This application claims priority of German patent application no. 10 2009 011 685.0, filed Mar. 4, 2009, the entire content of which is incorporated herein by reference.
The invention relates to a portable handheld work apparatus having an internal combustion engine for driving a work tool.
Portable handheld work apparatus driven by internal combustion engines are generally known. Usually, electric components are connected via a connecting cable in portable handheld work apparatus. Connecting cables are complex to place during assembly of the work apparatus. Because of the tight construction space in the work apparatus, the cables must be laid at fixedly pregiven positions in order to ensure that the cables will not become damaged during operation because of vibrations which are generated by the engine.
It is an object of the invention to provide a portable handheld work apparatus of the type described above wherein the assembly is simplified and the problem of damage to electric lines is reduced.
The portable handheld work apparatus of the invention includes: a work tool; an internal combustion engine for driving the work tool; the engine including a cylinder and a crankcase connected to the cylinder; the engine further including an ignition system; a housing component made at least partially of an electric non-conductive material; at least one electric line; at least one electric component provided on the housing component and being electrically connected to the electric line; and, the electric line having at least one segment embedded in the housing component.
The electric line is completely surrounded by the material of the housing component because of the embedment of the electric line therein and is thereby protected from ambient influences. Mechanical damage of the electric line can thereby be avoided. The line is embedded already during the manufacture of the housing component so that a subsequent placement of the line during assembly is unnecessary for the embedded segment thereof. In this way, the assembly of the work apparatus is significantly simplified.
Advantageously, the housing component is made at least partially of plastic and the segment of the electric line is injection molded into the housing component. The segment of the electric line is injection molded in the plastic of the housing component. In this way, the placement of the line takes place during injection of the plastic, that is, with the manufacture of the housing component in one work step. A subsequent placement of the line is therefore unnecessary. A simple configuration results when the embedded segment of the electric line is configured as a stamped conductor. Stamped conductors are stamped from sheet metal material and bent as required. Stamped conductors can be easily manufactured and can be placed in the injection molding form during the injection molding process. For contacting the embedded segment of the electric line, at least one contact is arranged on the embedded segment of the electric line and this contact projects out from the material of the housing component for making contact.
Advantageously, at least one contact is configured as a contact blade which functions for connecting to a connecting contact arranged on a connecting component. The contact blade is advantageously aligned in the joining direction of the connecting component. When connecting the component part to the housing component, the connecting contacts of the connecting component are connected to the contact blades because of the joining movement and thereby define an electric connection. An additional work step for making contact is then omitted. In this way, the assembly is significantly simplified. To facilitate joining, it is advantageous to provide a bevel on the end of the contact blade lying forward in the joining direction.
Advantageously, the electric component is a switch which is formed by at least two contacts and a bridging element which is movably journalled on the housing component and coacts with the contacts. A switch of this kind built from the contacts and the bridging element has a simple configuration. The contacts can advantageously be arranged on the stamped conductor so that a simple configuration without additional components results. The contacts are advantageously arranged so as to be mutually adjacent and the bridging element is a conducting cam. In this way, the switch can be built up to be compact. Only a common cam is needed for contacting the two contacts so that a simple assembly results.
The work apparatus is provided to have a pivotally journalled switch shaft with which an operating position, an off position and at least one start position can be set. The bridging element is arranged on the switch shaft. In this way, no additional components are needed for the bridging element. Rather, the switch shaft which is already provided can be used. Advantageously, a latch spring is integrated into the switch shaft and determines the different switch positions of the switch shaft. A simple assembly results when the bridging element with the latch spring is formed as one piece from a bent sheet metal piece.
Advantageously, the housing is the motor housing of the work apparatus. It is provided that at least one operating means tank of the work apparatus is integrated into the motor housing and that at least one embedded segment of an electric line runs in a wall of the operating means tank. An embedded segment of an electric line runs advantageously on the upper side of a fuel tank. In this way, the electric lines, which are usually on the upper side of the fuel tank, can be omitted. Advantageously, the crankcase of the engine is formed on the motor housing.
The electric component is especially a short circuit switch which establishes a connection between at least two contacts in the off position. A first contact is connected to a ground contact and a second contact is connected to the ignition device of the engine. The ground contact is connected to the cylinder of the engine. A simple configuration results when the crankcase has at least one bushing in which an attachment screw is threadably engaged for fixing the cylinder. The segment of the electric line embedded in the motor housing advantageously projects up to the bushing and is connected via the bushing to the cylinder. The electric line is especially embedded between the first contact and the bushing in the motor housing. The ground connection of the short circuit switch can thereby be realized without loose lines completely by a line especially injection molded and embedded in the housing.
The second contact is advantageously connected to a contact blade for connecting to a connecting cable for the ignition device. The electric line is embedded in the motor housing between the second contact and the contact blade. In this way, only the distance between the motor housing and the ignition device, which is usually arranged on the cylinder of the engine, need be bridged by the connecting cable. All other lines, which are needed for the short circuit switch, are embedded in the material of the motor housing and especially injection molded. In this way, a simple robust configuration results. The needed structural space for the connecting lines is significantly reduced.
Advantageously, an electric component is a heating element which is arranged on a heat distribution element. The heat distribution element distributes the heat uniformly in the handle generated by the heating element. In this way, the heating element itself can be configured to be comparatively small. A simple configuration results. The configuration of the work apparatus can be further simplified when at least one segment of the heat distribution element is configured as one piece with an embedded segment of an electric line. The heat distribution element can be configured together with the embedded segment of the electric line as a stamped conductor and be injection molded into the housing component. Here, it is advantageously provided that the heat distribution element mechanically fixes and electrically contacts the heating element. The segment of the heat distribution element, which mechanically fixes and electrically contacts the heating element, projects advantageously out from the material of the housing component. The heat distribution element can be configured as one piece and can be configured as one piece with the stamped conductor. It is, however, also possible to provide a multi-part heat distribution element. For example, respective segments of the heat distribution element can be provided in the handle half shells of the handle. Advantageously, a segment of the heat distribution element is configured as one piece with the stamped conductor and a further segment as a separate component.
The housing component is advantageously a handle housing of a handle. A simple assembly of the handle results when the handle has a connecting plug for connecting to a connecting cable and contact blades for connecting to connecting contacts. All electric lines between the connecting plug, the contact blades and the at least one electric component are embedded in the handle housing. The placement of loose electric lines in the handle housing is then omitted. All necessary electric lines are embedded in the material of the handle housing during manufacture of the handle housing, for example, they are coated with the material of the housing.
The invention will now be described with reference to the drawings wherein:
In
The engine 10 has a carburetor 11 on which an air filter 12 is arranged. An air/fuel mixture is drawn by suction by the engine 10 via the air filter 12 and the carburetor 11. An air channel for supplying scavenging advance air can additionally be provided. A throttle flap 13 and a choke flap 14 are pivotally journalled in the carburetor 11. For operating the engine 10, an operator-controlled switch 15 is provided which projects from the housing of the chain saw 1 next to the rearward handle 5. The operator-controlled switch 15 is shown in
In the operating position 51, the position of the throttle flap 13 is adjusted by the operator via the throttle lever 6. The choke flap 14 is in the completely open position. In the off position 52, a short circuit switch (not shown in
The operator-controlled switch 15 can be shifted by the operator between the different positions as indicated by the double arrow 16. From the warm start position 53, the operator-controlled switch 15 is moved into the operating position 51 with the actuation of the throttle lever 6.
As shown in
As shown in
In
As shown in
In the off position 52, the operator-controlled switch 15 closes a short circuit switch 33 shown in
The second stamped conductor 31 connects the second contact 35 to a contact blade 40 whereat the stamped conductor 31 advantageously projects approximately perpendicularly out of the material of the motor housing 2. The contact blade 40 connects to a connecting plug 42 of a connecting cable 41. The other end of the connecting cable 41 is connected to the ignition module 21 with a connecting plug 43. The ignition module 21 has a connecting cable 44 for connecting to a spark plug 22.
The two contacts 34 and 35 are arranged mutually adjacent on the upper side of the motor housing 2. In the off position 52 of the operator-controlled switch 15, the two contacts 34 and 35 are connected to each other via the cam 36. This is shown schematically in
The short circuit switch 33 is open in the operating position 51 shown in
The electric line 69 connects the microswitch 74 to a connector 99. The first line 69 is thereby the short circuit line. A second line 70 connects a connector 100 to a connector 101. A third line 71 functions as a ground line and connects the microswitch 74 to the heat distribution element 73, to a connector 102 and, via the heat distribution element 73, to a connector 103. The heat distribution element 73 contacts the heating element 75 at one end. At the opposite-lying end, the heating element 75 is contacted by a connector 105 which is connected via a line 72 to a connector 104.
The three connectors (99, 101, 103) connect the first handle 67 to the engine 10 or to a control with the engine 10 being mounted in the motor housing 2. The three connectors (100, 102, 104) are formed on contact blades (77, 78, 79) shown in
As
The grip handle 65 is pushed in a joining direction 88 into the handle housing 68. As shown in
The handle housing 68 is advantageously coated at least partially by a soft material which forms a jacket. The soft material can, for example, be a thermoplastic elastomer. The material of the jacket can, advantageously, pass via at least one inlet opening into the interior of the handle housing 68 and so form a seal for sealing off electric components.
For fixing the heating element 75, a receptacle pocket 60 is formed between the region of the heat distribution element 73, which projects upwardly from the material of the housing half shell 76, and the wall of the housing half shell 76 as shown in
In the embodiment, the heat distribution element 73 is configured as one piece with the stamped conductor 97. A further section of the heat distribution element 73 can be provided, for example, in the second housing half shell of the handle 67. This additional section of the heat distribution element 73 can be configured as a separate component, for example, as a stamped bent sheet metal piece.
An electric line, which is embedded in a housing component, for connecting to an electric component of a handheld portable work apparatus can also be provided in portable handheld work apparatus which do not have an internal combustion engine as a drive motor, rather, for example, an electric motor.
It is understood that the foregoing description is that of the preferred embodiments of the invention and that various changes and modifications may be made thereto without departing from the spirit and scope of the invention as defined in the appended claims.
Number | Date | Country | Kind |
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10 2009 011 685.0 | Mar 2009 | DE | national |