 material to be cut has fast cutting characteristics, with subsequent tiers cutting away kerf surfaces left by the preceding tier and thus cutting a new smoother kerf.

According to a first aspect of the present invention, there is provided a saw blade having a cutting edge provided with cutting means, characterised in that an end 25 region of the cutting edge is provided with cutting means having a finer cutting characteristic than a remaining region of the cutting edge.

According to a second aspect of the present invention, there is provided a saw blade having a cutting edge provided with cutting means, characterised in that the cutting 30 edge has at least two distinct regions along its length, the cutting means in each region having mutually distinct cutting characteristics.

e C * * - * C C X e e * * The cutting means may comprise saw teeth, in which case the saw teeth in each region have different pitches and/or profiles. For example, the end region of the cutting edge may have saw teeth with a relatively small pitch and/or profile and the 5 remaining region of the cutting edge may have saw teeth with a relatively large pitch and/or profile.

Alternatively, the cutting means in at least one region or in the end region may comprise abrasive particles bonded to the cutting edge, and the cutting means in other 10 regions or in the remaining region may comprise saw teeth with a predetermined pitch and/or profile.

The end region of the cutting edge is preferably the end located distal from a handle when the saw blade is fitted therewith to form a saw. Alternatively, the end region 15 may be located proximal to the handle.

The end region may comprise less than half of a total length of the cutting edge, preferably less than a third of the total length, even more preferably less than a quarter of the total length and most preferably less than an eighth of the total length. 20 In one preferred embodiment of the present invention, the end region of the cutting edge is provided with saw teeth having a pitch of 20 to 30 teeth per inch (8 to 12 teeth per centimetre) and the remaining region of the cutting edge is provided with saw teeth having a pitch of 5 to 10 teeth per inch (2 to 4 teeth per centimetre). In a 25 particularly preferred embodiment, the saw teeth in the end region of the cutting edge have a pitch of 26 teeth per inch (10. 4 teeth per centimetre) and those in the remaining region of the cutting edge have a pitch of 7 teeth per inch (2.8 teeth per centimetre).

Alternatively, where the end region of the cutting edge is provided with abrasive particles bonded to the cutting edge, the remaining region of the cutting edge is c 9 * * . :: * e 9 S' provided with saw teeth having a pitch of 5 to 10 teeth per inch (2 to 4 teeth per centimetre), preferably 7 teeth per inch (2.8 teeth per centimetre).

Jn some embodiments, the cutting means in each distinct region have a constant pitch 5 and/or profile. Alternatively, the cutting means in one or more of the regions may have a varying pitch and/or profile, for example as disclosed in US 4,265,285, provided always that the cutting means in one region have a finer cutting characteristic that the cutting means in at least one other region.

Preferably, the cutting edge is substantially straight or linear in extension.

When cutting an article, such as a piece of wood, with the saw blade of embodiments of the present invention, a user will first use the region of the cutting edge with the finest cutting characteristics to form a guide cut. Because of the fine cutting 15 characteristic, it is relatively easy to form a guide cut without the saw blade skipping or jumping and without causing excessive or any splitting of the edge of the material.

Once a sufficiently deep guide cut has been formed, the user then applies a region of the cutting edge with coarser cutting characteristics so as to speed the cutting process.

According to a third aspect of the present invention, there is provided a saw blade having a two generally opposed cutting edges each provided with cutting means, characterised in that one of the cutting edges is provided with cutting means having a finer cutting characteristic than the opposed the cutting edge.

The cutting means may comprise saw teeth, in which case the saw teeth on one cutting edge have a different pitch and/or profile than those on the other cutting edge.

Alternatively, the cutting means on one cutting edge may comprise abrasive particles bonded to that cutting edge, and the cutting means on the other cutting edge may comprise saw teeth with a predetermined pitch and/or profile. 30 en e * 0 * * 0 In a preferred embodiment, the cutting edge with the finer cutting characteristic is provided with saw teeth having a pitch of 20 to 30 teeth per inch (8 to 12 teeth per centimetre) and the opposed cutting edge is provided with saw teeth having a pitch of 5 to 10 teeth per inch (2 to 4 teeth per centimetre). In a particularly preferred 5 embodiment, the saw teeth of the cutting edge with the finer cutting characteristic have a pitch of 26 teeth per inch (10.4 teeth per centimetre) and those on the opposed cutting edge have a pitch of 7 teeth per inch (2.8 teeth per centimetre).

Alternatively, where the cutting edge with the finer cutting characteristic is provided 10 with abrasive particles bonded to the cutting edge, the opposed cutting edge is provided with saw teeth having a pitch of 5 to 10 teeth per inch (2 to 4 teeth per centimetre), preferably 7 teeth per inch (2.8 teeth per centimetre).

When the saw blade of the third aspect of the invention is fitted with a handle so as to 15 form a handsaw, the handle is preferably configured so as to allow comfortably operation of the handsaw both with the finer cutting edge facing downwardly and with the coarser cutting edge facing downwardly. In other words, the handle should be designed so as to enable comfortable use of the handsaw in two opposed orientations. Accordingly, the handle may advantageously be substantially 20 symmetrical about a plane extending longitudinally along, but substantially perpendicular to, the saw blade between the opposed cutting edges.

When using a saw blade of the third aspect of the present invention, a guide cut or groove is first formed in a work piece by using the cutting edge with the finer cutting 25 characteristic. Once a sufficient depth of guide cut or groove has been attained, the saw blade is removed and turned over, and cutting then continues using the coarser cutting edge.

Apart from providing increased ease of use, embodiments of the present invention 30 also provide for greater user safety, since skipping or jumping of the saw blade is ameliorated.

e 0. ..

e r # * 0 Saw blades of embodiments of the present invention may take any appropriate form, including ripsaw blades, crosscut saw blades, panel saw blades, tenon saw blades, hacksaw blades, padsaw blades, coping saw blades and any other appropriate saw blades.

According to a fourth aspect of the present invention, there is provided a saw including a saw blade of the first, second or third aspects of the present invention.

It is to be appreciated that, although the saw blade of embodiments of the present invention has been described in connection with a handsaw, it may advantageously be used in power saw applications.

For a better understanding of the present invention and to show how it may be carried 15 into effect, reference shall now be made by way of example to the accompanying drawing, in which: FIGURE 1 shows a handsaw.

The handsaw comprises a saw blade 1 fitted with a handle 2. The saw blade 1 has a substantially straight or linear cutting edge indicated generally at 3. An end region 4 of the cutting edge 3, distal from the handle 2, is provided with teeth 5 having a relatively small pitch and/or profile. The teeth 5 preferably have a fine pitch, shallow throat cutting profile. The end region 4 comprises less than one eighth of a total 25 length of the cutting edge 3. A remaining region 6 of the cutting edge 3, proximal to the handle 2, is provided with teeth 7 having a relatively large pitch and/or profile.

In an alternative embodiment (not shown), the end region 4 of the cutting edge 3 is not provided with teeth, but instead with abrasive particles bonded to the cutting edge 30 3.

- . . .. .. . 9S* e e S * In use, the end region 4 of the cutting edge 3 is placed upon a work piece to be cut, and the user applies several short, reciprocating strokes of the saw blade 1 such that only the end region 4 of the cutting edge 3 is used to form a start groove in the work piece. Once a satisfactory start groove has been formed, the user may then apply 5 progressively longer strokes of the saw blade 1 such that the larger teeth 7 come into use.

The preferred features of the invention are applicable to all aspects of the invention and may be used in any possible combination. 10 Throughout the description and claims of this specification, the words "comprise" and "contain" and variations of the words, for example "comprising" and "comprises", mean "including but not limited to", and are not intended to (and do not) exclude other components, integers, moieties, additives or steps.

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Claims

CLAIMS:

1. A saw blade having a cutting edge provided with cutting means, characterised 5 in that an end region of the cutting edge is provided with cutting means having a finer cutting characteristic than a remaining region of the cutting edge.

2. A saw blade as claimed in claim 1, wherein the cutting means in the end region comprise saw teeth with a relatively small pitch and/or profile, and wherein 10 the cutting means in the remaining region comprise saw teeth with a relatively large pitch and/or profile.

3. A saw blade as claimed in claim 1, wherein the cutting means in the end region comprise abrasive particles bonded to the cutting edge, and wherein the 15 cutting means in the remaining region comprise saw teeth.

4. A saw blade as claimed in any preceding claim, wherein the end region comprises less than half of a total length of the cutting edge.

5. A saw blade as claimed in any preceding claim, wherein the end region comprises less than a third of a total length of the cutting edge.

6 A saw blade as claimed in any preceding claim, wherein the end region comprises less than a quarter of a total length of the cutting edge. 25

7 A saw blade as claimed in any preceding claim, wherein the end region comprises less than an eighth of a total length of the cutting edge.

8. A saw blade as claimed in claim 2 or any claim depending therefrom, wherein 30 the saw teeth in the end region have a pitch of 20 to 30 teeth per inch.

* . . . v * I f e9 * *

9. A saw blade as claimed in claim 8, wherein the saw teeth in the end region have a pitch of 26 teeth per inch.

10. A saw blade as claimed in claim 2 or 3 or any claim depending therefrom, wherein the saw teeth in the remaining region have a pitch of 5 to 10 teeth per inch.

11. A saw blade as claimed in claim 10, wherein the saw teeth in the remaining region have a pitch of 7 teeth per inch.

12 A saw blade having a cutting edge provided with cutting means, characterised in that the cutting edge has at least two distinct regions along its length, the cutting means in each region having mutually distinct cutting characteristics.

13. A saw as claimed in any one of claims 9 to 11, substantially as hereinbefore described. _\L-

13. A saw blade as claimed in claim 12, wherein the cutting means comprise saw teeth, the saw teeth in each region of the cutting edge respectively having different pitches and/or profiles.

14. A saw blade as claimed in claim 12 or 13, wherein the cutting means in at least one region comprise abrasive particles bonded to the cutting edge.

15. A saw blade as claimed in claim 13 or 14, wherein the saw teeth in at least) one region have a pitch of 20 to 30 teeth per inch.

16. A saw blade as claimed in claim 13, 14 or 15, wherein the saw teeth in at least one region have a pitch of 5 to 10 teeth per inch.

17. A saw blade as claimed in any preceding claim, wherein the cutting edge is substantially straight or linear.

r * * *. * I: C S S * * * 18. A saw comprising a handle and a saw blade attached thereto, the saw blade being as claimed in any one of claims 1 to 11 and claim 17 depending from any one of claims 1 to 11.

19. A saw as claimed in claim 18, wherein the end region of the saw blade is located distal from the handle.

20. A saw as claimed in claim 18, wherein the end region of the saw blade is located proximal to the handle.

21. A saw comprising a handle and a saw blade attached thereto, the saw blade *) being as claimed in any one of claims 12 to 16 and claim 17 depending from any one of claims 12 to 16.

22. A saw blade having a two generally opposed cutting edges each provided with cutting means, characterised in that one of the cutting edges is provided with cutting means having a finer cutting characteristic than the opposed the cutting edge.

23. A saw blade as claimed in claim 22, wherein the cutting means on one cutting edge comprise saw teeth with a relatively small pitch and/or profile, and wherein the cutting means on the opposed cutting edge comprise saw teeth with a relatively large) pitch and/or profile.

24. A saw blade as claimed in claim 23, wherein the saw teeth with a relatively small pitch and/or profile have a pitch of 20 to 30 teeth per inch.

25. A saw blade as claimed in claim 23 or 24, wherein the saw teeth with a relatively large pitch and/or profile have a pitch of 5 to 10 teeth per inch.

26. A saw blade substantially as hereinbefore described with reference to the accompanying drawing.

* e * * 27. A saw substantially as hereinbefore described with reference to the accompanying drawing.

Amendments to the claims have been filed as follows CLAIMS: 1. A saw blade having a cutting edge provided with cutting means, wherein an 5 end region of the cutting edge is provided with cutting means having a finer cutting characteristic than a remaining region of the cutting edge, characterised in that the cutting means on the end region of the cutting edge comprise abrasive particles bonded to the cutting edge, and in that the cutting means on the remaining region of the cutting edge comprise saw teeth.

2. A saw blade as claimed in claim 1, wherein the end region comprises less than half of a total length of the cutting edge.

3. A saw blade as claimed in claim 1 or 2, wherein the end region comprises less 15 than a third of a total length of the cutting edge.

4 A saw blade as claimed in any preceding claim, wherein the end region . -comprises less than a quarter of a total length of the cutting edge.

5 A saw blade as claimed in any preceding claim, wherein the end region comprises less than an eighth of a total length of the cutting edge.

6. A saw blade as claimed in any preceding claim, wherein the saw teeth in the remaining region have a pitch of 5 to 10 teeth per inch (2 to 4 teeth per centimetre). 25 7. A saw blade as claimed in claim 6, wherein the saw teeth in the remaining region have a pitch of 7 teeth per inch (2.8 teeth per centimetre).

8. A saw blade as claimed in any preceding claim, wherein the cutting edge is 30 substantially straight or linear. 4nt_

9. A saw comprising a handle and a saw blade attached thereto, the saw blade being as claimed in any one of claims 1 to 8.

10. A saw as claimed in claim 9, wherein the end region of the saw blade is located distal from the handle.

11. A saw as claimed in claim 9, wherein the end region of the saw blade is located proximal to the handle.

12. A saw blade as claimed in any one of claims 1 to 8, substantially as hereinbefore described.