WO2012146168A1

WO2012146168A1 - Portable electric saw

Info

Publication number: WO2012146168A1
Application number: PCT/CN2012/074664
Authority: WO
Inventors: Youmei YAN
Original assignee: Bosch Power Tools (China) Co., Ltd.
Priority date: 2011-04-25
Filing date: 2012-04-25
Publication date: 2012-11-01
Also published as: CN202028816U

Abstract

A portable electric saw (100) comprises a main portion (1), a cutting saw blade (4), a base plate (3), and a guard (11) extending from the main portion (1) and covering a part of the cutting saw blade (4) which is above the base plate (3), wherein the portable electric saw is provided with at least one illuminating device for illuminating an area of the workpiece to be cut, and the at least one illuminating device comprises an adjustable device (6) for adjusting the illuminating area. With the portable electric saw, the workpiece to be cut can be well illuminated independent of the external light environment in the cutting process. The cutting precision and the working efficiency of the portable electric saw can be enhanced.

Description

Portable Electric Saw

Technical Field

The present invention relates to a portable electric saw, and particularly relates to a portable electric saw with an illuminating device.

Background Art

Portable electric saws are widely used for cutting metal, wood, plastics, fibers or other hard materials. A saw blade of a portable electric saw takes the form of a thin metal blade (called a "belt saw blade"), a thin metal circular disk (called a "circular saw blade") or the like. Hard materials can be cut through by a reciprocating belt saw blade or by a rotating circular saw blade.

Portable electric saws are of two general types: belt saws and circular saws. Usually, a cutting process of a belt saw or a circular saw is unfavorably affected due to dim light in the operating environment. Under these circumstances, there is a need to provide an external illuminating device to achieve necessary illumination.

However, if an external illuminating device is additionally introduced to illuminate the cutting area of a portable electric saw, the cost will be increased. Further, if the external illuminating device is not properly positioned, a light support of the illuminating device will cast a shadow on a working table of the portable electric saw. Then, the cutting precision will be negatively affected and the operating efficiency will be reduced.

Chinese Utility Model Patent No. CN201448686U published on July 9, 2009 discloses a belt saw comprising a plurality of illumination light bulbs 1 which are arranged in rows underneath a frame panel 3 of the belt saw. When a cutting process is performed, the plurality of illumination light bulbs 1 are switched on to illuminate a working table of the belt saw. A laser light source 2 is used to illuminate the cutting position so that a workpiece may be cut precisely.

Besides, cutting area of a conventional portable electric saw is hided in the shade of an upper guard of the portable electric saw. It is not easy for a user to observe the cutting area clearly. In some portable electric saws, light sources are fixed to the guards or other portions of the portable electric saws. Once the inclination angle of a saw blade of a portable electric saw, the depth of the saw blade or the position of a base plate of the portable electric saw is adjusted and set by the user in the cutting process, the light sources fixed to the upper guard or other portions of the portable electric saw are not able to provide sufficient illumination for the cutting process.

Summary of Invention l As mentioned above, in a conventional saw, sufficient illumination can not be provided for cutting processes. In view of the above disadvantages, an object of the present invention is to provide an improved portable electric saw, wherein the cutting process of the portable electric saw can be well illuminated, even when the lighting in the operating environment is poor, or after the inclination angle of the portable electric saw, the depth of a saw blade of the portable electric saw or the position of a base plate of the portable electric saw is set.

According to the present invention, a portable electric saw is provided which comprises a main portion; a cutting saw blade driven by a driving mechanism of the main portion; a base plate having a lower end surface abutting against a workpiece to be cut when the portable electric saw is performing a cutting operation, the main portion being attached to the base plate; and a guard extending from the main portion and covering a part of the cutting saw blade which is above the base plate, wherein the portable electric saw is provided with at least one illuminating device for illuminating an area of the workpiece to be cut, and the at least one illuminating device comprises an adjustable device for adjusting the illuminating area.

In the portable electric saw in accordance with the present invention, the adjustable device can provide sufficient illumination for the cutting process, to ensure that the user can easily observe the cutting area under various conditions, for example, after an inclination angle of the saw, the depth of the saw blade or the position of the base plate is adjusted.

In accordance with one preferred embodiment, the adjustable device is movably attached to the guard. The at least one illuminating device further comprises a fixed illuminating device which is fixed to the guard and configured for additionally illuminating the area of the workpiece to be cut.

In the portable electric saw of the present invention, both of the adjustable device and the fixed illuminating device are provided. The illuminated area of the workpiece to be cut is significantly increased, and the cutting operation can be facilitated.

In accordance with one preferred embodiment, the fixed illuminating device is mounted in a bottom end of the guard which faces toward the area of the workpiece to be cut.

In accordance with one preferred embodiment, the base plate has a through slot, and the cutting saw blade goes through the through slot. The fixed illuminating device comprises a plurality of illumination lights positioned around the through slot and adjacent the area of the workpiece to be cut.

In accordance with one preferred embodiment, the portable electric saw is provided with a switch button. The switch button is configured for controlling the power on/off of both the fixed illuminating device and the adjustable device.

In accordance with one preferred embodiment, the guard is provided in one of its side walls with a guiding slot. The adjustable device is slidably mounted in the guiding slot.

In accordance with one preferred embodiment, the fixed illuminating device comprises a plurality of light sources which are located at the bottom end of the guard and are arranged in rows.

In accordance with one preferred embodiment, the at least one illuminating device is powered by a power supply which powers the portable electric saw.

In accordance with one preferred embodiment, the adjustable device is pivotably connected to the guard.

In accordance with one preferred embodiment, the at least one illuminating device is an LED light.

In accordance with one preferred embodiment, the portable electric saw is a circular saw.

The portable electric saw of the present invention can provide the effective illumination for the cutting operation, even when the lighting in the operating environment is poor, or after the inclination angle of the portable electric saw, the depth of a saw blade of the portable electric saw or the position of a base plate of the portable electric saw is set.

With the portable electric saw of the present invention, a workpiece can be well illuminated independently of the external light environment in the cutting process, and the cutting precision and the working efficiency can be enhanced.

Brief Description of Drawings

Fig. 1 shows a portable electric saw 100 according to the present invention which is provided with an adjustable device in one side wall; and

Fig. 2 shows the portable electric saw 100 which is provided with a fixed illuminating device in the other side wall.

Detailed Description of Preferred Embodiments

Some preferred embodiments according to the invention will be described now with reference to the drawings.

The present invention is intended to protect a portable electric saw. Preferably, a portable electric saw 100 according to the invention is a circular saw. The portable electric saw 100 can be used for cutting a workpiece. The workpiece to be cut may be a metal plate, a wood board and other sheets or plates.

Fig. 1 shows a portable electric saw 100 according to the present invention which is provided with an adjustable device on one side wall. As shown in Fig. 1, the portable electric saw 100 mainly comprises a main portion 1 with a driving mechanism (not shown), a handle 2, a base plate 3, and a cutting saw blade 4 for cutting a workpiece. The cutting saw blade 4 is attached to the main portion 1, and particularly is mounted around a pivot shaft O of the main portion 1 of the portable electric saw 100.

Hereafter, a directional term "front" is defined as the right side in the view of Fig. 1 relative to the pivot shaft O of the portable electric saw 100, and a directional term "rear" is defined as the left side in the view of Fig. 1 relative to the pivot shaft O of the portable electric saw 100.

Fig. 2 shows the portable electric saw 100 of the present invention which is provided with a fixed illuminating device at the other side wall. As illustrated in Fig. 2, a directional term "left" is defined as the direction in which the pivot shaft O is perpendicularly directed away from the paper surface of Fig. 2, and a directional term "right" is defined as a direction opposite to the "left" direction.

The driving mechanism (for example, a motor) in the main portion 1 supplies the pivot shaft O with a driving force via a transmission mechanism (not shown). The cutting saw blade 4 mounted around the pivot shaft O is driven and rotated by the driving mechanism of the main portion 1, so as to cut the workpiece.

A guard 11 is attached to the main portion 1 of the portable electric saw 100. The guard 11 covers part of the cutting saw blade 4 above the base plate 3 to obstruct debris from the cutting saw blade 4 and to protect a user of the portable electric saw 100.

The user grasps the handle 2 of the portable electric saw 100 at the time of performing a cutting operation.

When the portable electric saw 100 is performing a cutting operation, the depth of the cutting saw blade 4 of the portable electric saw 100 is sometimes required to be adjusted in a cutting direction. A first connecting bracket 9 (a part of which is shaded by the handle 2 as shown in Fig. 2) is provided between the main portion 1 and the base plate 3. The first connecting bracket 9 has an adjusting lever 8 extending outwards. When the adjusting lever 8 is in the position as shown in Fig. 2, the first connecting bracket 9 is locked, and the main portion 1 and the base plate 3 can not be adjusted with respect to each other. Only after the adjusting lever 8 is rotated in a counter-clockwise direction, the relative orientations of the main portion 1 and the base plate 3 can be adjusted, and the depth of the cutting saw blade 4 of the portable electric saw 100 can be adjusted.

In other circumstances, the inclination angle of the cutting saw blade 4 of the portable electric saw 100 is required to be adjusted in order to cut the workpiece obliquely. Two second connecting brackets 10 are provided between the main portion 1 and the base plate 3. Each of the second connecting brackets 10 has a screw bolt (not shown) and a butterfly- shaped nut 7. When the nut 7 is tightened, the second connecting brackets 10 can not be rotated, and the main portion 1 and the base plate 3 are fixed with respect to each other. Only when each nut 7 is unscrewed, the user can rotate the second connecting brackets 10 and adjust the inclination angle of the cutting saw blade 4 with respect to the workpiece.

However, after the depth or the inclination angle of the cutting saw blade 4 is adjusted, a fixed illuminating device would not be able to provide sufficient illumination for the cutting operation.

In order to overcome the above disadvantages, the main portion 1 of the present portable electric saw 100 is provided with an adjustable device 6 for adjusting the illuminating area, as shown in Fig. 1. Specifically, the adjustable device 6 is attached to the guard 11 of the portable electric saw 100 so as to provide sufficient illumination for the cutting process, even after the inclination angle and the depth of the portable electric saw 100 and a position of the base plate 3 are adjusted and set. Thus, the user can easily observe the cut area under various conditions, and the disadvantages in the prior art can be overcome.

As described above, the adjustable device 6 is movably attached to the guard 11. For example, the adjustable device 6 may be slidably or pivotally attached to the guard 11. The adjustable device 6 can be an illumination light positioned in the guard 11.

The position or the orientation of the adjustable device 6 can be adjusted. The user can manually adjust the position or the orientation of the adjustable device 6, to ensure that the required area of the workpiece to be cut can be illuminated. Further, the adjustable device 6 can be rotated or swung so that an illumination area of the adjustable device 6 can be adjusted. As shown in Fig. 1, the total illumination range of the adjustable device 6 corresponds to a C-D portion plus a C'-D' portion of the illuminated area of the workpiece. Alternatively, the position or the orientation of the adjustable device 6 can be adjusted automatically.

In one embodiment, the adjustable device 6 is pivotably connected to a side wall of the guard 11, such that the adjustable device 6 can be used to illuminate different portions of the workpiece. In addition, as shown in Fig. 2, a fixed illuminating device 5 is preferably arranged on a side (i.e., the left side in Fig. 2) of the guard 11 of the portable electric saw 100. The fixed illuminating device 5 is used to illuminate the area of the workpiece to be cut during the cutting process of the portable electric saw 100, so that the user can observe and control the cutting operation easily.

The fixed illuminating device 5 is an illumination device secured or fixed to the guard 11 of the portable electric saw 100. Alternatively, the fixed illuminating device 5 is threadly connected to or is snapped in the guard 11. The illumination range on the workpiece illuminated by the fixed illuminating device 5 corresponds to an A-B portion shown in Fig. 2.

The adjustable device 6 and the fixed illuminating device 5 are arranged in the same side of the guard 11. Alternatively, the adjustable device 6 and the fixed illuminating device 5 may be arranged in opposite sides of the guard 11 respectively.

In the present invention, the portable electric saw 100 comprises the adjustable device 6 and the fixed illuminating device 5, and the total illumination area equals the C-D portion and the C'-D' portion plus the A-B portion. When the present portable electric saw 100 is performing a cutting process, the illuminated area of the workpiece or the bottom plate is significantly increased, and the cutting operation can be facilitated.

In one embodiment, the fixed illuminating device 5 may be mounted in a bottom end of the guard 11 which faces toward the workpiece to be cut. With such a position and orientation, the fixed illuminating device 5 can provide sufficient illumination for the cutting operation of the portable electric saw 100.

The base plate 3 of the portable electric saw 100 may be connected to or integral with the main portion 1. The base plate 3 has a lower end surface abutting against the workpiece to be cut when the portable electric saw 100 is performing a cutting operation. According to one preferred embodiment, the base plate 3 has a through slot through which the cutting saw blade 4 passes.

In a preferred embodiment, the fixed illuminating device 5 comprises a plurality of illumination lights positioned around the through slot and adjacent the area of the workpiece to be cut. With such an arranging manner, the fixed illuminating device 5 has a compact structure, and also provides sufficient illumination for the cutting operation.

In some cases, both of the adjustable device 6 and the fixed illuminating device 5 of the portable electric saw 100 are required to be powered on, so as to provide sufficient illumination during the cutting process. In one preferred embodiment, the portable electric saw 100 is provided with a switch button which is configured for controlling the power on/off of both the fixed illuminating device 5 and the adjustable device 6. Accordingly, only one switch button is used in the portable electric saw 100 of the present invention to control the power-on/off of both the fixed illuminating device 5 and the adjustable device 6. The structure of the portable electric saw 100 can also be simplified.

In one preferred embodiment, the guard 11 is provided in one of its side walls with a guiding slot. The adjustable device 6 is slidably mounted in the guiding slot. The guiding slot may be a slot which extends longitudinally or transversely or inclined at a certain degree. The illumination area of the adjustable device 6 may be significantly increased because the adjustable device 6 can be moved in the above guiding slot. With the adjustable device 6, the user can easily adjust the illuminated area of the workpiece in the cutting process.

Alternatively, the fixed illuminating device 5 may comprise a plurality of light sources, such as point light sources, which are located at the bottom end of the guard 11 and are arranged in rows. The plurality of light sources arranged in rows can increase the illumination area of the fixed illuminating device 5, so that the user can observe the area of the workpiece to be cut more easily.

In one preferred embodiment, the adjustable device 6 or the fixed illuminating device 5 is electrically connected to a power supply of the portable electric saw 100 to be supplied with power by the power supply. Thus, the adjustable device 6 and the fixed illuminating device 5 are powered by the power supply which powers the portable electric saw 100. An additional power supply for the adjustable device 6 or the fixed illuminating device 5 may be omitted.

Alternatively, the portable electric saw 100 may be equipped with a disposable battery which supplies electric power to the adjustable device 6 or the fixed illuminating device 5.

In one preferred embodiment, the adjustable device 6 and the fixed illuminating device 5 are light emitting diode units or LED lights. The LED lights have relatively small sizes and can emit very bright light.

The adjustable device 6 and the fixed illuminating device 5 are mounted in a portion of the guard 11 adjacent the area of the workpiece to be cut. The adjustable device 6 and the fixed illuminating device 5 of the present portable electric saw have a long service life because of good characteristics of the LED lights.

In the foregoing description, the portable electric saw 100 is described as a preferable example. However, after reading the above contents, those skilled in the art will understand that the principles of the present invention can also be applied to all types of saws (for example, a belt saw) and other types of power tools.

The foregoing is the description of the preferred embodiments of the present invention. However, these embodiments are provided for illustrative purposes only. It will be understood that the invention is not limited to the particular embodiments described herein. Various substitutions, changes and modifications may be made without departing from the scopes or spirits of the present invention. Such substitutions, changes and modifications all fall within the scope of protection defined by the appended claims.

Claims

1. A portable electric saw (100), comprising:

a main portion (1);

a cutting saw blade (4) driven by a driving mechanism of the main portion (1);

a base plate (3) having a lower end surface abutting against a workpiece to be cut when the portable electric saw (100) is performing a cutting operation, the main portion (1) being attached to the base plate (3); and

a guard (11) extending from the main portion (1) and covering a part of the cutting saw blade (4) which is above the base plate (3),

wherein the portable electric saw is provided with at least one illuminating device for illuminating an area of the workpiece to be cut, and

the at least one illuminating device comprises an adjustable device (6) for adjusting the illuminating area.

2. The portable electric saw (100) according to claim 1, wherein

the adjustable device (6) is movably attached to the guard (11), and

the at least one illuminating device further comprises a fixed illuminating device (5) which is fixed to the guard (11) and configured for additionally illuminating the area of the workpiece to be cut.

3. The portable electric saw (100) according to claim 2, wherein

the fixed illuminating device (5) is mounted in a bottom end of the guard (11) which faces toward the area of the workpiece to be cut.

4. The portable electric saw (100) according to claim 2, wherein

the base plate (3) has a through slot, the cutting saw blade (4) going through the through slot; and

the fixed illuminating device (5) comprises a plurality of illumination lights positioned around the through slot and adjacent the area of the workpiece to be cut.

5. The portable electric saw (100) according to claim 2, wherein

the portable electric saw (100) is provided with a switch button; and

the switch button is configured for controlling the power on/off of both the fixed illuminating device (5) and the adjustable device (6).

6. The portable electric saw (100) according to claim 1, wherein

the guard (11) is provided in one of its side walls with a guiding slot; and

the adjustable device (6) is slidably mounted in the guiding slot.

7. The portable electric saw (100) according to claim 3, wherein

the fixed illuminating device (5) comprises a plurality of light sources which are located at the bottom end of the guard (11) and are arranged in rows.

8. The portable electric saw (100) according to claim 1, wherein

the at least one illuminating device is powered by a power supply which powers the portable electric saw.

9. The portable electric saw (100) according to claim 1, wherein

the adjustable device (6) is pivotably connected to the guard (11).

10. The portable electric saw (100) according to claim 1, wherein

the at least one illuminating device is an LED light.