Backpack type operating unit

Abstract: Disclosed is a backpack type operating unit, which includes a backpack frame having a front portion and a left lateral side portion, an operating device and a motive power source for driving the operating device. The motive power source and the operating device is mounted on the backpack frame, and the front portion of the backpack frame faces toward a forward direction and the left lateral side portion facing toward a leftward direction, in which the forward direction and the leftward direction are perpendicular to each other and lying in a common horizontal plane. The operating unit comprises a supporting member mounted on the left lateral side portion of the backpack frame, a substantially longitudinal arm having two opposite end portions, the arm being pivotably mounted on the supporting member at one of the end portions so that the arm can be pivoted between a first pivotal position in which the arm points vertically upward with respect to the horizontal plane and a second pivotal position in which the arm points toward an inclined direction between the forward direction and the leftward direction, and mechanism provided on the arm for operating the motive power source.

Description: BACKGROUND OF THE INVENTION Field of the Invention This invention relates to a backpack type operating unit, more particularly to a backpack type operating unit having an operating device such as a chemical dispersion device, a blower or the like and a motive power source for driving the operating device such as an engine, both of which are mounted on a backpack frame. Description of the Prior Art One example of the conventional backpack type operating units having an operating device and an engine power is illustrated in U.S. Patent No. 4,552,100, in which the operating unit is provided with an arm having a throttle lever on its end for operating the engine. This arm is pivotably supported on a support member which is secured to the left lateral side of the operating unit so that the arm can be pivoted on a vertical plane at the left lateral side of the operating unit. According to the conventional unit, when operating the operating unit, the arm is pivoted forward on the plane so as to point straight toward the forward direction of the unit. On the other hand, when the operating unit is housed, the arm is pivoted on the plane so as to point vertically and upwardly. However, according to the conventional operating unit, when the arm points straight toward the forward direction of the unit, it extends along the side of an operator. As a result, the arm is liable to strike the body of the operator, depending on the type of operation and the physical characteristics of the operator, which results in the inconvenience during the operation of the unit. To solve this problem, an improved operating unit as disclosed in Laid Open Japanese Patent Application No. 64-28972 has been proposed. In the proposed operating unit, a mounting surface of the arm is faced toward a direction inclined downwardly and rearwardly with respect to the leftward direction of the operating unit in such a manner that the arm is rotated on a plane inclined with respect to the vertical plane generated at the lateral side of the operating unit. As a result, when the arm is pivoted forward to the front pivotal position, it points toward a direction inclined leftwardly with respect to the forward direction of the operating unit, that is, it extends toward a direction far from the operator, so that the arm rarely contacts with the body of the operator during the operation. However, in the proposed operating unit, the arm is inclined-outwardly not only at the front pivotal position but also at the upper pivotal position. Namely, even when the arm is pivoted upwardly, it is inclined outwardly with respect to the operating unit. This means that when the arm is pivoted upward to the operating unit, the arm remains being outwardly protruded. Consequently, the arm is likely to be damaged if it comes into contact with surroundings. Therefore, this outward inclination of the arm at the upper pivotal position is undesirable. Further, since the mounting surface of the arm is faced toward the direction as described above, that is, downwardly and rearwardly, a process of manufacturing a die of the arm is complicated. SUMMARY OF THE INVENTION An object of the present invention is to provide, with due consideration to the problems of such conventional apparatuses, a backpack type operating unit in which the arm points toward a direction inclined outwardly from the operator with respect to the forward direction of the operating unit at the front pivotal position during the operation, and when being stored or transported, the arm is pivoted so as to point vertically and upwardly in parallel with the side edge of the backpack frame. This object is achieved in the present invention by a backpack type operating unit as defined in claim 1. BRIEF DESCRIPTION OF THE DRAWINGS The features and advantages of the backpack type operating unit according to the present invention over the proposed backpack type operating unit will be more clearly understood from the following description of a preferred embodiment of the present invention taken in conjunction with the accompanying drawings in which: Fig. 1 is a side view of the embodiment of the backpack type operating unit according to the present invention. Fig. 2 is a side view showing the vertical position of the arm of the embodiment. Fig. 3 is a sectional plan view showing the forward position of the arm of the embodiment. DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT Referring now to the drawings, a preferred embodiment of the backpack type operating unit according to the present invention will be described. Figs. 1 to 3 show a backpack type operating unit of the present invention. As shown in the drawings, a backpack type operating unit 1 has the following configuration. Specifically, an operating device 2 (in this embodiment, a chemical dispersion device) is mounted on a backpack frame 3 of synthetic resin which has a horizontal portion 3a and a vertical portion 3b including a front portion 3f. The front portion 3f faces a forward direction when the unit is used. The operating unit 1 is provided with a fan casing 5 which incorporates a blowing fan, and a fuel tank 7. An engine 9 is mounted on the rear surface of the fan casing 5. A starting motor 8 for starting the engine 9 is provided on the rear portion of the engine 9. A chemical tank 11 is mounted on the top of the fan casing 5. An air tube 15 is connected to an air port 13 on the lower portion of the fan casing 5. The backpack frame 3 has a back contact pad 17 mounted on a front side of the vertical portion 3b of the backpack frame 3. A pair of backpack bands 19 are attached to the backpack frame 3 as shown in Fig. 1. During operation of the unit 1, an operator bears the operating unit 1 on his back under the condition that the front surface of the back contact pad 17 contacts with his back and each of the backpack bands 19 turns over his each shoulder. The vertical portion 3b of the backpack frame 3 has a lateral side portion facing toward a leftward direction of the operating unit 1, that is the leftward direction of the operator. The forward and leftward directions lie in the same horizontal plane, and are perpendicular with each other. On the lateral side portion of the vertical portion of the backpack frame 3, a support member 23 is mounted by screws 21. As shown in Fig. 3, a hollow section 24 is formed in the support member 23. A mounting surface 25 is defined on the support member 23. The mounting surface 25 is faced toward a direction inclined rearwardly at a predetermined angle with respect to the leftward direction of the operating unit 1. In other words, the mounting surface 25 is faced to the direction between the leftward and rearward directions of the operating unit 1. An arm 27 is pivotably mounted on the mounting surface 25 at the base portion thereof by means of a bolt 29 which penetrates the base portion and the mounting surface 25 perpendicularly to extend into the hollow section 24. The axis of the bolt 29 is extends horizontally to the direction between the leftward and rearward directions of the operating unit, which is the same direction as the direction of the mounting surface 25. The longitudinal axis of the arm 27 is directed perpendicular to the axis of the bolt 29 which constitutes the pivotal axis of the arm 27. A ring 30 is fitted on the tip portion of the bolt 29 in the hollow section 24. A spring 31 is provided onto the bolt 29 between the back surface of the mounting surface of the support member 23 and the ring 30. The arm 27 is pressed at a preset pressure against the mounting surface 25 by the biasing force of the spring 31. A projection 32a is provided on the mounting surface 25. An arc-shaped groove 32b engageable with the projection 32a is provided on an end surface 28 of the arm 27. The projection 32a is fitted in the groove 32b when the arm 27 is mounted to the mounting surface 25 to restrict the pivotal angle of the arm 27 relative to the support member 23. According to the above construction, the arm 27 is pivoted with respect to the axis of the bolt 29 on a plane including the plane of the mounting surface 25. As a result, when the arm is pivoted upward, the arm 27 points vertically upward as shown in Figs. 1 and 2, and the operating unit 1 is housed or transported in this condition. When the unit is operated, the arm 27 is pivoted toward the direction shown by the arrow A in Fig. 2 to the front position in which the arm 27 points toward an inclined direction between the leftward and the forward directions of the unit 1 as shown in Fig. 3. Namely, the arm 27 is inclined toward the outside of the operator within the horizontal plane so as to be far from the operator. On the tip portion of the arm 27, a throttle lever 35 is supported pivotably and retainably via a metal washer 37 by a bolt 39 so that the pivotal position of the throttle lever 35 can be shiftably and retainably adjusted with fingers. The throttle lever 35 is connected to an engine throttle valve (not shown in the drawing) by means of a wire 33 for operating the throttle valve. On the inner side surface of the tip portion of the arm 27, a push button type switch 41 is provided for stopping the engine 9 by shorting a primary ignition circuit of the engine. Another switch 42 of push button type is provided on the inner side surface of the center portion of the arm 27, which is connected to the electric circuit of the starting motor 8. On the lower surface of the center portion of the arm 27 in the front pivotal position (corresponding to the left side of the arm 27 of Fig. 2), a trigger-shaped choke lever 45 is pivotably mounted by means of a shaft 43 so that it can swing in a plane parallel to the pivotal plane of the arm 27. The choke lever 45 is connected to a choke valve (not shown in the drawing) of the engine through a wire 47. As shown in Fig. 2, the choke lever 45 is provided with a spring 49 as a biasing means. When the choke lever 45 is operated in the direction shown by the arrow B in Fig. 2, the choke valve is closed, and concentrated fuel is then fed into the cylinder. When the choke lever 45 is released, it is automatically pivoted by the spring 49 toward the direction opposite to the direction indicated by the arrow B, and then returns to the home position at which the choke valve is opened. According to the above construction, when the engine 9 is started, the arm 27 is pivoted toward the direction shown by the arrow A from the upright position shown in Figs. 1 and 2, so that it points to the inclined direction between the leftward and forward directions as shown in Fig. 3. The throttle lever 35 is maintained in an operating position which is suitable for starting. Then, the choke lever 45 is pulled against the spring 49 toward the direction shown by the arrow B in Fig. 2. When the starting switch 42 is pressed, the starting motor 8 is rotated and the engine 9 is then started. After this, the choke lever 45 is released to return to its home position, so that the engine 9 remains idling. During operation of the unit 1, the operator bears the operating unit 1 on his back and the arm 27 is pivoted so as to point in the inclined direction between the leftward and forward directions in Fig. 3. The operator grasps the air tube 15 which is provided at the right side of the operator with his right hand and operates the throttle lever 35 on the arm with his left hand, therefore the construction of the arm is suitable for the operator to operate the unit 1.

Claims: A backpack type operating unit (1) comprising an operating device (2), a motive power source (9) for driving the operating device (2), a backpack frame (3) on which the operating device (2) and the motive power source (9) are mounted for enabling an operator to carry the operating unit (1) on his back, a substantially longitudinal arm (27), control means (35,41,42,45) provided on the arm (27) for controlling the drive of the motive power source (9), a support member (23) fixedly mounted on a lateral side portion of the frame (3) to pivotly support the arm (27) on the frame at one end of the arm (27), wherein the arm (27) is pivotly supported by the support member (23), the pivotal axis of the arm (27) is directed to an inclined direction between the horizontally sideward and horizontally rearward direction, the pivotal axis and the longitudinal axis of the arm (27) are perpendicular to each other, the pivoting being realized by a mounting surface (25) of the support member (23) and an end surface (28) of the arm (27) exclusively in reciprocal frontal sliding contact and by means of a bolt (29) which couples the support member (23) and the end portion of the arm (27) and penetrates them along the pivotal axis of the arm (27), a pivoting movement of the arm (27) being defined between a first position at which the arm (27) points vertically upward close to the frame (3) and a second position at which the arm (27) points away from the frame (3) toward an inclined direction between the horizontally forward and the horizontally sideward direction. A backpack type operating unit according to claim 1, further comprising means (31) for pressing the end portion of the arm (27) against the mounting surface (25) of the support member (23) at a preset pressure, so that the pivotal position of the arm (27) relative to the support member (23) can be shiftably retained at an appropriate position between the first and second position. A backpack type operating unit according to claim 2, wherein the pressing means include a spring (31) disposed onto the bolt (29). A backpack type operating unit according to any of the preceding claims, wherein a projection (32a) is provided on the mounting surface (25) of the support member (23) and an arc-shaped groove (32b) fitted in said projection (32a) is provided on the end surface (28) of the arm (27), to define the pivotal angle of the arm (27) relative to the support member (23). A backpack type operating unit according to claim 1, wherein the control means comprise a starting push button (42), a stopping push button (41), a throttle lever (35), and a choke lever (45).

Inventors: MIURA TAKASHI, MIURA, TAKASHI
Applicants: KOMATSU ZENOA KK, KOMATSU ZENOAH CO.
Application year: 1990
Main classification: F02B63
IPC codes: F02D11, B05B7, F02B63