BLOCK COMPACTOR

Abstract

Provided is a block compactor equipped with a brake mechanism capable of securely locking rollers with a simple structure and stably maintaining a locked state and an unlocked state even when exposed to vibration. A brake pad 12 is fixed to a lower end portion of a brake shaft 11 and is configured to be rotatable together with the brake shaft 11 between two rollers 5 adjacent in the front and rear. By rotating a brake lever 13, the brake pad 12 can be switched between an unlocked state in which the brake pad 12 does not contact with the outer circumferential surfaces of the rollers 5, and the rollers 5 are free to rotate, and a locked state in which the brake pad 12 contacts with the outer circumferential surfaces of the rollers 5, and the rollers 5 cannot rotate with the friction force.

Claims

1. A block compactor, comprising: a base; a motor mounted on the base; an exciter that generates vibration by rotational drive force supplied from the motor; a plurality of rollers, at least the surface layers of which are made of an elastic material, and which are rotatably arranged on the underside of the base; and a parking brake mechanism that can lock the rotation of the rollers, wherein: the parking brake mechanism consists of a brake shaft, a brake pad, and a brake lever; the brake pad is fixed to the lower end portion of the brake shaft, and is configured to be rotatable together with the brake shaft at a position between two rollers adjacent in the front and rear among the plurality of rollers; and by rotating the brake lever, the brake shaft and the brake pad are rotated to switch between an unlocked state in which the brake pad does not contact with the outer circumferential surfaces of the two rollers, and these rollers are free to rotate, and a locked state in which the brake pad contacts with the outer circumferential surfaces of the two rollers, and these rollers are unable to rotate due to the frictional force.

2. The block compactor according to claim 1, wherein: the parking brake mechanism is configured such that a rotating side engagement means, which is formed on the brake lever, and a fixed side engagement means, which is fixed at a position near the brake lever, are engaged with each other to inhibit the rotation of the brake lever, when the parking brake mechanism is in the unlocked state and in the locked state.

3. The block compactor according to claim 2, wherein: two notches are formed on the brake lever as the rotating side engagement means; a positioning bolt is fixed on the base as the fixed side engagement means; and one of the two notches is formed at a position where it engages with the positioning bolt when the parking brake mechanism is in the unlocked state, and another notch is formed at a position where it engages with the positioning bolt when the parking brake mechanism is in the locked state.

4. The block compactor according to claim 2, wherein: the brake shaft or the fixed side engagement means is elastically held by a bushing formed of an elastic material so that it can be tilted from a basic posture, and the brake lever is subject to resistance by the elastic force of the bushing when the engagement of the rotating side engagement means and the fixed side engagement means is released.

5. The block compactor according to claim 1, wherein: bolt holes are respectively formed in the brake pad and the lower end portion of the brake shaft; the brake pad is attached to the brake shaft by inserting bolt into the respective bolt holes and tightening the bolt; the vertical length of the bolt holes formed in the brake pad or the lower end portion of the brake shaft is set to be longer than the diameter of the bolt to be inserted so that the mounting height position of the brake pad can be adjusted.

6. The block compactor according to claim 5, wherein: the brake pad is formed in an inverted trapezoidal shape.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] FIG. 1 is a side view of a block compactor 1 of the present invention.

[0015] FIG. 2 is a partial cross-sectional view showing a structure of a parking brake mechanism 10 (a locked state) shown in FIG. 1.

[0016] FIG. 3 is a plan view of a brake lever 13 constituting the parking brake mechanism 10 shown in FIG. 1.

[0017] FIG. 4 is a side view of a brake pad 12 (an unlocked state), constituting the parking brake mechanism 10 shown in FIG. 1.

[0018] FIG. 5 is a partial cross-sectional view showing a mode of operation of the parking brake mechanism 10 shown in FIG. 1.

[0019] FIG. 6 is an exploded perspective view of the brake pad 12 constituting the parking brake mechanism 10 shown in FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

[0020] Embodiments of the Block compactor of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows a side view of the block compactor 1 of the present invention. The block compactor 1 consists of a base 2, a motor 3 (an engine or an electric motor) mounted on the base 2, an exciter 4 that generates vibration by rotational drive force supplied from the motor 3, a plurality of rollers 5 (four in this embodiment) rotatably arranged on the underside of the base 2, an operation handle 6 extending towards the rear side of the machine body, and etc.

[0021] At least the surface layers of the rollers 5 are made of an elastic material (hard rubber or the like). Since the rollers 5 and the motor 3 are not dynamically connected, the rotational drive force output from the motor 3 is not transmitted to the rollers 5. Therefore, during compaction work, the compactor 1 is used by being manually pushed by an operator holding the operating handle 6.

[0022] The block compactor 1 of the present invention is characterized by having a parking brake mechanism 10 capable of locking the rotation of the rollers 5 (bring it to a state where rotation is impossible). FIG. 2 is a partial cross-sectional view showing a structure of the parking brake mechanism 10. The parking brake mechanism 10 consists of a brake shaft 11, a brake pad 12, a brake lever 13, and etc.

[0023] The brake shaft 11 extends vertically by passing through the horizontal portion of the base 2 in the vertical direction and is held in the base 2 so that it can be rotated around the vertical axis. The brake shaft 11 is mounted on the base 2 through a cylindrical bushing 15 formed of an elastic material (rubber in this embodiment). More specifically, as shown in FIG. 2, the bushing 15 is placed around the lower half portion of the brake shaft 11, and the outer side of the bushing 15 is held by the base 2 without direct contact between the brake shaft 11 and the base 2.

[0024] Therefore, the brake shaft 11 is elastically held by the bushing 15 and basically maintained in a state where its center axis line is vertical (a basic posture), and configured to tilt slightly (about 3) when an external force is applied.

[0025] The brake pad 12 is formed in a wedge shape (an inverted trapezoid shape), and fixed to the lower end portion of the brake shaft 11, and is configured to rotate with the brake shaft 11 at a position between two rollers 5 adjacent in the front and rear. The brake lever 13 has a base end portion that is fixed to an upper half portion of the brake shaft 11 (a part extending above the base 2) and is configured, by rotating horizontally (around a vertical axis), to rotate the brake shaft 11 and the brake pad 12.

[0026] FIG. 3 shows a plan view of the brake lever 13. In this embodiment, the brake lever 13 is configured to rotate within a range of 45 from the position shown by the solid line to the position shown by the broken line in FIG. 3, and the compactor 1 can be switched between unlocked state and locked state by rotating the brake lever 13.

[0027] More specifically, when the brake lever 13 is at the position shown by the solid line in FIG. 3 (an unlocked position), the brake pad 12 is not in contact with any of the outer circumferential surfaces of the two rollers 5 adjacent in the front and rear, as shown in FIG. 4, and these rollers 5 are in a rotatable state (an unlocked state). When the brake lever 13 is rotated from this state to the position shown by the broken line in FIG. 3 (a locked position), the brake pad 12 firmly contact with the outer circumferential surfaces of the two rollers 5 adjacent in the front and rear, as shown in FIG. 2, which generates a large amount of frictional force, and the rollers 5 are unable to rotate (a locked state).

[0028] The parking brake mechanism 10 employed in this embodiment is configured such that, when the parking brake mechanism is in the unlocked state and in the locked state, the brake lever 13 engages with a positioning bolt 14 (a fixed side engagement means) (see FIG. 2 and FIG. 3) fixed at a position near the brake lever 13, and the rotation of the brake lever 13 is inhibited to stably maintain the unlocked and locked states, respectively.

[0029] More specifically, as shown in FIG. 3, the brake lever 13 consists of a grip 13a for the operator to grasp, and an extension 13b which extends on the opposite side of the grip 13a interposing the brake shaft 11. Two notches 13c and 13d (a rotating side engagement means) are formed at the tip of the extension 13b, and an arc-shaped portion 13e is formed between the notches 13c and 13d.

[0030] The notches 13c and 13d are formed at an equal distance from the center axis line C of the brake shaft 11, at an angular interval of 45 measured from the center axis line C. The notch 13c is formed at a position where it engages with the positioning bolt 14 when the brake lever 13 is in the unlocked position (the position shown by the solid line in FIG. 3), and the notch 13d is formed at a position where it engages with the positioning bolt 14 when the brake lever 13 is in the locked position (the position shown by the broken line in FIG. 3). The arc-shaped portion 13e is formed in an arcuate shape having a dimension from the center axis line C that is slightly larger (1.5 mm in this embodiment) than that of the notches 13c and 13d.

[0031] The positioning bolt 14 is fixed on the base 2 and is formed at a position where the brake shaft 11 is maintained vertically when the positioning bolt 14 engages with the notch 13c and when it engages with the notch 13d. In other words, in this embodiment, the distance from the center axis line C of the brake shaft 11 in the vertical state (the basic posture) to the positioning bolt 14 is set to be equal to the distance from the center axis line C to the notches 13c and 13d.

[0032] As shown by the solid line in FIG. 3, when the positioning bolt 14 is engaged with the notch 13c of the brake lever 13, if a force is applied to brake lever 13 in its rotatable direction (towards the locked position shown by the broken line), the engagement of the positioning bolt 14 with the notch 13c is released and the positioning bolt 14 abuts against the arc-shaped portion 13e formed between the notches 13c and 13d. At this time, since the dimension from the center axis line C of the brake shaft 11 to the arc-shaped portion 13e is slightly larger than that from the center axis line C to the notches 13c and 13d, as shown in FIG. 5, the brake shaft 11 tilts slightly (from the vertical position C1 of the center axis line of the brake shaft 11 shown by the dotted line in FIG. 5 to the position C2 shown by the dot-dash line) in the direction opposite to the positioning bolt 14.

[0033] Therefore, any attempt to rotate the brake lever 13 with the positioning bolt 14 engaged in the notch 13c will be resisted by the elastic force of the bushing 15 holding the brake shaft 11. When the brake lever 13 is rotated and reaches the locked position shown by the broken line in FIG. 3, the positioning bolt 14 engages with the notch 13d and the brake shaft 11 returns to the vertical state (the basic posture). Also, when attempting to rotate the brake lever 13 towards the opposite direction (from the locked position shown by the broken line to the unlocked position shown by the solid line in FIG. 3), the rotation will be resisted by the elastic force of the bushing 15.

[0034] Thus, in this embodiment, the notch 13c or 13d of the brake lever 13 engages with the positioning bolt 14 to prevent the brake lever 13 from rotating even when exposed to vibration generated by the exciter 4 or during transportation. This enables avoiding situations such as the brake pads 12 in the unlocked state rotating and coming into contact with the rollers 5 or the brake pads 12 in the locked state rotating and getting unlocked, and stability of the unlocked and locked states can be maintained respectively.

[0035] In the above embodiment, the brake shaft 11 is configured to tilt when the positioning bolt 14 contacts the arc-shaped portion 13e, however, the positioning bolt 14 (the fixed side engagement means) may be configured to tilt elastically instead of the brake shaft 11.

[0036] In the above embodiment, two notches 13c and 13d (the rotating side engagement means) are formed in the brake lever 13, and the positioning bolt 14 (the fixed side engagement means) engages with one of the notches to prevent the brake lever 13 from rotating. Instead, it may be configured such that a member (not shown) formed with a plurality of notches is fixed to the positioning bolt 14 or the like as the fixed side engagement means, and a convex portion (the rotation side engagement means) (not shown) that can engage with one of the notches is formed in the brake lever 13, and the rotation of the brake lever 13 is inhibited by the engagement between the fixed side engaging means (the notches) and the rotation side engagement means (the convex portion).

[0037] In addition, a single notch (the rotation side engagement means or the fixed side engagement means) may be configured to engage a plurality of convex portions (the fixed side engagement means or the rotation side engagement means).

[0038] The parking brake mechanism 10 employed in this embodiment is configured to enable adjustment of the height position of the brake pads 12 that are attached to the brake shaft 11. Specifically, as shown in FIG. 6, the brake pads 12 are arranged one by one on both sides so as to sandwich the lower end portion 11a (formed in a plate shape) of the brake shaft 11, and are attached to the brake shaft 11 by inserting bolts 16 through the respective bolt holes 12a, 11b, 12b and tightening them.

[0039] As shown in FIG. 6, since the bolt hole 11b formed in the lower end portion 11a of the brake shaft 11 has a vertical length that is longer (about twice as long) than the diameter of the bolt 16 to be inserted, the mounting height position of the brake pads 12 can be adjusted by changing the insertion position of the bolt 16 vertically. Since the brake pads 12 are formed in a wedge shape (an inverted trapezoidal shape), changing the height position changes the contact pressure against the rollers 5 (see FIG. 2), enabling the braking force to be adjusted.

[0040] Even when the vertical length of the bolt holes 12a and 12b formed in the brake pads 12 are set to be longer than the diameter of the bolt 16 to be inserted, the mounting height position of the brake pad 12 can be adjusted, enabling the adjustment of the braking force.

REFERENCE NUMERALS

[0041] 1 Block compactor [0042] 2 Base [0043] 3 Motor [0044] 4 Exciter [0045] 5 Roller [0046] 6 Operation handle [0047] 10 Parking brake mechanism [0048] 11 Brake shaft [0049] 11a Lower end portion [0050] 11b Bolt hole [0051] 12 Brake pad [0052] 12a, 12b Bolt hole [0053] 13 Brake lever [0054] 13a Grip [0055] 13b Extension [0056] 13c, 13d Notch [0057] 13e Arc-shaped portion [0058] 14 Positioning bolt [0059] 15 Bushing [0060] 16 Bolt