U.S. patent application number 11/306873 was filed with the patent office on 2006-11-23 for water supply for a hand-held power tool.
This patent application is currently assigned to ANDREAS STIHL AG & Co. KG. Invention is credited to Frank Berbig, Sebastian Hansen, Daniel Herbst, Wolfgang Layher, Klaus-Martin Uhl.
Application Number | 20060260453 11/306873 |
Document ID | / |
Family ID | 35997996 |
Filed Date | 2006-11-23 |
United States Patent
Application |
20060260453 |
Kind Code |
A1 |
Layher; Wolfgang ; et
al. |
November 23, 2006 |
Water Supply for a Hand-Held Power Tool
Abstract
A water supplying device of a hand-held power tool has a
water-conveying line and a valve arrangement arranged in the line
for controlling the water flow through the line. The valve
arrangement has a control valve with a valve body adjustable across
a positioning travel. The opening cross-section of the control
valve, as a function of the positioning travel, has a progressive
characteristic line. An arrangement for actuating the water
supplying device has an actuator that is separate from additional
control elements of the power tool.
Inventors: |
Layher; Wolfgang;
(Waiblingen, DE) ; Uhl; Klaus-Martin; (Plochingen,
DE) ; Hansen; Sebastian; (Besigheim, DE) ;
Berbig; Frank; (Leipzig, DE) ; Herbst; Daniel;
(Karlsruhe, DE) |
Correspondence
Address: |
GUDRUN E. HUCKETT DRAUDT
LONSSTR. 53
WUPPERTAL
42289
DE
|
Assignee: |
ANDREAS STIHL AG & Co.
KG
Badstr. 115
Waiblingen
DE
|
Family ID: |
35997996 |
Appl. No.: |
11/306873 |
Filed: |
January 13, 2006 |
Current U.S.
Class: |
83/169 ;
137/560 |
Current CPC
Class: |
F16K 3/0254 20130101;
Y10T 137/88046 20150401; B23D 59/02 20130101; B24B 55/03 20130101;
Y10T 83/263 20150401; F16K 31/60 20130101; F16K 7/065 20130101;
F16K 1/12 20130101; Y10T 137/8376 20150401; B24B 27/08
20130101 |
Class at
Publication: |
083/169 ;
137/560 |
International
Class: |
F15B 13/00 20060101
F15B013/00; B26D 7/08 20060101 B26D007/08 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 17, 2005 |
DE |
10 2005 002 125.5 |
Claims
1. A water supplying device of a hand-held power tool, the device
comprising: a water-conveying line; a valve arrangement arranged in
the line for controlling a water flow through the line; the valve
arrangement comprising a control valve with a valve body adjustable
across a positioning travel; wherein an opening cross-section of
the control valve, as a function of the positioning travel, has a
progressive characteristic line.
2. The device according to claim 1, wherein the progressive
characteristic line comprises two at least approximately linearly
extending portions.
3. The device according to claim 2, wherein the two at least
approximately linearly extending portions are angled progressively
relative to one another.
4. The device according to claim 1, wherein the valve body is
configured to have an opening action away from a rest position of
the valve body which opening action is neutral relative to an
admission pressure of the water pressure at a supply side of the
control valve.
5. The device according to claim 1, wherein the control valve acts
as a shut-off valve.
6. The device according to claim 1, wherein the valve arrangement
comprises a shut-off valve that is connected flow-conductingly in
series to the control valve and is arranged upstream of the control
valve.
7. The device according to claim 6, wherein the shut-off valve is a
solenoid valve.
8. The device according to claim 6, wherein the shut-off valve is a
mechanical valve with pneumatic control.
9. The device according to claim 8, wherein the pneumatic control
employs a pneumatic signal that is an operating signal of a drive
motor of the power tool, wherein the operating signal is a
crankcase pressure of the drive motor.
10. An arrangement for actuating a water supplying device of a
hand-held power tool, the water supplying device comprising a
water-conveying line; a valve arrangement arranged in the line for
controlling a water flow through the line; wherein the valve
arrangement comprises a control valve with a valve body adjustable
across a positioning travel; wherein an opening cross-section of
the control valve, as a function of the positioning travel, has a
progressive characteristic line; the arrangement comprising: an
actuator acting on the valve arrangement, wherein the actuator is
configured separate from additional control elements of the power
tool.
11. The arrangement according to claim 10, wherein the actuator
comprises an actuating element that actuates the control valve and
further comprises an on/off switch that actuates the shut-off valve
and is separate from the actuating element.
12. The arrangement according to claim 10, wherein the actuator
comprises a rotatable setting roller.
13. The arrangement according to claim 10, wherein the actuator
comprises an actuating slide.
14. The arrangement according to claim 13, wherein the actuating
slide is pivotably guided in a groove.
15. The arrangement according to claim 10, wherein the actuator
comprises a pivotable setting lever connected to an axle stub that
projects at least partially outwardly and defines an axis of
rotation of the setting lever.
16. The arrangement according to claim 10, wherein the actuator has
an actuating knob that can be pushed in an axial direction of the
actuating knob.
17. The arrangement according to claim 16, wherein the actuator
comprises an on/off switch that is a pushbutton switchable between
two switching positions for actuating the shut-off valve, wherein
the actuating knob is part of the on/off switch.
18. The arrangement according to claim 10, wherein the actuator is
a pivot lever arranged on a handle of the power tool and projecting
from a surface of the handle.
19. The arrangement according to claim 18, wherein the pivot lever
is arranged on a bottom side of the handle and projects from the
bottom side.
20. The arrangement according to claim 10, wherein the actuator has
an on/off switch for actuating the shut-off valve, wherein
switching of the on/off switch is coupled to an operating readiness
or an operation of the power tool.
21. The arrangement according to claim 20, wherein the on/off
switch is switched by the weight of the power tool.
22. The arrangement according to claim 20, wherein the shut-off
valve is a pneumatic valve and the on/off switch is realized by
pressure loading the pneumatic valve by a pressure generated by a
drive motor of the power tool.
23. The arrangement according to claim 20, wherein the on/off
switch is switched by a part of the power tool that is moved upon
operation of the power tool.
Description
BACKGROUND OF THE INVENTION
[0001] The invention relates to a water supplying device of a
hand-held power tool, in particular for supplying a cutting wheel
of a cut-off machine with water. The water supplying device
comprises a water-conveying line and a valve arrangement arranged
in the line for controlling a water flow through the line. The
valve arrangement comprises a control valve with a valve body
adjustable across a positioning travel.
[0002] The invention also relates to an arrangement for actuating a
water supplying device of a hand-held power tool for actuating a
device for supplying water of the aforementioned kind, the
arrangement comprising an actuator acting on the valve
arrangement.
[0003] Hand-held power tools comprising a water supply through
which, for example, cooling water is supplied to the tool of the
power tool and/or to the workpiece are known. Particularly in the
case of a hand-held cut-off machine, the cutting wheel can be
supplied with water for binding dust produced when performing a
cut.
[0004] The control or regulation of the supplied amount of water is
not satisfactory in the known embodiments. By means of an external
valve, the water flow can be released before beginning the work to
be performed and can be interrupted after completion. After release
of the water flow, the water flows to the location to be worked on
even when the power tool is not in operation. Before and after the
actual working steps as well as during short work interruptions,
unwanted quantities of water escape that, in addition to increasing
water usage, also compromise the location to be worked on with an
unnecessary quantity of water.
[0005] U.S. Pat. No. 6,442,841 B1 discloses an arrangement with a
device for supplying water to a hand-held power tool in which a
shut-off valve for opening or closing a water line is provided. The
shut-off valve is actuatable by means of a throttle trigger lock
with which also the throttle trigger for adjusting the output of
the drive motor can be released. By actuating the throttle trigger
lock, a water supply is provided only when readiness to operate the
power tool with power is indicated by releasing the throttle
trigger.
[0006] A disadvantage of the disclosed arrangement is that, for
example, when opening the throttle for warming up the drive motor
during cold start, water can be released even when no working
process is to be performed. Adjustment of the water flow rate is
difficult as is the adjustment in regard to different water
pressure available at the intake. Coupling the throttle trigger
lock to the shut-off valve causes the basic function of the power
tool, such as simple acceleration or performing a dry cut, to be
made difficult when the valve is dirty, stiff and/or damaged.
[0007] It is an object of the present intention to provide a water
supplying device of a hand-held power tool that enables improved
adjustment of the conveyed amount of water to the actual water
demand.
[0008] The invention further has the object to provide an
arrangement for actuating the aforementioned device which
arrangement enables an improved control of the water supply.
SUMMARY OF THE INVENTION
[0009] According to the present invention, this object is solved in
regard to the water supplying device that the opening cross-section
of the control valve, as a function of the positioning travel, has
a progressive characteristic line.
[0010] According to the present invention, this object is solved in
regard to the arrangement in that the actuator is configured
separate from additional control elements of the power tool.
[0011] A water supplying device of a hand-held power tool
comprising a water-conveying line and a valve arrangement arranged
in the line is proposed wherein the valve arrangement comprises a
control valve with a valve body that is adjustable across a
positioning travel. In this connection, an opening cross-section of
the control valve has, depending on the positioning travel, a
progressive characteristic line. By means of suitable actuating
means the valve body can be moved into any position within its
positioning travel so that the corresponding opening cross-section
can be adjusted. The flow rate of the water flow is thus adjustable
as needed. The progressive characteristic line enables
alternatively a connection of water sources of different pressure
wherein the flow rate can be finally adjusted with the same valve
without additional devices. The progressive characteristic line
leads to a significant positioning travel being required for moving
the valve body away from its rest position in order to release a
comparatively minimal opening cross-section. For a water supply at
high pressure, for example, from a waterline network, the required
water flow can be adjusted finely. Alternatively, a water supply
can be provided, for example, from a separate water container
wherein the water container is arranged at a certain height
relative to the power tool. The height difference between the water
container and the power tool effects a static pressure which is
sufficient for water conveying. The absolute value of the water
pressure is however comparatively minimal. A finely adjustable
control of the water flow at a corresponding minimal pressure is
possible by opening the control valve farther wherein the
progressive characteristic line within the range of the
predetermined positioning travel enables a correspondingly large
opening cross-section. As a whole, the required conveying rate can
be adjusted precisely to the water demand that is required
respectively with simple means without requiring switching devices
or the like to different pressure supply systems.
[0012] In an advantageous embodiment, the control valve is
configured such that the progressive characteristic line has two at
least approximately linearly extending portions that are preferably
progressively angled relative to one another. A first comparatively
flat portion of the characteristic line is adjustable to a water
supply at high pressure wherein the linear course enables control
characteristics for the user that are finely adjustable and
predictable. The same holds true essentially also for the second
steeper characteristic line portion where the steepness in a simple
way enables its use with a low-pressure water supply, for example,
from a transport container, without requiring pumps or the
like.
[0013] The control valve is expediently configured as a globe valve
with a straight positioning travel. The configuration as a globe
valve with linear actuation is not sensitive with regard to soiling
and requires only minimal adjusting forces even at high water
pressures while fulfilling corresponding seal tightness
requirements.
[0014] The control valve is particularly designed such that the
valve body is configured to have an opening action away from its
rest position that is neutral relative to admission pressure of the
water pressure at the supply side. The required actuating forces
are at least approximately independent of the water pressure that
is present. Because of the at least approximately constant
actuating forces that can be sensed by the user, an excellent
adjustability of the water flow independent of the water pressure
that is present is promoted.
[0015] In an expedient embodiment the control valve also provides a
shut-off valve. For example, the positioning travel of the valve
body is selected such that the control valve in one end position is
closed and, starting from this closed end position, an increasing
progressive opening action can be realized. In this way, a simple,
cost-saving and space-saving configuration is provided without
requiring a separate shut-off valve. In an expedient alternative,
the shut-off valve is connected in series to the control valve in
flow communication within the valve arrangement and, in particular,
is arranged upstream of the control valve. In the closed state of
the shut-off valve the control valve is pressureless. The control
valve can be adjusted in the desired way with minimal actuating
forces without the water pressure having an effect.
[0016] In an expedient embodiment the shut-off valve is a solenoid
valve that is in particular a 2/2-way valve. The solenoid drive can
be coupled, for example, with an ignition coil of the internal
combustion drive engine or the like so that the water supply is
automatically switched on, as is desired, only when the power tool
is started and is also automatically switched off after shutting
down the power tool.
[0017] In an advantageous variant, the shut-off valve is a
mechanical valve with pneumatic control. For actuation, a pressure
that is generated by the power tool and in particular by the drive
motor can be used so that in this way an automatic on/off switching
coupled, as is desired, to the operation of the power tool is
provided. A manual operation of additional actuating elements is
not required. Coupling of the water flow to the operation of the
power tool or of the drive motor prevents unnecessary water
discharge.
[0018] For driving the pneumatically controlled valve, a diaphragm
loadable with pressure can be used in particular. The
correspondingly designed large-surface area diaphragm enables, for
example, in connection with a lever mechanism, correspondingly high
actuating forces while requiring only a minimal pressure
difference. Minimal operating pressures, for example, the crankcase
pressure that is taken from the crankcase of an internal combustion
engine provided as a drive or the intake vacuum in the area of the
carburetor can be sufficient for actuating the valve.
[0019] As a pneumatic control signal, advantageously an operating
signal of the internal combustion drive engine is connected to the
valve wherein the operating signal preferably is the crankcase
pressure of the internal combustion engine. The release of the
water flow is thus coupled to the operation of the internal
combustion engine. An accidental water discharge before or during
the starting process is prevented.
[0020] The valve arrangement has advantageously a hose clamp that
is especially embodied as a roller clamp. Such clamps are simple in
regard to their configuration and robust and a have a long service
life.
[0021] An arrangement for actuating a water supplying device of a
hand-held power tool is proposed that comprises a valve arrangement
and an actuator acting on the valve arrangement, wherein the
actuator is configured to be separate from additional control
elements of the power tool. By means of the additional control
elements, an internal combustion engine of the power tool or also
an electric drive motor can be actuated, for example, without this
mandatorily causing the water supply to be activated also. Warming
up the drive motor is possible as well as performing a dry cut
without this requiring that a connected water supply be interrupted
beforehand. A change between two operating modes is possible
without problems even during operation. Independent of the
operation of the power tool, the water supply can be released or
interrupted precisely when this is deemed necessary by the user by
actuating the separate actuator.
[0022] In an advantageous further embodiment the actuator comprises
an actuating element for actuating the control valve and, separate
therefrom, an on/off switch for actuating the shut-off valve. A
separate actuation of the control valve and of the shut-off valve
is possible in that, for example, the control valve beforehand is
adjusted to a desired position for a desired water flow while in
operation of the power tool only the shut-off valve is actuated as
needed for releasing or interrupting the water flow.
[0023] In an expedient embodiment, the power tool has a first
handle with the additional control elements for operating the power
tool, wherein at least a part of the actuator for the valve
arrangement is arranged on this first handle or at least in the
area of the first handle. The handle can be gripped by one hand of
the operator wherein, as needed, without having to reposition the
hand, the corresponding control elements and also the actuator for
the water supply can be actuated. The power tool can be moved into
the position required for working wherein it is possible to release
the water flow just immediately before performing the work to be
performed. Preparatory work such as starting the drive motor as
well as warming up the motor can be performed in the desired way
without water supply. Without repositioning the hand, a
readjustment of the supplied water quantity can be realized also on
the work-ready power tool in addition to releasing or interrupting
the water supply.
[0024] In this connection, the actuator is in particular arranged
in the lateral forward area of the first handle. This provides easy
accessibility by the thumb of the hand that grips the handle. The
position relative to the thumb enables the application of
comparatively high actuating forces without impairing during
operation a secure gripping action on the handle.
[0025] In an expedient embodiment, the actuator has a rotatable
setting roller. The setting roller is actuated essentially by the
force of a thumb or finger applied to its cylindrical surface. By
repeated actuation, it is possible to achieve large positioning
travels or large positioning angles with only minimal force
expenditure.
[0026] In another expedient variant, the actuator comprises a
setting slide that is guided in a groove, particularly in a
pivotable way. The travel of the setting slide is easily visible
for the operator by the course of the groove wherein the position
of the setting slide relative to the groove is an easily
recognizable indicator for the selected valve position.
[0027] Expediently, the actuator comprises a setting lever that
with its axis of rotation projects at least partially outwardly. By
applying a pressure on the setting lever, comparatively high forces
can be applied wherein, for example, in the case of repair work in
connection with dirty or damaged valves, the axle can be engaged by
a tool.
[0028] In a further expedient embodiment, the adjustor has an
axially movable actuating knob. The adjusting know is in particular
suitable as an on/off switch and, by means of its easily detectable
position, provides unquestionable information in regard to the
selected valve position.
[0029] The actuating knob can advantageously be a part of the
on/off switch in the form of a pushbutton that can be switched
between two switching positions for actuating the shut-off valve.
The shut-off valve can be switched on and off by repeated pushing
of the switchable pushbutton in an ergonomic way similar to the
mechanics of a ballpoint pen.
[0030] Expediently, the actuating element for actuating the control
valve is arranged in the area of the pushbutton, in particular so
as to annularly surround the pushbutton. At the same location, the
required amount of water can be readjusted with the annular
actuating element without repositioning the hand. Subsequently, as
needed, by actuating the pushbutton the readjusted water flow can
be released or interrupted. This results in the a compact
configuration in particular in connection with the above described
global valve that has a simple configuration and is easy to
actuate.
[0031] In an advantageous variant, the control device is configured
as a pivot lever that projects from a surface of the handle and, in
particular, from the bottom side of the handle. The power tool can
be picked up by gripping the handle and can be started. During
operation, the pivot lever is in the area of the fingers that grip
the handle and can be actuated as needed for releasing a water flow
without repositioning the hand.
[0032] It can also be expedient that when the power tool is
designed to have a second handle, at least a part of the actuator
is arranged on this second handle. Because of the spatially
separate correlation of the different control and actuating means
to the different handles, confusing the individual actuating
elements can be prevented; however, the actuator is still arranged
in direct vicinity of the hand guiding the power tool. For example,
the control elements for the motor are correlated with the first
handle and the actuating elements for controlling the water flow
are correlated with the second handle. Both control and actuating
elements can be actuated without repositioning the hand during or
after operation of the power tool.
[0033] In an advantageous configuration the on/off switch is
arranged such that an actuation is coupled to readiness of
operation or to the operation of the power tool. In an embodiment
suitable for this purpose, the on/off switch is, for example,
actuatable by the weight of the power tool. In particular, the
on/off switch is arranged in the area of a support surface of the
power tool. When setting down the power tool, the weight actuates
the switch such that water supply is interrupted. By lifting the
power tool, its readiness for operation is signalized; the switch
that is now relieved of the weight of the power tool releases the
water flow. An automatic water control is provided that prevents
faulty manual operation.
[0034] In an advantageous variant of this concept, the on/off
switch is configured as a push switch that is integrated into the
surface of the handle. When starting the power tool, the handle is
gripped by a hand of the operator and the push switch is thus
actuated automatically without further action being required. The
power tool can be carried by the other handle without releasing the
water supply. In preparation of work to be performed, the handle
provided with the push switch can be gripped so that the water
supply its triggered. In this way, there is also an automatic
coupling to the operational readiness of the power tool so that
faulty manual operation is prevented.
[0035] It can also be expedient to actuate the on/off switch by
means of a part of the power tool that is moved upon operation of
the power tool. In this connection, it can be provided in
particular that the on/off switch is a magnetic clutch coupled to
the part of the power tool that rotates upon operation. By means of
the rotating drive motor or by means of a rotating tool, e.g. in
connection with a centrifugal clutch, a moment can be generated
through the magnetic clutch as a result of operation that is
suitable for triggering the shut-off valve. In an advantageous
variant, the on/off switch is actuatable by a circulating belt
drive of the power tool. In a further advantageous variant, the
on/off switch is actuatable by a vane that is loaded by an airflow
generated by a fan wheel of the drive motor. The aforementioned
variants can be constructed with simple means and can be designed
such that an actuation of the connected valve is realized only at a
certain engine speed. This engine speed can be adjusted such that
idle or partial load operation is possible without triggering a
water supply. An automated water supply is realized only upon
reaching a predetermined working speed so that the water supply is
coupled directly to performing the working process. An unnecessary
water discharge is prevented.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] Embodiments of the invention will be explained in the
following with the aid of the drawing.
[0037] FIG. 1 is a perspective overview illustration of a power
tool exemplified by a cut-off machine with a device for supplying
water.
[0038] FIG. 2 is a schematic overview illustration of an embodiment
of the water supply according to FIG. 1.
[0039] FIG. 3 is a longitudinal section illustration of a control
valve configured as a globe valve.
[0040] FIG. 4 shows the progressive characteristic line of the
control valve according to FIG. 3 in a diagram form.
[0041] FIG. 5 is a schematic section illustration of a
pneumatically actuated shut-off valve.
[0042] FIG. 6 shows details of an embodiment of the control valve
according to FIG. 5 with a connected diaphragm in a schematic
illustration.
[0043] FIG. 7 is a variant of the valve according to FIG. 6 in an
embodiment as a 2/2-way solenoid valve.
[0044] FIG. 8 shows in a schematic perspective illustration the
handle arrangement of the power tool according to FIG. 1 with a
laterally arranged setting roller for actuating the valve
arrangement according to FIG. 2.
[0045] FIG. 9 is a variant of the arrangement according to FIG. 8
with a setting roller positioned transversely to the handle
axis.
[0046] FIG. 10 shows a further variant of the arrangements
according to FIG. 8 and FIG. 9 with an actuating element configured
as a pivotable setting lever.
[0047] FIG. 11 is an embodiment with an actuating element embodied
as a setting slide.
[0048] FIG. 12 shows a further handle arrangement variant with a
pushbutton as an on/off switch and an actuating element for
adjusting the water rate.
[0049] FIG. 13 shows in an enlarged detail view the arrangement
according to FIG. 12 in the area of the pushbutton and the
actuating element in connection with the globe valve of FIG. 3.
[0050] FIG. 14 shows in a perspective view an embodiment of the
shut-off valve in the form of a hose roller clamp.
[0051] FIG. 15 shows in a perspective view an embodiment of the
handle arrangement of the power tool according to FIG. 1 with a
pivot lever projecting from the surface of the handle.
[0052] FIG. 16 shows in a schematic illustration a plan view of an
embodiment with a setting roller integrated into a grip pipe.
[0053] FIG. 17 shows in a perspective illustration a variant of the
grip arrangement of the power tool according to FIG. 1 with two
parallel extending levers for separate configuration of the pivot
lever for water control and the throttle trigger lock.
[0054] FIG. 18 is a variant of the embodiment of FIG. 17 with a
rocker switch integrated into the handle.
[0055] FIG. 19 shows in a perspective detail view a section of the
support surface of a power tool according to FIG. 1 with the
pivotably supported support leg and an integrated on/off switch in
the form of a hose clamp.
[0056] FIG. 20 shows in a schematic illustration a magnetic clutch
as a part of an on/off switch.
[0057] FIG. 21 is a schematic illustration of an airflow-loaded
vane for actuating an on/off switch.
[0058] FIG. 22 shows in a schematic side view the belt drive of the
power tool according to FIG. 1 with a connected roller for
operation-triggered actuation of the on/off switch of the water
supply.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0059] FIG. 1 shows in a perspective overview illustration a power
tool 1 exemplified by a hand-held cut-off machine. The cut-off
machine has a drive motor 32 embodied as an internal combustion
engine by means of which a cutting wheel 2 can be driven by a belt
drive 34. The power tool can also be a power drill or another
comparable hand-held power tool. The drive motor 32 can also be
configured as an electric motor.
[0060] For guiding the power tool 1, a first handle 20 is provided
on a handle housing 71 and a second handle 30 is provided that is
positioned in front of the first handle 20 in the direction toward
the cutting wheel 2. The second handle 30 is embodied in the
illustrated embodiment as a grip pipe. The power tool 1 has a
support surface 80 with support legs 81 for setting it down.
[0061] For actuating and for controlling the drive motor 32, a
number of control elements 17 are provided of which a throttle
trigger 38, a stop lever 39 as well as a throttle trigger lock 40
are arranged on the first handle 20.
[0062] For supplying water to the cutting wheel 2, the power tool 1
has a water supplying device 15 with which, as needed, a water flow
5 is conducted through a line 3 to the cutting wheel 2. In the
illustrated embodiment, the line 3 extends through the second
handle 30 embodied as a grip pipe, wherein for controlling the
water flow an actuator 16 is provided in the second handle. The
actuator 16 is embodied as an annular actuating element 18 that is
rotatable about the pipe axis of the tubular handle 30 for
adjusting as needed the water quantity flowing through.
[0063] FIG. 2 shows in a schematic illustration an embodiment of
the water supplying device 15 according to FIG. 1 with a valve
arrangement 4 that comprises a control valve 6 and a shut-off valve
11 arranged in series upstream of the control valve 6. The control
valve 6 and the shut-off valve 11 are arranged in the line 3 and
are provided for controlling or adjusting the water flow 5. At the
supply side of the line 3, a hose coupling 41 is provided with
which, alternatively, a transportable water container or, by means
of a hose, a pressurized waterline network can be connected.
[0064] The shut-off valve 11 has a valve body 7 that can be
actuated by means of a push rod 44 via an on/off switch 19. By
pressing down the on/off switch in the direction of arrow 42, the
valve body 7 is lifted against the water pressure at the
supply-side so that the flow path is released by the shut-off valve
11. Intermediate positions between an open position and a closed
position of the shut-off valve 11 are not provided. Instead, the
shut-off valve 11 is provided in the sense of an on/off function
for releasing or interrupting the water flow 5.
[0065] The magnitude of the water flow 5 resulting in the open
position of the shut-off valve 11 can be controlled by means of the
control valve 6. For this purpose, an actuating element 18 is
provided that acts on the control valve and in the illustrated
embodiment is rotatable in the direction of arrow 43 so that the
control valve 6 can be moved into any desired flow rate position.
The adjustment of the control valve 6 can be realized in particular
in the closed position of the shut-off valve 11 in which position
the control valve 6 is pressureless. In the open position of the
shut-off valve 11, the water flow 5 flows through line 3 at a flow
volume that is predetermined by the position of the control valve
6. The water flow 5 is guided by means of the line 3 through an
injection nozzle 77 to the cutting wheel 2 (FIG. 1).
[0066] In the illustrated embodiment, the actuating element 18 and
the on/off switch 19 are separately configured and enable
independent actuation. The on/off switch 19 and the actuating
element 18 are part of the actuator 16 that acts on the valve
arrangement 4 and are both independent of the additional control
elements 17 (FIG. 1). It can also be expedient that such an
independent configuration is provided only for the actuating
element 18 while the on/off switch 19 is, for example, formed by
the throttle trigger lock 40 (FIG. 1).
[0067] FIG. 3 shows in a longitudinal section view the control
valve 6 according to FIG. 2; it is a globe valve 10 with a
cylindrical valve seat 48 in the illustrated embodiment. The globe
valve 10 comprises a valve housing 45 having a unitary intake
nipple 46 positioned at a right angle to the longitudinal axis of
the valve housing. An outlet nipple 47 is screwed into the valve
housing 45 at the end face in the longitudinal direction. In the
interior of the valve housing 45, the valve body 7 is arranged; it
rests seal-tightly with two axially spaced apart sealing rings 50
radially outwardly against the cylindrical valve seat 48. On the
end of the valve body 7 opposite the outlet nipple 47, a pressure
pin 51 is provided that projects from the valve housing 45. By
means of the pressure pin 51, the valve body 7 can be axially moved
away from its rest position by a positioning travel a. In the
direction toward the outlet nipple 47, a radially extending
depression is machined into the valve seat 48 for forming a valve
opening 49 with a bent contour. When forcing the valve body 7 by
means of the pressure pin 51 into the valve housing, the sealing
ring 50 facing the outlet nipple 47 is moved into a position
overlapping the valve opening 49. In this valve position, the water
flow 5 can flow through the intake nipple 46 and the intermediate
space between the two sealing rings 50 radially externally past the
sealing ring 50 through the valve opening 49 and the outlet nipple
47. The contour of the valve opening 49 bent in the circumferential
and radial directions is selected such that an opening
cross-section A of the control valve 6 has a progressive
characteristic line as a function of the positioning travel a.
[0068] The characteristic line of the opening cross-section A
dependent on the positioning travel a is illustrated in an
exemplary fashion in the form of a diagram in FIG. 4. Accordingly,
the progressive characteristic line comprises two at least
approximately linearly extending portions 8, 9 that are
progressively angled toward one another. The first portion 8
extends comparatively flat so that across a first positioning
travel a.sub.1--starting at the closed state--only minimal increase
of the opening cross-section A.sub.1 results. The second portion 9
of the characteristic line adjoins the first portion 8 at an angle
so that upon further actuation of the valve body 7 up to a
positioning travel a.sub.2--because of the steeper course of the
portion 9--a greater increase of the opening cross-section A up to
the maximum opening cross-section A.sub.2 results. It can be
expedient to provide a curved progressive extension of the
characteristic line.
[0069] In the embodiment according to FIG. 3, the valve body 7 is
guided along a straight positioning travel a. It is also possible
to provide a configuration for producing the progressive
characteristic line (FIG. 4) where the valve body 7 is guided in a
rotatable or pivotable way.
[0070] In the embodiment according to FIG. 3, the illustrated rest
position of the valve body 7 is selected such that the sealing ring
50 in the area of the valve opening 49 rests about its entire
circumference seal-tightly against the valve seat 48 and in this
way interrupts the water flow 5 completely. The illustrated globe
valve 10 is configured as a control valve 6 for adjusting the flow
rate as well as a shut-off valve 11 for interrupting or releasing
the water flow 5. Also, an arrangement can be expedient where the
positioning travel a is adjusted such that the flow volume passing
through is adjusted to be greater or smaller; a shut-off function
is then assigned to a separate shut-off valve 11.
[0071] The two sealing rings 50 and the valve seat 48 externally
surrounding them have an approximately uniform diameter. In the
case of water pressure loading at the supply side through the
intake nipple 46, the pressure forces acting in both axial
directions on the valve body 7 compensate one another at least
approximately. The actuating forces to be applied onto the pressure
pin 51 are essentially independent of the water pressure that is
present. The valve body 7 is designed such that its opening action
away from its illustrated rest position is neutral relative to the
admission pressure of the water pressure at the supply side.
Closing of the valve body 7 can be realized, for example, actively
by applying a tension force or by arrangement of a pressure spring
(not illustrated to keep the drawing simple) drawings). A
construction can also be expedient where flow through the globe
valve 10 is directed in the opposite direction. The water pressure
that is acting at the supply side on the valve body 7 loads the
valve body 7 with a closing force against which the valve body 7 is
to be opened away from its rest position; the pressure-caused
closing force leads, as needed, to an automatic closing of the
valve body 7.
[0072] FIG. 5 shows in a schematic section illustration one
embodiment of the shut-off valve 11 in the form of a mechanical
2/2-way valve 13. The valve housing 52 is provided with an intake
opening 60 and an outlet opening 63 wherein a valve body 53 is
arranged in the interior transversely to the water flow 5 and is
movable in the direction of double arrow 54 against the force of a
pressure spring 62. On the side of the pressure spring 62, a
pressure opening 56 is provided in the valve housing 52 through
which the interior is loaded by ambient pressure in accordance with
the illustrated arrow 57. At the opposite end, a pressure opening
58 for pneumatic pressure loading of the valve body 53 in
accordance with arrow 59 is provided in the valve housing 52. A
pressure produced by the operation of the power tool 1 (FIG. 1),
for example, pressure from the crankcase of an internal combustion
engine, can be introduced through the pressure opening 58 so that
the actuation of the shut-off valve 11 is coupled to the operation
of the power tool 1. When applying an operating pressure in
accordance with arrow 59, the valve body 53 is moved against the
force of the pressure spring 62 such that the through opening 55 in
the valve body 53 overlaps with the intake opening 60 and the
outlet opening 63. In this way, the function of the shut-off valve
11 with an on/off function is provided without taking into
consideration intermediate parameters. The disclosed pressure
supply 59 acts thus as an on/off switch 19 as a function of
operation of the power tool 1.
[0073] FIG. 6 shows an embodiment of the schematically illustrated
arrangement according to FIG. 5 in which the mechanical 2/2-way
valve 13 is arranged in an exemplary fashion in a closed pressure
chamber 64. In a wall of the pressure chamber 64 an elastic
diaphragm 14 is inserted that transmits a force as a result of
occurring pressure differences via a pressure plate 68, a plunger
67, and a lever 66 onto a pressure pin 65 of the valve 13. With
minimal pressure differences at the diaphragm 14, in accordance
with its large-surface area configuration and in connection with
the lever action of the lever 66, high actuating forces can be
exerted onto the pressure pin 65 and the passage from the intake
opening 60 to the outlet opening 63 can be released. For this
purpose, an external overpressure loading of the diaphragm 14 can
be provided wherein an interior 69 of the pressure chamber 64 is
loaded, for example, with atmospheric pressure. It can also be
expedient to provide in the case of external ambient pressure the
interior 69 with underpressure, for example, from the intake area
of a carburetor. In the illustrated embodiment, the crankcase
pressure of the drive motor 32 (FIG. 1) is selected as the
pneumatic control signal that actuates the valve 13 by means of the
diaphragm 14. The crankcase pressure is generated only upon
operation of the drive motor 32 and is thus an operating signal
that indicates running of the drive motor 32 and releases the water
flow through the valve 32.
[0074] FIG. 7 shows in a schematic illustration a variant of the
shut-off valve 11 according to FIGS. 5 and 6 that is embodied as an
solenoid valve 12. In an exemplary fashion, a configuration as a
2/2-way valve is provided. The valve body with the intake opening
60 and the outlet opening 63 matches the configuration of FIG. 6
while for operating it a schematically indicated solenoid 70 is
provided. The solenoid 70 can be, for example, connected to an
ignition coil or to another electric device of the drive motor 32
(FIG. 1) so that an on/off switch is provided that is coupled to
the operation of the power tool 1 (FIG. 1).
[0075] FIG. 8 shows in a schematic perspective illustration the
area of the first handle 20 of the power tool 1 according to FIG.
1. On the handle 20, a throttle trigger 38 for adjusting the motor
output, a stop lever 39 for turning off the drive motor 32, as well
as a throttle trigger lock 40 for preventing accidental operation
of the throttle trigger 38 are arranged as control elements 17 for
operating the drive motor 32 (FIG. 1). A part of the actuator 16 in
the form of actuating element 18 is arranged in the area of the
first handle 20. A further part of the actuator 16, not
illustrated, for example in the form of an on/off switch 19 (FIG.
2), can be arranged e.g. on the second handle 30 or at another
location of the power tool 1 (FIG. 1). In the illustrated
embodiment, the control element 18 is configured as a setting
roller 21 partially recessed into the handle housing 71. An axis of
rotation (not illustrated) of the setting roller 21 is positioned
within the handle housing 71 and extends transversely underneath
the first handle 20.
[0076] FIG. 9 shows a variant of the arrangement according to FIG.
8 in which the setting roller 21 is arranged laterally in the
forward area of the first handle 20 wherein the axis of rotation of
the setting roller 21 extends axis-parallel to the axis of the
first handle 20.
[0077] In the embodiment according to FIG. 10, an actuating element
18 in the form of a pivotable setting lever 25 is provided in the
forward lateral area of the first handle 20; it has an axle stub
that projects at least partially outwardly from the handle housing
and has an axis of rotation 24. The actuating element 18 can be
actuated by means of the setting lever 25 as well as by means of
the projecting axle stub.
[0078] A further variant is illustrated in FIG. 11 in which the
actuating element 18 is configured as a setting slide 23; in the
illustrated embodiment, it extends slidably in a curved groove 22.
It is also possible to provide a linearly movable setting slide 23.
The axis of rotation 24 according to FIG. 10 and the pivot axis
according to FIG. 11 are positioned approximately perpendicularly
to the longitudinal axis of the first handle 20 wherein the two
axes at least approximately intercept one another, respectively.
The arrangement of the actuating element 18 according to FIGS. 8
through 11 is selected such that in the usual operating position
they can be actuated by the thumb of a hand gripping the handle 20
without having to reposition the hand.
[0079] The same holds true also for the embodiment according to
FIG. 12 in which the actuator 16 is arranged together with the
actuating element 18 and the on/off switch 19 laterally relative to
the handle 20 approximately at the level of its longitudinal axis.
The actuator 16 has an actuating knob 26 that can be pushed in
axially in a direction transversely to the longitudinal axis of the
handle 20; it is surrounded annularly by the actuating element
18.
[0080] FIG. 13 shows in a partially sectioned illustration details
of the actuator 16 according to FIG. 12; here the actuator 16 is
connected directly to the globe valve 10 according to FIG. 3. The
actuating knob 26 is part of the on/off switch 19 which is in the
form of a pushbutton 27 that can be switched between two switching
positions for actuating the globe valve 10. By means of the
ring-shaped actuating element 18 surrounding the pushbutton 27, the
positioning travel a (FIG. 3) of the globe valve 10 can be
preadjusted. By alternatingly pushing the pushbutton 27 in
accordance with a known ballpoint pen mechanism the pressure pin 51
is moved in and out alternatingly. The valve body 7 (FIG. 3) can
thus be switched between its closed position and its open position
that is preadjusted by means of the actuating element 18.
[0081] For controlling the water flow 5 (FIG. 1), it can also be
provided that the valve arrangement 4, for example, comprises a
hose clamp 61 according to FIG. 14. The perspective illustration of
FIG. 14 illustrates that the hose clamp 61 for forming a roller
clamp has a roller 74 that is movable by means of the actuating
knob 26 (FIG. 12) in the direction of the double arrow 95. The
actuating knob 26 is embodied as a continuous rod that projects,
for example, in the embodiment according to FIG. 12, alternatingly
from one or the other lateral surface of the handle housing 71. A
hose line 73, indicated by a dashed line, extends between the
roller 74 and a ramp 75 of the hose clamp 61. By axial displacement
of the actuating knob 26, the roller 74 rolls on the hose line 73
so that, depending on the axial positioning travel in connection
with the slanted shape of the ramp 75, pinching of the hose line 73
to a greater or lesser degree results. Depending on the axial
adjustment of the actuating knob 26, the flow-conducting
cross-section of the hose line 73 is adjustable, wherein the
illustrated embodiment of the hose clamp 61 in connection with the
actuating knob 26 as an on/off switch is embodied in combination
with shut-off valve 11. It can also be expedient to configure the
hose clamp 61 as a control valve 6 (FIG. 2) with progressive
characteristic line (FIG. 4), in particular in connection with a
corresponding shaping of the ramp 75.
[0082] FIG. 15 shows an embodiment of a handle arrangement of the
power tool 1 according to FIG. 1 in which the on/off switch 19 is
additionally arranged directly on the handle 20 separate from the
control elements 17. The on/off switch 19 is embodied as a pivot
lever 29 arranged on the bottom side of the handle 20 and
projecting from a surface 28 of the handle 20. Independent of the
lever 38, the stop lever 39, and the throttle trigger lock 40, the
pivot lever 29 can be actuated, for example, by the little finger
when the hand grips the handle 20.
[0083] FIG. 16 shows in a schematic illustration a plan view of a
variant of the power tool 1 according to FIG. 1 wherein a setting
roller 21 is arranged on the second handle 30 that is arranged
between the first handle 20 and the cutting wheel 2. The axis of
rotation of the setting roller 21 is positioned axis-parallel to
the axis of the first handle 20 or transversely to the axis of the
second handle 30. Its actuating direction extends in the direction
of an extended thumb of the hand 76 gripping the second handle 30
and can be actuated easily by flexing movements of the thumb.
[0084] According to FIG. 17, an embodiment of the handle 20 is
provided in which the on/off switch 19 is a push switch 31 and is
positioned for actuation of the shut-off valve 11 (FIG. 2) directly
adjacent the throttle trigger lock 48 that is shaped identically.
The pivot lever 29 and the throttle trigger lock 40 project
upwardly from the surface 28 of the handle 20. Upon gripping the
handle 20 with one hand and upon subsequent lifting of the power
tool 1 (FIG. 1), the power tool 1 is ready for operation wherein,
as a result of the pressure applied by the hand, the throttle
trigger lock 40 and the push switch 31 are simultaneously and
automatically suppressed as a function of the operating readiness
of the power tool. The water flow 5 (FIG. 2) is released. As
needed, by means of the throttle trigger 38 the motor output can be
increased or, after completion of the working process, can be
turned off by the stop lever 39 of the power tool 32 (FIG. 1).
After releasing the hand from the handle 20, the push switch 31
automatically returns, for example, as a result of a spring force,
into its initial position; the water supply is interrupted.
[0085] FIG. 18 shows a variant of the arrangement according to FIG.
17 in which the on/off switch 19 comprises a push switch 31 that is
embodied as an elastic springy rocker switch 79 on the topside of
the handle 20. The rocker switch 79 is actuatable against the
pressure of an intermediately positioned pressure spring 78. With
regard to its function, the rocker switch 79 corresponds to the
push switch 31 according to FIG. 17.
[0086] FIG. 19 shows in a detail illustration the area of the
support surface of the power tool 1 according to FIG. 1 with a
support leg 81. The support leg 81 is pivotably supported about
pivot axis 82; a hose line 73 extends between support leg 81 and
the handle housing 71. When setting down the power tool 1 (FIG. 1),
the weight acting on the support leg 81 causes a pivot movement
that leads to pinching of the hose line 73. The pinching action is
released when lifting the power tool 1. The power tool 1 is ready
to operate and the free cross-section of the hose line 73 is
released. The water flow 5 (FIG. 1) can flow through the hose line
73; in the illustrated arrangement an on/off switch 19 in the form
of a hose clamp 94 is formed.
[0087] FIGS. 20 to 22 show in schematic illustrations embodiments
in which the on/off switch 19 is actuatable by a part of the power
tool (FIG. 1) that moves upon operation of the power tool. In the
embodiment according to FIG. 20 the on/off switch 19 is a magnetic
clutch 33 coupled to a part of the power tool 1 that rotates during
operation of the power tool. Instead of the magnetic clutch it is
also possible to employ an eddy current clutch, an eddy current
brake or similar devices. The part rotating during operation is for
example a shaft 83 that can be a crankshaft of the drive motor 32
or a bearing shaft of the cutting wheel 2 (FIG. 1). A magnet 84 is
provided on the shaft 83 and is rotated at a spacing past an iron
plate 85. The iron plate 85 is pivotably supported on a shaft 86
against the restoring moment of a spiral spring 87. When a
constructively predetermined speed of the magnet 84 is reached, a
suitable pivot moment is transmitted onto the iron plate 85; this
is sufficient for actuating the schematically illustrated shut-off
valve 11.
[0088] According to FIG. 21, an embodiment is provided in which the
power tool 1 in operation generates an airflow 36. In the
illustrated embodiment, a fan wheel 35 of the drive motor 32 (FIG.
1) is provided that, together with the schematically illustrated
vane configuration 89, can be driven in rotation in the direction
of arrow 90 about an axis of rotation 88. The airflow 36 for
cooling the drive motor 32 is generated as a result of the
rotational movement. The vane 37 is exposed to the air flow 36. The
vane 37 is supported to be pivotable against the restoring moment
of a spiral spring 91 so that by means of the vane 37 a
schematically illustrated on/off switch 19 can be actuated. The
blower arrangement in combination with the airflow 36 and the vane
37 forms the on/off switch 19 whose function, as in the embodiment
according to FIG. 20, is coupled to the operation of the power tool
1 (FIG. 1).
[0089] FIG. 22 shows a detail of the area of the belt drive 34 with
cutting wheel 2 of the power tool 1 according to FIG. 1, wherein a
roller 92 runs on the belt 93 of the belt drive 34. At a limit
speed preset by operating conditions, an actuation of the
schematically shown shut-off valve 11 is realized by means of the
roller 92 so that an on/off switch 19 is formed. Instead of the
roller 92 it is also possible to provide a gliding element or
similar means that interacts with the belt drive 34.
[0090] While specific embodiments of the invention have been shown
and described in detail to illustrate the inventive principles, it
will be understood that the invention may be embodied otherwise
without departing from such principles.
* * * * *