AU2003262117A1 - Concrete Vibrating and Finishing Apparatus - Google Patents

Description

CONCRETE VIBRATING AND FINISHING APPARATUS Technical Field This invention relates to concrete vibrating and finishing apparatus.

Background Art The processing of laying of concrete foundations and slabs is greatly assisted by the use of mechanical vibrators and finishing apparatus.

Numerous kinds of concrete vibrators are in common usage.

One popular form of vibrator is the so called pencil vibrator. Pencil vibrators come in various forms and all have in common a pencil-like vibrator head.

The vibrators are driven by a petrol, electric of air motors which can either be connected to the vibrator head or positioned remotely therefrom.

Currently available pencil vibrating apparatus is relatively expensive, heavy and not always convenient to use.

After concrete has been poured and vibrated it is usually screeded by hand and then finished by machine. In one form mechanical finishers are provided with a screeding head which supports a rotary blade or blades, means for driving the blades and an extensible arm which is used to manoeuvre the apparatus. In another form the screeds are provided with an elongate screed bar, a vibrator and means for manoeuvring the screed over previous hand screeded concrete.

Mechanical finishers are generally relatively expensive and heavy.

It is an object of the present invention to provide concrete vibrating and finishing apparatus which is relatively inexpensive and lightweight.

It is a further object of the present invention to provide a mechanical screed driven by a combustion engine.

Further objects and advantages of the present invention will become apparent from the ensuing description which is given by way of example.

Disclosure of Invention According to the present invention there is provided a concrete vibrating and finishing apparatus comprising a petrol engine connected to a rotatable vibrating head by a flexible drive and throttle means for effecting linear control of the working speed of the engine and the vibrating head, characterised in that the vibrating head comprises a tubular outer casing, a tip at one end of the casing, a coupling at the other end of the casing and an eccentric rotor journalled within the casing which is connected to the flexible drive by said coupling.

The casing of the vibrating head can be fabricated from metal and the tip of the vibrating head fabricated from metal which is heavier than the metal used to fabricate the casing.

The tip can be semi-circular and has a threaded boss which can be secured to an internal thread at one end of the casing.

The coupling can comprise an annular portion, a threaded boss extending from one side of the annular portion which is secured to an internal thread of the casing and an elongate collar which receives the flexible drive.

Brief Description of the Drawings Aspects of the present invention will now be described with reference to the accompanying drawings in which; Figure 1 is a perspective view of a concrete vibrator in accordance with one possible aspect of the present invention, and Figures 2 to 2c are exploded and sectional views of a flexible drive coupling and elements of a vibrator head in accordance with one possible embodiment of the present invention, and Figure 3 is a diagrammatic perspective view of a concrete finisher in accordance with another possible embodiment of the present invention, and Figures 4 and 4a of the drawings illustrate a screeding apparatus in accordance with a further aspect of the present invention.

With respect to figure 1 of the drawings the apparatus illustrated has a lightweight petrol engine I with a throttle control 2 mounted on gripping means generally indicated by arrow 3.

The gripping means 3 can include a tubular shaft 4, and a hand grip A flexible drive generally indicated by arrow 6 connects the shaft 4 to a vibrator head generally indicated by arrow 7.

The engine 1 is adapted to drive a rotating element within the vibrator head 7.

A flexible drive of any length, sometimes known as a flexi-drive (not shown) extends from the engine to a rotating element of the vibrating head and rotates same. Flexi-drive apparatus generally comprise a flexible hose and adaptors for connection to a prime mover and a tool. A flexible wire or cord is coupled to the tool and the motor.

Figure 2 of the drawings illustrates elements of the flexible drive unit 6 of the apparatus of figure 1. The flexible drive comprises male and female couplings 8 and 9 respectively connected to the ends of a flexible hose 10. The coupling 8 is adapted for connection to the vibrator head 7 and the coupling 9 is adapted for connection to the shaft 4.

Each of the couplings 8, 9 is characterised by a hose connection boss 11 having an axial passage 12 for accommodating a flexible drive cord or wire.

With respect to figures 2a to 2c of the drawings the vibrating head 7 illustrated comprises a tubular outer casing 13, a tip 14 at one end of the casing, a coupling 15 at the other end of the casing and a rotatable eccentric rotor 16 journalled within the head.

The tip 14 comprises a semi-circle portion 16 a threaded boss 17 and an internal passage 18. The boss 17 is adapted for engagement with an internal thread 19 at one end of casing 13. A ring seal 20 is mounted in a shoulder between the tip 14 and boss 17.

The coupling 15 comprises an annular portion 21, a threaded boss 22 extending from one side of the portion 21 and a collar 23 which extends from the other end of portion 21. An internal passage 24 allows a flexi-drive cord to be attached to a rotatable eccentric rotor journalled within the casing 13 and generally indicated by arrow The rotor 25 with shafts 26, 27 adapted to engage with roller bearing sets 28. Between the shafts 26, 27 an eccentric crank 29 supported from shaft attachments 30 is provided.

The interiors of the casing 13 can be filled with a suitable lubricant.

The shaft 27 is provided with a spigot for engagement with the end of a flexi-drive cord (not shown).

The casing 13 can be fabricated or moulded in lightweight aluminium or another metal and the tip 14 is fabricated from a heavier material such a 4140 steel.

When the rotor 25 is rotated by the flexi-drive the crank produces vibration head 7 which can be lessened or intensified by adjustment of the throttle of the engine 1.

The fact that the tip 14 is heavier than the casing creates a "snaking" effect when the vibrator head is placed in moist concrete, enhancing the efficiency of the apparatus.

Whilst the vibrating head described is an eccentric vibrator, the vibrating head may be vibrated by other forms of mechanism in particular a pendulum system.

With respect to figure 3 of the drawings and in accordance with a further aspect of the present invention there is provided a rotary finishing apparatus driven by a two-stroke petrol engine via a shaft in a similar set-up to that previously described in relation to the vibrator. In this case shaft 4 has an extended portion 4a which connects via a universal coupling (not shown) and frame 32 to a rotary finishing blade 33.

With respect to figures 4 and 4a of the drawings a screeding apparatus may comprise an elongate screed plank 34 from which extends a handle system 35. A two-stroke engine 36 is mounted on a crossbar 37 extending between the handle system. A drive system 38 (which may be a flexi-drive system) extends between the engine 36 is connected to a damping plate 40 which is mounted to the screed plank 34 by damping members 41.

Aspects of the present invention have been described by way of example only and it will be appreciated that modifications and additions thereto may be made without departing from the scope thereof as defined in the appended claims.

Claims (3)

1. Concrete vibrating and finishing apparatus comprising a petrol engine connected to a rotatable vibrating head by a flexible drive and throttle means for effecting linear control of the working speed of the engine and the vibrating head and a shaft mounting the engine, the throttle, a handgrip and the flexible drive, characterised in that the vibrating head comprises a tubular outer casing, a tip at one end of the casing, a coupling at the other end of the casing and an eccentric rotor journalled within the casing which is connected to the flexible drive by said coupling.

2. Apparatus as claimed in claim I wherein the casing of the vibrating head is fabricated from metal and the tip of the vibrating head is fabricated from metal which is heavier than the metal used to fabricate the casing.

3. Concrete vibrating and finishing apparatus as claimed in claim 1 and substantially as herein described with reference to the accompanying drawings. DATED this 12 th day of November 2003 GEORGE JOHN KERR By his Patent Attorneys CULLEN CO.