The instant application should be granted the priority date of May 11, 2007, the filing date of the corresponding German patent application DE 10 2007 022 155.2.
The present invention relates to a manually guided implement, such as a power saw, a cut-off machine, or the like.
With manually guided implements, it is known to mount the drive motor in such a way that it is vibration-neutralized from the handles that serve to guide the implement. It is also known to use anti-vibration elements that include coil springs. Anti-vibration elements having a coil spring result in a good vibration dampening. Anti-vibration elements that include a coil spring are customarily horizontally disposed, as viewed in the working direction, between the drive motor and the handle. Such an arrangement of the anti-vibration elements is known, for example, from U.S. Pat. No. 7,219,433.
During operation, handle and drive motor carry out relative movements in the plane perpendicular to the longitudinal axis of the anti-vibration elements. In this direction, coil springs can be loaded to only a limited extent. For this reason, stops or abutments must be additionally provided for limiting the relative movements in this direction.
It is therefore an object of the present invention to provide a manually guided implement of the aforementioned general type that has a straightforward construction.
This object, and other objects and advantages of the present invention, will appear more clearly from the following specification in conjunction with the accompanying schematic drawings, in which:
The manually guided implement of the present application comprises a drive motor for driving a tool of the implement, wherein the drive motor is provided with a drive shaft that is rotatably driven about an axis of rotation; a handle on which is disposed at least one control element for the drive motor, wherein the implement has an imaginary longitudinal plane that extends perpendicular to the axis of rotation and a longitudinal axis of the handle is disposed in the longitudinal plane, and wherein the implement has an imaginary transverse plane that extends perpendicular to the longitudinal plane and the axis of rotation of the drive shaft is disposed in the transverse plane; at least one anti-vibration element, wherein a vibration space is formed between the handle and the drive motor and is spanned by the anti-vibration element, and wherein at least one of the anti-vibration elements includes a coil spring having a longitudinal axis that extends approximately perpendicular to the imaginary longitudinal plane of the implement; and at least one connecting element having a longitudinal axis that is inclined relative to the imaginary transverse plane of the implement, wherein the vibration space is spanned by the connecting element.
The connecting element of the implement of the present application delimits the relative movements between drive motor and handle in a straightforward manner. Consequently, an impermissible movement of the anti-vibration elements transverse to their longitudinal direction is easily avoided. In particular when the connecting element is embodied as an anti-vibration element, the inclined arrangement of the longitudinal axis of the connecting element results in a good vibration dampening of the entire system. At the same time, the connecting element can be easily integrated into the existing installation space, resulting in a small overall size of the implement.
The longitudinal axis of the connecting element is the axis that connects the two securement points of the connecting element. For an anti-vibration element having a coil spring, the longitudinal axis is the longitudinal central axis of the coil spring, in other words, the axis about which the coils of the coil spring are wound.
The angle between the longitudinal axes of the connecting element and of the transverse plane is advantageously less than 80°. The angle is in particular less than 60°, and is advantageously from about 10° to about 45°. With this arrangement, good vibration dampening characteristics of the implement result especially if the connecting element includes an anti-vibration element. At the same time, the relative movement of drive motor and handle transverse to the longitudinal axis of the horizontally disposed anti-vibration element is easily limited.
The handle is advantageously a rear handle, and the connecting element is advantageously disposed on that side of the transverse plane that faces the rear handle. The operator introduces a greatest part of the operating forces via the rear handle. In particular if the implement is a power saw, during operation, to carry out a back hand cut, pressure is applied to the rear handle and a tubular handle of the implement is pulled. These forces counteract the cutting forces on the tool. As a result, the rear handle moves downwardly relative to the drive motor and thus expands or widens the vibration space. This relative movement is limited by the connecting element. Due to the fact that the connecting element is disposed on that side of the transverse plane that faces the rear handle, there results an arrangement of the connecting element in the region of the greatest relative movement.
The implement advantageously includes a housing in which the drive motor is disposed. A first end of the connecting element is in particular connected with the handle while the second end is connected with the housing of the implement. The connecting element is thus connected with the drive motor that is disposed in the housing via the housing. The implement can have a tubular handle for guiding the implement; the tubular handle extends over the housing adjacent to a front end of the housing that faces the tool. The tubular handle and the rear handle portion of a handle housing of the implement are advantageously securely connected to one another, especially by being screwed together. The implement is accordingly composed of a handle housing and a housing in which the drive motor is disposed. These two housings are interconnected via anti-vibration elements and the connecting element in a vibration-neutralized manner. The first end of the connecting element is advantageously secured to the handle housing in a region between the tubular handle and the rear handle.
To achieve a good vibration dampening, at least two anti-vibration elements are disposed perpendicular to the longitudinal plane of the implement, whereby a first anti-vibration element is disposed adjacent to the front end of the tubular handle, and one end of a second anti-vibration element is secured to the tubular handle. A straightforward construction of the implement, with good vibration dampening characteristics, results if the connecting element is embodied as an anti-vibration element. The anti-vibration element that is formed as the connecting element is consequently not disposed horizontally, in other words perpendicular to the longitudinal plane, but rather is disposed at an angle. In this way good vibration dampening characteristics can be achieved, while at the same time achieving a limitation of the transverse load of the two horizontally disposed anti-vibration elements. Good vibration dampening characteristics result in particular if the first end of the anti-vibration element that forms the connecting element is secured to the handle housing further from the transverse plane than is the second end, which is secured to the housing. Thus, the upwardly facing side of the anti-vibration element, in the customary disposition of the implement, is inclined toward the front. As a result, the forces that occur during operation can be effectively absorbed. In addition, the installation space that is available can be well utilized.
Good dampening characteristics result in particular if the anti-vibration element that forms the connecting element includes a coil spring.
The connecting element can include means to protect against over extension. Such means delimit the path that the housing and handle housing can travel relative to one another. The means to protect against over extension is advantageously disposed in the interior of the coil spring of an anti-vibration element that forms the connecting element. The connecting element thus includes not only an anti-vibration element but also a means to protect against over extension. However, it would also be possible for the connecting element to be formed only by an anti-vibration element, in other words, in particular only by a coil spring. The coil spring also delimits the path of travel between housing and handle housing. Due to the spring characteristics of the anti-vibration element, there results a soft delimitation, since the path is a function of the active force, and at greater acting forces a greater relative movement is possible. In contrast, the means to protect against over extension represents an absolute delimitation of the relative path independent of the forces that are active. The connecting element is advantageously embodied as a separate means to protect against over extension, and includes a safety cable. Where the connecting element is embodied as a separate means to protect against over extension, it would also be possible to provide an arrangement where the connecting element is not inclined relative to the transverse plane of the implement. The safety cable delimits the possible maximum relative path in a straightforward manner.
The safety cable is advantageously disposed at least partially in the direction of the operating force that during operation acts on the rear handle. The safety cable is advantageously oriented in the direction of the operating force. The safety cable is expediently made of polymeric material, in particular aramid. For a simple securement of the safety cable, a connection fitting can be provided at each end of the safety cable. The connection fittings are advantageously made of polymeric material and are extruded or injected on the safety cable. A reliable securement results when the polymeric material of the connection fitting is molded about the safety cable.
A first receiving means for the first connection fitting of the safety cable is advantageously formed on the handle housing, and a second receiving means for the second connection fitting of the safety cable is advantageously formed on the housing. A straightforward mounting of the means to protect against over extension is possible if the first connection fitting is cylindrical and the second connection fitting has a multi-sided cross-section, whereby the diameter of the first connection fitting is less than the smallest diameter of the multiple sides of the second connection fitting. The multi-sided cross-section of the second connection fitting ensures that the safety cable cannot twist during operation. Due to the fact that the first connection fitting has a smaller diameter than the smallest diameter of the second connection fitting, the first connection fitting can be inserted through the receiving means of the second connection fitting and can be fixed in the receiving means for the first connection fitting. This results in a straightforward and reliable fixation of the means to protect against over extension.
Further specific features of the present invention will be described in detail subsequently.
Referring now to the drawings in detail, as an exemplary embodiment for a manually-guided implement,
A rear handle 3 and a tubular handle 5 are provided for guiding the power saw 1. The tubular handle 5 extends over the housing 2 of the power saw 1 adjacent to the front end 39. The rear handle 3 extends from the back end 40 of the housing 2, which is disposed remote or facing away from the front end 39. A control element 38 for the drive motor 9 is disposed on the rear handle 3. The control element 38 is embodied as a throttle trigger. The rear handle 3 is rigidly connected with the tubular handle 5 and together with the tubular handle forms a handle housing 21. The handle housing 21 is mounted in a vibration-neutralized manner relative to the housing 2, which has the drive motor 9. For this purpose, anti-vibration elements 15, 16 and 17 are provided that each have one end secured to the handle housing 21 and the other end secured to the housing 2 or to the drive motor 9. A vibration gap or space 14 is formed between the handle housing 21 and the housing 2, and is bridged or spanned by the anti-vibration elements 15, 16, 17. To distinguish the assemblies that are movable relative to one another, in
The rear handle 3 has a longitudinal axis 4 that extends parallel to the plane of the guide bar 6 and that in the position of the power saw 1 shown in
As shown in
A second anti-vibration element 16 extends between the tubular handle 5 and the drive motor 9, and is secured in an upper region of the drive motor 9. The second anti-vibration element 16 has a longitudinal axis 19 that extends parallel to the longitudinal axis 18 of the first anti-vibration element 15, parallel to the transverse plane 13, and perpendicular to the longitudinal plane 60. Thus, in the position of the power saw 1 shown in
A third anti-vibration element 17, as a connecting element, is provided between the handle housing 21 and the housing 2. The third anti-vibration element 17 has a first end 22 that is secured to the handle housing 21 in a region between the rear handle 3 and the tubular handle 5. A second end 23 of the third anti-vibration element 17 is fixed on the housing 2. The third anti-vibration element 17 has a longitudinal axis 20, which is inclined relative to the transverse plane 13. As shown in
As shown in
As shown in
As shown in
The forces that act upon the power saw 1 during operation are schematically illustrated in
The third anti-vibration element 17 and the means 32 to protect against over extension are disposed in that region of the vibration space 14 in which the relative movement between the rear handle 3 and the housing 2 is the greatest. The third anti-vibration element 17 is disposed on that side of the transverse plane 13 that faces the rear handle 3 in a region, as viewed in the direction of the longitudinal central axis 12, that is disposed between the rear handle 3 and the tubular handle 5. As a result, the third anti-vibration element 17 delimits the relative movements between housing 2 and rear handle 3.
The third anti-vibration element 45 can, as can also the two anti-vibration elements 15 and 16, also have a means to protect against over extension that corresponds to the means 32 to protect against over extension of the third anti-vibration element 17 of the power saw 1 as shown in
The means 42 to protect against over extension, and the third anti-vibration element 45, are shown in
The second connection fitting 49 is disposed in a receiving means 54 on the housing 2. As shown in
The specification incorporates by reference the disclosure of German priority document DE 10 2007 022 115.2 filed May 11, 2007.
The present invention is, of course, in no way restricted to the specific disclosure of the specification and drawings, but also encompasses any modifications within the scope of the appended claims.
Number | Date | Country | Kind |
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10 2007 022 115.2 | May 2007 | DE | national |