WO2011078710A1

WO2011078710A1 - Saw blade with series of teeth providing oppositely directed dual cutting edges

Info

Publication number: WO2011078710A1
Application number: PCT/PH2009/000022
Authority: WO
Inventors: Chung Kuang Chen
Original assignee: Nardone, Jennifer, R.
Priority date: 2009-12-22
Filing date: 2009-12-22
Publication date: 2011-06-30

Abstract

The invention relates to saw blade with series of teeth providing oppositely directed dual cutting edges comprising a blade body (10, 10') that is mountable to a sawing device or machine, preferably a circular saw machine, and a series of teeth (11, 11') protruding individually and directionally disposed along the toothed edge portion of the body (10, 10'). The invention is characterized by the series of teeth (11, 11') which comprises of complementing oppositely directed symmetrical cutting edges (12, 12'), wherein the cutting edge (12) that is in an active cutting position pointing towards the direction of cutting, effects a cutting action upon contact with a workpiece (13) during a cutting operation, while the trailing cutting edge (12') that is in a non-cutting inverse position pointing away from the direction of cutting, effects a complementing cut-smoothing action following the cutting action resulting in a quality smooth cut.

Description

SAW BLADE WITH SERIES OF TEETH PROVIDING OPPOSITELY DIRECTED DUAL CUTTING EDGES

FIELD OF THE INVENTION

The invention generally relates to saw blades and more particularly to a 5 saw blade with series of teeth characterized by oppositely directed dual cutting edges, preferably embodied in respective double-edged teeth.

BACKGROUND OF THE INVENTION

It is well known in the art to which this invention appertains that saw blades and in particular, circular saw blades, have a series of unidirectional

10 teeth. Hence, such feature leaves no choice to the user but to mount the saw blade on a spindle of a respective sawing machine in a manner that it must be ascertained that the teeth is facing or pointing towards the forward stroke or thrust direction of cutting or directional rotation of the spindle, otherwise no cutting action would be possible.

i s Furthermore, such saw blades are of two categories, namely: rip cut or cross cut saw blades with smaller number of teeth that provide or effect quick/ fast but rough cuts characterized by a poor surface finish; and finish cut saw blades with relatively large number of teeth that provide or effect slow but smooth clean cuts, especially in wood. Thus, there is always a disadvantage 0 or downside when opting or choosing a kind of cut when using both types of saw blades. Certainly, a kind of single saw blade that can cut fast with a clean smooth cut is desirable for users as well as for manufacturers since one blade in lieu of or as substitute for the two conventional blades would practically and obviously incur and translate into significant raw material savings and reduced 5 environmental pollution.

Quite a number of prior art documents or references would show that the trend of advancement is headed towards or confined with merely improving the unidirectional blades used singly or in combination as shown in the following patents. Clarke US Patent No. 4,641 ,562 relates to a circular saw blade that operates with two differently sized and toothed blades mounted coaxially adjacent to one another such that when used to cut through a workpiece, the larger first blade makes a fast rough cut and the second smaller blade follows partially within the path of the first blade and provides a smooth, finished cut.

Vollmer et. al. US Patent No. 4,133,240 pertains to unidirectional cutting teeth for circular saw blades, and discloses an improved raker and low teeth inserts whose inclinations or angularities of planar surface faces and/or facets defining cutting edges are improved, are alternatively positioned about the periphery of the circular saw blade purposely for a substantially improved blade performance, particularly in the area of wear.

Ericsson US Patent Pub. No. US 2004/0182217 A1 relates to a pair of unidirectional saw blades of opposite directional rotations that are adjacently mounted face to face with a spacer means provided therebetween. SUMMARY OF THE INVENTION

The present invention seeks to overcome the shortcomings of the prior art by providing a saw blade with series of teeth that is characterized by or provides oppositely directed dual cutting edges. Depending on the direction of the blade's forward thrust/motion or rotation, the cutting edges that point towards such direction are the active cutting edges effecting a fast rough cut into a workpiece, while the non-active cutting edges pointing to the opposite direction trailing or following right behind the active cutting edges effect a cut- smoothing or cleaning action, i.e. scraping or chipping off unwanted cut debris, remnants or imperfection, resulting in a quickly done clean and smooth cut. Thus, with the use of only one saw blade of the invention in lieu of the two conventional blades: rip or cross cut and finish cut saw blades performing a two-stage cutting process, i.e. rough cross cut and smooth finish cut, a fast but smoothly finished cut is achieved.

It is therefore the primary object of the invention to provide a saw blade with series of teeth that is characterized by or provides oppositely directed dual cutting edges that is capable of making a smooth cut at a relatively and favorably fast cutting rate or speed as collective result of a series of cutting and trailing cut-smoothing action combination by each of the oppositely directed dual cutting edges of the series of teeth during a cutting operation.

Another object thereof is to provide a saw blade with series of teeth that is characterized by or provides oppositely directed dual cutting edges that can be installed or mounted on a sawing device or machine without any particular reference to forward thrust or rotational direction of cutting such as the spindle direction of a circular saw machine.

Still another object thereof is to provide a saw blade with series of teeth that is characterized by or provides oppositely directed dual cutting edges that can be flipped or turned over for another use just like a new saw blade in which the positive sharp angle or active cutting edges of the previous use now become the inverse angle or inactive cutting edges to do the cut-smoothing action and vice versa.

Yet another object thereof is to provide a saw blade with series of teeth that is characterized by or provides oppositely directed dual cutting edges that incurs significant reduction of steel consumption and hard alloy used for manufacturing saw blades by about 50%, resulting in substantial reduction of environmental pollution. BRIEF DESCRIPTION OF THE DRAWINGS

Other objects, features and advantages of the invention are better understood and appreciated from the following detailed description made in conjunction with the appended drawings, in which:

FIG. 1 is a cut-away, perspective view of a preferred embodiment or illustrative example of the present invention;

FIG. 2 is a cross-sectional view thereof taken along line 2-2 of FIG. 1; and

FIG. 3 is a plan view thereof as adopted or embodied on a circular saw blade. DETAILED DESCRIPTION

Before describing the invention in detail, it is to be understood that the phraseologies and terminologies employed herein are for purposes of description only to support an enabling disclosure that describes the best 5 mode or illustrative example/embodiment of the invention, thus should not be regarded as limiting.

Referring now to the drawings in detail wherein like reference numerals designate the same parts or elements all throughout the description, there is shown in FIG. 1 a saw blade with series of teeth providing oppositely directed l o dual cutting edges generally designated by reference numeral 9 comprising a mountable cutter head or blade body 10 that is capable of being mounted to or installed in a sawing device or machine (not shown), and a series of teeth 11 , each of which individually protruding and directionally disposed along the toothed edge portion of the body 10. It is a preference herein to use and

15 describe as an illustrative example or preferred embodiment of the invention, a circular body 10' of a circular saw blade 9' being suited for a circular saw machine (not shown). The saw blade 9,9' is characterized in that the series of teeth 11 comprises of complementing oppositely directed dual or symmetrical cutting edges 12,12' (shown in bold lines) wherein the cutting edge 12 is the 0 one facing or pointing (shown by arrows "A1") towards the direction of cutting (shown by an arrow "A"), while the other cutting edge 12' is the one at the opposite side of the cutting edge 12, which faces or points (shown by arrows "A2") towards the opposite direction. In a cutting operation or process through the cutting direction "A", the cutting edge 12 is in an active sharp cutting angle 5 or position pointing towards (shown by the arrow "A1") the direction of cutting "A" such that it effects a cutting action as shown by arrows "B1", preferably performing a fast rough cut, upon contact with a workpiece 13. On the other hand, also during such operation, the cutting edge 12', preferably performing a fast finish cut, is in a non-cutting inverse angle or position pointing away

30 (shown by the arrow "A2") from the direction of cutting "A" with the blunt or unsharpened back portion 12a thereof being the one acting against the cut surface immediately after the cutting action "B1" as shown by arrows "B2", hence, the result would be one of scraping, surface cleaning and smoothing of the cut surface, producing a quality smooth and clean finish cut, most especially in wood or metal.

It is preferred that each of the series of teeth 11 is a unitary element having the oppositely directed symmetrical cutting edges 12,12' being made integral and unitary parts thereof, making the series of teeth 11 composed of double-edged teeth 11'. As shown in FIGs. 1 and 2, the double-edged teeth 11' have convergently and downwardly tapered top edge portion 11a defining a pair of oppositely directed pointed cutting corners 11b and forming a generally dovetail-like tooth profile. Thus, mounting or installing of the saw blade 9,9' into the sawing machine, e.g. circular saw machine, can be done without any particular reference to directional rotation (or forward thrust for a non-circular sawing device) of the machine's spindle 15, which is for the convenience of the user.

Whether being preferably comprised of a unitary, double-edged and dovetail-like profiled teeth 11', or complementing oppositely directed and adjacently disposed separate elements/teeth (not shown), the series of teeth 11 has the cutting edges 12,12' thereof being made parts of respective cutting elements 14 that define the teeth's opposite sides. With such set-up and features, the cutting and cut-smoothing actions (shown by the arrows "B1","B2") take place or are effected along the top edge 14a and opposite side edges 14b of the cutting elements 14 or teeth 11,11' during the cutting operation. Further, the saw blade 9,9' can be flipped or turned over for another use just like a new saw blade in which the positive sharp angle or active cutting edges of the previous use now become the inverse angle or inactive cutting edges to do the cut-smoothing action and vice versa, especially when used as counter facing and oppositely rotating twin blades in a pair of circular saw blades for medium to heavy duty cutting operations. Preferably, the cutting elements 14 are made of hard metal or any suitable cutting material, and the sawing device or machine can be a band saw, circular saw, hack saw, or ordinary hand saw.

Before defining the scope of the following claims, it is to be understood 5 that the invention is not limited in its applications to the details of the illustrative examples or variations set forth in the preceding description and drawings. It is to be noted that the invention is capable of other variations and limitless applications not disclosed herein. Further, this invention is likewise capable of being practiced and carried out in various ways falling within the l o teaching and scope of the following claims.

Claims

CLAIMS What is claimed is:

1. A saw blade with series of teeth providing oppositely directed dual cutting edges comprising a blade body (10,10') that is mountable to a sawing device or machine, and a series of teeth (11,11') protruding individually and directionally disposed along the toothed edge portion of said body (10,10'); characterized in that said series of teeth (11,11') comprises of complementing oppositely directed symmetrical cutting edges (12,12'), in which the cutting edge (12) that is in an active cutting position pointing towards the direction of cutting, effects a cutting action upon contact with a workpiece (13) during a cutting operation, while the cutting edge (12') that is in a non-cutting inverse position pointing away from the direction of cutting, effects a complementing cut-smoothing action following said cutting action resulting in a quality smooth cut.

2. A saw blade according to claim 1 wherein a pair of said oppositely directed symmetrical cutting edges (12,12') forms an integral and unitary part of each of the teeth (11) making the latter double-edged teeth (11').

3. A saw blade according to claim 2 wherein said double-edged teeth (11 ') have convergently and downwardly tapered top edge portion (11a) defining a pair of oppositely directed pointed cutting corners (11b) and forming a generally dovetail-like tooth profile.

4. A saw blade according to claim 1 or 2 wherein said cutting edges (12,12') are parts of respective cutting elements (14) that define the opposite sides of said teeth (11,11') such that the cutting and cut-smoothing actions take place or are effected along the top edge (14a) and opposite side edges (14b) of said cutting elements (14) or teeth (11,11') during the cutting operation.

A saw blade according to claim 4 wherein said cutting elements (14) made of hard metal.

6. A saw blade according to claim 1 wherein the sawing device or machine is selected from the group consisting of circular saw, band saw, hack saw, and ordinary hand saw.