Technical Field

The invention relates to a portable cutting tool with illuminating means. Background Art

Various portable cutting tools for cutting workpieces or materials are known in the art. In general, an operator often draws a cutting line or makes a mark on a workpiece to be cut for indicating cutting position and path. Before a cutting operation, the operator looks at a target cutting line through an upper window formed in a protective guard of the cutting tool, aligns a front edge portion of the cutting blade to the cutting line, and then turns on the cutting tool to initiate the cutting operation. During operation, the operator keeps the cutting blade moving forwards along the cutting line while looking through the window.

However, for the reasons of protection, structure design and the like, the window in the protective guard cannot have a large size, and the protective guard itself obstructs exterior light from reaching the cutting area of the workpiece. As a result, the line of sight of the operator through the window to the cutting area is not in a good condition, especially when environment illumination is not good, and thus the operator cannot perform precise cutting.

In order to account for these problems, some cutting tools are equipped with means for illuminating the cutting area of the workpiece during operation to improve cutting precision and cutting efficiency.

As an example, patent application publication CN1318456A discloses a cutting tool having illumination function. The cutting tool comprises a blade guard and a lamp disposed in the blade guard. The lamp is offset from a saw blade in a lateral direction and is adapted to be aligned to a cutting line on a workpiece. In some similar cutting tools, illuminating means is similarly disposed in an upper portion of a protective guard adjacent to the plane defined by the saw blade but offset laterally from the blade. Some problems have been found from the cutting tool disclosed in the above patent application as well as similar known cutting tools. First, the blade guard (protective guard) itself has a small lateral dimension, so the illuminating means can be offset from the saw blade laterally by only a short distance. Thus, the area in the cutting area that can be reached by light beams is small, and the illumination brightness or strength is low. Second, although the illuminating means is offset laterally from the saw blade, the offset distance is not enough. Thus, cutting chips are attached to the illuminating means directly or after deflected by the protective guard, and thus cover the illuminating means. In addition, in high speed cutting operations, cutting chips flying between the illuminating means and the cutting area also obstruct light beams. The amount of the cutting chips attached during operation varies in accordance with the arranging location of the illuminating means in the protective guard, but in any case the attachment of the cutting chips to the illuminating means is unavoidable. Thus, it is difficult to maintain the illuminating condition during operation and to clean the tool after operation.

Further, heat generated by the illuminating means is not easy to be dissipated since the illuminating means is mounted in the protective guard. For this reason, it generally needs to cool the illuminating means actively (for example, as described in CN1318456A), which will definitely increase the cost of the cutting tool.

Thus, it is desirable to overcome the above defects found from the prior art.

Summary of the Invention

The invention is aimed at solving one or more of the following problems existed in portable cutting tools with illuminating means: small illumination area, low illuminating strength, easy attachment of cutting chips to the illuminating means, needing active cooling to the illuminating means, and the like.

For this end, the invention provides a portable cutting tool comprising a plate shaped base having a lower surface configured to abut against a workpiece and an upper surface which carries a driving mechanism thereon, the base further having an opening formed therethrough; a cutting blade driven by the driving mechanism, the cutting blade being mounted in a manner of passing through the opening of the base; and illuminating means which comprises a light emitting element mounted to the base in a distance from a plane defined by the cutting blade, the light emitting element being adapted for generating an illumination area surrounding a cutting point of the cutting blade on the workpiece. In this way, an illumination area can be generated around the cutting point by means of the light emitting element. Since the light emitting elements is mounted to the base, the distance between the light emitting element and the cutting point is very short, and thus light beams emitted from the light emitting element can reach the illumination area efficiently.

In accordance with a preferred embodiment of the invention, the light emitting element comprises a plurality of light emitting elements disposed on opposite sides of the plane defined by the cutting blade.

In accordance with a preferred embodiment of the invention, the plurality of light emitting elements are disposed at different heights with respect to the base and/or in different distances from the plane defined by the cutting blade.

In accordance with a preferred embodiment of the invention, the cutting tool further comprises a protective guard covering a portion of the cutting blade which is above the base, wherein the light emitting element is disposed in a position where its light beams are not obstructed by the protective guard.

In accordance with a preferred embodiment of the invention, the cutting tool further comprises a carrier mounted to the base for carrying the light emitting element.

In accordance with a preferred embodiment of the invention, the light emitting element is equipped with a seat which is configured to be able to provide the light emitting element with an adjustable irradiation angle. By means of this adjustable seat, the irradiation angle of the light emitting element can be adjusted.

Further preferably, the seat is configured to have a structure with an adjustable height and/or adjustable horizontal positions. Thus, the position and angle of the light emitting element can be adjusted integrally, so that optimal illumination effect can be obtained.

In accordance with a preferred embodiment of the invention, the cutting tool further comprises, for the light emitting element, a switch and a brightness controlling knob. Each light emitting element may be provided with an individual switch and an individual brightness controlling knob; alternatively, a common switch and a common brightness controlling knob can be used for controlling all the light emitting elements.

In accordance with a preferred embodiment of the invention, the light emitting element is powered by the same power source with the driving mechanism (for example, an electric motor) of the cutting blade (a transformer may be added when necessary), or is powered by a separate power source, for example, a battery.

In accordance with a preferred embodiment of the invention, the cutting blade is a rotary and/or reciprocating saw blade. That is to say, the cutting blade may be a rotary blade (for example, a saw blade), a reciprocating blade (for example, a reciprocating saw blade), or a blade able to perform both rotary and reciprocating movements (for example, a rotary and reciprocating circular saw blade).

According to the portable cutting tool of the invention, one or more light emitting elements of the illuminating means are disposed in an outer periphery area surrounding the cutting area on the base of the cutting tool, thus there is an enough space for arranging the illuminating means. Thus, the total number, the positions and the power levels of the light emitting elements can be determined according to expected operations to meet requirements in the size of the illumination area, the illumination strength and other aspects.

Further, one or more light emitting elements are disposed on the base of the cutting tool in outer periphery areas surrounding the cutting point, as opposed to being disposed in the protective guard where they will be impacted directly by cutting chips. Thus, cutting chips generated and moved out from the workpiece by the cutting blade are not likely to reach the light emitting elements, so that good illuminating condition can be maintained. In addition, even if there are a few cutting chips fall onto the illuminating means during operation, the illuminating condition can be substantially maintained.

Furthermore, the illuminating means is arranged outside the protective guard, thus one or more light emitting elements are easy accessible from outside. As a result, it is easy to remove the cutting chips attached onto the illuminating means after operation and to exchange light emitting elements. In addition, as compared with the structure where light emitting elements are mounted in the protective guard, it is easier for removing heat from light emitting elements mounted outside the protective guard, thus no additional special cooling to them is needed.

In summary, the invention provides a useful option to users.

Brief Description of the Drawings

Figure 1 is a top view of a portion of a portable cutting tool with illuminating means according to an embodiment of the invention;

Figure 2 is a bottom view of the portion of the cutting tool;

Figure 3 is a top-down perspective view of the portion of the cutting tool.

Detailed Description of Preferred Embodiments

A portable cutting tool with illuminating means according to preferred embodiments of the invention will be described now with reference to the drawings.

The invention relates to portable cutting tools for cutting various workpieces, such as circular saws, stone cutters and the like. The term "workpiece" here means any bulk or plate shaped cuttable material, such as wood, plastics, glass, metals and the like.

The cutting tool may comprise a power cable so that the tool can be put into work by connecting with an outer power source. Alternatively, the cutting tool may not comprise such a power cable; rather, it works with its own battery, such as a rechargeable battery.

As shown in Figures 1-3, the illustrated portable cutting tool is a circular saw which comprises a base 1. The base is preferably made of a durable material, such as metal. In the embodiment shown in the figures, the base 1 is in the form of a substantially rectangular plate, having scale marks on a front edge and/or a back edge in a forward cutting direction F, as shown in Figure 1. Of course, it is also possible that the base has other shapes.

The base 1 has a flat bottom surface which is configured to abut against an upper surface of a workpiece during a cutting operation.

The cutting tool further comprises a cutting blade 2, which is shown in the figures and described below as a rotary blade, such as a circular saw blade. It can be understood, however, that the cutting blade may be alternatively a reciprocating blade, or a blade having both rotating and reciprocating abilities.

When the cutting blade is a rotary blade, it has preferably an adjustable height with respect to the base 1, so that the depth of the blade cutting into the workpiece can be adjusted. Mechanisms for achieving such an adjustable height are known in the art, and thus detailed description to it is omitted.

Further, the cutting blade 2 may be mounted to the base 1 via a bracket 10. The angle formed between the cutting blade 2 and the base 1 can be adjusted and then fixed by means of the bracket 10. In general, the cutting blade 2 is perpendicular to the base 1, that is to say, the blade is cutting into the workpiece in an orientation perpendicular to the upper surface of the workpiece. However, some times the blade should cut into the workpiece in a manner that the blade forms a certain angle with respect to the upper surface of the workpiece. In this condition, the cutting blade 2 is set in a desired tilting orientation with respect to the base 1 by means of the tiltable bracket 10. The bracket 10 is provided with a tilting-angle scale for indicating the tilting angle of the cutting blade 2 with respect to the base 1. Such a tiltable bracket is known in the art, and thus detailed description to it is omitted.

A portion of a lower half of the cutting blade 2 passes through an opening 16 formed in the base 1 so as to be exposed from a lower surface of the base in a manner of being able to cut into the workpiece. During operation, a portion of the cutting blade 2 which is above the base 1 is enclosed by a protective guard 5 to prevent cutting chips attached to the blade from flying out to hurt operators. During operation, the cutting blade 2 generally has a direction of rotation along which a front edge portion (saw tooth) of the cutting blade 2 in the forward cutting direction F shown in Figures 1 and 2 moves upwards from the workpiece and into the protective guard 5. Of course, the invention does not exclude the condition that the cutting blade rotates in an opposite direction along which the front edge portion (saw tooth) of the cutting blade in the forward cutting direction cuts into the workpiece. In either case, a cutting point or cutting area can be defined as the intersecting point between the front edge portion (saw tooth) of the cutting blade in the forward cutting direction and the upper surface of the workpiece. As described above, the blade has an adjustable height, and the tilting angle of the blade is also adjustable, thus the cutting point is actually variable within a rectangular region 12 schematically shown in Figure 2.

In general, an operator draws a cutting line or makes a mark on the workpiece previously for indicating cutting position and path. Before a cutting operation, the operator aligns the front edge portion of the cutting blade to the cutting line, and then turns on the cutting tool to initiate the cutting operation. During operation, the operator should keep the cutting blade moving forwards along the cutting line.

In order that the front edge portion of the blade aligns to the cutting line when the cutting operation is initiated and that the cutting line is properly followed in the cutting operation, the cutting point and its surrounding area need to be illustrated.

For this end, the cutting tool according to the invention comprises illuminating means for generating an illumination area 20 (as shown in Figures 1 to 3) at the cutting point and its surrounding area. The illuminating means comprises one or more light emitting elements 3 mounted to the base 1. The light emitting elements are disposed in such positions that the cutting point is within lighting areas of the light emitting elements.

In the illustrated embodiment, the illuminating means comprises five light emitting elements 3. Figure 2 shows all the light emitting elements, while in Figures 1 and 3 which are made from above, some light emitting elements are shielded by the protective guard 5 from being seen.

As shown most clearly in Figure 2, these light emitting elements 3 are disposed on lateral opposite sides of the cutting point or the rectangular region 12.

In order that light beams can be emitted towards the cutting point and its surrounding area in different angles and thus it is easy to set the covering range and the brightness or strength of the illumination area 20, it is preferable to dispose a plurality of light emitting elements around the cutting point. However, according to a simplest embodiment, a single light emitting element can be disposed on only one lateral side of the cutting point or the rectangular region 12. The illuminating range of the single light emitting element should cover the cutting point and a portion of its surrounding area.

The light emitting elements 3 should be disposed in a distance from a plane defined by the cutting blade 2 (the plane in which the cutting blade 2 lies). This distance is selected so that a combined illumination area 20 which is large enough to cover the cutting point and its surrounding area is formed by respective lighting areas of these light emitting elements and the combined illumination area 20 has enough light beam strength.

The light emitting elements 3 may be mounted to the base 1 directly, for example mounted to the upper surface of the base 1 or to the peripheries of the opening 16 in the base 1. However, for arranging the light emitting elements 3 at suitable heights with respect to the base 1 and/or in suitable distances from the plane defined by the cutting blade 2, the light emitting elements 3 may be mounted to the base 1 by means of one or more carriers 4. The carriers 4 may have certain heights so that the light emitting elements 3 carried by them can emit light beams towards the cutting point from obliquely above, which is advantageous in increasing the brightness in the illumination area 20.

A single carrier 4 may be provided for supporting several or even all the light emitting elements 3. Alternatively, several carriers 4, each supporting one or more of the light emitting elements 3, can be provided.

The carrier or carriers 4 may be made of an insulative material, such as plastics, having vibration absorb property. In this way, vibrations generated by the cutting tool during a cutting operation is not easy to be transmitted to the light emitting elements 3 via the base 1, so that the life time of the light emitting elements can be prolonged.

The carrier or carriers 4 may comprise any possible structures, such as a pad like structure as shown, or any other structures that can be designed by those skilled of the art, such as post like structures or the like.

There may be several light emitting elements 3 disposed at different heights with respect to the base 1 and/or in different distances from the plane defined by the cutting blade 2. In this way, it is easier to set the covering range and the brightness of the illumination area 20.

If it is necessary to arrange one or more light emitting elements 3 at significant heights from the base 1, one or more carriers 4 may be used for this purpose.

In the condition that several carriers 4 are adopted, the carriers may be configured to have different heights, so that the light emitting elements 3 can be supported at different heights.

According to a preferred embodiment, one or more of the light emitting elements 3 may be provided with seats (not shown) which are configured to be able to provide adjustable irradiation angles to the light emitting elements. By means of the seats, the irradiation angles of the light emitting elements 3 can be adjusted, and thus the covering range and the brightness of the illumination area 20 can be adjusted to meet requirements of different cutting operations. It should be note that, although the illumination area 20 is represented in the figures by a rectangular block, the real shape of the illumination area 20 is dependent on various factors, such as the total number, the distribution and respective lighting areas of the light emitting elements 3 and the like. Thus, the real size and shape of the illumination area may be different from the illumination area 20 shown in the figures.

According to a preferred embodiment, some or even all of the light emitting elements 3 have adjustable heights and/or adjustable horizontal positions (lateral and/or longitudinal). For example, the seats may be configured to have a height and/or horizontal position adjustable structure. For controlling the operation of the light emitting elements 3, the cutting tool comprises one or more switches (not shown) for the light emitting elements.

A single switch may be provided for controlling all the light emitting elements 3. By means of the single switch, all the light emitting elements 3 can be turned on or off simultaneously. The switch for the light emitting elements may be disposed near a main switch of the cutting tool or near an activating switch (for example, a trigger) of the cutting blade. For example, the switch for the light emitting elements may be attached to a handle of the cutting tool or other easy-accessible portions of the tool together with the main switch of the cutting tool or the activating switch of the cutting blade.

According to a possible embodiment, several switches for light emitting elements are provided, each switch being configured for controlling one or several light emitting elements 3. In this way, according to different requirements of cutting operations, different light emitting elements 3 can be turned on or off by means of different switches. Each switch may be provided for example near the activating switch of the cutting blade or near the light emitting element controlled by it.

Further, the cutting tool may comprise one or ore brightness controlling knobs for controlling the brightness of the light emitting elements.

A single brightness controlling knob may be provided for controlling the brightness of all or some of the light emitting elements 3. Alternatively, several brightness controlling knobs may be provided, each brightness controlling knob being configured for controlling one or several light emitting elements 3. By means of the brightness controlling knob or knobs, the brightness of each section of the illumination area 20 can be adjusted to an optimal level.

The brightness controlling knob may be arranged for example near the switch for light emitting element or near the light emitting element controlled by it.

The light emitting elements 3 may be powered by the same power source as the driver (for example, an electric motor) of the cutting blade, such as external AC power sources. In this condition, for light emitting elements 3 operating at a low voltage (for example, 12 or 24 volts), high external voltages provided by the external AC power sources (for example, 200 volts) should be transformed into the low voltage by means of a transformer of the tool. Of course, the light emitting elements 3 and the driver of the cutting blade can be powered by a common internal battery, such as a rechargeable battery.

According to a possible embodiment, the light emitting elements 3 are powered by an individual internal power source such as an internal battery (for example, a dry battery or a rechargeable battery), or powered by an individual external power source.

Each light emitting element 3 can be covered by a transparent casing or cover for protecting the light emitting element 3 from external objects such as cutting chips, while not blocking the light path from the light emitting element to the cutting point and its surrounding area.

When there is one or more light emitting elements 3 disposed in heights above the upper surface of the base 1, the protective guard 5 should not block the light path of the light emitting elements 3. For this end, the lower edge of the front part of the protective guard 5 should be located above the light paths of the light emitting elements 3 so as leave spaces to the light paths. Alternatively, the lower portion of the front part of the protective guard 5 may be made of a transparent material, so that even if the lower portion of the front part of the protective guard 5 is located in the light paths during operation, it will not block the light beams of the light emitting elements 3.

According to the cutting tool of the invention, the light emitting elements 3 of the illuminating means are disposed on the base 1 of the cutting tool in outer periphery areas surrounding the cutting point, as opposed to being restricted within the protective guard (blade guard) 5 which has a limited space, thus there are enough spaces for arranging the light emitting elements 3 of the illuminating means. As a result, there provides a high flexibility in arranging the light emitting elements 3. For example, the total number, the positions (horizontal and vertical positions) and the power levels of the light emitting elements 3 can be determined according to expected operations to meet requirements in the size of the illumination area, the illumination strength and other aspects.

Further, the light emitting elements 3 are disposed on the base 1 of the cutting tool in outer periphery areas surrounding the cutting point, as opposed to being disposed in the protective guard 5 where they will be impacted directly by cutting chips. Thus, cutting chips generated and moved out from the workpiece by the cutting blade are not likely to reach the light emitting elements 3, so that good illuminating condition can be maintained.

Furthermore, the light emitting elements 3 are disposed on the base 1, as opposed being mounted in the protective guard, thus the light emitting elements are easy accessible from outside. As a result, it is easy to clean the light emitting elements after operation and to exchange aged or defective light emitting elements.

In addition, as compared with the structure where light emitting elements are mounted in the protective guard, it is easier for removing heat from light emitting elements mounted outside the protective guard, thus no additional special cooling to them is needed. Of course, according to some specific usages, if it needs to actively cool the light emitting elements of the cooling tool of the invention, cooling or heat dissipation means may be provided for the light emitting elements.

Furthermore, according to some embodiments of the invention, switching on/off, irradiation angles, brightness and the like of some or all of the light emitting elements are adjustable. Thus, the illumination area and the brightness can be set and adjusted according to concrete operations, which is not able to be achieved in the prior art where light emitting elements are disposed in the protective guard.

In summary, the cutting tool of the invention can provide significantly improved accuracy and convenience in cutting operations.

While certain embodiments have been described, these embodiments are presented by way of example only, and are not intended to limit the scope of the inventions. The attached claims and their equivalents are intended to cover all the modifications, substitutions and changes as would fall within the scope and spirit of the invention