GB2621625A

GB2621625A - An improved cutting fluid control arrangement for a handheld cutter saw

Info

Publication number: GB2621625A
Application number: GB2212088.5A
Authority: GB
Inventors: Donson Simon; Lerwill Nick
Original assignee: Evolution Power Tools Ltd
Current assignee: Evolution Power Tools Ltd
Priority date: 2022-08-18
Filing date: 2022-08-18
Publication date: 2024-02-21
Also published as: GB202212088D0

Abstract

A cutting fluid control arrangement controls a flow of cutting fluid to a dispensing arrangement formed on a handheld power tool saw adjacent its movable blade. The arrangement includes an inlet 210 for receiving cutting fluid; an outlet 212 in fluid communication with the dispenser; and first and second control valves 216, 218 located in a flow-path 214 between the inlet and outlet. The first control valve has a first position in where cutting fluid is prevented from flowing from the inlet to the outlet and a second position where cutting fluid is permitted to flow. The first and second positions are discrete. The second control valve is continuously variable between minimum and maximum positions to enable the selection of flow rate for cutting fluid from the outlet. The first valve may be operable via a user control which could be part of a trigger mechanism which may operate a power unit of the saw to move the blade. The trigger may cause a predetermined time delay between moving the valve from its first to its second position and the subsequent operation of the power unit. The first valve may include a solenoid valve and the second valve may include a ball valve.

Description

An Improved Cutting Fluid Control Arrangement For A Handheld Cutter Saw The present invention relates to a handheld cutter saw. More particularly, the present invention relates to a handheld cutter saw having improved cutting fluid control.

Portable, manually-wielded cutter saw power tools are known in a number of applications. One such class of cutter saw power tool is a disc cutter saw which a toothed or abrasive circular blade which can be used to cut stone, concrete, metal and other materials. Such saws are commonly used in the construction and building industry, and in domestic to environments, to make cuts with a substantially vertically arranged circular blade which rotates about a generally horizontal axis.

Disc cutter saws may be driven and powered by any suitable means. For example, an electric motor may be powered used which is powered by mains (AC) electricity or a battery. Alternatively, an internal combustion engine may be used which comprises a fuel tank for storing fuel such as petrol.

Other forms of cutter saw power tool having a circular blade are known. Examples include tile saws and wall chaser saws which are generally smaller handheld power tools for use in buildings and fittings construction.

Finally, handheld cutter saws in the form of concrete-cutting chainsaws are also used in the construction and building industry, and in domestic environments.

All of the above-described handheld cutter saws share a common problem that when cutting materials such as concrete, stone or brick, considerable airborne dust, dirt and debris is generated. This can be problematic for a user of the machine in terms of health and safety considerations.

A known way to address this is to provide injection of a suitable cutting fluid such as water onto or adjacent the cutting blade when the cutting saw is in use. In use, the cutting fluid mixes with the dust, dirt and debris generated during a cutting operation and forms a paste or slurry of cutting waste as opposed to airborne particles.

However, known fluid control arrangements for cutter saws suffer from a number of disadvantages, not least in terms of ergonomics and usability. The present invention seeks, in embodiments, to address the disadvantages of the known art.

According to a first aspect of the present invention, there is provided a cutting fluid control arrangement for a handheld cutter saw power tool having a movable blade, the cutting fluid control arrangement being configured and arranged to control, in use, a flow of cutting fluid to a cutting fluid dispensing arrangement formed on the handheld cutter saw power tool adjacent the movable blade, the cutting fluid control arrangement comprising: an inlet for receiving cutting fluid from a cutting fluid source; an outlet arranged, in use, to be in fluid communication with the cutting fluid dispensing arrangement; and first and second control valves located in a flowpath between the inlet and outlet, wherein the first control valve has a first position in which, in use, cutting fluid is prevented from flowing from the inlet to the outlet and a second position in which, in use, cutting fluid is permitted to flow from the inlet to the outlet, the first and second positions being discrete; and wherein the second control valve is continuously variable between minimum and maximum positions to enable selection of a flow rate for cutting fluid from the outlet.

zo In one embodiment, further comprising a user-operable control for operating the first control valve, the user-operable control being remote from the first control valve.

In one embodiment, the user-operable control is configured and arranged to form part of a trigger mechanism forming part of the handheld cutter saw power tool.

In one embodiment, the trigger mechanism is operable, in use, to operate a power unit of the handheld cutter saw power tool, the power unit being operable, in use, to move the movable blade.

In one embodiment, the first control valve is electronically or hydraulically actuated.

In one embodiment, the first control valve is electronically actuated and comprises a solenoid valve.

In one embodiment, the solenoid valve is configured to move the first control valve from the first position to the second position upon actuation of the user-operable control.

In one embodiment, the second control valve comprises a manually-operable valve.

In one embodiment, the second control valve comprises a ball valve.

In one embodiment, the minimum position enables selection of a zero flow rate.

In one embodiment, the first and second control valves are located within a common housing.

In one embodiment, the inlet, outlet and flowpath therebetween are formed in the common housing.

In one embodiment, wherein the first control valve is located upstream of the second control valve.

In one embodiment, the movable blade is rotatable.

In one embodiment, the movable blade is disc-shaped.

In one embodiment, the cutter saw power tool comprises a disc cutter power tool.

According to a second aspect of the present invention, there is provided a handheld cutter saw power tool comprising: a main body; a cutting head arranged to support, in use, a movable blade; and a cutting fluid arrangement, the cutting fluid arrangement comprising: a fluid control arrangement operable, in use, to control a flow of cutting fluid; and a cutting fluid dispensing arrangement located and arranged to dispense, in use, cutting fluid adjacent the movable blade, the fluid control arrangement comprising: an inlet for receiving cutting fluid from a cutting fluid source; an outlet arranged, in use, to be in fluid communication with the cutting fluid dispensing arrangement; and first and second control valves located in a flowpath between the inlet and outlet, wherein the first control valve has a first position in which, in use, cutting fluid is prevented from flowing from the inlet to the outlet and a second position in which, in use, cutting fluid is permitted to flow from the inlet to the outlet, the first and second positions being discrete; and wherein the second control valve is continuously variable between minimum and maximum positions to enable selection of a flow rate for cutting fluid from the outlet.

In one embodiment, further comprising a user-operable control for operating the first control valve, the user-operable control being remote from the first control valve.

In one embodiment, further comprising a trigger mechanism actuable by a user, and wherein the user-operable control is configured and arranged to form part of the trigger mechanism.

In one embodiment, the trigger mechanism is configured, upon actuation by a user, to move the first control valve from the first position to the second position and to operate the power unit of the handheld cutter saw power tool.

In one embodiment, the trigger mechanism is configured, upon actuation by a user, to cause a predetermined time delay between movement of the first control valve from the first position to the second position and subsequent operation of the power unit of the handheld cutter saw power tool.

In one embodiment, the inlet, outlet and flowpath therebetween are formed in the common to housing.

In one embodiment, the movable blade is rotatable.

In one embodiment, the movable blade is disc-shaped.

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings, in which: Figure 1 shows a front perspective view of a disc cutter saw power tool according to a first embodiment of the present invention; Figure 2 shows a rear perspective view of the disc cutter saw power tool of Figure 1; Figure 3 is a side view of the disc cutter saw power tool of Figures 1 and 2; Figure 4 is a rear perspective view of the handle assembly of the disc cutter saw power tool of Figures 1 and 2; Figures 5 to 8 are various views of a fluid control unit according to an embodiment of the present invention; Figure 9 is a section view showing the fluid control unit of Figures 5 to 8 on the disc cutter saw power tool of Figures 1 to 3; and Figures 10 and 11 are front and section views of an outlet head of the disc cutter power tool of Figures 1 to 3.

The general configuration of an embodiment of a cutter saw power tool in the form of a disc cutter saw will be described with reference to Figures 1 to 3.

Figures 1 to 3 show a battery-powered handheld disc cutter saw 100 according to an embodiment of the present invention. Figure 1 shows a front perspective view and Figure 2 a rear perspective view. Figure 3 shows a side view of the disc cutter saw 100.

The disc cutter saw 100 comprises a main body 102, a drive assembly 104 and rear handle assembly 106.

The main body 102 has a substantially rectangular central section 102a comprising a motor unit (not shown) and a drive arm 102b. The drive assembly 104 is connected to the drive arm 102b The drive assembly 104 is located at a distal end of the drive arm 102b and comprises a drive hub 108 and a circular cutting blade 110 having a toothed cutting surface. However, this is not limiting and other types of circular blade, for example a circular blade with a continuous edge or abrasive surface, may be used. The skilled person would readily appreciate the types of blade which could be used with the disc cutter saw 100 of the present invention.

The cutting blade 110 is rotatable about an axis of rotation X-X which is substantially perpendicular to a longitudinal axis Y-Y of the main body 102.

A guard assembly 112 is arranged on the drive assembly 104 and comprises a guard cover 114 which functions as a hood for at least a part of the cutting blade 110. The guard assembly 112 is pivotable through a range of angles to expose a desired proportion of the blade 110 during a cutting operation.

The main body 102 further comprises a forward handgrip assembly 116 including a looped handgrip 118 which extends from an upper portion of the main body 102 around the main body 102 to a base portion 120. The handgrip 118 is connected to an upper surface of the main body 102 and extends upwardly, passes across the main body 102 and then passes down the left hand side of the main body 102 to loop under the main body to the base portion 120. The handgrip assembly 116 may be formed from any suitable material; for example, metal or reinforced plastic. If formed from metal, the handgrip assembly 116 may be powder coated or plastic coated for user convenience.

to The handgrip 118 has a portion arranged perpendicular to, and elevated relative to, the longitudinal axis Y-Y of the main body 102 such that this portion can be gripped by a user in use. The base portion 120 of the handgrip 118 connects to a lower part of the main body 102 and forms a frame for a skid portion 122 which, in use, acts as a support base for the disc cutter saw 100 when located on a ground surface.

The rear handle assembly 106 is shown in detail in Figure 4. The rear handle assembly 106 is in the form of a cutlass shape and comprises a graspable handle 124 and a lower member 126. The graspable handle 124 has a dog-leg shape and comprises a handgrip 124a for a user of the disc cutter saw 100 and a rear section which extends downwardly to meet the lower member 126. The handgrip 124a is elongate and extends in a direction which is substantially parallel to the drive arm 102b.

A trigger 128 is located on an inner wall of the handgrip 124a. The handgrip 124a is shaped and contoured to enable a user to grasp the handle 124 with one hand and activate the trigger 128 with one or two fingers. A safety button 130 (Figure 4) is located on the side of the graspable handle 124. When the safety button 130 is activated together with the trigger 128, a saw operation switch (now shown) is actuated by the movement of the trigger 128 and the disc cutter saw 100 is caused to operate.

The lower member 126 extends main body 102 and is configured as a resting or support surface for the disc cutter saw 100 when placed on a ground surface. The lower member 126 has a base surface which is substantially parallel to a base of the main body 102a

S

and which sits parallel to ground surface when the disc cutter saw 100 is in the resting configuration on the ground surface.

A cutting fluid system 200 will now be described. A cutting fluid system 200 is provided in order to inject a suitable cutting fluid such as water onto or adjacent the cutting blade when the cutting saw is in use. In use, the cutting fluid mixes with the dust, dirt and debris generated during a cutting operation and forms a paste or slurry of cutting waste as opposed to airborne particles which may cause harm to an operator. In addition, the cutting fluid acts to cool the blade and concomitantly extend blade life, as well as improving the quality of the cut. In embodiments, the cutting fluid is water.

However, known arrangements for controlling the dispensation of cutting fluid are cumbersome and inaccurate. Often, the fluid flow has to be established by trial and error and, once established, the operator then begins a cutting operation. This is time-consuming, inefficient and wasteful of cutting fluid. The present invention seeks to address these issues.

The cutting fluid system 200 comprises a fluid control unit 202, a dispensing head 204 and connecting pipework 206.

The fluid control unit 202 is arranged adjacent the rear handle assembly 106 and is operable to control selectively the flow of cutting fluid through the cutting fluid system 200. The dispensing head 204 is arranged on the guard cover 114 and is shaped and arranged to enable a user to grasp the dispensing head 204 to adjust the guard cover 114. The connecting pipework 206 extends between the fluid control unit 202 and the dispensing head 204 around the external surface of the disc cutter saw 100 and is secured thereto with one or more releasable clamps.

Figures 5 to 9 show the fluid control unit 202 in more detail. In embodiments, the fluid control unit 202 is connected to, and partially integrated into, the lower member 126 of the rear handle assembly 106 as shown in Figure 4. This enables easy access for a user holding the disc cutter saw 100 in use. Figures 5 to 8 show the fluid control unit 202 separate from the remainder of the disc cutter saw 100 for clarity. Figure 9 shows a section view of the fluid control unit 202 on the saw 100.

The fluid control unit 202 comprises a main body 208 and a cover 208a. The main body 208 comprises an inlet 210, an outlet 212 and a fluid pathway 214 therebetween. In embodiments, the inlet 210, outlet 212 and fluid pathway 214 are integrally formed with the main body 208. The main body 208 may be formed from any suitable material, for example plastic. The main body 208 may be formed by injection moulding such that the fluid pathway 214 is integrally moulded thereinto. However, other materials and formation methods may be used. For example, the main body may be formed from resin or metal.

The inlet 210 comprises a connector operable to receive a proximal end of a hose or other conduit (not shown) for connection thereto. The hose or conduit is suitable for conveying cutting fluid therethrough to the fluid control unit 202. In use, the hose is connected at a remote end to a cutting fluid source such as a fluid reservoir (not shown) or mains water source.

In use, the cutting fluid is under pressure such that the cutting fluid flows under pressure from the fluid reservoir to the fluid control unit 202. The pressure may be generated by any suitable means, for example a pump (manual or automatic) or other device to create a head of pressure on the fluid reservoir. Alternatively, mains water pressure may be used if so connected. In embodiments, the fluid pressure supported by the fluid cutting system 200 may be up to 10 bar and the flow rate up to 15 litres/minute.

Two valves are located in the fluid pathway 214 between the inlet 210 and outlet 212. A master control valve 216 is provided downstream of the inlet 210 and a flow control valve 218 is provided downstream of the master control valve 216 and upstream of the outlet 212. The valves 216, 218 are separate and connected by an intermediate section 214a of the fluid pathway.

Both valves 216, 218 are integrated into the fluid control unit 202 and the fluid-acting sections of the valves 216, 218 are formed within the main body 208. In embodiments, the main body 208 comprises an integral unit including the first and second valves 216, 218.

The main body 208 forms a housing for the valves 216, 218. In other words, the valves are both formed in the main body 208 although actuation mechanisms (described below, and which may, in embodiments, comprise a solenoid body for the valve 216 and a flow control handle for the valve 218) may be located externally of the main body 208 but attached thereto.

The master control valve 216 is arranged to permit or prevent the flow of cutting fluid from the outlet 212. The master control valve 216 has an open and a closed position. The open and closed positions are discrete. By discrete is meant that the master control valve 216 has a single open position and a single closed position and, as such, is not continuously variable. Whilst the valve components will move, in use, between open and closed positions, the valve 216 has discrete positions in that, in normal use, the valve 216 can be held in only fully open and fully closed positions.

When the master control valve 216 is closed, no cutting fluid will flow from the outlet 212.

When the master control valve 216 is open, then cutting fluid will flow from the outlet 212. In that sense, the master control valve 216 is an on/off valve in the manner of a switch to select either a fluid flow condition or no fluid flow condition from the outlet 212.

In embodiments, the operation of the master control valve 216 is triggered by a user but the valve mechanism itself is opened and closed electronically, mechanically and/or hydraulically.

The flow control valve 218, in embodiments arranged downstream of the master control valve 216, is arranged to control the magnitude of the cutting fluid flow in a stepless and continuous manner. The flow control valve 218 is operable to enable continuously variable adjustment of the flow rate of the cutting fluid from the outlet 212 between minimum and maximum values.

The flow control valve 218, in embodiments, is a manually adjustable valve which can be set by the user at a particular position between the maximum and minimum values available, the particular position corresponding to a desired flow rate for the user. In non-limiting embodiments, the minimum position may be such that the valve is fully closed and so zero flow of cutting fluid passes therethrough. In non-limiting embodiments, the maximum position may be fully open such that the fluid control valve 218 has no impact on the fluid flow from the intermediate section 214a.

Together the master control valve 216 and flow control valve 218 provide useful advantages to the user. In contrast to known arrangements which must be set by trial and error whilst cutting fluid is flowing, a user can set the desired flow rate of cutting fluid for a particular application or cutting operation using the flow control valve 218, before actuating the master control valve 216 when the user is prepared and ready to perform the cutting operation. This reduces wastage of cutting fluid, and enables an optimum cut to be achieved without the trial and error approach of known arrangements.

In embodiments, the master control valve 216 comprises a solenoid diaphragm valve. This is shown best in Figures 6 to 9. The solenoid master control valve 216 comprises a solenoid body 216a comprising a solenoid coil (not shown) and power connections to an electrical source. The solenoid body 216a is secured to the main body 208 by screws or other fixing means (not shown).

The solenoid valve 216 further comprises an actuator 216b having a valve body 216c operable to engage with a valve seat 216d. The valve body 216c and valve seat 216d form the diaphragm valve controlled by the solenoid 216a and actuator 216b. A spring biases the actuator 216b into a normally-closed position such that in the absence of input current through the actuator coils, the valve 216 remains in the closed position.

In embodiments, the solenoid valve 216 may be powered by a DC electric source having a value which is, for example, 18V DC. A nominal current of 1.75 A may be supported.

The solenoid valve 216 is remotely actuated by means of a switch (not shown) located in the rear handle assembly 106. The switch may comprise a microswitch. In embodiments, the switch is located and arranged such that the switch is actuated when the trigger 128 is actuated. In embodiments, the switch (or microswitch) may be located adjacent or within the trigger 128.

In embodiments, the switch is configured and arranged to enable actuation of the cutting fluid flow prior to the actuation of the power source for the cutting blade 110. This means that the cutting fluid flow will be established before the cutting blade 110 begins to rotate. This ensures the longevity of the blade, and that the cutting fluid flow is correctly established before the user begins to make a cut.

In embodiments, the actuation delay may be implemented in any suitable manner. For example, the location of the solenoid valve 216 switch may be such that the switch is actuated by a first portion of travel of the trigger 128, before a second and further portion of travel activates a control switch to start rotation of the cutting blade 110. This may be achieved through configuration of the trigger 128 travel, or through appropriate location of the solenoid valve switch relative to the control switch for cutting blade activation.

Alternatively or additionally, the solenoid switch and the blade control switch may be substantially simultaneously activated but a time delay implemented for the blade control switch to allow establishment of the cutting fluid flow. As a further alternative or addition, a single switch may be used for both the solenoid valve and the cutting blade activation, and suitable control logic used to specify desired time delays to establish the cutting fluid flow prior to a cutting operation.

As shown best in Figures Band 9, the valve body 216c and valve seat 216d are formed within a chamber 220 in fluid connection to the inlet 210, fluid pathway 214 and intermediate section 214a. The chamber 220 has an inlet 220a in communication with the inlet 210 and an outlet 220b in communication with the intermediate section 214a. The actuator 216b and valve body 216c are operable to close off the fluid pathway via the outlet 220b to prevent fluid reaching the flow control valve 218 and outlet 212.

In the disclosed embodiments, the flow control valve 218 comprises a ball valve. The flow control valve 218 comprises a rotatable ball body 218a comprising one or more apertures therethrough such that rotation of the ball body 218a changes the orientation of the apertures relative to the intermediate section 214a and so continuously varies the maximum flow which can pass therethrough.

The ball valve 218 comprises a spigot 218b connected to a control lever 218c which is arranged to be manually actuated by a user to open and close the valve 218. In embodiments, as shown in Figure 4, the control lever 218c is arranged adjacent the lower member 126 and facing the handgrip 124a to enable convenient access by a user.

In embodiments, the control lever 218c has a 90 degree rotation between maximum and minimum positions. The maximum and minimum positions may be defined in any suitable manner. For example, in embodiments, the minimum position may specify zero flow rate. In such a situation, the flow control valve 218 functions as a further flow stopping device.

The outlet 212 is located downstream of the valve 218 and comprises a barbed nozzle for connection to fluid conduit 206. As shown in Figures 2 and 3, the fluid conduit 206 extends around the external surface of the main body 102 of the disc cutter saw 100 and is secured thereto by suitable fixing means such as clamps, hooks or ties. In embodiments, the fluid conduit 206 comprises a flexible PVC hose.

As shown in Figures 10 and 11, a distal end 222 of the connecting pipework 206 is connected to an outlet unit 224 of the dispensing head 204. The outlet unit 224 is connected to an upper part of the guard cover 114. The outlet unit 224 has an external surface shaped and arranged to define a convenient gripping location for adjustment of the guard cover 114.

The outlet unit 224 acts as a mounting position for the distal end 222 of the fluid conduit 206. An internal manifold 224a is formed within the outlet unit 224 which comprises two branch conduits 224b. The branch conduits 224h lead to outlets 224c arranged either side of the cutting blade to enable cutting fluid flow therefrom in use.

In use, a user connects a supply pipe or hose from a cutting fluid reservoir or fluid supply to the inlet 210 of the fluid control unit 202. Cutting fluid pressure is then established. A user then sets a desired flow rate of cutting fluid using the flow control valve 218. This can, advantageously, be set before a cutting operation takes place, improving the user experience and ensuring that the disc cutter saw 100 has an optimal set up prior to a cutting operation.

The user then holds the disc cutter saw 100 using the forward handgrip assembly 116 (with one hand) and the rear handgrip assembly 106 (with another hand). When the disc cutter saw 100 is correctly positioned for a cutting operation, the user can activate trigger 128 (whilst engaging safety button 122) to begin the cutting operation.

Prior to the start of rotation of the blade 110, the solenoid valve 216 is activated by actuation of the solenoid valve switch and cutting fluid flows through the fluid control unit 202 and exits the outlet 212 at a flow rate desired by the user and set by the position of the flow control valve 218. The cutting fluid flows along fluid conduit 222 to the outlets 224c of the outlet unit 224 to provide cutting fluid on either side of the blade 110. At a predetermined time period after actuation of the solenoid valve, the cutting blade 110 is started and a cutting operation can begin.

By providing such an arrangement with first and second valves in a fluid control unit, an efficient and accurate cutting fluid flow can be established prior to a cut. Once set up, the production of cutting fluid at a desired flow rate is automatic and a user simply needs to activate the trigger 128 to begin a cutting operation.

Variations of the above embodiments will be apparent to the skilled person. The precise configuration of components may differ and still fall within the scope of the present invention.

For example, whilst the above description relates to a handheld cordless disc cutter saw powered by an electric motor and associated battery, the skilled person would recognise that the present invention is applicable to a wider class of cutter saws. For example, a disc cutter saw may be AC mains powered. Alternatively, the disc cutter saw may be powered by an internal combustion power source such as a petrol motor, in which case the master control valve 216 may comprise a hydraulically actuated valve or an electronically actuated valve connected to an alternative power source such as an alternator or associated battery.

The present invention is not limited to disc cutter saws. The present invention may be used with other forms of cutter saw power tool having a circular blade, for example tile saws and wall chaser saws.

In addition, the cutter saw need not have a circular blade. The invention is equally applicable to handheld cutter saws in the form of concrete-cutting chainsaws.

The described embodiments are not intended to be limiting. For example, whilst the embodiments show a master control valve upstream of a flow control valve, this may be to reversed such that the flow control valve is located upstream of the master control valve.

In addition, whilst both valves are shown in the same housing this need not be the case, and the valves may be spaced apart or in separate housings connected by a suitable fluid conduit.

In embodiments, the cutting fluid is water. However, this need not be the case and alternative cutting fluids may be used. For example, water-based cutting fluids containing additional components or suspensions may be used.

Embodiments of the present invention have been described with particular reference to the examples illustrated. While specific examples are shown in the drawings and are herein described in detail, it should be understood, however, that the drawings and detailed description are not intended to limit the invention to the particular form disclosed. It will be appreciated that variations and modifications may be made to the examples described within the scope of the present invention.

Claims

CLAIMS1. A cutting fluid control arrangement for a handheld cutter saw power tool having a movable blade, the cutting fluid control arrangement being configured and arranged to control, in use, a flow of cutting fluid to a cutting fluid dispensing arrangement formed on the handheld cutter saw power tool adjacent the movable blade, the cutting fluid control arrangement comprising: an inlet for receiving cutting fluid from a cutting fluid source; an outlet arranged, in use, to be in fluid communication with the cutting fluid dispensing arrangement; and first and second control valves located in a flowpath between the inlet and outlet, wherein the first control valve has a first position in which, in use, cutting fluid is prevented from flowing from the inlet to the outlet and a second position in which, in use, cutting fluid is permitted to flow from the inlet to the outlet, the first and second positions being discrete; and wherein the second control valve is continuously variable between minimum and maximum positions to enable selection of a flow rate for cutting fluid from the outlet.
2. A cutting fluid control arrangement according to claim 1, further comprising a user-operable control for operating the first control valve, the user-operable control being remote from the first control valve.
3. A cutting fluid control arrangement according to claim 2, wherein the user-operable control is configured and arranged to form part of a trigger mechanism forming part of the handheld cutter saw power tool.
4. A cutting fluid control arrangement according to claim 3, wherein the trigger mechanism is operable, in use, to operate a power unit of the handheld cutter saw power tool, the power unit being operable, in use, to move the movable blade.
5. A cutting fluid control arrangement according to claim 2, 3 or 4, wherein the first control valve is electronically or hydraulically actuated.
6. A cutting fluid control arrangement according to claim 5, wherein the first control valve is electronically actuated and comprises a solenoid valve.
7. A cutting fluid control arrangement according to claim 6, wherein the solenoid valve is configured to move the first control valve from the first position to the second position upon actuation of the user-operable control.
8. A cutting fluid control arrangement according to any one of the preceding claims, wherein the second control valve comprises a manually-operable valve.
9. A cutting fluid control arrangement according to claim 8, wherein the second control valve comprises a ball valve.
10. A cutting fluid control arrangement according to claim 8 or 9, wherein the minimum position enables selection of a zero flow rate.
11. A cutting fluid control arrangement according to any one of the preceding claims, wherein the first and second control valves are located within a common housing.
12. A cutting fluid control arrangement according to claim 11, wherein the inlet, outlet and flowpath therebetween are formed in the common housing.
13. A cutting fluid control arrangement according to any one of the preceding claims, wherein the first control valve is located upstream of the second control valve.
14. A handheld cutter saw power tool comprising: a main body; a cutting head arranged to support, in use, a movable blade; and a cutting fluid arrangement, the cutting fluid arrangement comprising: a fluid control arrangement operable, in use, to control a flow of cutting fluid; and a cutting fluid dispensing arrangement located and arranged to dispense, in use, cutting fluid adjacent the movable blade, the fluid control arrangement comprising: Is an inlet for receiving cutting fluid from a cutting fluid source; an outlet arranged, in use, to be in fluid communication with the cutting fluid dispensing arrangement; and first and second control valves located in a flowpath between the inlet and outlet, wherein the first control valve has a first position in which, in use, cutting fluid is prevented from flowing from the inlet to the outlet and a second position in which, in use, cutting fluid is permitted to flow from the inlet to the outlet, the first and second positions being discrete; and wherein the second control valve is continuously variable between minimum and to maximum positions to enable selection of a flow rate for cutting fluid from the outlet.
15. A handheld cutter saw power tool according to claim 14, further comprising a user-operable control for operating the first control valve, the user-operable control being remote from the first control valve.
16. A handheld cutter saw power tool according to claim 15, further comprising a trigger mechanism actuable by a user, and wherein the user-operable control is configured and arranged to form part of the trigger mechanism.
17. A handheld cutter saw power tool according to claim 16, wherein the trigger mechanism is operable, in use, to operate a power unit of the handheld cutter saw power tool, the power unit being operable, in use, to move the movable blade.
18. A handheld cutter saw power tool according to claim 17, wherein the trigger mechanism is configured, upon actuation by a user, to move the first control valve from the first position to the second position and to operate the power unit of the handheld cutter saw power tool.
19. A handheld cutter saw power tool according to claim 18, wherein the trigger mechanism is configured, upon actuation by a user, to cause a predetermined time delay between movement of the first control valve from the first position to the second position and subsequent operation of the power unit of the handheld cutter saw power tool.
20. A handheld cutter saw power tool according to any one of claims 15 to 19, wherein the first control valve is electronically or hydraulically actuated.
21. A handheld cutter saw power tool according to claim 20, wherein the first control valve is electronically actuated and comprises a solenoid valve.
22. A handheld cutter saw power tool according to claim 21, wherein the solenoid valve is configured to move the first control valve from the first position to the second position upon actuation of the user-operable control.
23. A handheld cutter saw power tool according to any one of claims 14 to 22, wherein the second control valve comprises a manually-operable valve.
24. A handheld cutter saw power tool according to any one of claims 14 to 23, wherein the first and second control valves are located within a common housing.
25. A handheld cutter saw power tool according to claim 24, wherein the inlet, outlet and flowpath therebetween are formed in the common housing.