CA2280330A1

CA2280330A1 - Improved circular saw

Info

Publication number: CA2280330A1
Application number: CA002280330A
Authority: CA
Inventors: Jeffrey M. Zeiler; Jeffrey S. Holly; Richard P. Brault; Jeffrey C. Hessenberger; Thomas P. James; Brian P. Wattenbach
Original assignee: Jeffrey M. Zeiler; Jeffrey S. Holly; Milwaukee Electric Tool Corporation; Richard P. Brault; Jeffrey C. Hessenberger; Thomas P. James; Brian P. Wattenbach
Current assignee: Milwaukee Electric Tool Corp
Priority date: 1998-08-14
Filing date: 1999-08-13
Publication date: 2000-02-14
Also published as: GB9919195D0; JP2000313001A; DE19938524A1; US6301789B1; FR2782288A1; ITMI991820A1; ITMI991820A0; IT1313107B1; GB2340445A; GB2340445B

Abstract

A circular saw having an improved line-of sight. The circular saw comprises a motor for rotatably driving a saw blade about an axis to cut a workpiece, a bevel angle being defined between the cutting plane of the saw blade and a surface of the workpiece; a housing supporting the motor; a shoe plate supporting the circular saw on the workpiece to be cut, the shoe plate being pivotably connected to the housing to adjust the bevel angle; a main handle supported by the housing; an auxiliary handle supported by the housing; and an indicator for indicating the bevel angle. Preferably, the main handle, the auxiliary handle and the indicator are arranged so that, in the cutting position, the operator can view the saw blade as the saw blade cuts the workpiece and can view the indicator. The operator holds the main handle with one hand and the auxiliary handle with the other hand. When the operator holds the auxiliary handle with the other hand, the operator's other hand and the auxiliary handle do not obscure the operator's view of the saw blade as the saw blade cuts the workpiece.

Description

IMPROVED CIRCUI;,AR SA~'t' 'This .~ppVcalion claims the benefit of prior filed co-pEndmg provisional patent application, serial number 60/096,522, filed on Augtest 14, 1998.
BACKGROUND OF THE TNvEN?ION
The present in~entton relates to circular saws, and, more particularly, to a circular sa~M haying an improved line-of sight for the operator.
A typical circular saw includes a housing supporting a motor which rotatably drives a saw blade- The hollstng also forms a blade guard cowering the upper portion of the saw blacJe. A shoe plate supports the circular sa~u on the surface of a workpiece. The circular sa~v also includes a main operator s handle mountEd on the motor housing and an auxiliary handle supported on the housing or the shoe plate. Due to the arrangement of the components of tI3e circular saw, only a portion of the outward face of the saw blade ~s generally visible ~s the saw blade cuts the workpiece.
During tutting operations, the operator typically grasps the main handle .with one hand (the right hand) and grasps the auxiliary handle with the other hand (the left hand). In an optimal tutting position. the operator holds the circular saw

2 0 so that the circular saw is centered relative to the operator's body.
Ho~ue~er. to view the saw blade as the saw blade cuts the workpiece, the operator must stand in a position so that the outward face of the saw blade is visible. To do so, the operator must lean over the outward face of the sa~.~~ blade (generally on the right 5tde of the circular saw).
z 5 In some circular saws, the shoe plate is pivotally connected to the housing so that the angle at which the saW blade cuts the workPiece (the bevel angle) is adjustable. Typically. the circular caW includes an indicator located toward the front of the circular sa~~ and indicating the be~ei angle of the saw blade.
Tn some constn~ctions, the indicator faces the front of the circular saw,

3 o a~uay from the operator. To view such a front indicator, the operator must hold the circular sa~u so that the front of the circular saw faces towards the operator.
Tn some other constructions, the indicator faces to~A~ards one side of the circular saw (the left side, opposite the out~uard face of the saw blade) and is generally parallel with the edge of the shoe plate. To view such a side-facing _2_ indicator, the operator must hold the circular saw so that the side of the circular saw faces towards the operator.
SUMMARY OF THE INVENTION
S One problem With the above-described circular saw is that, to view the saw blade as the saw blade cuts the workpiece, the operator must be in a position to view the outward face of tlZe saw blade below the blade guard. The operator must lean across their body to the outward side of the circular saw to view the saw blade. In this position. the operator is not in the optimal cutting stance, centered to behind the circular saw, and is not holding the circular saw in the optimal cutting position. This position is awkward, and the operator's stance may not be balanced.
Also, because the operator s body weight is not centered bEhind the circular saw, the operator has less precise control of the circular saw. In addition, the operator is in a relatively exposed position and may be hit by debris cut by the saw blade.
15 One problem with the above-described circular saws including a bevel angle adjustment assembly is that, in order to adjust tltc bevel angle, the operator must move from the cutting position, in which the saw bladE is visible, to a position in which the bevel angle indicator is visible and in which tile saw blade is no longer visible. The operator must then move back to the cutting position to 2 0 resume cutting opcraiions. ?here movements decrease the operator's efficiency during combined straight and bevel cutting operations.
Another problem With the above-described circular saw including a bc~el angle adjustment assembly is that, as the housing is moved relative to the shoe plate to change the bc~cl angle of the saw blade, the upper blade guard is moved 25 outwardly and downwardly toward the surface of the workpiece. Tn a beveled cutting position (i.e., 45° bevel an ble), the upper blade guard obscures the operatoi s view of the outward face of the saw blade as the saw blade cuts the workpiece. In order to ~icw the saw blade. the operator lean further outwardly and downwardly. increasing the awkwardness and imbalance in the operatoi s 3 o stance during cutting operations.
The present invention provides a circular saw with an improved line-of-stght to alleviate the problems with the above-described circular saws. The invEtition provides a circular saw in ~uhrch the operator can ~ieW the saw blade as it cuts the ~~orkpiece white maintaining a comfortable and balanced stance and while holding the circular saw in an optimal cutting position. The components of the circular sa~u arc arranged so that the operator can view the inward face of the saw blade (the face of the saw blade facing a substantial portion of the circular saw). The operator can remain tn a centered bEhind the circular saw during cutting operations.
Also, the present invention provides a circular saw including a bE~el angle ad3ustment assEmbly having a bc~ei angle indicator which is risible to the operator while the operator is in the optimal cutting stance with the circular saw in the optimal cutting position. Preferably, the bevel angle indicator is risible to the opErator generally along the opcratoi s line-of sight of the saw blade.
One ad~antagc of the present invention is that, l~hile viewing the sau blade as it cuts the workpiece, the operator can maintain the optimal cutting stance and hold the circular sa« in the optimal cutting position. The operator can thus maintain a comfortable and balanced stance, have more precise control of the circular saw during cutting operations, and be less exposed to debris. Also, the addition oC air flow directing means in the area of the operator's line-of sight controls the flow of debris cut by the saw blade. further reducing the operator's 2 o exposure to this debris.
Mother advantage of the present invEntion is that, because the bevel angle indicator is msible to the operator in the optimal cutting stance and with the circular saw in the optimal cutting position, the operator can adjust the bevel angle of the saw blade while maintaining the optimal stance and cutting position.
This increases the efficiency of combined straight and bevEl cutting operations.
A further advantage of the present invention is that, during be~cl cutting operations (i.c., with the saw blade in a 45° be~El angle position), the operator's line-of sight of the sav bladE as it cuts the ~uorkpiecc is not obscured and does not require the operator to adjust their stance.
3 o Other features and advantages of the invention will become apparent to those skilled in the art upon review of the following detailed description, claims and drawings.

-4-DESCRIPT10N OF' THE DRAWINGS
Fig. 1 is a perspective view of a circular saw embodying the invention and illustrating the circular saw as the saw blade cuts a workpiece.
Fig. 2 is an enlarged view of the forward portion of the circular saw shown tn Fig. l .
Fig. 3 is a front view of the circular saw shown in Fig. 1 and illustrating the adjustment of the bevel angle of the saw blade.
Figs. 4A-C are enlarged side views of the forward portion of the circular 1 o sa~u shown in Fig_ 1 and illustrating the adjustment of the bevel angle of the saw blade.
F3efore one embodiment of the invention is explained in detail, it is to be understood that the invention is not limned in i.ts application to the details of the construction and the an-atsgements of the components set forth in the follo~ving description or illustrated in the drawings. The invention is capable of other embodiments and of bEing practiced or carried out in various ~vays. Also, it is understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.
z o DETAILED DLSCRIPTION OF TIME PRLFI:RRI:D EMBODIMENT
A circular saw 10 embodying the irivention is tltustratcd in Fig. I . The circular saw 10 includes a motor housing 14 supporting an electric motor (not down). The motor is corutectable to a power source and is operable to rotatably drive a saw blade 18 about an axis 22 to cut a workpiece W. The saw blade 18 defines a cutting plane and has an inward face 26 and an outward face (not shown) facing opposite the inward face 26. The inward face 26 of the sau~ blade 18 faces toward a substantial portion of the circular saw 10. A main operator s handle 30 ~s supported on the housing I4. An orJoff switch (not shown) is supported on the main handle 30 and selectively connects the motor to the Power source.
3 o A i fixed blade guard 34 surrounds an upper portion of the saw blade 18.
An opening 36 is formed on the forward inward side of the blade guard 34 through which the inward face 26 of the sa~v blade 1 S is visible. Preferably, air flow

-5-control means are provided adjacent the opening 36 to control the flow of air and debris cut by the saw blade 18 and to substanttaily prevent debris from flowing through the opening 36. In the illustrated constntction, the air flow control means are prodded by a tooth 37 supported by and, prefErably, fotTncd with the fixed S blade guard 3d_ The tooth 37 substantially directs the flow of air and debrss away from the opening 36.
A movable guard 39 (see Fig. 3) selectively covers the lower portion of the sa~x~ blade 18. The guards 34 and 39 arc arranged so that a portion of the out~vard face (riot shown) of the saw blade 18 is visible during cutting of the workpiece.
1 o The circular saw 10 also includes a shot plate 40 connected to the housing 14 and supporting the circular saw 10 on the surface of the workpiece W. A
portion of the saw blade 18 is extEndable through an aperture 42 defined in the shoe plate 40.
In the illustrated construction, the circular saw 10 includes a front picot 15 depth adjustment assembly d6 (patt.ially shown) to adjust the depth of cut of the saw blade i 8. In other constructions (not shown), the circular saw 10 may mclttde, for example, a rear depth adjustment assembly or a drop shoe depth adjustment assembly rather than the front pivot depth adjustment assEmbly 46.
I~owevcr, it should be understood that the present invention applies to a circular z o sa~u with any type of dept>'t adjusttneni assembly or with no depth adjustment assembly.
The circular saw 10 also includes an auxiliary handle 50 supported on the forward portion of the circular sa~u 10. In the illustrated constntction, a support post 54 (see Figs. 2-4) extends upwardly from the shoe plate a0, and the auxiliary 2 5 handlE 50 is taxed to the support post 54. In other constructions (not shown), the auxiliary handle 54 may be supported on the circular saw 10 in a different manner while complying ~uith the teachings of the present Invention.
In the illustrated tonstruction. the circular saw 10 includes (see Figs. I-4) a bevEl angle adjustment assembly 58 for adjusting the angle bet~vccn the cutUng 3 o plane of the saw blade 18 relative to the surface of the Warkpiece W (the bevel angle). It should be understood that the present invention. with respect to the operator s line-of sight of the saw blade 18 as the saw blade 18 cuts the ~uorkpiece

-6-W (as explained in more detail bElvw), also applies to a circular sav in which the bevel angle of the saw blade is not adjustable_ The bevel angle adjustment assembly 58 pivotally connects the shoe plate 40 to the housing 14. The bevel angle adjushncnt assembly 58 includes (see Fig. 3) a pivot member G2 pivotally connECting the shot plate 40 to the guard for movement about a pivot axis GG.
The bevel angle adjustment assembly 58 also includes (see Figs. 1, 2 and 4A-C) a bevel plate 70 connected to the housing 14 through the guard 34 so that the bevel plate 70 is movable with the housing 14 relative to the shoe plate 40. As l0 shown in Fig. 1, an arcuate groove 74 is defined in the bevel plate 70.
A connecting member or fastener 78 (see Figs. 1-4) extends through the support post.54 and through the arcuate groove 74 in the bevel plate 70 to connect the support post 54 to flue bevel plate 70. A left-threaded locking nut 82 is threadedly connected to the fastener 78 and is operable to apply a clamping force 1 S to the bevel plate 70 to fix the bevel plate 70 to the support post 54.
The bevel angle adjustment assembly 58 also includes a locking lever 86 tonrtected to the nut 82. The locking lever 86 is movable between a locking position (see Figs. 1, Z, and 4A and as shown in solid lines in Fig_ 3), in which the bevel angle of the saw blade 18 is fixed, and an unlocked position (see Figs.

2 0 and as shown in phantom lines in F'ig. 3), in which the bevel angle of the saw blade i8 is adjustable. ThE nut 82 is attached to the rearward end of the fastener 78 so that the lever 8G does not interfere with the auxiliary handle 50 during adjustment of the bevci angle adjustment assembly 58.
In the locked position (shown in Figs. l, 2 and 4A and in solid lines in Fir.
2 S 3), the nut $2 applies a Clamping force to the bevel plate 70 so that Lhe bevel plate 70 is fixed to the support post 54. The housing 14 is Cxed relative to the shoe plate 40, and the bevEl angle of the saw blade 18 is fixed.
In the unlocked position, the nut 82 does not apply a clamping force to the bevel plate 70, and the fastener 78 is movable m and along the arcuate groove 74.
30 The bevel plate 70 is movable rElaRve to the support post 54. and the housing 14 is movable relative to the shoe plate 40 to adjust the bevel angle of the sa~v blade 1 s.

The bevel angle adJustment assembly 58 also includes an indicator 90 for indicating the bevel angle of the saw blade 18. The Indicator 90 includes a first indicator member or pointer 94 lixed to the shoe plate d0. in the illustrated constructiot,, the pointer ~d is connECted to the auxiliary handle 50.
The indicator 90 also includes a plurality of second indicator members 98 fixed to the housing 14. In the ihustrated constntction, the second indicator mctnbers 98 arc Corned on a scale 102 formed on the bevel plate 70. The scale 1021s oriented at an angle relative to the side edge of the shoe plate 40 and faces gEnerally reatwardly and outwardly relative to the circular saw 10. To indicate the 1 o bevel angle, the pointer 94 is aligned with one of the second indicator members 98.
It should be understood that, in other constructions, the bevel angle adjustment assembly 58 may include other components and atTangements WhilE
complying with the teachings of the present Invention.
To adjust the bevel angle of the saw blade 7 8, the lever 8G is moped from the locked position (shown in Figs. 1, 2 and dA and as shown in solid lines in Fig.
3) to the unlocked position (sho~~n in Figs. 4B-C and as shown in phantom lines in Fig. 3). The housing 14 is moved relative to the shoe plate 40 until the sa~x~
blade 18 is m the desired bevel angle position (as indicated by the pointer 94 2 o alignment with the selected second indicator member 98). Once the operator has positioned the saw blade 18 in the desired bevel angle position, the locking leer 86 is movEd to the locked position so that the nut 82 clamps the bevel plate 70 to the support post Sd, During cutting operations, as shown in Fig. 1, the operator grasps the main z 5 handle 30 with the right hand and grasps the auxiliary handle 50 with the left hand. The operator maintains a centered position relative to the circular sa~u 10.
This position is the operatoi s optimal cutting stance and the optimal cutting position for holding the circular saw 10.
The operator's line-of sight is indicated by arrow A. Tn the optimal cutting 3 o stance and cutting position, the operator can view the inward face 26 of the saw blade 18 through the opening 3G in the in~uard sole of the blade guard 3d, The components of the circular saw 10, such as the housing 14, the auxiliary handle _g_ 50, the support post Sd and the components of the bevel angle adjustment mechanism 58 are arranged so that an open space is formed and so that the inward face 26 of the saw blade t 8 is visible through the open space as the saw blade 18 cuts the workpiece W. The operator s left hand and the auxiliary handle SO do not obscure the operator's line-of sight.
With the operator in this optitnai cutting stance and cutting position, the operator is not as directly exposed to debris cut by the saw blade 18. The air flow control means. in the form of the tooth 37, further reduces the operator's exposure to debris by substantially preventing the debris from flowing through the opening 3fi info the open space.
It should be understood that the components of the circular saw 10 can be arranged in other locations so long as the operator's Line-of sight of the saw blade 18 as the saw blade 18 cuts the Workplace W is generally maintained.
As shown in Fig. 1. the operator's line-of sight of the indicator ~0 is Z 5 indicated by arrow B. From the operator's point-of view (.while in the optimal cutting stance arid with the circular saw I O held in the optimal cutting position), the indicator 90 is risible along generally the same line-of sight as indicated by arrow A. As a result, the operator can adjust the bevel angle adjustment assembly 58, as explained above, while generally maintaining the optimal cutting stance and z 0 optimal cutting position.
As shown in Fig. 4tr, wish the bevel angle adjustment assembly 58 adjusted for bevel cutting operations, the operator can still vices the in~~ard face 2G
of the saw blade 18 through the opening 3G itt the inward side of the blade guard 34 (along line-of.sight arrow p). Also, the indicator 90 is still risible along lirte-2 S of sight arrow B, generally the same lint-of sight of the sa~u blade 18 as the saw blade 18 cuts the workplace W (arrow A). The operator can thus adjust the saw blade 18 between straight cutting and bevel cutting positions while maintaining the optimal cutting stance and optimal cutting position.
various features of the invention are set forth in the following claims.

Claims

-9- We claim:

1. A circular saw comprising:
a motor for rotatably driving a saw blade about an axis to cut a workpiece;
a housing supporting said motor;
a shoe plate connected to said housing and supporting said circular saw on the workpiece to be cut;
a main handle supported by said housing; and an auxiliary handle supported by one of said housing and said shoe plate;
wherein, in a cutting position, while cutting the workpiece with the saw blade, an operator holds said main handle with one hand and said auxiliary handle with the other hand, and wherein said first handle and said second handle are arranged so that. in an optimal cutting position, the operator can view the saw blade as the saw blade cuts the workpiece.

2. The circular saw as set forth in Claim 1 wherein the saw blade has an inward face and an outward face, and wherein, in the optimal cutting position, the operator can view the inward face of the saw blade as the saw blade cuts the workpicce.

3. The circular saw as set forth in Claim 2 wherein said housing defines an opening through which the inward face of the saw blade is visible, and wherein said circular saw further comprises air flow control means supported adjacent said opening and controlling a flow of air and debris created by the saw blade.

4. The circular saw as set forth in Claim 3 wherein said air flow control means includes a tooth supported adjacent said opening, said tooth substantially presenting the debris from flowing through said opening.

The circular saw as set forth in Claim 1 wherein the saw blade has opposite faces, wherein one of the opposite faces of the saw blade faces a substantial portion of said circular saw, and wherein, in the optimal cutting position, the operator can view the one of the opposite faces of the saw blade as the saw blade cuts the workpiece.

6. The circular saw as set forth in Claim 1 wherein, when the operator holds said auxiliary handle with the other hand, the operator's other hand and said auxiliary handle do not obscure the operator's view of the saw blade as the saw blade cuts the workpiece.

7. The circular saw as set forth in Claim 1 wherein said auxiliary handle is supported by said shoe plate.

8. The circular saw as set forth in Claim 7 and further comprising a support post mounted on said shoe plate, wherein said auxiliary handle is supported on said support post and wherein said support post and said auxiliary handle are arranged so that, in the optimal cutting position, the operator can view the saw blade as the saw blade cuts the workpiece.

9. The circular saw as set forth in Claim 8 wherein, when the operator holds said auxiliary handle with the other hand, the operator's other hand and said auxiliary handle do not obscure the operator's view of the saw blade as the saw blade cuts the workpiece.

10. The circular saw as set forth in Claim 8 wherein said support post and said housing are arranged to provide therebetween a space, and wherein, in the optimal cutting position, the operator can view the saw blade cutting the workpiece through said space.

11. The circular saw as set forth in Claim 1 wherein the operator views the saw blade as the saw blade cuts the workpiece along a line-of-sight, wherein the saw blade defines a cutting plane, wherein a bevel angle is defined between the cutting plane of the saw blade and a surface of the workpiece, wherein said circular saw further comprises a bevel angle adjustment assembly pivotally connecting said shoe plate to said housing so that the bevel angle is adjustable, said bevel angle adjustment assembly including an indicator for indicating the bevel angle, wherein said indicator is arranged so that, in the optimal cutting position, the operator can view the indicator along generally the line-of-sight of the saw blade as the saw blade cuts the workpiece.

12. A circular saw comprising:
a motor for rotatably driving a saw blade about an axis to cut a workpiece, the saw blade defining a cutting plane, a bevel angle being defined between the cutting plane of the saw blade and a surface of the workpiece;
a housing supporting said motor;
a shoe plate supporting said circular sale on the workpiece to be cut, said shoe plate being pivotably connected to said housing to adjust the bevel angle;
a main handle supported by said housing;
an auxiliary handle supported by said housing; and an indicator for indicating the bevel angle, said indicator being supported by at least one of said housing and said shoe plate;
wherein, in a cutting position, while cutting the workpicce with the saw blade, an operator holds said main handle with one hand and said auxiliary handle with the other hand, and wherein said indicator is supported so that, in the cutting position, the operator can view said indicator.

13. The circular saw as set forth in Claim 12 wherein said indicator includes a first indicator member supported on one of said housing and said shoe plate, and a plurality of second indicator members supported on the other of said housing and said shoe plate, wherein said first indicator member is alignable with one of said plurality of second indicator members to indicate a first bevel angle, and wherein said first indicator member is alignable with another of said plurality of second indicator members to indicate a second bevel angle.

14. The circular saw as set forth in Claim 13 wherein said first indicator member is supported by said shot plate and said plurality of second indicator members are supported by said housing.

15. The circular saw as set forth in Claim 11 wherein the operator has a line-of-sight of the saw blade as the saw blade cuts the workpiece, and wherein said indicator is arranged so that. in the cutting position, the operator can view the indicator along generally the line-of-sight of the saw blade as the saw blade cuts the workpiece.

16. The circular saw as set forth in Claim 15 wherein the saw blade has an inward face and an outward face, and wherein, in an optimal cutting position, the operator can view the inward face of the saw blade along the line-of-sight as the saw blade cuts the workpiece.

17. A circular saw comprising:
a motor for rotatably driving a saw blade about an axis to cut a workpiece, the saw blade defining a cutting plane, a bevel angle being defined between the cutting plane of the saw blade and a surface of the workpiece;
a housing supporting said motor:
a shoe plate supporting said circular saw on the workpiece to be cut, said shoe plate being pivotably connected to said housing to adjust the bevel angle:
a main handle supported by said housing;
an auxiliary handle supported by said housing: and an indicator for indicating the bevel angle, said indicator being supported by at least one of said housing and said shoe plate;
wherein, in a cutting position, while cutting the workpicce with the saw blade, an operator holds said main handle with one hand and said auxiliary handle with the other hand, wherein said main handle, said auxiliary handle and said indicator are arranged so that, in the cutting position, the operator can view the saw blade as the saw blade cuts the workpiece and can view said indicator.

18. The circular saw as set forth in Claim 17 wherein the saw blade has an inward face and an outward face, and wherein, in an optimal cutting position, the operator can view the inward face of the saw blade as the saw blade cuts the workpiece.

19. The circular saw as set forth in Claim 18 wherein said housing defines an opening through which the inward face of the saw blade is visible, and wherein said circular saw further comprises air flow control means supported adjacent said opening and controlling a flow of air and debris created by the saw blade.

20. The circular saw as set forth in Claim 19 wherein said air flow control means includes a tooth supported adjacent said opening, said tooth substantially preventing the debris from flowing through said opening.

21. The circular saw as set forth in Claim 17 wherein the operator views the saw blade as the saw blade cuts the workpiece along a line-of-sight, and wherein the operator views said indicator along generally the line-of-sight of the saw blade as the saw blade cuts the workpiece.

22. The circular saw as set forth in Claim 21 and further comprising a bevel angle adjustment assembly pivotably connecting said shoe plate to said housing and operable to adjust the bevel angle. wherein. the operator can operate said bevel angle adjustment assembly while substantially maintaining the optimal cutting position.