FIELD OF THE INVENTION

The present invention is related to cement grinding, and in particular to an easy-detachable grinding device for a cement walk-behind trowel machine (ride-on trowel machine).

BACKGROUND OF THE INVENTION

In civil engineering, it is often necessary to pave cement on ground. Firstly, wet cement is paved on the ground, and then grinding knives are used to flat the cement. The grinding knives are installed on a walk-behind trowel machine (ride-on trowel machine) which has a grinding knife device. It has a rotatable frame and a plurality of grinding knives installed thereon. The grinding knives have the function of flattening wet cement ground.

In above mentioned prior art, the grinding knives cannot completely flat the ground because after the cement is solidified, the cement ground is still uneven. This is not beneficial for the succeeding works and it also presents an unbeautiful outlook. If it is desired to flatten the solidified cement ground, another tools are necessary. This causes overall cost to be increased.

SUMMARY OF THE INVENTION

Accordingly, the object of the present invention is to provide an easy-detachable grinding device for a cement walk-behind trowel machine (ride-on trowel machine), wherein advantages of the present invention are that installing units are arranged on a seat which is installed with the central disk and the outer rotary disks. In use, it is only needed to buckle the installing units to the grinding knives of a power source of a cement walk-behind trowel machine so that the central disk and the outer rotary disks are assembled to the cement walk behind trowel machine. The installing work is easy and convenient. The original grinding knives are unnecessary to be detached from the cement walk behind trowel machine. Furthermore the grinding device of the present invention can be detached easily as it is not used, while the original used grinding knives can be used again. No more vehicle is needed. In the present invention, the outer rotary disks are arranged on the periphery of the central disk so as to have a large grinding area. By the revolution of the outer rotary disks with respective to the central disk and the rotation of the outer rotary disks, the cement surface can be ground effectively so that the whole cement surface is uniformly ground to present a beautiful outlook. This is beneficial to the succeeding works.

To achieve above object, the present invention provides an easy-detachable grinding device for a cement walk-behind trowel machine which is installed to a power output shaft of a power source of a cement walk-behind trowel machine, the grinding device comprising: a rotation frame including a primary body and a plurality of supporting frames connected to the primary body; a center of the primary body having a through hole; in assembly, the power output shaft of the power source being inserted into the through hole so that the power source can drive the rotation frame to rotate; each supporting frame extending from the primary body; an outer side of each supporting frame be installed with a grinding knife unit; a seat installed below the rotation frame; an upper periphery of the seat being formed with a plurality of installing unit; each installing unit being positioned below an outer side of a respective supporting frame; the installing seat serving to be connected to a grinding knife unit; rotation of the rotation frame will drive the seat to rotate; a central disk located below the seat; a center of the central disk having an installing hole; a rotating shaft being installed in the installing hole; the rotating shaft being fixed therein by using a stepped bearing so that rotation of the rotating shaft does not drive the central disk to rotate; the rotating shaft extending from the installing hole upwards; an upper end of the rotating shaft connected to the seat; the through hole and the rotating shaft being coaxial; when the rotation frame rotates, the seat is driven to rotate so as to drive the rotating shaft to rotate; and a plurality of outer disks arranged below the seat; a center of each outer disk having an assembly hole; an axial post being installed in the assembly hole; an upper end of each axial post being connected to the seat; a bottom of each outer disk being installed with at least one outer grinding sheet; and wherein when the power output shaft rotates, the seat is driven to rotate, the power output shaft drives the rotation frame to rotate so that the outer disks revolve around the central disk; as a result, the outer grinding sheets rotate around the central disk so as to grind the surface of the cement ground; and one side of the installing unit installed with a trench; in assembly state, one side of the grinding knife unit being embedded into the trench so tha the installing unit being tightly engaged with the grinding knife unit; on side of the grinding knife unit can be folded upwards so that the grinding knife unit being extremely steadily fitted to the trench of the installing unit.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is a schematic view of the present invention.

FIG. 2 is an exploded schematic view about the elements of the present invention.

FIG. 3A is a cross sectional schematic view of the present invention along line A-A of FIG. 1.

FIG. 3B is a cross sectional schematic view along line B-B of FIG. 1.

FIG. 4A is a cross sectional schematic view along line C-C of FIG. 1.

FIG. 4B is cross sectional schematic view showing another assembly way for the grinding knife unit shown in FIG. 4A.

FIG. 5 is a lower side schematic view showing the assembly of the central disk and the outer rotary disks.

FIG. 6 is a schematic view showing that the present invention is assembled to a two head cement walk-behind trowel machine.

FIG. 7 is a schematic view showing that the present invention is assembled to a single head cement walk-behind trowel machine.

DETAILED DESCRIPTION OF THE INVENTION

In order that those skilled in the art can further understand the present invention, a description will be provided in the following in details. However, these descriptions and the appended drawings are only used to cause those skilled in the art to understand the objects, features, and characteristics of the present invention, but not to be used to confine the scope and spirit of the present invention defined in the appended claims.

The easy detachable grinding unit 5 of the present invention is installed to the power output shaft 61 of the power source 60 of a cement walk-behind trowel machine (ride-on trowel machine) 6 which may have two grinding sets (referring to FIG. 6) or a single one grinding set (referring to FIG. 7). The grinding unit 5 includes the following elements.

A rotation frame 1 includes a primary body 11 and a plurality of supporting frames 12 connected to the primary body 11. A center of the primary body 11 has a through hole 111. In assembly, the power output shaft 61 of the power source 60 is inserted into the through hole 111 so that the power source 60 can drive the rotation frame 1 to rotate. Each supporting frame 12 extends outwards from the primary body 11. An outer side of each supporting frame 12 is installed with a grinding knife unit 121.

A seat 14 is installed below the rotation frame 1. An upper periphery of the seat 14 is formed with a plurality of installing unit 141. Each installing unit 141 is positioned below an outer side of a respective supporting frame 12. The installing seat 141 serves to be connected to a grinding knife unit 121. Rotation of the rotation frame 1 will drive the seat 14 to rotate. One side of the installing unit 141 is installed with a trench 142. In assembly state, one side of the grinding knife unit 121 is embedded into the trench 142 so tha the installing unit 141 is tightly engaged with the grinding knife unit 121, as shown in FIG. 4A. On side of the grinding knife unit 121 can be folded upwards so that the grinding knife unit 121 is extremely steadily fitted to the trench 142 of the installing unit 141.

The seat 14 has a flat sheet form. Preferably, all trenches 142 of installing units 141 are arranged at the same side along a circulate path (clockwise or counterclockwise) so that all grinding knife units 121 can be engaged into the trenches 12 along a clockwise or counterclockwise path. Preferably, rotation direction of the rotation frame 1 is identical to the direction that the grinding knife units 121 engages into the trenches 142 of the installing units 142, so that as the rotation frame 1 rotates, the grinding knife units 121 resists against inner walls 143 of the trenches 142 for preventing the grinding knife units 121 from dropping out from the trenches 141.

A central disk 2 is below the seat 14. A center of the central disk 2 has an installing hole 25. A rotating shaft 21 is installed in the installing hole 25. The rotating shaft 21 is fixed therein by using a stepped bearing 251 so that rotation of the rotating shaft 21 does not drive the central disk 2 (referring to FIG. 2). The rotating shaft 21 extends from the installing hole 25 upwards. An upper end of the rotating shaft 21 connected to the seat 14. The through hole 111 and the rotating shaft 21 are coaxial. When the rotation frame 1 rotates, the seat 14 is driven to rotate so as to drive the rotating shaft 21 to rotate.

A plurality of outer disks 3 are arranged below the seat 14 and around the periphery of the central disk 2. A center of each outer disk 3 has an assembly hole 35. An axial post 31 is installed in the assembly hole 35. An upper end of each axial post 31 is connected to the seat 14. A bottom of each outer disk 3 is installed with at least one outer grinding sheet 32. In this example, the grinding unit 5 includes four outer disks 3. A bottom of each outer disk 3 is installed with three outer grinding sheets 32.

In grinding a surface of the cement ground, the grinding unit 5 of the present invention may be installed to a two head walk-behind trowel machine 6 (see FIG. 6) or to a one head walk-behind trowel machine 7 (see FIG. 7). In assembly, the power output shaft 61 of the power source 60 of the grinding machine 5, 6 is inserted into the through hole 111 of the rotation frame 1. When the power source 60 operates, the power output shaft 61 will drive the grinding unit 5 to grind. Preferably, the power source 60 is a motor or an engine.

When the power output shaft 61 rotates, the power output shaft 61 will drive the rotation frame 1 to rotate and thus further to drive the seat 14 to rotate so that the outer disks 3 revolve around the central disk 2. As result, the outer grinding sheets 32 rotate around the central disk 2 so as to grind the surface of the cement ground.

With reference to FIGS. 1, 2, 3B and 5, an outer periphery of the central disk 2 is formed with an outer teeth unit 231 so that the whole structure is as a central belt wheel 23. Each outer disk 3 includes disk body 37 and an outer belt wheel 33 fixed to the disk body 37. The assembly hole 35 is formed in a center of the outer belt wheel 33. A lower end of the axial post 31 is fixed to the assembly hole 35 of the outer disk 3 by using a stepped bearing 351 to buckle the axial post 31 therein. The outer grinding sheets 32 are installed at a bottom of the disk body 37. The grinding unit 5 of the present invention further includes a transfer unit 4 which encircles the central belt wheel 23 and the outer belt wheels 33. When the rotation frame 1 rotates to drive the seat 14 to rotate, the outer grinding sheets 32 of the outer disks 3 are driven to revolve around the central disk 2 to grind and moreover the transfer unit 4 further drives the outer belt wheels 33 to rotate and the outer disks 3 rotates around a center of itself. As a result each outer grinding sheet 32 revolves around the axial post 31 of the outer disk 3 so as to further grind. Then, the central belt wheel 23 may rotate or not rotate with the transfer unit 4. The transfer unit 4 may be belt or chain 23.

Preferably, the outer disks 3 are arranged to be spaced with an equal space.

In the preferred embodiment of the present invention, a lower side of the central belt wheel 23 is arranged with a slide proof pad 22 (referring to FIG. 3B). A plurality of elastic bodies 24 are arranged between the central belt wheel 23 and the slide proof pad 22. By the elasticity of the elastic bodies 24, the slide proof pad 24 may move up and down for generating slide proof effect to the rotation of the outer disk 3 and to reduce the rotation speed of the central disk 2 by the slide proof between the slide proof pad 22 and the cement surface. Therefore, since the diameter of the central belt wheel 23 is larger than that of the outer belt wheel 33, the speed reduction of the central belt wheel 23 will cause the transfer unit 4 properly adjusts the rotation speed of the outer belt wheel 33.

An outer periphery of the seat 14 is formed with a plurality of connecting holes 70 each of which receives an upper end of an axial post 31 of a respective outer disk 3. The connecting holes 70 are classified as at least one retaining hole 71 and at least one active hole 72. The axial post 31 installed into the retaining hole 71 is unmovable, while the axial post 31 installed into the active hole 72 is movable within the active hole 72. An inner side of each active hole 72 of the seat 14 is installed with a pushing unit 80. The pushing unit 80 is further installed with a transversal rod 81 which is movable inwards and outwards. An outer end of the transversal rod 81 is connected to an upper end of the axial post 31 within the active hole 72 so as to change the position of the outer disk 3 (outer belt wheel 33, pulley) for adjusting the tightness of the transfer unit 4 circulating the outer belt wheel 33). As a result, the transfer unit 4 is capable of driving each outer belt wheel 33 effectively.

An upper end of each axial post 31 is formed with a locking means 36 which is position above the connecting hole 70. The locking means 36 is locked into a locking hole of the axial post 31 by a longitudinal stud 361 so that the seat 14 is clamped between the locking means 36 and the axial post 31 while the axial post 31 is retained to a respective connecting hole 70. The locking means 36 above the active hole 72 is connected to an outer end of a respective transversal rod 81.

As illustrated in FIG. 23A, each supporting frame 12 includes an insertion tube 123 and an outer tube 124. The insertion tube 123 extends outwards from the primary body 11. The insertion tube 123 has an insertion groove 1231 An inner side of the outer tube 124 is inserted into the insertion groove 1231. An outer side of the outer tube 124 is inserted into a respective one of the grinding knife units 121. An axial surface of the outer tube 124 is formed as a first plane 1241 and a surfaces of the insertion groove 1231 is formed with a second plane 1232 at a position corresponding to the first plane 1241 of the outer tube 124. When the outer tube 124 is inserted into the insertion groove 1231, the first plane 1241 is aligned with the second plane so that the insertion tube 123 does not axially rotate with respect to the outer tube 124.

Advantages of the present invention are that installing units are arranged on a seat which is installed with the central disk and the outer rotary disks. In use, it is only needed to buckle the installing units to the grinding knives on a power source of a cement walk-behind trowel machine so that the central disk and the outer rotary disks are assembled to the cement walk behind trowel machine. The installing work is easy and convenient. The original grinding knives are unnecessary to be detached from the cement walk behind trowel machine. Furthermore the grinding device of the present invention can be detached easily as it is not used, while the original used grinding knives can be used again. No more vehicle is needed. In the present invention, the outer rotary disks are arranged on the periphery of the central disk so as to have a large grinding area. By the revolution of the outer rotary disks with respective to the central disk and the rotation of the outer rotary disks, the cement surface may be ground effectively so that the whole cement surface is uniformly ground to present a beautiful outlook. This is beneficial to the succeeding works.

The present invention is thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the present invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.