Handle system for a handheld power tool

TECHNICAL FIELD

0001The present invention relates to a power driven hand tool comprising a detatchable handle.

0002It also relates to a method for mounting and securing a handle to a power driven hand tool.

BACKGROUND

0003Power driven hand tools, such as, but not limited to, hedge trimmers, sometimes are provided with a handle, which is detachable from a main body of the tool. Further, this handle may also be rotatable with respect to the tool for providing ergonomic working positions in various working environments.

0004Document <patcit id="pcit0001" dnum="US6108867A"><text>US 6 108 867 A</text></patcit> discloses a power tool according to the preamble of claim 1.

0005The current systems for mounting a detachable handle on the power tool usually include some fastening components, such as screws or clips. These small components may easily get lost. Also, the assembly procedure may get time consuming if several fastening components need to be installed during the assembly. Further, fastening components such as screws require the use of a screwdriver or the like. Another problem with such systems is that, as these systems are used with power tools such as hedge trimmers that generate a lot of vibrations, the fastening components may loosen over a period of operating time, and ultimately the fastening components may detach from the tool.

0006There is a need for an improved system for mounting a detachable handle on a handheld power tool, which will overcome the disadvantages of the existing systems.

SUMMARY

0007In view of the above, it is an objective to provide an efficient system for mounting a detachable handle on a power driven hand tool. In particular, an objective is to provide devices and methods for simple and safe mounting of a detachable handle on a power driven hand tool without using external fastening components.

0008This objective is achieved by the invention as defined by claim 1.

0009Since the locking mechanism is automatic, no external fastening means are required. Thereby, the handle can be mounted on the power driven hand tool in a simple and time efficient way.

0010According to claim 2, the first rotational position of the handle relative to the connecting part is a non-operating position. An advantage with this is that a user would not think of operating the tool when the handle is still in its insertion position and thus not locked to the connecting part. Thereby a safe mounting of the handle on the tool is achieved.

0011According to claim 3, the second position of the handle relative to the connecting part is located at one end of a predefined continuous angular range of positions, which comprises one or more operating positions. Thereby, the handle is always locked to the tool before it reaches an operating position.

0012According to claim 4, the one or more operating positions include a central position and the first rotational position is substantially an upside-down position of the handle in relation to the central position and to the connecting part. With this design, it is clear to the user that the insertion position is not a position intended for working with the tool.

0013According to claim 5, the front end of the handle has a substantially tubular shape and is provided with a protrusion extending outwards in a substantially radial direction. Further, the connecting part is provided with a corresponding recess. Also, the recess and the protrusion are arranged in such a way that the protrusion can slide in the recess at insertion of the handle into the connecting part. This makes insertion of the handle into the connecting part simple.

0014According to claim 6, the protrusion and the recess are adapted to restrict the position of the handle to a non-operating position in relation to the connecting part, when it is inserted into the connecting part. This way the user will not be mislead to operating the power driven hand tool when the handle is in its insertion position and not locked to the connecting part.

0015According to claim 7, the recess of the connecting part extends in a substantially axial direction of the connecting part. An advantage with this arrangement is that the handle is easily inserted as it is kept in the same rotational position until it is fully inserted into the connecting part.

0016According to claim 8, the snap locking mechanism is arranged in such a way that the handle can be rotated in the connecting part until the protrusion passes the snap locking mechanism. Further, on passing the snap locking mechanism the handle will reach a predefined continuous angular range of positions which includes one or more possible operating positions. As the handle reaches the range of positions including the operating positions upon passing the snap locking mechanism, it is clearly indicated to the user when the handle has reached this range.

0017According to claim 9, the snap locking mechanism is provided approximately 90° from the central operating position. Since many tools with a rotatable handle have two operating positions of the handle located 90° off the central position (one on each side of the central position), a snap locking mechanism located about 90° from the central position will be close to one of the lateral operating positions.

0018According to claim 10, the power driven hand tool is a hedge trimmer.

0019To solve the problem posed there is provided a method according to claim 11 for assembling a handle and a connecting part of a power driven hand tool according to claims 1 - 10.

0020Since the locking mechanism is automatic, no external fastening means are required. Thereby, the handle can be mounted on the power driven hand tool in a simple and time efficient way.

0021According to claim 12 the first rotational position of the handle relative to the connecting part is a non-operating position. Since the insertion position is not an operating position, the user is not likely to operate the tool when the handle is still in its insertion position and thus not locked to the connecting part. Thereby, a safe mounting of the handle on the tool is achieved.

0022According to claim 13 the second rotational position of the handle relative to the connecting part is located at one end of a predefined continuous angular range of positions, comprising one or more operating positions. Thereby, the handle is always locked to the tool before it reaches an operating position.

0023According to claim 14, the one or more operating positions include a central position and the first rotational position is substantially an upside-down position of the handle in relation to the central position and to the connecting part. With this design, it is clear to the user that the insertion position is not a position intended for working with the tool.

0024According to claim 15, the front end of the handle has a substantially tubular shape and is provided with a protrusion extending outwards in a substantially radial direction. Further, the connecting part is provided with a corresponding recess. Also, the recess and the protrusion are arranged in such a way that the protrusion can slide in the recess at insertion of the handle into the connecting part. This makes insertion of the handle into the connecting part simple.

0025According to claim 16, the protrusion and the recess are adapted to restrict the position of the handle at insertion into the connecting part to a non-operating position in relation to the connecting part. This way the user will not be mislead to operating the power driven hand tool when the handle is in its insertion position and not locked to the connecting part.

0026According to claim 17, the snap locking mechanism is arranged in such a way that the handle after insertion into the connecting part can be rotated in the connecting part such that the protrusion passes the snap locking mechanism. Further, on passing the snap locking mechanism the handle reaches the predefined continuous angular positions, which comprises one or more operating positions. As the handle reaches the range of positions including the operating positions upon passing the snap locking mechanism, it is clearly indicated to the user when the handle has reached this range.

BRIEF DESCRIPTION OF THE DRAWINGS

0027The invention will in the following be described in more detail with reference to the enclosed drawings, wherein: <ul id="ul0001" list-style="none"><li><figref idref="f0001">FIG. 1</figref> illustrates a perspective view of a power driven hand tool, according to an embodiment of the present invention;</li><li><figref idref="f0002">FIG. 2</figref> illustrates a perspective view of a handle and a connecting part as seen from one angle before they are joined together, according to an embodiment of the present invention;</li><li><figref idref="f0003">FIG. 3</figref> illustrates a perspective view of the handle and the connecting part as seen from another angle before they are joined together, according to an embodiment of the present invention;</li><li><figref idref="f0004">FIG. 4</figref> illustrates a perspective view of the handle in a first position, after insertion into the connecting part, according to an embodiment of the present invention;</li><li><figref idref="f0005">FIG. 5</figref> illustrates a perspective view of the handle in a second position, according to an embodiment of the present invention;</li><li><figref idref="f0006">FIG. 6</figref> illustrates a perspective view of the handle in a central position, according to an embodiment of the present invention;</li><li><figref idref="f0007">FIG. 7</figref> is a schematic view illustrating various non-operating and operating positions for the handle mounted on the power driven hand tool, according to an embodiment of the present invention; and</li><li><figref idref="f0008">FIG. 8</figref> is a flowchart illustrating a method for mounting the handle on the power driven hand tool, according to an embodiment of the present invention.</li></ul>

DESCRIPTION OF EMBODIMENTS

0028The present invention will be described more fully hereinafter with reference to the accompanying drawings, in which example embodiments of the invention incorporating one or more aspects of the present invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. For example, one or more aspects of the present invention can be utilized in other embodiments and even other types of devices. In the drawings, like numbers refer to like elements.

0029<figref idref="f0001">FIG. 1</figref> illustrates a perspective view of a power driven hand tool <b>100,</b> according to an embodiment of the present invention. In the exemplary embodiment shown in <figref idref="f0001">FIG. 1</figref>, the power driven hand tool <b>100</b> is a hedge trimmer. However, the present invention may also be used in other equipments such as, but not limited to, shears, chainsaws or other cutting or pruning tools that are provided with a detachable handle, without departing from the essence of the present invention.

0030Further, the power driven hand tool <b>100</b> may include a working member <b>102.</b> The working member <b>102</b> may be a blade, a saw chain or the like. In the embodiment illustrated in <figref idref="f0001">FIG. 1</figref>, the working member <b>102</b> is a cutting blade. The power driven hand tool <b>100</b> may also include a main body <b>104,</b> which in turn may include a housing <b>106</b> and a base portion <b>108.</b> The housing <b>106</b> may further include a drive unit (not shown), such as an engine or an electric motor. The drive unit may drive the working member <b>102</b> of the power driven hand tool <b>100.</b>

0031The power driven hand tool <b>100</b> may further include a handle <b>110.</b> The handle <b>110</b> may be of any shape that provides ergonomic handling of the power driven hand tool <b>100.</b> Further, the handle <b>110</b> may include various controls mounted on it for controlling the working of the power driven hand tool <b>100.</b> The controls may include a throttle control, a mode control, an on/off control and the like. The handle <b>110</b> may be rotatable with respect to the power driven hand tool <b>100</b> for adapting to different working environments. Further, the handle <b>110</b> may be detachable from the power driven hand tool <b>100.</b>

0032In an embodiment of the present invention, a connecting part <b>112</b> may be provided for connecting the handle <b>110</b> with the main body <b>104.</b> The connecting part <b>112</b> may be a separate part fixedly mounted on the main body <b>104</b> or an integral part of the main body <b>104.</b> Further, as illustrated in <figref idref="f0002">FIG. 2</figref>, the connecting part <b>112</b> may have a locking mechanism <b>208</b> for securing the handle <b>110</b> with the connecting part <b>112</b> and the main body <b>104.</b> It may also include a related means for functionally connecting the controls provided on the handle <b>110</b> with the power driven hand tool <b>100.</b>

0033Further, the handle <b>110</b> may have a central position in relation to the power driven hand tool <b>100</b> and to the connecting part <b>112.</b> In <figref idref="f0001">FIG. 1</figref>, the handle <b>110</b> of the power driven hand tool <b>100</b> is positioned in its central position. Here, the central position is a position of the handle <b>110</b> suited for cutting in a substantially horizontal plane.

0034<figref idref="f0002">FIG. 2</figref> illustrates a perspective view of the handle <b>110</b> and the connecting part <b>112</b> as seen from an angle before they are joined together, according to an embodiment of the present invention. The handle <b>110</b> is positioned in an insertion position in relation to the connecting part, referred to as a first rotational position, which in this embodiment is an up-side-down position in relation to the connecting part <b>112.</b> A front end of the handle <b>110</b> may have a tubular shape, and a protrusion <b>202</b> extending outwards in a substantially radial direction. Also, the handle <b>110</b> may have a protruding ring <b>204.</b> Further, the connecting part <b>112</b> may have a tubular shape at an inner side of its rear end, where it is connected to the handle <b>110,</b> and a recess <b>206</b> corresponding to the protrusion <b>202</b> on the handle <b>110.</b> The recess <b>206</b> may extend in a substantially axial direction of the tubularly shaped part of the connecting part <b>112.</b> The recess <b>206</b> and the protrusion <b>202</b> may be arranged in such a way that the protrusion <b>202</b> can slide in the recess <b>206</b> at insertion of the handle <b>110</b> into the connecting part <b>112.</b>

0035In alternative embodiments (not shown), the handle <b>110</b> and the connecting part <b>112</b> may have a plurality of protrusions and a plurality of corresponding recesses respectively. In an embodiment, there may be only one protrusion on the handle <b>110,</b> but either several recesses or one single recess which is wider than the width of the protrusion <b>202,</b> so that several positions of the handle <b>110</b> are possible for insertion into the connecting part <b>112.</b> Also, in an embodiment, the recess or recesses may extend in a direction which is not the axial direction of the tubularly shaped part of the connecting part <b>112.</b> For example, the recess may extend obliquely, so that the handle <b>110</b> is rotated during the insertion into the connecting part <b>112.</b>

0036The locking mechanism provided for securing the handle <b>110</b> to the connecting part <b>112</b> is an automatic locking mechanism and may be a snap locking mechanism <b>208.</b> In a preferred embodiment, illustrated in <figref idref="f0002">FIG. 2</figref>, <figref idref="f0004">4</figref> and <figref idref="f0005">5</figref>, the snap locking mechanism <b>208</b> is located approximately 90° from the central position. In an alternative embodiment, there may be two snap locking mechanisms <b>208</b> of this type, each of them located approximately 90° off the central position on either side of the central position.

0037To achieve a stable connection between the handle <b>110</b> and the connecting part <b>112,</b> the connecting part <b>112</b> may be provided with one or more snap locking mechanisms of a second type, here referred to as snap fasteners <b>210.</b> In an embodiment, as illustrated in <figref idref="f0002">FIG. 2</figref>, the connecting part has one snap fastener <b>210</b> which is located 180° from the recess <b>206.</b> Further, the snap fastener <b>210</b> may indicate that the handle <b>110</b> has been inserted far enough into the connecting part to be rotated inside the connecting part.

0038<figref idref="f0003">FIG. 3</figref> illustrates another perspective view of the handle <b>110</b> and the connecting part <b>112</b> as seen from an angle before they are joined together. The power driven hand tool <b>100</b> may have to be used in a variety of different operating areas and held at a plurality of different angles. Hence, the handle <b>110</b> of the power driven hand tool <b>100</b> may have to be adapted to be rotated. This figure illustrates different rotational positions <b>302, 304, 306, 308</b> and <b>310</b> of the handle <b>110</b> in relation to the connecting part <b>112,</b> in which the power driven hand tool <b>100</b> can be operated. For the locking in a selected rotational position a latch device is normally provided. The latch device is not shown in the figures and will not be further described.

0039<figref idref="f0004">FIG. 4</figref> illustrates a perspective view of the handle <b>110</b> and the connecting part <b>112</b> where the connecting part is seen mainly from the bottom side of it to clearly illustrate the locking mechanism <b>208.</b> The handle <b>110</b> is positioned in a first rotational position in relation to the connecting part <b>112</b> (and to the power driven hand tool <b>100</b>) after insertion into the connecting part <b>112.</b>

0040The first rotational position is a position, in which the protrusion <b>202</b> can enter the recess <b>206</b> and the tubular part of the handle <b>110</b> can be inserted into the connecting part <b>112.</b> In a preferred embodiment of the present invention, the first rotational position is a non-operating position, i.e. a position which is not intended for operation of the power driven hand tool <b>100.</b> The protrusion <b>202</b> and the recess <b>206</b> are adapted to restrict the rotational position of the handle <b>110</b> at insertion into the connecting part <b>112</b> to a non-operating position. In an embodiment of the present invention, the first, non-operational, rotational position may be substantially an upside-down position of the handle <b>110</b> with respect to the central position and to the connecting part <b>112.</b> In this position the handle <b>110</b> does not provide an ergonomic grip for operating the power driven hand tool <b>100</b> and the user is not likely to start operating the power driven hand tool <b>100</b> in this position.

0041In an alternative embodiment of the present invention, the first, non-operating, rotational position may be one of a plurality of non-operating positions in which the handle <b>110</b> can be inserted into the connecting part <b>112.</b> This may be achieved (as described above) by either providing several recesses <b>206</b> on the connecting part <b>112</b> or providing one recess <b>206</b> which is wide enough to provide a range of different non-operating positions.

0042<figref idref="f0005">FIG. 5</figref> illustrates a perspective view of the handle <b>110</b> in a second position in relation to the connecting part <b>112</b> (and to the power driven hand tool <b>100</b>) after it has been inserted into and rotated in the connecting part <b>112,</b> according to an embodiment of the present invention. The second rotational position is the position, in which the handle <b>110</b> can be locked to the connecting part <b>112</b> by means of the automatic snap locking mechanism <b>208.</b> In a preferred embodiment, the second rotational position is located at the end of a predefined range of positions of the handle including one or more operating positions, i.e. positions which are intended for operation of the power driven hand tool <b>100.</b> The handle <b>110</b> reaches this predefined range of positions when the handle <b>110</b> has been rotated from the initial non-operating position to a position where the protrusion <b>202</b> has passed the snap locking mechanism <b>208.</b> In the embodiment of <figref idref="f0005">FIG. 5</figref>, the second rotational position is located approximately 90° from the initial non-operating position.

0043In the illustrated embodiment, where there are two lateral operating positions located approximately 90° from the central position, the second position may be very close to or essentially the same as one of the lateral positions

0044In one embodiment, the plurality of operating positions correspond to the rotational positions <b>302, 304, 306, 308</b> and <b>310</b> illustrated in <figref idref="f0003">FIG. 3</figref>. In an alternative embodiment, the handle <b>110,</b> on reaching the snap locking mechanism <b>208,</b> may have to further traverse a predetermined rotational distance to reach the predefined continuous angular range of positions.

0045<figref idref="f0006">FIG. 6</figref> illustrates a perspective view of the handle <b>110</b> in the central position in relation to the connecting part <b>112</b> (and to the power driven hand tool <b>100</b>) after it has been inserted into the connecting part <b>112</b> and rotated approximately 180°. In an embodiment, this central position is one of the plurality of operating positions located within the predefined continuous angular range of positions. Further, at least one operating position may be present on either side of the central position, located approximately 90° from the central position, and adapted for performing the operation of the power driven hand tool <b>100</b> in a substantially vertical plane. The central position is adapted for performing the operation of the power driven hand tool <b>100</b> in a substantially horizontal plane.

0046The different arrangements of various possible operating and non-operating positions will be further explained in conjunction with <figref idref="f0007">FIG. 7</figref>.

0047For removing the handle <b>110</b> from the connecting part <b>112</b> a tool, such as a screw driver or the like, may be needed. By means of the tool the snap locking mechanism <b>208</b> may be adjusted for enabling the protrusion <b>202</b> to be rotated back past the snap locking mechanism <b>208.</b> Similarly, the tool may be used for adjusting the snap fastener <b>210</b> for enabling the protruding ring <b>204</b> to be slipped past the snap fastener <b>210</b> and out of the connecting part.

0048This type of assembly eliminates the need for external fastening components such as, screws, and also enables the operation of the power driven hand tool <b>100</b> only when the handle <b>110</b> is properly secured on the power driven hand tool <b>100.</b>

0049<figref idref="f0007">FIG. 7</figref> is a scheme for illustrating various non-operating and operating positions of the handle <b>110</b> in relation to the connecting part <b>112</b> (and to the power driven hand tool <b>100</b>), according to an embodiment of the present invention. The power driven hand tool <b>100</b> may have a continuous range of non-operating positions <b>702,</b> in which one non-operating position <b>704</b> is a preferred position for insertion of the handle <b>110</b> into the connecting part <b>112.</b> The range of non-operating positions <b>702</b> may have an angular size of approximately 180°.

0050In the illustrated embodiment, the non-operating position <b>704,</b> i.e. the first rotational position of the handle in relation to the connecting part <b>112,</b> is substantially an upside-down position in relation to the central position <b>714.</b>

0051In an embodiment of the present invention, there may be a predefined continuous angular range of positions <b>708</b> including one or more operating positions, which can be reached by rotating the handle <b>110</b> inside the connecting part <b>112</b> from the first rotational position and such that the protrusion <b>202</b> passes the snap locking mechanism <b>208.</b> In a preferred embodiment, the handle needs to be rotated approximately 90° from the first rotational position for the protrusion <b>202</b> to pass the snap locking mechanism <b>208.</b> The continuous angular range of positions <b>708</b> includes a plurality of operating positions <b>710, 712, 714, 716</b> and <b>718</b> that correspond to rotational positions <b>302, 304, 306, 308</b> and <b>310.</b> In an embodiment of the present invention, the predefined continuous angular range of positions <b>708</b> has an angular size of approximately 180°.

0052<figref idref="f0008">FIG. 8</figref> is a flowchart illustrating a method <b>800</b> for mounting and securing the handle <b>110</b> on the power driven hand tool <b>100,</b> according to an embodiment of the present invention. As explained in previous figures, the connecting part <b>112</b> may be provided for connecting the handle <b>110</b> with the main body <b>104</b> of the power driven hand tool <b>100.</b> In an embodiment of the present invention, the front end of the handle <b>110</b> may have a tubular shape and a protrusion <b>202,</b> extending in a substantially radial direction. Further, the connecting part <b>112</b> may have a tubular shape at the inner side of its rear end, where it is connected to the handle <b>110,</b> and the recess <b>206</b> corresponding to the protrusion <b>202</b> on the handle <b>110.</b> The recess <b>206</b> may extend in a substantially axial direction of the tube shaped part of the connecting part <b>112.</b> The recess <b>206</b> and the protrusion <b>202</b> are arranged in such a way that the protrusion <b>202</b> may slide in the recess <b>206</b> at insertion of the handle <b>110</b> into the connecting part <b>112.</b>

0053In step <b>802,</b> the front end of the handle <b>110</b> is inserted into the rear end of the connecting part <b>112,</b> in a first rotational position in relation to the connecting part <b>112</b> (and to the power driven hand tool <b>100</b>). The first rotational position is a position, in which the protrusion <b>202</b> can enter the recess <b>206</b> and the tube shaped part of the handle <b>110</b> can be inserted into the connecting part <b>112.</b> In a preferred embodiment of the present invention, the first rotational position is a non-operational position <b>704</b> of the handle <b>110,</b> i.e. a position which is not intended for operation of the power driven hand tool <b>100.</b> Further, there may be a plurality of non-operating positions suitable for insertion of the handle <b>110</b> into the connecting part <b>112.</b> The protrusion <b>202</b> and the recess <b>206</b> are adapted to restrict the rotational position of the handle <b>110</b> at insertion into the connecting part <b>112,</b> to a non-operating position <b>704.</b> In an embodiment of the present invention, the first, non-operating, rotational position may be substantially an upside-down position of the handle <b>110</b> with respect to the central position.

0054Further, in step <b>804</b> the handle <b>110</b> may be rotated into the second rotational position in relation to the connecting part <b>112</b> (and to the power driven hand tool <b>100</b>). The second rotational position is the position, in which the handle <b>110</b> is locked to the connecting part <b>112</b> by means of an automatic locking mechanism. In a preferred embodiment of the present invention, the automatic locking mechanism is a snap locking mechanism <b>208.</b> Further, the second rotational position of the handle <b>110</b> is located at one end of a continuous angular range of positions <b>708.</b> The continuous angular range of positions <b>708</b> include one or more operating positions. In an embodiment of the present invention, the one or more operating positions <b>710, 712, 714, 716</b> and <b>718</b> may include the central position.

0055In an embodiment of the present invention, the snap locking mechanism <b>208</b> is arranged in such a way that the handle <b>110</b> can be rotated inside the connecting part <b>112,</b> such that the protrusion <b>202</b> on the handle <b>110</b> passes the snap locking mechanism <b>208</b> and reaches the continuous angular range of positions <b>708,</b> from the initial non-operating position.

0056Though the above mentioned invention explains the working with respect to a hedge trimmer, a person skilled in the art may know that such a system may be easily implemented on other tools like, but not limited to, chainsaws.

0057In the drawings and specification, there have been disclosed preferred embodiments and examples of the invention and, although specific terms are employed, they are used in a generic and descriptive sense only and not for the purpose of limitation, the scope of the invention being set forth in the following claims.