US2765531A

US2765531A - Tool for electrically heating and removing paint

Info

Publication number: US2765531A
Application number: US253616A
Authority: US
Inventors: Jr John A Campbell; Joseph W Jeffries
Original assignee: Campbell Technologies Inc
Current assignee: Campbell Technologies Inc
Priority date: 1951-10-29
Filing date: 1951-10-29
Publication date: 1956-10-09
Anticipated expiration: 1973-10-09

Description

96h 9, 1956 J. A. CAMBELL, JR., ETAL 2,765,531

TOOL FOR QLECTRICALLY HEATING AND REMOVING PAINT Filed Oct. 29, 1951 2 Sheets-Sheet 1 Bk 5 INVENTORS JOHNA-CAMPBEL'LJR- JQSEPH w- JVEFFRIES Oct. 9, 1956 J. A. CAMBELL, JR, ET AL 2,765,531

TOOL FOR ELECTRICALLY HEATING AND REMOVING PAINT Filed 001:. 29, 1951 2 Sheets-Sheet 2 INVENTORS JOHN A CAMPBELL,JR- BY JOSEPH W- JEFFRIES rooL FOR ELECTRICALLY HEATING AND REMOVING PAINT John A. Campbell, .lr.,

Lakewood, Ohio; bell Berea, and Joseph W. Jeffries, said .leifries assignor to said Camp This invention relates to a tool for removing paint, varnishes and like coatings from the surfaces of various kinds of materials by first softening and loosening the coating and then acting to scrape and scoop or lift it from the material underneath.

Heretofore, paint heating and scraping tools have utilized the softening and loosening effect of a heating means in proximity to the coated surface, and such tools have been provided with a scraping edge or knife which is moved across the loosened paint to further loosen or remove the same.

An object of the present invention is to provide a tool of this general character, which, however, has advantages of uniformly and quickly heating the paint or like coating to soften and loosen the same, and which is provided with a combination of paint scraping and paint cutting and lifting means.

Other objects include the provision of such a tool which shall be simple in construction, efficient in operation and easy to handle, and by which an individual operator may remove a larger amount of coating in a given time and with a given electrical power input for the heating.

Other objects include so constructing such a tool that it may be most convenient to handle with either one or two hands of an operator moving it along the coated surface, and which may be set at rest while heating or while remaining heated without the heat endangering any adjacent surface or material.

A more specific object is to so construct the tool that it may be made of parts produced by stamping or comparably efiicient cheap methods of production, and which may be convenient to assemble and be light in weight relative to its high degree of effectiveness.

The tool includes a heating element of like simple construction which may be firmly mounted and contained while being so arranged as to most effectively direct and apply heat to the coating to be removed.

Another specific object is to so arrange the tool that it has a simple etficient scraper at one end adapted to be applied to the coating and generally at substantially a right angle to the surface, while having a scooping or lifting shaving knife spaced therefrom and adapted to cut or shave the loosened coating from the surface.

In using our tool it has been found that larger areas of a given paint or like coating may be removed at a given time. Likewise, it has been proven to be efficient in removing larger numbers of multiple coatings such as many layers of paint.

Other features and characteristics will become apparent in the following description which relates to the accompanying drawings in which is shown a preferred embodiment. It is to be understood that various modifications may be made without departing from the spirit of our invention as defined in the appended claims.

In the drawings,

Fig. l is a side elevation of our heating and coating removing tool;

2,765,531 Patented Oct. 9, 1955 ice Fig. 2 is a plan of the same;

Fig. 3 is a view on a reduced scale showing the removing tool standing inverted in a non-use position;

Fig. 4 is a transverse section taken substantially on a plane indicated by the line 4-4 of Fig. 1;

Fig. 5 is a transverse section taken substantially on a plane indicated by the line 55 of Fig. 1;

Fig. 6 is a side elevation of the heating element body partly in section;

Figs. 7 and 8 are details of a protective ferrule for the lead-in wires;

Fig. 9 is a fragmentary perspective view showing the bottom of the heating element carrier;

Fig. 10 is a diagrammatic view of a suitable arrangement of a heating element; and

Fig, 11 is a perspective view illustrating a modified form of scraper knife.

Describing the structure shown in the drawings by the use of reference numerals, the body of our paint-removing tool is shown as comprising essentially a hood member 1 formed of sheet metal and having its side Walls forming a rectangle with a closed top portion, rounded corners and an open bottom.

Fitted into and extending upwardly between the side walls are flanges 6 formed on a bottom member 5, and which may be removably secured as by screws, indicated at 7.

The member 5 is essentially a closure plate and has a similar upturned flange 8 at its forward end. Between the flange 8 and forward wall of the housing 7 may be fitted ascraper blade 10 held in position by screws 11 passing therethrough and into the flange 8.

The bottom plate 5 is shown as provided with rearwardly extending extensions 15 forming supports for a scraping, cutting and lifting blade.

As shown, this cutting and lifting blade comprises a transverse strip 20 having a knife edge 21 pointed forwardly. The ends of the strip are turned upwardly at 22 and then inwardly as indicated at 23, and over the supporting extensions 15, and there secured by screws indicated at 24.

The end portions 22 may be cut away at their forward sides as shown at 25. A substantially slot-like passage is thus formed, between the strip 20 and the rear end of the plate 5, through which the paint material may pass as it is cut, scraped, or peeled and lifted from its surface, somewhat after the manner of shavings cut by a carpenters hand plane.

Rising from the top of the hood 1 is a box-like housing support having an upwardly sloping top surface and extending upwardly and rearwardly to a suitable handle 30, and on which is mounted a knob-like handle 32 for the other hand to make it convenient to use the tool with two hands.

The handle support may also house the wiring connections, as will be hereinafter described. The handle supports, of course, may be of any suitable construction preferably capable of being formed of stampings or of strips and stampings.

As shown, a strip member 35 may extend over the top of the handle 30 and then be curved downwardly and forwardly at 36 where it lies along and may be suitably secured to the top or the cover of the hood 1.

A strip of similar material of the same width, designated 40, may lie along the outer end of the strip 35, over the handle, and extend downwardly and forwardly toward the front of the housing 1, and then rearwardly as at 42 along the top of the housing and there be secured to the hood as by welding, riveting, or the like.

The strip 35 may be provided with a longitudinal head or rib 37, while a portion of the strip 40 may likewise be strengthened by a bead portion 43 for a considerable 3 distance of its length and over a portion of the handle 30.

The handle 30 may be secured to the rearwardly projecting coextensive ends of the

strips

35 and 40 by a screw 34. These ends may also be spot-welded together along their contiguous portions, if desired.

Side plates, indicated at 50 and 51, may close the sides of the opening between the strips, forming an elongated substantially triangular housing, thus improving the appearance, adding strength and also enclosing the wiring connections.

Decorative slots are indicated at 52, which also serve for ventilation of the housing, somewhat inhibiting the passage of heat through the handle supporting structure to the metal adjacent the handles.

The handle 32' is shown as fitted over a portion of the bead 43, and as secured byasuitable bolt 60 having its head set inwardly from a flat face 62.

The flat surface 62 is at such an angle that its plane is substantially in alignment with the upper end of the supporting strip 40 at the top of the handle 30. Thus, when the tool is heated, and it is desired to set it aside momentarily or after using, this may be safely done by inverting the tool, the fiat surface 62 and the handle end resting upon any fiat support such as indicated at S in Fig. 3.

The

plates

50 and 51 may be held in position by counter sunk screws 54 at the three corners of the plates, screws extending through and across the width of the

strips

35 and 40, the heads preferably being flush in one plate, and the opposite ends of the screws being threaded into the other plate.

Within the elongated housing formed by the hood 1 and bottom plate is contained a means for heating the plate 5 to a high enough temperature that when brought into proximity with the paint, it quickly softensfacilitating its removal.

In the form shown the heating means comprises a coiled resistance wire 60 laid in downwardly facing grooves 65 in a refractory carrier block 66, after the manner of heating devices such as electric hot plates, or the like.

The coils are arranged in connected adjacent parallel paths in the grooves 65, as shown in Fig. 10, and are connected with contact members in the form of bolts indicated at 70, to which terminals 72 of lead-in wires may be secured by the usual nuts, as shown.

These lead-in wires may be the ends of a suitable twowire conductor cord. We prefer. to use a type known as neoprene heater cord, the two wires being individually insulated, and the neoprene coating for each wire adhering to the other to form a composite conductor cord, as indicated at 75 in Figs. 5, 7 and 8.

An opening may be formed in one of the side plates, and a resilient securing ferrule 80 may be fitted therein, embracing the composite cord and tightly gripping the same to resist longitudinal pull as well as protecting the cord against a sharp bending.

The ferrule is shown as a split hollow member which may be pressed sideways over the cord, and then inserted in the opening. i

The grooved heating element carrier 66 is, of course, made of suitable ceramic material of desired heat-resisting character, and its lower grooved face is held in close contact with the plate 5, and the radiant heat from the coiled resistance wire may thus pass directly to the plate 5.

Above and at the ends of the ceramic body is a space which may be packed with a suitable insulating material such as fibreglass or the like, as indicated at 85.

As a substitute for the straight edge blade ll' we may use blades having special curvatures suited to the profile contour of particular moldings. For example, in Fig. 11, we have shown a blade 90, having openings for the screws 11, and which may thus be held in the position and in the manner described for the scraper blade The cutting or scraping edge 91 is shown as shaped to fit curves and a groove of a mold. This is illustrative only of a number of shapes, and obviously various blades such as this may be used in place of the scraper element 10.

To use our paint-removing tool, the current may be turned on and the tool be allowed to heat the plate 5 preferably while standing in a safe position, such as that of the inverted or upside-down position of Fig. 3.

After a short heating interval, the tool may be set against and moved along the surface having the paint to be removed, and as the tool is moved along the surface, the heat softens the paint sufficiently that the knife edge 20 may cut and peel it free from the wood or other surface.

The paint so removed passes out over the plate 20 and under the inturned portions and rear end of the plate 5, after the manner of shavings from a hand wood-cutting plane. The paint so removed quickly hardens, and, of course, may be easily disposed of.

It is important to note that an essential feature of our paint-removing tool is that of providing the scraping or cutting tools at opposite ends of the heated bottom plate 5. The hot area of the plate between the front scraper and back scraper or peeler is thus maintained uniformly spaced from the paint surface. The heat radiation is not interrupted or impeded, and the most effective heating distance or spacing between the fiat surface of the plate 5 and the paint surface is maintained with assurance and in the natural use of the tool.

The most frequently used stroke, for the greater part of a given paint area, is a continuous slow motion pressing the tool toward the paint surface, and many layers of old, hard dry paint may be removed with great rapidity. For example, several layers of old paint have been removed from wood at an average rate of three square feet per minute with a tool having a heating plate six or seven inches long and a width of approximately three inches.

The scraper blade 10 may be passed over the heated paint to aidin removal and loosening, and may get into corners, offsets andspots not reached by the peeler or cutting blade 20.

The tool is easy to use and does not require hard pushing or scraping. The temperatures required are reasonably safe and may be controlled so that it may be effectively used, while notbeing dangerous. The heat is preferably so controlled that inflammable materials or even paper will not be ignited by the tool, and yet the heating of the paint maybe very rapid for the effective and easy removal described.

It is understood, of course, that for the sake of further safety it is desired to set the tool at rest in the inverted position.

It will be further seen from the construction described that the device may be made of sheet and strip material with a minimum of cutting, stamping and pressing operations; may be readily assembled, is durable in use, and otherwise attains the objectives set forth.

Having thus described our invention, what we claim l. A paint removing tool comprising an electrical heating element, an elongated fiat plate having upturned flanges, a housing fitting over and secured to said flanges, means for supporting said heating element within said housing and in substantial parallelism with saidplate, the heating element being positioned to radiate and distribute heat substantially co-extensively with the plate, a removable thin metal scraper blade secured to the forward end of the plate and being substantially transversely co-extensive with the width of the plate and projecting downwardly and presenting a scraping edge to the paint, a peeler blade rigidly secured to the rear end of the plate and having connections at its ends fixed to the plate and spaced therefrom and forming an open space between the blade and the plate, the housing having a top with an opening therein, and the heating element support having electrical connecting elements extending upwardly through said opening, insulating means surrounding said connecting elements, wires leading to said connecting elements, a hollow handle supporting structure mounted on the top of the housing and surrounding the electrical connections, and having a rearward extension pusher handle secured thereto, and a second handle secured to the forward portion of said handle structure, the position of the blades being such that as the tool is moved on a paint surface the first-mentioned blade acts as a loosening scraper while the peeler blade acts to lift and peel the paint, passing it through the opening between the blade and the heating plate.

2. The tool described in claim 1 in which the peeler blade is a fiat transverse knife-like member having a sharp cutting edge positioned to present its cutting edge toward the plate and toward the forward end of the tool.

3. A heating, scraping and cut-ting paint-removing tool comprising an elongated fiat plate, a transverse blade projecting downwardly therefrom at the forward end, a flat cutting blade extending substantially parallel to the plane of the plate and spaced downwardly therefrom at the rear end, a heating element and refractory material supporting the same above the plate, a hood inclosing the heating element and said material, a handle and a supporting means therefor rising from and secured to the top of the hood, said supporting means comprising a hollow structure having spaced side walls and an opening for receiving a current-conducting cord and an upward rearward extension rigid therewith, and means for attaching the handle to said extension.

4. The tool described in claim 3, in which the flat cutting blade at the rear comprises a transverse strip having a forwardly projecting cutting edge and having integral end portions turned upwardly and inwardly and in substantial alignment with the sides of the heating plate, the heating plate having rearward extensions to which the inwardly turned portions may be secured.

5. The structure described in claim 1, in which the second handle secured to the forward portion of said handle structure is formed with a transverse top fiat surface on which the tool may rest when in an inverted posi- HOD.

6. The tool structure defined in claim 3 in which the handle supporting means comprises metal strip members extending upwardly and rearwardly from the hood and supporting a downwardly extending handle spaced from the rear of the hood, and in which is provided an upwardly extending handle toward the forward end of the hood, the latter handle and the strip members forming a support for the tool when in an inverted position.

7. The paint removing tool described in claim 1, in which the forward scraper blade is removably secured to said plate and said plate has a rearward extension projecting outwardly from the rear of said housing, and in which said peeler blade comprises a flat knife-like structure having its end portions extending at right angles thereto and then inwardly and engaging the rearward extension of the plate, and removable means for securing said end portions to the plate extension.

References Cited in the file of this patent UNITED STATES PATENTS 1,156,652 Aiken Oct. 12, 1915 1,408,623 Manley Mar. 7, 1922 1,575,425 Hamada Mar. 2, 1926 2,063,894 Jack et a1. Dec. 15, 1936 2,256,648 Preisser Sept. 23, 1941 2,258,027 Mossback et a1. Oct. 7, 1941 2,491,716 Collins Dec. 20, 1949 2,684,531 Smith July 27, 1954 2,686,248 Green Aug. 10, 1954 FOREIGN PATENTS 408,535 Great Britain Apr. 12, 1934