Hand tool device with damper

p0001The invention relates to a power tool having an outer housing, a drive, a percussion, two anti-vibration handles, each having a support element, a longitudinal axis and a bearing portion at a first end portion having, and with two extending at an angle to the longitudinal axis of the handle handle mounting axes, respectively are at least in areas covered by the bearing portion of a handle, a Dämpfhülse of an elastic material is provided as the first damping member between the bearing portion of the handle and the handle attachment axis.

p0002Big hand tool device with percussion, such as heavy electrically or pneumatically operated chisel hammers and demolition hammers are dropped often and hit it on the ground or underground. The energy of impact may need to be completely absorbed by the power tool on the handles. This results in high case forces or for a longer period of use of the power tool for damage or even fractures of individual components of the power tool. To protect the user from the generated during operation of the power tool vibration, it is known to form the handles vibration damping.

p0003From the <patcit id="pcit0001" dnum="US3824417A"><text>US 3,824,417 A</text></patcit> is a hand tool having an outer housing, an electric drive, a percussion and two vibration-damped handles known which are mounted with vibration damping in a first plane and steamed in a second, perpendicular to the first plane extending plane against shocks. The handles each have a support member, a longitudinal axis and two bearing portions at a first end. In the hand tool are in each case two, are provided perpendicularly to the longitudinal axes of the handles and parallel to one another handle mounting axes per handle, which are covered by the bearing portion of the handles. Between the handle mounting shaft and the sleeve-shaped bearing portions a sleeve-shaped damping element is provided made of elastic material, respectively.

p0004A disadvantage of the known solution is that the force applied to the hand tool when you drop energy can be substantially reduced only to the bearing point of the handles. In order to ensure sufficient guidance, in particular for heavy hand power tools also during operation, the storage of the handles must have a sufficient stability. For larger forces the sleeve-shaped damping element therefore is not enough for a sufficient degradation or conversion of the incident energy, which can lead to damage to individual components of the power tool.

p0005The object of the invention is to provide a power tool with vibration-damped handles, the hand tool has a high resistance to damage as a result of falling of the power tool.

p0006The object is achieved by the features of the independent claims. Advantageous developments are set forth in the dependent claims.

p0007According to the invention a damping body provided as a second damping member at the free, opposite the first end region of the handle end, wherein the damping body comprises, based on the longitudinal axis of the handle has an extension in the radial direction which is greater than the minimum radial extent of the handle at the free end is.

p0008When you drop the power tool on the handles much of the impact energy of the damping body is received. The radially peripheral portion which is present due to the greater radial extent of the Dämpfkörpers relative to the radial extension of the handle, is deformed during the impact of the power tool. This 60% to 80% of the impact energy eliminated by this damping body. The Dämpfhülse between the bearing portion of the handle and the handle mounting axis destroyed the bulk of the remaining still acting on the hand tool impact energy. By created by the first and second damping multistage damping the individual components are exposed to much lower forces during drop of the power tool, as it is the case with conventional hand tool devices with essentially only anti-vibration handles. the damping body is advantageously made of an elastomer. Further, the damping body may be formed as a buffer member with a fastener, comprising for example a metal part and a metal part connected to the elastic element. Via the fastening means, the buffer member on the support member can be fixed.

p0009Also, the support members of the handles themselves no longer need to compensate for high impact forces, which substantially prolongs their suitability for use and the manufacturing cost of the handles significantly reduced.

p0010Preferably corresponds to the radial extent of Dämpfkörpers the 1.05 times to 1.8 times, particularly advantageous to 1.2 times to 1.5 times, the minimum radial extent of the handle at its free end, which a sufficiently large radial circumferential, easily deformable bulbous section the Dämpfkörpers forms.

p0011Preferably, the z. B. metal-made support member of the handle is at least regionally surrounded by a grip sleeve made of an elastic material as a third damping member, said sleeve surrounds the free end of the support element of the handle at least in regions and the damping body is adjoined by the handle. the grip sleeve of a Nitrilbutylrubber (NBR) is advantageously fabricated. Alternatively, a natural rubber (NR) or polyamide (PA) is used for the production of the grip sleeve. When falling of the power tool, a part of the remaining, still existing impact energy is absorbed by the support element of the handle and the part of the grip sleeve, which is provided between the damping body to the free end of the handle and the free end of the support element. Thus, the multi-stage damping device in a further stage, which reduces the still absorbed in the interior of the power tool impact energy again.

p0012Preferably, the grip sleeve is made of two materials, wherein the the supporting member facing material has a lower elasticity than the side facing away from the support element material. For example, the support element facing material is a hard plastic, which ensures the stability of the grip sleeve, and that the support element facing away material is a soft plastic, which ensures a sufficient grip of the handle. The materials are chosen such that they can deform under load and thus destroy a portion of the impact energy.

p0013Preferably, the handles are each pivotably mounted about a mounting axis, the handle pivot axis forming in the hand tool and a stop member formed of an elastic material, it is for limiting the pivotability of the handles provided as a fourth damping. the stop element of a Nitrilbutylrubber (NBR) is advantageously fabricated. A Dämpfhülse each is provided as the first damping member between the pivot axis and the bearing portion of the handle. The stop member forms a further damping to eliminate the impact forces, which ensures an advantageous Tip-Over of the power tool. By pivoting, the handles on a high vibration damping, at the same time the most Dämpfhülse still can absorb impact energy absorbed.

p0014Preferably an insert element made of an elastic material is provided as a fifth damping member between a radially projecting collar portion of the handle and the outer housing. the insert element of a Nitrilbutylrubber (NBR) is advantageously fabricated. The insert element further improves the damping properties of the multi-stage damping.

p0015The invention is illustrated below with reference to an embodiment. Show it:<dl id="dl0001"><dt>Fig. 1</dt><dd>An inventive power tool with partial cuts; and</dd><dt>FIG. 2</dt><dd>a detailed section of a handle according to detail II in <figref idrefs="f0001">Fig. 1</figref>,</dd></dl>

p0016Basically, the same parts with the same reference numerals in the figures.

p0017The in <figref idrefs="f0001">figures 1</figref> and <figref idrefs="f0002">2</figref> illustrated hand tool 11 in the form of a heavy chisel hammer has an outer housing 12, a drive 13, a percussion mechanism 14 and two vibration-dampened handles 21st The drive 13 includes, for. Example, an engine and a transmission for operation of the hammer mechanism 14. At the free end of the percussion mechanism 14, a tool holder 15 is provided for a tool not shown here.

p0018Each handle 21 has respectively a supporting member 22 made of steel, a longitudinal axis 23 and a bearing portion 24 at a first end portion 25th In the hand-held tool 11 has two perpendicular to the longitudinal axis 23 of the handle 21 and parallel to one another handle mounting shafts 30 are provided which are each surrounded with a bearing portion 24 of a handle 21st The handles 21 are each pivotally supported about a pivot axis in the power tool 11, wherein the respective pivot axis is formed by the handle mounting axis 30th Between the bearing portion 24 of the handle 21 and the handle mounting axis 30, a Dämpfhülse 31 is provided made of an elastic material as the first damping member. In the hand tool device 11 a stop member 46 is provided for limiting the pivotability of the handles 21 of an elastic material as a fourth damping. The handles 21 have the first end region 25 to be brought with the stopper member 46 in contact contour.

p0019At the free, the first end portion 25 of the handle 21 opposite end 26 is a dampening body 36 is provided as a second buffer member, which on the longitudinal axis 23 of the handle 21 has an extension D comprising, based in the radial direction which is greater than the corresponding extension T of the handle 21 at is the free end of the 26th The radial extension D of the Dämpfkörpers 36 corresponds to from about the 1.2- to 1.5-times the minimum radial extension T of the handle 21 at the free end 26 to form a circumferential bead.

p0020The supporting element 22 of the handle 21 is in regions 41 surrounded by a grip sleeve made of an elastic material as a third damping member, wherein the grip sleeve 41, the free end of the support element 22 of the handle 21 surrounding regions, and the damping body 36 is adjoined by the grip sleeve 41st The gripping sleeve 41 is made of two materials, wherein the the supporting member 22 facing material has a lower elasticity than the side facing away from the supporting element 22 material. The damping body 36 is fixed by means of an engaging into the support element 22 of the handle 21 the fastening means 37, for. Example in the form of a screw. Advantageously, the fastening means 37 at one end a broadening, such as a screw head. of the shaft on, for example, a screw head. and it is a steel sleeve 38 is provided between this broadening of the fastener 37 and the free end of the support element 22 for an advantageous introduction of a portion of the impact energy in the support element 22nd

p0021Next 27 of the handle 21 and the outer casing 12 is an insert element 51 is provided made of an elastic material as a fifth damping member between a radially protruding collar portion.

p0022The individual damping elements together form a multi-stage damping for the hand tool 11, which forms a high Tip-Over, ensuring a high protection against damage of the power tool 11th Here an advantageous damping of vibrations generated by the power tool is still provided.