GB1588675A

GB1588675A - Surface-smoothing machines

Info

Publication number: GB1588675A
Application number: GB15096/78A
Authority: GB
Original assignee: Dynapac AB
Current assignee: Dynapac AB
Priority date: 1977-05-12
Filing date: 1978-04-18
Publication date: 1981-04-29
Also published as: FR2389731B1; NO143640B; CA1094340A; NO781285L; NL7803653A; BR7802536A; NO143640C; DE2819653A1; DK150337B; BE867044A; JPS53140826A; DK163878A; FR2389731A1; DE2819653C2; AU3491278A; SE400600B; AU515486B2; JPS638259B2; IT7809451A0; FI60756B

Description

(54) IMPROVEMENTS IN OR RELATING SURFACE-SMOOTHING MACHINES (71) We, DYNAPAC MASKIN AKTIE BOLAG, a Swedish Company, of Box 1103, S-171 22 Solna, Sweden, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to surface-smoothing machines, and more specifically, but not exclusively to a machine for smoothing newly laid concrete. A known machine comprises a rotor with two or more radially arranged arms having pivotally arranged thereon working elements which can be adjusted by means of a regulating mechanism.

When newly placed concrete is finished or smoothed by means of rotating smoothing elements water present in the concrete has a tendency to seep up to the surface.

This increase in the volume of water necessitates a successive change in the angle of the smoothing elements in relation to the surface being smoothed. In addition, it is desirable for this change to take place while the machine is in operation and in a manner that is practical for the machine operator.

Surface-smoothing machines are known in which the angle of the smoothing elements relative to the surface being smoothed can be changed from the operating handle of the machine. That part of the regulating mechanism which co-acts directly with the smothing elements is, however, often complicated, requiring the provision of levers and articulated joints, and is so mounted on the machine that it may easily come into direct contact with the concrete, which makes continuous inspection and cleaning necessary.

An object of the invention is to provide a surface-smoothing machine in which the smoothing elements can be adjusted more readily and in a more efficient manner than with known machines, and which permits separate adjustment of the angle of the smoothing elements relative to the surface being smoothed.

Accordingly, this invention consists in a surface-smoothing machine comprising a motor and a rotor interconnected without the use of any belt drive by at least two meshing gears having parallel axes of rotation, said rotor having two or more arms extending radially therefrom, surfacesmoothing elements pivotally mounted on respective ones of said arms, and means for adjusting the angle of said smoothing elements relative to the surface to be smoothed, said adjusting means comprising an elongate hollow locating member rigidly connected to and arranged coaxially with the hub of the rotor, a camming member axially movable with respect to said locating member, control means extending axially of said rotor and of said locating member for moving said camming member axially with respect to said locating member, and cam followers cooperating with said camming member to cause rotation of respective ones of said smoothing elements about their pivots in response to axial movement of said camming member.

Each said smoothing element may comprise an elongate holder pivotally mounted on a respective one of said arms and a plate-like smoothing member mounted on said holder, and each of said cam followers may be in the form of an adjusting pin extending from said holder and arranged to be brought into contact with a camming surface on said camming member in a manner such that axial movement of said camming member causes a pivoting movement of said holder via said pin. Said camming surface may be of conical or prismatic configuration.

Preferably, the elongate hollow locating member is a right circular cylinder and said camming member is a piston slidable in said cylinder. In such a case, each adjusting pin is a screw which is arranged at right angles to the rotational axis of the holder, and of which a portion extends through an opening in the locating member so that one end of said screw rests against said camming surface.

Said control means preferably includes a flexible cable which is rotatably connected at one end to said camming member. Moreover, said gears are preferably accommodated within a gear housing to which one end of a foldable handle is pivotally connected. At least a part of said handle may be hollow, said flexible cable being enclosed within said hollow part.

The invention will now be described in greater detail with reference to the accompanying schematic drawing, in which : Figure 1 illustrates a concrete finishing machine in perspective, and Figure 2 illustrates an embodiment of a device, constructed in accordance with the invention, for adjusting the blade-like smoothing elements of the machine.

The machine illustrated in the drawing is a concrete-finishing machine and comprises a rotor 1 equipped with four arms, the rotor being supported by smoothing or working elements 2 each of which is pivotally connected to a respective arm.

Mounted on the rotor is a motor 3 which, via an integral gear transmission 4, causes the rotor 1 and its four working elements 2 to rotate with its rotational axis principally vertical.

The machine is controlled by means of a steering bar 5 which is pivoted on a gear housing 4' and which at its upper end carries a handlebar 6 especially designed for the machine in question.

The angle of the working elements pivoted on the rotor arms in relation to the surface is adjusted by means of a blade-adjusting knob 7 arranged at the upper end of arm 5 which via a wire 8 is connected with a piston 9 arranged in the centre of the machine coaxially with the rotational axis of the rotor. The piston 9 is completely enclosed in a cylindrical section 10 of a rotor hub 11 and can be caused to move axially in relation to section 10 by means of the knob 7 and the wire 8 connected to it. However, the piston is so mounted that it rotates with section 10 when the cruciform rotor is driven round by motor 3. To prevent the wire 8 from rotating also, it is rotationally journalled inside the piston 9.

Each of the working elements 2 of the concrete-finishing machine comprises a flat wing-like plate mounted on a holder 12. The holder is pivotally mounted on a respective rotor arm and extends along most of the length of the rotor arm. Extending through the holder and the cylindrical section 10 through an opening 10' into engagement with a camming surface on the piston 9 is an adjusting screw 13 which is screwed into the holder at right angles to its axis of rotation so that its inner end projects into the locating cylinder 10 through the opening 10' and rests against the piston 9.In the illustrated embodiment, said camming surface is formed on a part of the piston which is of conical configuration, and when the piston is moved axially by means of the adjusting knob 7 and the wire 8, the adjusting screws 13 are actuated and cause the holders 12 with working elements 2 to rotate, whereby the angle between the working surface of the working elements and the concrete surface is changed. It is important for all working elements to assume the same angle and this is accomplished by means of the adjusting screws 13. Through their interaction with the conical portion of piston 9, separate adjustment of the angle of working elements 2 in relation to the concrete surface is possible.Initial adjustment should preferably be carried out on a flat surface, whereby the adjusting screws 13 are unscrewed by such an amount that their inner ends do not rest against piston 9, in which position the working elements lie against the surface on which they rest.

The adjusting knob 7 is rotated until the wire 8 is under no tension whatsoever.

Afterwards the adjusting screws are screwed in until they rest lightly against the conical portion of piston 9, whereafter the wire 8 is tensioned and all the working elements 2 are simultaneously adjusted to the desired angle in relation to the surface.

In the illustrated embodiment, the adjusting knob 7 is provided with a rod 14 which extends into an upper, tubular portion 15 of the steering bar 5. At its inner end this rod is threaded and screwed into one end of an adapter 16 which slides axially inside the tube and at the opposite end of which the wire 8 is secured. When the knob 7 is rotated, the adapter 16 slides axially inside the tube 15 with a corresponding displacement of the piston 9 and thus rotation of working elements 2 as a result.

WHAT WE CLAIM IS:- 1. A surface-smoothing machine comprising a motor and a rotor interconnected without the use of any belt drive by at least two meshing gears having parallel axes of rotation, said rotor having two or more arms extending radially therefrom, surface-smoothing elements pivotally mounted on respective ones of said arms, and means for adjusting the angle of said smoothing elements relative to the surface to be smoothed, said adjusting means comprising an elongate hollow locating member rigidly connected to and arranged coaxially with the hub of the rotor, a camming member axially movable with respect to said locating member, control means extending axially of said locating member for moving said camming member axially with respect to said locating member, and

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. a flexible cable which is rotatably connected at one end to said camming member. Moreover, said gears are preferably accommodated within a gear housing to which one end of a foldable handle is pivotally connected. At least a part of said handle may be hollow, said flexible cable being enclosed within said hollow part. The invention will now be described in greater detail with reference to the accompanying schematic drawing, in which : Figure 1 illustrates a concrete finishing machine in perspective, and Figure 2 illustrates an embodiment of a device, constructed in accordance with the invention, for adjusting the blade-like smoothing elements of the machine. The machine illustrated in the drawing is a concrete-finishing machine and comprises a rotor 1 equipped with four arms, the rotor being supported by smoothing or working elements 2 each of which is pivotally connected to a respective arm. Mounted on the rotor is a motor 3 which, via an integral gear transmission 4, causes the rotor 1 and its four working elements 2 to rotate with its rotational axis principally vertical. The machine is controlled by means of a steering bar 5 which is pivoted on a gear housing 4' and which at its upper end carries a handlebar 6 especially designed for the machine in question. The angle of the working elements pivoted on the rotor arms in relation to the surface is adjusted by means of a blade-adjusting knob 7 arranged at the upper end of arm 5 which via a wire 8 is connected with a piston 9 arranged in the centre of the machine coaxially with the rotational axis of the rotor. The piston 9 is completely enclosed in a cylindrical section 10 of a rotor hub 11 and can be caused to move axially in relation to section 10 by means of the knob 7 and the wire 8 connected to it. However, the piston is so mounted that it rotates with section 10 when the cruciform rotor is driven round by motor 3. To prevent the wire 8 from rotating also, it is rotationally journalled inside the piston 9. Each of the working elements 2 of the concrete-finishing machine comprises a flat wing-like plate mounted on a holder 12. The holder is pivotally mounted on a respective rotor arm and extends along most of the length of the rotor arm. Extending through the holder and the cylindrical section 10 through an opening 10' into engagement with a camming surface on the piston 9 is an adjusting screw 13 which is screwed into the holder at right angles to its axis of rotation so that its inner end projects into the locating cylinder 10 through the opening 10' and rests against the piston 9.In the illustrated embodiment, said camming surface is formed on a part of the piston which is of conical configuration, and when the piston is moved axially by means of the adjusting knob 7 and the wire 8, the adjusting screws 13 are actuated and cause the holders 12 with working elements 2 to rotate, whereby the angle between the working surface of the working elements and the concrete surface is changed. It is important for all working elements to assume the same angle and this is accomplished by means of the adjusting screws 13. Through their interaction with the conical portion of piston 9, separate adjustment of the angle of working elements 2 in relation to the concrete surface is possible.Initial adjustment should preferably be carried out on a flat surface, whereby the adjusting screws 13 are unscrewed by such an amount that their inner ends do not rest against piston 9, in which position the working elements lie against the surface on which they rest. The adjusting knob 7 is rotated until the wire 8 is under no tension whatsoever. Afterwards the adjusting screws are screwed in until they rest lightly against the conical portion of piston 9, whereafter the wire 8 is tensioned and all the working elements 2 are simultaneously adjusted to the desired angle in relation to the surface. In the illustrated embodiment, the adjusting knob 7 is provided with a rod 14 which extends into an upper, tubular portion 15 of the steering bar 5. At its inner end this rod is threaded and screwed into one end of an adapter 16 which slides axially inside the tube and at the opposite end of which the wire 8 is secured. When the knob 7 is rotated, the adapter 16 slides axially inside the tube 15 with a corresponding displacement of the piston 9 and thus rotation of working elements 2 as a result. WHAT WE CLAIM IS:-

1. A surface-smoothing machine comprising a motor and a rotor interconnected without the use of any belt drive by at least two meshing gears having parallel axes of rotation, said rotor having two or more arms extending radially therefrom, surface-smoothing elements pivotally mounted on respective ones of said arms, and means for adjusting the angle of said smoothing elements relative to the surface to be smoothed, said adjusting means comprising an elongate hollow locating member rigidly connected to and arranged coaxially with the hub of the rotor, a camming member axially movable with respect to said locating member, control means extending axially of said locating member for moving said camming member axially with respect to said locating member, and

cam followers cooperating with said camming member to cause rotation of respective ones of said smoothing elements about their pivots in response to axial movement of said camming member.

2. A machine as claimed in Claim 1, wherein each said smoothing element comprises an elongate holder pivotally mounted on a respective one of said arms and a plate-like smoothing member mounted on said holder, and wherein each of said cam followers is in the form of an adjusting pin extending from said holder and arranged to be brought into contact with a camming surface on said camming member in a manner such that axial movement of said camming member causes a pivoting movement of said holder via said pin.

3. A machine as claimed in Claim 2, wherein said camming surface is of conical or prismatic configuration.

4. A machine as claimed in Claim 2 or Claim 3, wherein the elongate hollow locating member is a right circular cylinder and said camming member is a piston slidable in said cylinder.

5. A machine as claimed in Claim 4, wherein each adjusting pin is a screw which is arranged at right angles to the rotational axis of the holder, and of which a portion extends through an opening in the locating member so that one end of said screw rests against said. camming surface.

6. A machine as claimed in any of the preceding Claims, wherein said control means includes a flexible cable which is rotatably connected at one end to said camming member.

7. A machine as claimed in any one of the preceding Claims, wherein said gears are accommodated within a gear housing to which one end of a foldable handle is pivotally connected.

8. A machine as claimed in Claim 7 when appended to Claim 6, wherein at least a part of said handle is hollow, said flexible cable being enclosed within said hollow part.

9. A surface-smoothing machine substantially as hereinbefore described with reference to, and as illustrated in, the accompanying drawing.