DRIVING TOOL

Abstract

A driving tool including a first mode wherein a mechanical starting control is performed, and a second mode wherein an electrical starting control is performed, where these modes are configured to be switchable. Only in the second mode, if the elapsed time between the on-operation of a trigger and an on-operation of a contact arm does not exceed a reference time T.sub.0, then a second actuation portion can be turned to an on-position to perform a driving operation. In the first mode, in contrast to the electric control, without consuming battery power, the driving operation can be performed by the mechanical control that is made by an operational order of the trigger and subsequently the contact arm. Because of this configuration, even if power supply is shut off, the driving operation by the first mode can be continued.

Claims

1. A driving tool, comprising: a trigger; and a contact arm, wherein: the driving tool performs a driving operation only if the driving precondition, that both an on-operation of the trigger and an on-operation of the contact arm occur, is satisfied; a first mode, in which the driving operation is performed by the main body only when the trigger is on-operated after the contact arm is on-operated, and a second mode, in which the driving operation is performed by the main body regardless of an operational order of the on-operations of the trigger and the contact arm, are configured to be switchable from one mode to the other; and only in the second mode, a timer control routine is performed such that the driving operation is performed by the main body of the driving tool only when, for said on-operation of the trigger and the contact arm, a time difference between the time when either of the trigger or the contact arm is on-operated and a time when the other is on-operated is within a predetermined time period.

2. The driving tool according to claim 1, wherein; compressed air is used as a driving source for the driving operation; the driving tool comprises a starting valve through which a state of supplying the compressed air and a state of discharging the compressed air can be switched to each other with respect to the main body; the driving tool further comprises; a first actuation portion that is integrally provided with the contact arm and moves between an on-position where a starting valve is turned on and an off-position where the starting valve is turned off; and a second actuation portion that moves between the on-position and the off-position independently of the first actuation portion; where the first actuation portion includes a function that turns on and off the starting valve both in the first mode and the second mode; and where the second actuation portion includes a function that turns on and off the starting valve only in the second mode.

3. The driving tool according to claim 2, wherein the second actuation portion is configured to move to the on-position by the compressed air as a driving source, the compressed air being supplied by switching of an electromagnetic valve.

4. The driving tool according to claim 3, wherein the compressed air that is supplied to the second actuation portion by switching the electromagnetic valve is derived from an accumulator chamber for accumulating compressed air for supplying the main body.

5. The driving tool according to claim 2, wherein; the driving tool further comprises a first idler and a second idler that are configured to move relatively with the trigger; the first idler is moved to an on-position by being pushed by a movement of the first actuation portion to the on-position; the second idler is moved to an on-position by being pushed by a movement of the second actuation portion to the on-position; when the first idler is moved to the on-position, the second idler is moved to the on-position synchronously with the first idler; the second idler is moved to the on-position independently of the first idler; and the second idler is engaged with a valve stem of the starting valve and the valve stem is moved to an on-position by the movement of the second idler to the on-position, thereby supplying the compressed air to the main body.

6. The driving tool according to claim 3, wherein the driving tool further comprises; a first on-position detection member for detecting the on-position of the contact arm; and a second on-position detection member for detecting the on-position of the trigger.

7. The driving tool according to claim 6, wherein the 1 driving tool further comprises an electronic controller for performing an on and off control of the electromagnetic valve based on a positional information of the contact arm and the trigger that is obtained by the first on-position detection member and the second on-position detection member and also based on a time difference between a time when the contact arm is on-operated and a time when the trigger is on-operated.

8. The driving tool according to claim 7, wherein; the driving tool further comprises a mode selector lever for switching the first mode and the second mode to each other; and only when the mode selector lever is switched to the second mode, power is supplied to the electronic controller to perform the on and off control of the electromagnetic valve based on the positional information of the contact arm and the trigger and also on the time difference between the on-operations of the contact arm and the trigger.

9. A driving tool, comprising: a main body; a magazine of members to be driven; a grip; a mode switch lever; an electronic controller with a timer circuit; a trigger; a tip end; and a contact arm which may vertically contact an external material onto which said members are to be driven, wherein: the driving tool is configured such that whereupon contact with such a material if the driving tool is pushed downward then the contact arm would move upward, whereupon moving upward by a particular protruding length corresponds to an on-operation of the contact arm, and pulling the trigger back by a particular distance corresponds to the on-operation of the trigger, wherein the driving tool performs a driving operation for driving a member from the magazine onto a contacted external material only if the driving precondition, that both an on-operation of a trigger and an on-operation of a contact arm occur, is satisfied; a first mode, in which the mode switch lever is switched to a first position, where power is not supplied to the electronic controller and in a fully mechanical operation, the driving operation may be performed by the main body only when the trigger is on-operated after the contact arm is on-operated, and a second mode, in which the mode switch lever is switched to a second position, where power is supplied to the electronic controller, and a driving operation may be performed by the main body regardless of an operational order of the on-operations of the trigger and the contact arm, wherein the modes through the mode switch lever are configured to be switchable from one mode to the other; and only in the second mode, a timer control routine is performed by the timer circuit of the controller, wherein the driving operation is only performed when, for said on-operation of the trigger and contact arm, a time difference between the time when either of the trigger or the contact arm is on-operated and a time when the other of the two is on-operated is within a predetermined time period.

10. The driving tool according to claim 9, wherein; the on-operation of both the trigger and contact arm are detected by microswitches fitted into a support block within the main body, which are electronically connected to the controller; where compressed air is used as a driving source for the driving operation; the driving tool comprises a starting valve through which a state of supplying the compressed air operates a piston, leading to a rod-shaped driver to move downwards and drive one driven member from the magazine out of the tip end of the driving tool, wherein depending on whether the valve is open or closed a state of supplying of compressed air and a state of discharging the compressed air can be switched with respect to each other; where the driving tool further comprises; a first actuation portion comprising a cylindrical rod portion within the support block within the main body, where the first actuation portion is integrally provided with the contact arm and moves between an on-position where the starting valve is turned on and an off-position where the starting valve is turned off; and a second actuation portion also comprising a cylindrical rod portion as well as a piston beneath the cylinder portion wherein the second actuation portion is also housed within the support block, within a hollow cylindrical space and a torsion spring fitted around interposed between the top of the piston and the upper chamber of the hollow space within the support block, where the second actuation portion moves between the on-position and the off-position independently of the first actuation portion; where the first actuation portion is capable of turning the starting valve on or off both in the first mode and the second mode; and where the second actuation portion is only capable of turning the starting valve on and off in the second mode.

11. The driving tool according to claim 10, wherein the second actuation portion is configured to move to the on-position by the compressed air as a driving source, the compressed air being supplied by switching of an electromagnetic valve driven by operation of the controller based on information from the microswitches.

12. The driving tool according to claim 11, wherein the compressed air that is supplied to the second actuation portion by switching the electromagnetic valve is derived from an accumulator chamber for accumulating compressed air for supplying the main body.

13. The driving tool according to claim 10, wherein; the driving tool further comprises a first idler and a second idler that are configured to move rotatably around a common support shaft; the first idler is moved to an on-position by being pushed by a movement of the first actuation portion upward to the on-position; the second idler is moved to an on-position by being pushed by a movement of the second actuation portion upward to the on-position; where when the first idler is moved to the on-position, the second idler is moved to the on-position synchronously with the first idler where the second idler comprises a lateral face that is in touching contact with the first idler; where the second idler is moved to the on-position independently of the first idler; and where when the second idler is engaged with a valve stem of the starting valve and the valve stem is moved to an on-position by the movement of the second idler to the on-position, compressed air is then supplied to the main body.

14. The driving tool according to claim 13, wherein the electronic controller performs an on and off control of the electromagnetic valve based on positional information of the contact arm and the trigger that is obtained by the microswitches and also based on its timer circuit analyzing a time difference between a time when either of the trigger or the contact arm is on-operated and a time when the other of the two is on-operated is within a predetermined time period.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] FIG. 1 is an overall lateral view of a driving tool according to an invention of the present invention.

[0025] FIG. 2 is a longitudinal sectional view of a main body and a starting device of the driving tool.

[0026] FIG. 3 is a perspective view of the starting device of the driving tool.

[0027] FIG. 4 is a control block diagram of the starting device.

[0028] FIG. 5 is a figure showing an operational state of the starting device. This figure shows an initial state. In this initial state, both a trigger and a contact arm are positioned at an off position. A valve stem of a starting valve is positioned at an off position.

[0029] FIG. 6 is a figure showing an operational state of the starting device in a first mode. This figure shows that the trigger is operated and turned on.

[0030] FIG. 7 is a figure showing an operational state of the starting device in the first mode. This figure shows a state in which after the trigger is on-operated, the contact arm is operated and turned on. In this state, the starting valve is not turned on and thus a driving operation is not performed.

[0031] FIG. 8 is a figure showing an operational state of the starting device in the first mode. This figure shows a state in which the contact arm is operated and turned on.

[0032] FIG. 9 is a figure showing an operational state of the starting device in the first mode. This figure shows a state in which after the contact arm is on-operated, the trigger is operated and turned on. In this state, the starting valve is turned on and thus a driving operation is performed.

[0033] FIG. 10 is a figure showing an operational state of the starting device in a second mode. This figure shows a state in which the trigger is operated and turned on.

[0034] FIG. 11 is a figure showing an operational state of the starting device in the second mode. This figure shows a state in which after the trigger is on-operated, the contact arm is operated and turned on. In this state, a second idler is pushed to an on-position by a second actuation portion, and as a result, the starting valve is turned on and a driving operation is performed.

[0035] FIG. 12 is a figure showing an operational state of the starting device in the second mode. This figure shows a state in which the contact arm is operated and turned on.

[0036] FIG. 13 is a figure showing an operational state of the starting device in the second mode. This figure shows a state in which after the contact arm is on-operated, the trigger is operated and turned on. In this state, both a first idler and the second idler are pushed to an on-position, and as a result, the starting valve is turned on and a driving operation is performed.

INVENTIONS FOR CARRYING OUT THE INVENTION

[0037] Next, an embodiment of the present invention, based on FIGS. 1 to 13, will be explained. As shown in FIG. 1 and FIG. 2, in the present embodiment, a compressed-air-driven nail gun is exemplified as an example of a driving tool 1. The driving tool 1 comprises a main body 2 in which a piston 21 reciprocated by a compressed air as a driving force is internally mounted, a grip 3 that protrudes from a lateral part of the main body 2 in a lateral direction, a nose part 4 for driving that extends from a lower part of the main body 2 in a downward direction (in a driving direction of driven members), and a magazine 5 with which a plurality of driven members can be loaded and which is provided straddling the nose part 4 as well as the grip 3.

[0038] At a downward tip end of the nose part 4, a contact arm 6 is supported so as to move relative to the driving tool 1 in an up-down direction. The relative movement of the contact arm 6 in the upward direction when the contact arm 6 is pushed toward a material to be driven is one of the conditions for performing a driving operation. The contact arm 6 includes an annular-shaped contact portion 6a that is located around an injection opening at the tip of the nose part 4, and an extension portion 6b that extends from the contact portion 6a towards a vicinity of a trigger 12 in the upward direction. The contact portion 6a and the extension portion 6b are supported so as to be synchronously moved in the up-down direction within a predetermined range along the nose part 4.

[0039] A starting device 10 according to the present embodiment is disposed at a lateral part of the main body 2 around a base of the grip 3. A starting valve 11 is turned on by a starting operation of the starting device 10. When the starting valve 11 is turned on, compressed air is supplied to an upper piston chamber 2b of the main body 2. When the compressed air is supplied to the upper piston chamber 2b, a piston 2a moves downwards in a cylinder 2c. A long rod-shaped driver 2d is attached to a lower surface of the piston 2a. By the downward movement of the piston 2a, and in turn the movement of the driver 2d with the nose part 4 due to the movement of piston 2a, one driven member is driven out of the tip end (the injection opening) of the nose part 4. The driven member is supplied one by one to the nose part 4 from the magazine 5.

[0040] As shown in FIG. 1, a mode selector lever 7 for selecting a first mode or a second mode with regard to a driving mode of the driving tool 1 is provided on a lateral part of the main body 2. In a case where the mode selector 7 is switched to the first mode position, when the trigger 12 is turned on by being pulled after the contact arm 6 is firstly on-operated, the on-operation of the trigger 12 becomes mechanically effective as discussed infra, and a driving operation can be performed. In contrast, when the contact arm 6 is turned on after the trigger 12 is on-operated by being pulled, the on-operation of the contact arm 6 is ineffective and a driving operation is not performed. In the first mode, as described above, a sequential control (mechanical starting control) is performed in which a driving operation can be performed only when the on-operation of the contact arm 6 is first made with respect to an operational sequence of the contact arm 6 and then subsequently the trigger 12. Because of this fixed sequence, the first mode corresponds to a single drive mode in which a subsequent driving operation cannot be performed unless the trigger 12 is turned off after original driving operation has been performed.

[0041] In the case where the mode selector lever 7 is switched to the second mode position, a swung driving (continuous driving) operation can be performed in which a driving operation can be repeatedly performed by swinging the driving tool 1 in the up-down directions with the trigger 12 being pulled and performing the on-off operation of the contact arm 6 repeatedly. As shown in FIG. 4, a switching positional state of the mode selector lever 7 can be detected by a mode selector switch 31. When the mode selector lever 7 is switched to the second mode, the mode selector switch 31 is turned on. An output signal of the mode selector switch 31 is input to the controller 30 as positional information of the mode selector lever 7, as discussed infra. A micro-switch is used for the mode selector switch 31.

[0042] The present embodiment has unconventional features with respect to the starting device 10. A modification is not particularly required with respect to the basic configuration of the driving tool 1 of the present embodiment and thus detailed explanation will be omitted. Details of the starting device 10 of the present embodiment are shown in FIGS. 2 to 4. The starting device 10 of the present embodiment comprises the aforementioned starting valve 11, the trigger 12, a first actuation portion 13, and a second actuation portion 14. The starting valve 11 is housed in a lower surface on the base side of the grip 3. A lower part of the valve stem 11a protrudes towards the trigger 12. The valve stem 11a of the starting valve 11 is supported so as to be movable in the up-down direction (on position and off position). FIG. 2 shows a state in which the valve stem 11a is located in the off position. The starting valve 11 is turned on by the valve stem 11a being moved upwards from the off position against a spring biasing force. When the starting valve 11 is turned on, a head valve 2e is moved downwards by an air pressure that is applied downwards and the head valve 2e opens. When the head valve 2e opens, compressed air accumulated in an accumulator chamber 3a in the grip 3 is supplied to the upper piston chamber 2b. When the valve stem 11a is returned in the downward direction by the spring biasing force, the starting valve 11 is turned off. When the starting valve 11 is turned off, the head valve 2e is moved upwards by an air pressure applied in the upward direction, which causes the upper piston chamber 2b to close with respect to the accumulator chamber 3a. The upper piston chamber 2b is opened to the atmosphere at the same time when the upper piston chamber 2b is closed, which causes the piston 2a that has moved downwards to return to a top dead center position (initial position).

[0043] The trigger 12 is supported so as to be tiltable around a support shaft 12a in the up-down direction. A first idler 15 and a second idler 16 are supported on a backside (an upper side) of the trigger 12. The first idler 15 and the second idler 16 are supported so as to be tiltable independently relative to each other in the up-down direction around a common support shaft 17. Both the first idler 15 and the second idler 16 are biased in a direction to be tiltable in the upward direction by a torsion spring 18 (on-position side).

[0044] As shown in FIG. 3, an engagement edge portion 16a is provided integrally with the second idler 16 on the backside of the second idler 16. The engagement edge portion 16a protrudes towards the back face side of the first idler 15. In an initial state, the engagement edge portion 16a is brought into contact with the back face of the first idler 15, and the first idler 15 and the second idler 16 are held in a side-by-side manner such that a front face of the first idler 15 is disposed to be flush with that of the second idler 16. Because of this construction, when the first idler 15 is pushed upwards (to the on-position side), the first idler 15 is tilted upwards integrally with the second idler 16. On the other hand, when the second idler 16 is pushed upwards, only the second idler 16 is tilted upwards. In this way, the first idler 15 can be moved to the on-position integrally with the second idler 16, and the second idler 16 can be moved to the on-position independently. When the second idler 16 is moved to the on-position by itself, the engagement edge portion 16a is separated from the back face of the first idler 15. Because of this configuration, a state where only the first idler 15 is disposed in the off-position can be allowed. A state where the first idler 15 is disposed in the off-position and the second idler 16 is moved to the on-position occurs when the trigger 12 is on-operated first in the second mode (FIG. 11). This operating state will be discussed infra.

[0045] As shown in FIG. 3, the starting device 10 of the present embodiment comprises the first actuation portion 13 and the second actuation portion 14. The first actuation portion 13 is provided integrally with the contact arm 6. The first actuation portion 13 is provided integrally with an upper part of the extension portion 6b of the contact arm 6 and extends towards the trigger 12 (in the upward direction). As shown in FIG. 3 and FIG. 4, a tip end of the first actuation portion 13 is directed towards an upper part of the first idler 15. As the contact arm 6 is moved to the on-position by pushing the material to be driven, the first actuation portion 13 is moved towards the first idler 15 together with the contact arm 6.

[0046] As discussed infra, in an on-position state where the trigger 12 is pull-operated, the first actuation portion 13 passes above the first idler 15 (useless operation) when the contact arm 6 is on-operated. In an off-position state where the trigger 12 is not pull-operated, the first actuation portion 13 impinges on the upper part of the first idler 15 when the contact arm 6 is on-operated. By a pull-operation of the trigger 12 with this impinging state being held, the first idler 15 is then further pushed to the on-position against the torsion spring 18. When the first idler 15 is pushed by the first actuation portion 13 and moved to the on-position, the second idler 16, due to the presence of the engagement edge portion 16a, is moved to the on-position synchronously with the first idler 15. With the second idler 16 being moved to the on-position, the valve stem 11a of the starting valve 11 is pushed to the on-position and the actuation valve 11 is turned on. As discussed earlier, when the starting valve 11 is turned on, the piston 2a moves downwards to perform a driving operation.

[0047] As shown in FIG. 4, the first actuation portion 13 and the second actuation portion 14 are supported by a support block part 20 that is provided in the main body 2. The first actuation portion 13 is supported by the support block 20 so as to be movable in the up-down direction. In the support block 20, a cylinder 20a is provided which houses the piston 14a provided in the second actuation portion 14. The cylinder 20a and the piston 14a constitute single acting cylinder. A portion that corresponds to a rod of this cylinder is the second actuation portion 14. An upper chamber 20aa of the cylinder 20a (a right-hand chamber with respect to the piston 14a as shown in the figure) is opened to the atmosphere. A compression spring 21 is interposed between the upper chamber 20aa of the cylinder 20a and the piston 14a. By a biasing force of the compression spring 21, the second actuation portion 14 is returned to the off-position as shown in FIG. 4.

[0048] A lower chamber 20ab of the cylinder 20a (a left-hand chamber with respect to the piston 14a as shown in the figure) is air-tightly sealed. An electromagnetic valve 23 is connected to the lower chamber 20ab of the cylinder 20a through an air-pipe 22. The compressed air is supplied to and discharged from the lower chamber 20ab by switching the electromagnetic valve 23. When the compressed air is supplied to the lower chamber 20ab, the piston 14a is moved upwards, which causes the second actuation portion 14 to project in the upward direction (to the on-position) towards the second idler 16. When the second actuation portion 14 is projected upwards by the force of the air pressure, the tip end thereof impinges on the second idler 16. When the second idler 16 is furthermore projected with this impinging state being held, the second idler 16 is pushed upwards against the torsion spring 18. The second idler 16 is pushed by the second actuation portion 14 to move to the on-position, and then the valve stem 11a of the starting valve 11 is pushed to the on-position side, which causes the starting valve 11 to turn on.

[0049] When the electromagnetic valve 23 is switched to a close position, the lower chamber 20ab of the cylinder 20a is shut off from the accumulator chamber 3a and is instead opened to the atmosphere (compressed air is discharged from the accumulator chamber 3a). When the lower chamber 20ab is opened to the atmosphere, the piston 14a moves downwards by the biasing force of the compression spring 21 and the second actuation portion 14 is returned to the off-position. An air pipe 24 that is divided from the accumulator chamber 3a of the grip 3 is connected to the electromagnetic valve 23. Because of this configuration, the compressed air is supplied from the accumulator chamber 3a to the lower chamber 20ab of the cylinder 20a through the electromagnetic valve 23. The open position and the close position of the electromagnetic valve 23 can be switched from one to the other by power that is supplied via the controller 30 that will be discussed infra.

[0050] The on-position of the contact arm 6 can be detected by a first on-position detection member 25. As shown in FIG. 4, a detection portion 6c of the contact arm is provided at the upper end of the extension portion 6b of the contact arm 6. The detection portion 6c is spring-biased in an upward protruding direction such that an impact with respect to the first on-position detection member 25 can be absorbed. A compression spring 8 is interposed between the upper end of extension portion 6b and the support block 20. By a biasing force of this compression spring 8, the contact arm 6 is biased to a lower off-position configuration (initial position). When the contact arm 6 is disposed at said initial position, the contact portion 6a thereof is configured to protrude by a protruding length downward in a protruding direction with respect to the tip end (injection opening) of the nose part 4. A position where the contact arm 6 is relatively moved upwards by this same protruding length is configured to be the on-position of the contact arm 6.

[0051] The first on-position detection member 25 is disposed vertically opposite along the up-down axis to the detection portion 6c. The first on-position detection member 25 is supported by the support block 20. When the contact arm 6 is moved to the on-position, the detection portion 6c is brought into contact with the first on-position detection member 25 and the first on-position detection member 25 is turned on. An on-signal of the first on-position detection member 25 is input to a timer circuit 33 of the controller 30 that will be discussed infra.

[0052] An on-position of the trigger 12 is detected by a second on-position detection member 26. The second on-position detection member 26 is supported by the support block 20. When the trigger 12 is pulled to the on-position, a tilted base portion of the trigger 12 is brought into contact with the second on-position detection member 26 and the second on-position detection member 26 is turned on. An on-signal of the second on-position detection member 25 is also input to the timer circuit 33 of the controller 30. Push-button type micro-switches comprise the first and second on-position detection members 25 and 26, respectively.

[0053] Both the on-signal of the first on-position detection member 25 and the on-signal of the second on-position detection member 26 are input to the timer circuit 33 of the controller 30. The timer circuit 33 measures an absolute value of input time difference (elapsed time T.sub.1) between the on-signal of the on-position detection member 25 and the on-signal of the on-position detection member 26. When it is judged that the input elapsed time T.sub.1 between the on-signal of the on-position detection member 25 and the on-signal of the on-position detection member 26 is within a predetermined reference time T.sub.0(T.sub.1T.sub.0), power is supplied from a battery 32 to the electromagnetic valve 23 by a power supply command of the controller 30. When power is supplied from the battery 32, the power is used to switch the electromagnetic valve 23 to the open position to facilitate communication between the air pipe 22 and the air pipe 24, thereby supplying the compressed air from the accumulator chamber 3a to the lower chamber 20ab of the cylinder 20a. When the compressed air is supplied to the lower chamber 20ab, the second actuation portion 14 moves upward into the on-position. When the second actuation portion 14 moves into the on-position, the second idler 16 is consequently pushed to the on-position location by the movement of second actuation portion 14. By the second idler 16 being pushed to the on-position location, the valve stem 11a in turn is also moved to the on-position, thereby turning on the starting valve 11. Finally, by the starting valve 11 being turned on, a driving operation is performed by the main body 2.

[0054] The stroke extension length between the on-position and the off position of the second actuation portion 14 is set to be approximately equal to the stroke extension length between the on-position and the off-position of the first actuation portion 13. Because of this configuration, as shown in FIGS. 3 and 4, in a case where both the first actuation portion 13 and the second actuation portion 14 are positioned in the off-position, the tip end of the first actuation portion 13 and the tip end of the second actuation portion 14 are separated by a substantially equal space with respect to the first idler 15 and the second idler 16 in the vertical direction, wherein both of the idlers are disposed side by side and rotatably supported around the support shaft 17.

[0055] The starting device 10 is provided with the battery 32 that supplies power to the controller 30, the electromagnetic valve 23, the first on-position detection member 25, and the second on-position detection member 26. When the mode selector lever 7 is switched to the second mode position, the mode selector switch 31 is turned on so as to supply power from the battery 32 to the controller 30, the first on-position detection member 25, and the second on-position detection member 26. Furthermore, in the lever's second mode position, under a predetermined condition, power can be supplied from the battery 32 to the electromagnetic valve 23. In contrast, when the mode selector lever 7 is switched to the first mode position, the mode selector switch 31 is turned off and power supply from the battery 32 to the controller 30, the electromagnetic valve 23, the first on-position detection member 25, and the second on-position detection member 26 is shut off.

[0056] Because of this configuration, in the first mode, the on-and-off operation of the starting valve 11 can be mechanically controlled only by the first actuation portion 13 of the contact arm 6. Furthermore, in the first mode, the on-position of the first actuation portion 13 is not detected by the first on-position detection member 25 and the on-position of the trigger 12 is not detected by the second on-position detection member 26. In the first mode, the electromagnetic valve 23 is in a stopped state because power supply is shut off, and thus the second actuation portion 14 is not activated and is held in the off-position that is shown in FIG. 4.

[0057] In FIGS. 5 to 13, operating states of the starting device 10 in the first mode and in the second mode are shown. In the following description, operating states of the starting device 10 in the first mode and the second mode will be explained. FIG. 5 shows an initial state of the starting device 10, showing a non-operating state in which the contact arm 6 is not on-operated and the trigger 12 is not pull-operated. The initial state of the first mode is common to that of the second mode except the position of the mode selector lever 7 (refer to FIG. 1). Thus, FIG. 5 shows the initial state of both modes.

[0058] At first, a case where the mode selector lever 7 is switched to the first mode position will be described. In FIGS. 5 to 9 that show the first mode, the second actuation portion 14, the first on-position detection portion 25, the second on-position detection portion 26, and the detection portion 6c, which function only in the second mode, are not shown. FIG. 6 shows that in the first mode, the trigger 12 is first pull-operated from the initial state shown in FIG. 5. In this state, as shown in the figure, the first idler 15 and the second idler 16 are pushed downwards by a downwards biased spring force of the valve stem 11a. As a result, each of the tilted tip ends of the idlers is tilted in a direction to move in the downward direction (leftwards in the figure). Because of this configuration, as shown in FIG. 7, even when the first actuation portion 13 is moved upwards, or in the right direction as viewed in the figure, by the on-operation of the contact arm 6, after the trigger is pull-operated as shown in FIG. 6, the first actuation portion 13 passes a lateral side of the first idler 15 (useless operation). As a result, the first idler 15 is not pushed to the on-position location by the first actuation portion 13 and furthermore the second idler 16 is not moved to the on-position either. As the second idler 16 is not moved to the on-position, the valve stem 11a is also not pushed to the on-position location, which keeps the starting valve 11 in the off-position. As the starting valve 11 is not turned on, a driving operation is not performed in this case.

[0059] Next, FIG. 8 shows the case where still in the first mode, the contact arm 6 is first on-operated from the initial state shown in FIG. 5. In this state, the first idler 15 is pushed to the starting valve 11 side by the first actuation portion 13. Because of this configuration, where as shown in FIG. 8 the first idler 15 has first been pushed by the contact arm 6, when the trigger 12 is pull-operated afterwards, a tilted tip end of the first idler 15 is pushed by the first actuation portion 13 and a tilted base portion of the first idler 15 is moved to the starting valve 11 side (on location) due to the force of the trigger 12, as shown in FIG. 9. The first idler 15 is moved to the on position and as a result, the second idler 16 is moved to the on position synchronously with the first idler 15 due to the presence of the engagement edge portion 16a as explained supra. Consequently, due to the second idler 16 being moved to its on position, the valve stem 11a is pushed to its on-position, thereby switching on the starting valve 11. By the starting valve 11 being switched on, a driving operation is performed by the main body 2.

[0060] When the contact arm 6 is switched to its off-position by lifting the driving tool 1 from the material to be driven after having completed the driving operation, the driving tool 1 is returned to the state shown in FIG. 6. As shown in the figure, when the contact arm 6 is in its off-position, the first idler 15 is also pushed by the spring force of the valve stem 11a to return to its off-position, thereby switching off the starting valve 11. In such a case, even if the trigger is pull-operated and then the contact arm 6 is turned on again, a driving operation (continuous driving) would not be performed because the first actuation portion 13 does not push the first idler 15 to the on-position as shown in FIG. 7. In this case, after the contact arm 6 is turned off, the pulling operation of the trigger 12 must be released to return the tool to the initial state as shown in FIG. 5, thereby making it capable again of performing the next driving operation.

[0061] As explained above, in the first mode, in a case where the trigger 12 is first pull-operated (FIG. 6) and then the contact arm 6 is on-operated (FIG. 7), a driving operation is not performed. Because of this configuration, for example, in a case where the driving tool 1 is carried while the grip 3 is held and the trigger 12 is hooked by a finger (while the trigger 12 is pull-operated), even if the contact portion 6a of the contact arm 6 inadvertently comes into contact with any other portion, a driving operation cannot be performed. In the first mode, only when the contact arm 6 is first on-operated (FIG. 8) and the trigger 12 is then pull-operated (FIG. 9) a driving operation can be performed. Furthermore, in the first mode, unless the trigger 12 is turned off, a subsequent driving operation cannot be performed (singe driving).

[0062] Next, operation states of the starting device 10 when the mode selector lever 7 is switched to the second mode position will be explained. In the initial state shown in FIG. 5, both the first actuation portion 13 and the second actuation portion 14 (not shown in FIG. 5) are disposed in the off-position configuration. As shown in FIG. 10, when the trigger 12 is pull-operated to the on-position from the initial state, the second on-position detection member 26 is switched on and the output signal of said member is input to the timer circuit 33 of the controller 30. However, in this stage, because the first on-position detection member 25 is not switched on, power is not supplied from the controller 30 to the electromagnetic valve 23 and thus the electromagnetic valve 23 is held in the closed position and the second actuation portion 14 is positioned in its off-position. At the moment when the signal from the second on-position detection member 26 is inputted to the timer circuit 33, the timer is activated to measure an elapsed time T.sub.1 after that.

[0063] As shown in FIG. 11, when the contact arm 6 is on-operated after the pull-operation of trigger 12, the first on-position detection member 25 is turned on and the output signal of said member is inputted to the timer circuit 33 of the controller 30. In the timer circuit 33, the elapsed time T.sub.1 after the signal of the second on-position detection member 25 is input to the timer circuit 33 of the controller 30 until the signal of the first on-position detection member 26 is input, is compared to the predetermined reference time T.sub.0. When it is judged that the elapsed time T.sub.1 is within the reference time T.sub.0(T.sub.1T.sub.0), a power circuit of the controller 30 is closed and power is supplied from the battery 32 to the electromagnetic valve 23. When power is supplied to the electromagnetic valve 23, the electromagnetic valve 23 is switched to the open position. When the electromagnetic valve 23 is switched to the open position, the air pipe 22 is in fluid communication with the air pipe 24, making it able to supply the compressed air to the lower chamber 20ab of the cylinder 20a from the accumulator chamber 3a, thereby allowing the second actuation portion 14 to move to the on-position against the compression spring 21 and turning on the starting valve 11 to perform a driving operation by the main body 2.

[0064] In contrast, in a case where the elapsed time T.sub.1 after one of the on-signals of the first on-position detection member 25 and the second on-position detection member 26 is input to the timer circuit 33 of the controller 30 until the other of the on-signals is input is larger than the reference time T.sub.0(T.sub.1>T.sub.0), power is not supplied to the electromagnetic valve 23 from the battery 32. Because of this configuration, a driving operation is not performed in this case.

[0065] In this way, in the second mode, when the trigger 12 is first on-operated and the contact arm 6 is then on-operated within the reference time T.sub.0, the first actuation portion 13 is moved to the on-position and the second actuation portion 14 is also moved to the on-position almost simultaneously by the power supply to the electromagnetic valve 23. Similar to the first mode, the trigger 12 is first pull-operated, and accordingly the first actuation portion 13 passes the lateral side of the first idler 15 (useless operation). However, in the second mode, the second actuation portion 14 is moved to the on-position, which causes the second idler 16 to be individually tilted to the on-position.

[0066] As further shown in FIG. 11, in a state where the second idler 16 is tilted to the on-position, the first actuation portion 13 passes the lateral side of the first idler 15. Because of this configuration, although the first idler 15 is biased upward in a direction to tilt to the on-position location by the biasing force of the torsion spring 18, the first idler 15 is restricted to move to the on-position location by the presence of the first actuation portion 13 and thus the first idler 15 is held in the off-position. In the present embodiment, the idler, which is single in the prior art, is split into the first idler 15 and the second idler 16, and thus the second idler 16 is allowed to move to the on-position individually while the first idler 15 is held in the off-position.

[0067] The second idler 16 is tilted to the on-position by the pneumatic force of the cylinder 20a, thereby pushing the valve stem 11a by a required distance and reliably moving to the on-position. The valve stem 11a is pushed by the movement of the second actuation portion 14 and the second idler 16, thereby turning on the starting valve 11 and accordingly performing a driving operation by the main body 2.

[0068] When the contact arm 6 is turned off with the trigger 12 being pull-operated after one driving operation is performed, the starting device 10 is returned to the condition shown in FIG. 10. As described earlier, in this condition, the first on-position detection member 25 is turned off by turning off the contact arm 6, thereby shutting off power from the controller 30 to the electromagnetic valve 23. Because of this configuration, the electromagnetic valve 23 is switched to its closed position and the lower chamber 20ab of the cylinder 20a is opened to the atmosphere, which causes the second actuation member 14 to be moved to the off-position side. The pushing force by the second actuation portion 14 is not applied to the second idler 16 in the on-position location, thereby returning the second idler 16 to the off-position by the spring force of the valve stem 11a and turning off the starting valve 11. The first idler 15 is not restricted by the first actuation portion 13, but because of the presence of the engagement edge portion 16a, the first idler 15 is held side by side with the second idler 16 (in its off-position). Furthermore, by the contact arm 6 being turned off, the first on-position detection member 25 is turned off, thereby resetting the timer circuit 33.

[0069] After the starting device 10 returns to the state shown in FIG. 10, when the contact arm 6 is on-operated again within the reference time T.sub.0 with the trigger 12 being first pull-operated, then the second actuation portion 14 is again moved to the on-position to push the second idler 16, thereby switching the starting valve 11 to its on position to perform a driving operation again (continuous driving). By bringing the contact portion 6a of the contact arm 6 repeatedly into contact with the material to be driven to turn on the contact arm 6 within the reference time T.sub.0 while the trigger 12 is pull-operated, the starting device 10 alternates between the state shown in FIG. 10 and the state shown in FIG. 11, thereby performing a continuous driving operation.

[0070] In the second mode, even in a case where the contact arm 6 is first on-operated and after that the trigger 12 is on-operated, contrary to the above case for the second mode, a driving operation can be performed. FIG. 12 shows that the contact arm 6 is first on-operated from the initial state shown in FIG. 5. At this stage, the first on-position detection member 25 is turned on. However, since the trigger 12 is not pull-operated, the second on-position detection member 26 is in the off state and thus power is not supplied to the electromagnetic valve 23 from the controller 30. In a state where power is not supplied, the electromagnetic valve 23 is held switched to the close position and thus compressed air is not supplied to the lower chamber 20ab of the cylinder 20a, thereby holding the second actuation portion 14 in the off-position.

[0071] When the trigger 12 is pull-operated as shown in FIG. 13 within the reference time T.sub.0 after the contact arm 6 is on-operated, a movement of the tilted tip end side of the first idler 15 is restricted by the first actuation portion 13 and thus the first idler 15 is restricted to move to the off-position side. According to the pull-operation of the trigger 12, the valve stem 11a is pushed to its on-position, and as a result the starting valve 11 is turned on. By the starting valve 11 being turned on, in turn, a driving operation is performed by the main body 2.

[0072] The second on-position detection member 26 is turned on by the pull-operation of the trigger. Because of this procedure, the electromagnetic valve 23 is switched to the open position due to the power being supplied from the controller 30, and thus compressed air is supplied to the lower chamber 20ab of the cylinder 20a, thereby moving the second actuation portion 14 upwards to its on-position. As discussed above, in a case where the contact arm 6 is first on-operated in the second mode, both the first actuation portion 13 and the second actuation portion 14 move to the on-position side. However, the first idler 15 only is being pushed by the first actuation portion 13 that is first moved to the on-position, the second idler 16 is also synchronously pushed to the on-position, thereby turning on the starting valve 11.

[0073] By turning on the starting valve 11, a driving operation is performed by the main body 2. When the pulling operation of the trigger 12 is released after the driving operation, the starting device 10 is returned to the state shown in FIG. 12. Because of this procedure, by pulling the trigger 12 again from the state shown in FIG. 12 within the reference time T.sub.0, the starting valve 11 is turned on again, thereby performing the driving operation again. By repeatedly turning on and off the trigger 12 within the reference time T.sub.0 while the contact arm 6 is on-operated, the starting device 10 alternates between the state shown in FIG. 12 and the state shown in FIG. 13. According to the second mode in the present embodiment, for example, a so-called dragged driving can be efficiently performed in which while the contact arm 6 is held switched-on, the trigger 12 is on-operated as the driving tool 1 is shifted in the lateral direction. In this dragged driving, one driving operation is performed every time the trigger 12 is on-operated. Because of this procedure, the dragged driving can be considered as a single driving operation along with the first mode.

[0074] According to the starting device 10 of the present embodiment as discussed above, in the second mode, in a case where a time difference (elapsed time T.sub.1) between the time when the trigger 12 is on-operated and the time when the contact arm 6 is on-operated is within the reference time T.sub.0, timer control is performed such that a driving operation is performed by the main body 2. In order to do this, in the second mode, power for operating the controller 30 in which the timer control is performed (power for electric control) is supplied from the battery 32. Because of this procedure, in the second mode, at a time when power from the battery 32 is interrupted or a remaining capacity of the battery 32 decreases, the controller 30 cannot be operated, and as a result the driving tool 1 assumes an operation stopped state. However, in the exemplified driving tool 1, even if this situation happens, subsequent switching of the operating mode to the first mode can separate the timer control of the controller 30 and operate the driving tool 1 (even if power is not supplied), thereby continuing a current driving operation (a single driving by a mechanical starting control). Because of this procedure, continued workability of the driving tool 1 can be improved.

[0075] Furthermore, in the first mode, in a case where the trigger 12 is first pull-operated, the on-operation of the contact arm 6 becomes ineffective (useless operation) and as a result the driving operation is not performed (mechanical starting control). Because of this configuration, for example, in a case where the driving tool 1 is carried while the grip 3 is held and the trigger 12 is hooked by a finger, even if the contact portion 6a of the contact arm 6 mistakenly comes into contact with any other portion (the contact arm 6 is on-operated), an unintended driving operation cannot be performed.

[0076] Furthermore, in the second mode, in a case where a time difference between a time when the trigger 12 is on-operated and a time when the contact arm 6 is on-operated exceeds the reference time T.sub.0, power cannot be supplied to the controller 30 and the electromagnetic valve 23 etc. and thus a driving operation cannot be performed by the main body 2. Because of this configuration, in a case where the mode selector lever 7 is switched to the second mode position and where the driving tool 1 is carried while the grip 3 is held and the trigger 12 is hooked by a finger, even if the contact portion 6a of the contact arm 6 mistakenly comes into contact with another portion (the contact arm 6 is on-operated), an unintended driving operation cannot be performed.

[0077] Furthermore, according to the exemplified starting device 10, the second actuation portion 14 is configured to move to the on-position by the pneumatic force. Accordingly, compared to a configuration in which, for example, a solenoid actuator is used as a power source, the second actuation portion 14 can be moved over a longer distance by a larger force, thereby unfailingly moving the valve stem 11a of the starting valve 11 to the on-position.

[0078] Furthermore, the compressed air, which is supplied as the power source for driving the main body 2, is configured to be divided to use for moving the second actuation portion 14, and accordingly the supplied compressed air can be effectively used for operating the second actuation portion 14 and eventually the starting device 10.

[0079] Furthermore, the driving tool 1 is configured such that electric power of the battery 32 is used only in the second mode and is not consumed in the first mode. Accordingly, compared to a case where electric power is consumed for all driving operations, electric power can be saved.

[0080] Various modifications can be made to the embodiments described above. For example, the exemplary configuration uses compressed air as a driving force for moving the second actuation portion 14 to the on-position. Instead, the driving tool 1 can be configured such that an electric motor and a rack-pinion mechanism are used, or a solenoid actuator is used. In these cases, the exemplified electromagnetic valve 23 does not need to be used.

[0081] Furthermore, the second actuation portion 14 is configured to move between the on-position and the off-position by the action of piston 14a in the cylindrical space 20a that is actuated by turning on and off the electromagnetic valve 23. Because of this configuration, the moving direction of the second actuation portion 14 does not necessarily have to be the same as that of the first actuation portion 13, but can be reconfigured to move in a direction different from that of the first actuation portion 13. Furthermore, by extending the air pipe 22, the electromagnetic valve 23 can be arranged to be apart from the second actuation portion 14 (for example, inside the grip 3), thereby improving freedom in the layout of the starting device 10. The controller 30 and the battery 32 may also arranged inside the grip 3.

[0082] Furthermore, the nail gun in which the compressed air is used as the driving force is exemplified as the driving tool 1, but the exemplified starting device 10 can also be applied to a driving tool in which an electric motor is used as the driving force.