Hand-held power finisher

Abstract

A hand-held power finisher includes a handle for being gripped by a user, and a mounting hub attached for rotation at one end of the handle. A plurality of blades extend outwardly from the mounting hub. A drive shaft is operatively connected to the mounting hub. A motor is operatively connected to the drive shaft, and is adapted for rotating the mounting hub and blades relative to the handle. The blades engage and finish a solid surface.

Description

TECHNICAL FIELD AND BACKGROUND OF THE INVENTION

This invention relates to a hand-held power finisher especially applicable for finishing solid surfaces, such as concrete countertops. Concrete countertops are relatively lightweight, come in limitless colors and textures, are essentially seamless, and can be formed into a number of interesting complex shapes and designs.

Concrete countertops are becoming more popular across the country. The manufacturing process, however, is labor intensive and requires intricate hand work in making the forms. The forms are either pre-cast in a workshop where conditions are controlled, or built on-site to custom design the countertop to a particular client's needs including radius edges, curved corners, and the like. The countertops are made of cement, lightweight aggregates, and a combination of additives such as fiber reinforcement, silica fume, pozzolan, and acrylic. Some type of reinforcement is generally used, such as structural steel, wire mesh, fiberglass, and/or fibers.

After curing, the countertops are typically finished using progressively finer polishing stones, and then sealed using an epoxy sealer. The polishing stones grind off the cement surface “skin” which forms on all concrete. This achieves two important objectives; durability and beauty. The skin creates a unwanted barrier which would otherwise prevent the protective sealer from penetrating the concrete. Grinding and honing the concrete also reveals the complex patterns of aggregate and colored cement that would lie hidden beneath the drab, monochromatic cement skin. While polishing stones are generally effective, the time and labor required to grind and hone the concrete form is substantial.

SUMMARY OF INVENTION

Therefore, it is an object of the invention to provide a hand-held power finisher which is especially applicable for finishing solid surfaces, such as concrete countertops.

It is another object of the invention to provide a hand-held power finisher which reduces the time and labor required to grind and hone solid surfaces.

It is another object of the invention to provide a hand-held power finisher which utilities rotating finishing blades.

It is another object of the invention to provide a hand-held power finisher which has a large pitch-control range giving complete control over finishing and floating for application versatility during operation.

It is another object of the invention to provide a hand-held power finisher transmits power to the finishing blades through gears.

It is another object of the invention to provide a hand-held power finisher which produces a swirl-free flat finish.

It is another object of the invention to provide a hand-held power finisher which is applicable for finishing concrete, terrazzo, marble, granite, and other solid surfaces.

It is another object of the invention to provide a hand-held power finisher which utilizes replaceable and exchangeable finishing blades.

It is another object of the invention to provide a hand-held power finisher which utilizes combination blades for rough surfaces and finishing blades for final smoothing.

These and other objects of the present invention are achieved in the preferred embodiments disclosed below by providing a hand-held power finisher. The power finisher includes a handle for being gripped by a user, and a mounting hub attached for rotation at one end of the handle. A plurality of blades extend outwardly from the mounting hub. A drive shaft is operatively connected to the mounting hub. A motor is operatively connected to the drive shaft, and is adapted for rotating the mounting hub and blades relative to the handle. The blades engage and finish a solid surface.

According to another preferred embodiment of the invention, a light is provided for illuminating the solid surface.

According to another preferred embodiment of the invention, an air spray is provided for directing air flow towards the solid surface.

According to another preferred embodiment of the invention, a water spray is provided for spraying a water mist upon the solid surface.

According to another preferred embodiment of the invention, means are provided for adjusting the pitch of each of the plurality of blades.

Preferably, the pitch of each of the plurality of blades is adjustable within a range of 0-40 degrees.

According to another preferred embodiment of the invention, each of the plurality of blades has a textured grit surface adapted for engaging the solid surface.

According to another preferred embodiment of the invention, the power finisher includes more than three blades.

According to another preferred embodiment of the invention, each of the plurality of blades has a length less than 8 inches.

According to another preferred embodiment of the invention, each of the plurality of blades has a width less than 4 inches.

According to another preferred embodiment of the invention, the motor is operable for rotating the blades at speeds greater than 50 rpm.

BRIEF DESCRIPTION OF THE DRAWINGS

Some of the objects of the invention have been set forth above. Other objects and advantages of the invention will appear as the description proceeds when taken in conjunction with the following drawings, in which:

FIG. 1 is a perspective view of a hand-held power finisher according to one preferred embodiment of the present invention;

FIG. 2 is a schematic view illustrating the gear assembly adapted for driving the finishing blades of the power finisher;

FIG. 3 is a fragmentary perspective view of the power finisher showing the gear key of the tilt adjustment shaft in a normal position away from the blade mounting hub; and

FIG. 4 is a fragmentary perspective view of the power finisher showing the tilt-adjustment shaft in a depressed condition inserting the gear key into a keyway formed with the tilt-adjustment gear, and demonstrating tilt adjustment of the finisher blades upon rotation of the tilt control knob.

DESCRIPTION OF THE PREFERRED EMBODIMENTS AND BEST MODE

Referring now specifically to the drawings, a hand-held power finisher according to the present invention is illustrated in FIG. 1, and shown generally at reference numeral 10. The power finisher 10 is especially applicable for sanding, grinding, honing, polishing, and cleaning solid surface countertops constructed of concrete, terrazzo, marble, or granite. The finisher 10 comprises an ergonomic, contoured handle 11 with a number of optional accessories including a water/air spray 12 and light 14. The light illuminates an area of the solid surface being finished. The water spray applies a light mist upon the solid surface during finishing, while the air spray promotes drying. The water and air sprays are emitted from a single nozzle, and separately activated using any suitable and conventional triggering means (not shown).

As best shown in FIGS. 1 and 2, a number of radially-extending finishing blades 15 are carried by a mounting hub 16 arranged at one end of the handle 11. The mounting hub 16 is attached for rotation relative to the handle 11, and is actuated by a standard gear assembly including a drive shaft 17, spur gear 18, and motor 19. The spur gear 18 operatively engages a complementary gear 21 formed with the mounting hub 16. The motor 19 is housed within the handle 11, and is operatively connected to the drive shaft 17 for rotating the mounting hub 16 and attached finishing blades 15. The motor may be any suitable AC or DC electric motor with an operating voltage of 115v/60 Hz and current of between 5-10 Amps. Preferably, the mounting hub 16 and blades 15 rotate at speeds ranging from 50-450 rpm. Alternatively, the finisher 10 may utilize a small pneumatic or hydraulic motor. The motor 19 may be activated by any conventional means including a simple on-off switch, or a finger trigger allowing variable speed adjustment.

The blades 15 are replaceable and exchangeable, and preferably have a textured or grit surface for engaging the solid surface being finished. The surface-engaging portion of the blade 15 may comprise a flexible fiber mesh impregnated with diamond powder, a resin diamond, a rigid aluminum, or semi-rigid rubber. The grit ranges from 70-3000. For honing and polishing concrete, for example, the blade grit is preferably between 70 and 1800. According to one embodiment, each blade 15 is approximately 6-inches long and approximately 3-inches wide.

Referring to FIGS. 2, 3, and 4, each blade 15 is carried on an elongated arm 22 secured to the mounting hub 16. Respective bevel gears 23 are located at proximal ends of the blade arms 22, and are positioned in meshing alignment with a complementary bevel gear 24 located inside the mounting hub 16. A tilt-adjustment shaft 25 is axially-biased away from the gear 24, and has an integrally-formed gear key 25A designed for inserting into a complementary shaped keyway 24A formed through the tilt-adjustment gear 24. When the drive motor 19 is stopped or idle, the tilt-adjustment shaft 25 is depressed, as indicated by arrow 26, causing the gear key 25A to insert into the keyway 24A of the tilt-adjustment gear 24. With the gears 23 and 24 engaged, a knob 28 at an opposite end of the tilt-adjustment shaft 25 is manually rotated, as indicated by arrow 29, to actuate the gears 23, 24 and simultaneously adjust the tilt angle of blades 15, as indicated at arrows 31 and 32. Once adjusted, the shaft 25 retracts to its normal position away from the tilt-adjustment gear 24. Preferably, the tilt-adjustment gear 24 has a built-in ratchet mechanism which restricts its rotation in one direction, thereby fixing the tilt orientation of the blades 15 during operation of the finisher 10. Thus, as the rotating tilted blades 15 are applied against the solid surface, the meshing arm gears 23 and tilt-adjustment gear 24 cooperate to prevent flattening of the blade angle. Preferably, the blade angle is adjustable between 0-40 degrees. Examples of power trowels with tilt adjustable blades are provided in prior U.S. Pat. Nos. 6,739,798; 5,405,216; and 4,673,311. The complete disclosures of these patents are incorporated herein by this reference.

A hand-held power finisher is described above. Various details of the invention may be changed without departing from its scope. Furthermore, the foregoing description of the preferred embodiment of the invention and best mode for practicing the invention are provided for the purpose of illustration only and not for the purpose of limitation-the invention being defined by the claims.

Claims

1. A hand-held power finisher, comprising:

(a) a handle for being gripped by a user;

(b) a mounting hub attached for rotation at one end of said handle;

(c) a plurality of blades extending outwardly from said mounting hub;

(d) a drive shaft operatively connected to said mounting hub; and

(e) a motor operatively connected to said drive shaft, and adapted for rotating said mounting hub and blades relative to said handle, said blades adapted for engaging and finishing a solid surface.

2. A hand-held power finisher according to claim 1, and comprising a light adapted for illuminating the solid surface.

3. A hand-held power finisher according to claim 1, and comprising an air spray adapted for directing air flow towards the solid surface.

4. A hand-held power finisher according to claim 1, and comprising a water spray adapted for spraying a water mist upon the solid surface.

5. A hand-held power finisher according to claim 1, and comprising means for adjusting the pitch of each of said plurality of blades.

6. A hand-held power finisher according to claim 5, wherein the pitch of each of said plurality of blades is adjustable within a range of 0-40 degrees.

7. A hand-held power finisher according to claim 1, wherein each of said plurality of blades comprises a textured grit surface adapted for engaging the solid surface.

8. A hand-held power finisher according to claim 1, wherein said plurality of blades comprises greater than three blades.

9. A hand-held power finisher according to claim 1, wherein each of said plurality of blades has a length less than 8 inches.

10. A hand-held power finisher according to claim 1, wherein each of said plurality of blades has a width less than 4 inches.

11. A hand-held power finisher according to claim 1, wherein said motor is operable for rotating said blades at speeds greater than 50 rpm.

12. A hand-held power finisher, comprising:

(a) a handle for being gripped by a user;

(b) a mounting hub attached for rotation at one end of said handle;

(c) at least three blades extending outwardly from said mounting hub;

(d) a drive shaft operatively connected to said mounting hub;

(e) a motor operatively connected to said drive shaft, and adapted for rotating said mounting hub and blades relative to said handle, said blades adapted for engaging and finishing a solid surface; and

(f) means for adjusting the pitch of each of said blades within a range of 0-40 degrees.

13. A hand-held power finisher according to claim 12, and comprising a light adapted for illuminating the solid surface.

14. A hand-held power finisher according to claim 12, and comprising an air spray adapted for directing air flow towards the solid surface.

15. A hand-held power finisher according to claim 12, and comprising a water spray adapted for spraying a water mist upon the solid surface.

16. A hand-held power finisher according to claim 12, wherein each of said plurality of blades comprises a textured grit surface adapted for engaging the solid surface.

17. A hand-held power finisher according to claim 12, wherein each of said plurality of blades has a length less than 8 inches.

18. A hand-held power finisher according to claim 12, wherein each of said plurality of blades has a width less than 4 inches.

19. A hand-held power finisher according to claim 12, wherein said motor is operable for rotating said blades at speeds greater than 50 rpm.

20. A hand-held power finisher, comprising:

(a) a handle for being gripped by a user;

(b) a mounting hub attached for rotation at one end of said handle;

(c) at least three blades extending outwardly from said mounting hub;

(d) a drive shaft operatively connected to said mounting hub;

(e) a motor operatively connected to said drive shaft, and adapted for rotating said mounting hub and blades relative to said handle, said blades adapted for engaging and finishing a solid surface;

(f) means for adjusting the pitch of each of said blades within a range of 0-40 degrees;

(g) a light adapted for illuminating the solid surface;

(h) an air spray adapted for directing air flow towards the solid surface; and

(i) a water spray adapted for spraying a water mist upon the solid surface.