GB2148770A

GB2148770A - Method and apparatus for stripping

Info

Publication number: GB2148770A
Application number: GB08424022A
Authority: GB
Inventors: Ian Douglas Marlow; William Nicholson
Original assignee: Individual
Current assignee: Individual
Priority date: 1983-09-22
Filing date: 1984-09-20
Publication date: 1985-06-05
Also published as: GB8325346D0; GB8424022D0

Abstract

A power operated hand tool for stripping paint, wallpaper or the like has a stripping blade (e) driven by an electric motor (a) through a mechanism (b, j, h) for turning rotary into reciprocatory motion. Lost motion in this mechanism enables drive to be transmitted to blade (e) only when loaded by the user. The blade executes short reciprocating movements and strips off the wallpaper as the apparatus is advanced by the user. <IMAGE>

Description

SPECIFICATION Method and apparatus for stripping This invention relates to a method and apparatus for stripping. An example of a method of stripping to which the invention is applicable, is the stripping of paint or wallpaper from walls and the like.

The problem of acting on large surfaces, for example when scraping wallpaper or stripping paint, has only been satisfactorily solved hitherto by hard labour using hand tools. There is therefore a considerable need for some improved method for stripping paint, wallpaper and the like.

An object of the present invention is to provide a method and apparatus for stripping, offering improvements in relation to matters mentioned above, or generally.

According to the invention there is provided a method and apparatus for stripping, as defined in the accompanying claims.

In an embodiment described below, a stripping device is provided in which the primary energy for the stripping action is not provided by the operator, but by an external source, the device thus providing a power stripping tool. As a result, the operator is required only to attend to the tasks of locating, supporting and guiding the stripping tool.

In the embodiment, the stripping device, providing a powered stripper or scraper, employs a motion similar to that of a conventional hand scraper. The scraper blade or element contacting the surface being acted on, moves backwards and forwards in a reciprocating or flat rotary motion in the plane of the surface to be scraped or stripped.

The invention also provides a method and apparatus comprising any novel feature or concept or novel combination of features or concepts disclosed herein.

An embodiment of the invention will now be described by way of example with reference to the accompanying drawing in which there is shown an exploded view of stripping apparatus according to the invention.

As shown in the drawing, an electric motor (a) turns a double cam (b) when energised by operation of a hand trigger switch (c). The cam (b) rotates within the mechanism's frame (d).

A stripping or scraping blade or element (e) is attached by a screw to the slide (f).

When the blade (e) is pressed against the surface to be stripped, it moves the slide (f) inwards against the spring (g), thereby taking up clearance or lost motion, and the slide comes into contact with cam (b), thereby producing reciprocating motion.

The slide (f) does not contact the cam (b) directly, but through a nylon block (h) having a hardened steel shoe (j) providing a wear surface to directly contact the cam.

The slide (f) is kept in the frame (d) by the hollow retaining peg (k). The frame (d) consists of two steel plates separated by two steel spacers, secured by four screws, and the slide runs on eight small steel balls, four above and four below.

The frame (d) is secured to the motor (a) by two screws through the top plate, and the spring (g) is retained by a rear spacer (I).

The whole mechanical unit is encased by a plastic body which is clipped and screwed together.

In use, when the motor is first energized, the cam (b) freely rotates within the clearance opening provided in the slide (f) so that no reciprocating motion is thereby generated in the slide or in the blade (e).

As soon as the operator presses the blade against the work surface, the lost motion is taken up and, according to the inward thrust exerted on the blade, the amplitude of the reciprocating motion generated therein is increased.

It will be understood that the device can rapidly strip wallpaperfrom a wall with little effort on the part of the operator.

Many modifications can be made in the above embodiment while remaining within the scope of the invention. Included among such modifications are the following: 1. Modifications in the design and co-operation of the moving parts of the mechanism for translating rotary motion into reciprocating motion.

2. The motion of blade (e) does not need to be pure reciprocating motion, and it could include a rotary component. The blade need not therefore be guided for strict linear movement, but could be suitably mounted in several different ways for back and forth motion.

3. Many variations could be provided in the lost motion device provided between the cam drive and the reciprocating slide member.

In the above embodiment, the nylon block (h) is preferably of an oil impregnated nylon, and no doubt many alternative materials could be used.

4. It might be possible to apply to the stripping blade or element, a motion having a very short stroke and which therefore might be considered to be more of a vibratory motion. Such motion might be generated by an electrical vibrator mechanism ratherthan by a rotary motor or the like.

5. Naturally, the shape of frame (e) can be varied considerably, as indeed can the external shape of the housing of the apparatus as shown in the drawing.

6. Other motor drive arrangements may be provided including a hydraulic or a pneumatic drive.

7. Alternative means and/or additional means may be provided for damping the movement of the stripping blade or element.

1. A stripping or scraping device operating on a repetitive short stroke action.

2. A device according to claim 1 wherein the action is produced by a motorised power source.

3. A device according to claim 1 or claim 2 wherein the action or motion produces force against the material to be removed or acted on.

4. A device according to any preceding claim wherein the force produced by the action is generated against inertia of the device and operator.

5. A power operated stripping device having a reciprocatable stripping blade or element.

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Method and apparatus for stripping This invention relates to a method and apparatus for stripping. An example of a method of stripping to which the invention is applicable, is the stripping of paint or wallpaper from walls and the like. The problem of acting on large surfaces, for example when scraping wallpaper or stripping paint, has only been satisfactorily solved hitherto by hard labour using hand tools. There is therefore a considerable need for some improved method for stripping paint, wallpaper and the like. An object of the present invention is to provide a method and apparatus for stripping, offering improvements in relation to matters mentioned above, or generally. According to the invention there is provided a method and apparatus for stripping, as defined in the accompanying claims. In an embodiment described below, a stripping device is provided in which the primary energy for the stripping action is not provided by the operator, but by an external source, the device thus providing a power stripping tool. As a result, the operator is required only to attend to the tasks of locating, supporting and guiding the stripping tool. In the embodiment, the stripping device, providing a powered stripper or scraper, employs a motion similar to that of a conventional hand scraper. The scraper blade or element contacting the surface being acted on, moves backwards and forwards in a reciprocating or flat rotary motion in the plane of the surface to be scraped or stripped. The invention also provides a method and apparatus comprising any novel feature or concept or novel combination of features or concepts disclosed herein. An embodiment of the invention will now be described by way of example with reference to the accompanying drawing in which there is shown an exploded view of stripping apparatus according to the invention. As shown in the drawing, an electric motor (a) turns a double cam (b) when energised by operation of a hand trigger switch (c). The cam (b) rotates within the mechanism's frame (d). A stripping or scraping blade or element (e) is attached by a screw to the slide (f). When the blade (e) is pressed against the surface to be stripped, it moves the slide (f) inwards against the spring (g), thereby taking up clearance or lost motion, and the slide comes into contact with cam (b), thereby producing reciprocating motion. The slide (f) does not contact the cam (b) directly, but through a nylon block (h) having a hardened steel shoe (j) providing a wear surface to directly contact the cam. The slide (f) is kept in the frame (d) by the hollow retaining peg (k). The frame (d) consists of two steel plates separated by two steel spacers, secured by four screws, and the slide runs on eight small steel balls, four above and four below. The frame (d) is secured to the motor (a) by two screws through the top plate, and the spring (g) is retained by a rear spacer (I). The whole mechanical unit is encased by a plastic body which is clipped and screwed together. In use, when the motor is first energized, the cam (b) freely rotates within the clearance opening provided in the slide (f) so that no reciprocating motion is thereby generated in the slide or in the blade (e). As soon as the operator presses the blade against the work surface, the lost motion is taken up and, according to the inward thrust exerted on the blade, the amplitude of the reciprocating motion generated therein is increased. It will be understood that the device can rapidly strip wallpaperfrom a wall with little effort on the part of the operator. Many modifications can be made in the above embodiment while remaining within the scope of the invention. Included among such modifications are the following: 1. Modifications in the design and co-operation of the moving parts of the mechanism for translating rotary motion into reciprocating motion. 2. The motion of blade (e) does not need to be pure reciprocating motion, and it could include a rotary component. The blade need not therefore be guided for strict linear movement, but could be suitably mounted in several different ways for back and forth motion. 3. Many variations could be provided in the lost motion device provided between the cam drive and the reciprocating slide member. In the above embodiment, the nylon block (h) is preferably of an oil impregnated nylon, and no doubt many alternative materials could be used. 4. It might be possible to apply to the stripping blade or element, a motion having a very short stroke and which therefore might be considered to be more of a vibratory motion. Such motion might be generated by an electrical vibrator mechanism ratherthan by a rotary motor or the like. 5. Naturally, the shape of frame (e) can be varied considerably, as indeed can the external shape of the housing of the apparatus as shown in the drawing. 6. Other motor drive arrangements may be provided including a hydraulic or a pneumatic drive. 7. Alternative means and/or additional means may be provided for damping the movement of the stripping blade or element. CLAIMS

6. A device according to claim 5 wherein the stripping element is driven by a motor through a reciprocator mechanism.

7. A device according to claim 5 or claim 6 wherein lost motion means is provided in the reciprocator mechanism to limit reciprocating motion of the stripper element.

8. A device according to claim 7 wherein loading of the stripper element against a workpiece acts to take up said lost motion.

9. A power-operated stripping device comprising a reciprocatable stripping element wherein a lost motion device in the drive to the stripper element is provided whereby the reciprocating motion of the stripper element may be controlled by the user.

10. A device according to claim 9 wherein an increase in the loading on the stripper element by the operator tends to increase the reciprocating motion of the stripper element.

11. A method of stripping comprising powerdriving a reciprocatable stripping element.

12. A method according to claim 11 comprising the step of providing lost motion in the drive to the stripper element and taking up said lost motion by loading the stripper element against a workpiece, so as to increase the amplitude of the motion of the stripper element.

13. A stripping device substantially as described herein with reference to the accompanying drawing.

14. A method of stripping substantially as described herein with reference to the accompanying drawing.