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Publication numberUS2237870 A
Publication typeGrant
Publication dateApr 8, 1941
Filing dateApr 29, 1940
Priority dateApr 29, 1940
Publication numberUS 2237870 A, US 2237870A, US-A-2237870, US2237870 A, US2237870A
InventorsSmith William J
Original AssigneeSmith William J
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Plaster cutter
US 2237870 A
Abstract  available in
Images(2)
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Claims  available in
Description  (OCR text may contain errors)

April 1941- w. J. SMITH 2.237.870

PLASTER CUTTER Filed April 29, 1940 2 Sheets-Sheet 2 .23 C .5 I 4 I 5 I 5 l 25 I 22 I ,z I l I I 21 .15 I I G i a E f I 25 i is jl Inventor h/uL/AM J fi/VIITH, Q 9 By @Mm A itorney Patented Apr. 8, 1941 UNITED STATES PATENT OFFICE PLASTER. CUTTER William J. Smith, Highland Park, N. J.

Application April 29, 1940, Serial-No. 332,333

3 Claims.

This invention relates to a plaster cutter, and has for the primary object the provision of a power driven portable device of the above stated character which is especially adapted for preparing plastered walls or ceilings which have been cracked or damaged prior to decorating, the device being of such a construction that a workman may accurately and rapidly remove loose plaster about a crack or defect in the wall or ceiling so that when pointed up or patched the material used will readily adhere and remain in place permitting the ceiling or wall after being decorated to appear free of imperfections usually caused by imperfect patching and the failure of patch material to properly remain in place due a to loose plaster.

With these and other objects in view, as will become apparent as the description proceeds, the invention consists in certain novel features of construction, combination and arrangement of parts as will be hereinafter more fully described and claimed. I

For a complete understanding of my invention, reference is to be had to the following description and accompanying drawings, in which Figure 1 is a side elevation illustrating a plaster cutter constructed in accordance with my invention.

Figure 2 is a front elevation illustrating the device and showing a power means connected thereto for its operation.

Figure 3 is an end elevation illustrating the device.

Figure 4 is a sectional view taken on the line 4-4 of Figure 2.

Figure 5 is a sectional view taken on the line 5-5 of Figure 4.

Figure 6 is a sectional View taken on the line l5--fi of Figure l.

Referring in detail to the drawings, the numeral 5 indicates an elongated hood or casing one wall of which is fully open to form the workengaging part of the hood or casing. The end wall 6 of the hood or casing has formed therein a slot 1 which communicates with the open part of the hood or casing for the purpose of permitting cutting elements to pass outwardly of the hood or casing and which will be hereinafter more fully described. The other end wall 3 and a portion of the side walls have formed therein a guard receiving chamber 9 in which a guard Ill may move freely. The edges of the side walls at the work-engaging side oi the hood or casing are formed so as to present sloping edges H and straight edges l2. The pivots of the guard ID are located where the straight edges [2 merge into the sloping edges II and are indicated by the character 13. The side portions of the guard ID are of substantially triangular shape while the connecting portion 1 4 thereof is arcuately curved. The side portions of the guard present straight edges l5 and may move into alignment with the sloping edges H of the hood or casing by the influence of coil springs 15 confined within grooves ll formed in the walls of the hood or casing. However, t will be seen that when excessive pressure is brought onto the hood it may pivot into the chamber 9 and bring the straight edges l5 thereof at an angle to the sloping edges ll of the hood or casing. This arrangement permits the hood or casing to be brought into various angular positions with respect to a wall or ceiling for the purpose of cutting loose plaster adjacent to a crack or defect.

The sloping edges ll of the hood or casing merge gradually into the end wall 6 thereof while the end wall 8 has integral therewith a discharge neck ll to which a dirt collecting receptacle it may be detachably secured.

Mounted in the hood or casing 5 are spaced shafts l9 connected together by sprocket gears 23 and sprocket chains 2|.

One of the shafts It! extends exteriorly of the casing or hood and is coupled to a flexible shaft 20' of an electric motor 2 I. The sprocket chains 2| form a support for an endless belt 22 on which is mounted a plurality of cutters 23. It is to be understood that the electric motor 2! will drive the endless belt 22 and the cutters travel therewith and move first outwardly through the hood by way of the slot 1 and continue exteriorly of the hood for a limited distance along the open portion of the hood which is brought against the plaster to be out. After the cutters have traveled a limited distance along the open side of the hood or casing they move into the guard and from thence into the hood or casing carrying therewith plaster cut from the wall or ceiling. The plaster cut and entering the hood or casing may gravitate therefrom into the collection receptacle [8 by way of the neck I'l.

Thus it will be seen that a workman can readily grasp and handle the hood or casing to move the latter along a certain portion of a damaged or cracked wall or ceiling for the purpose of cutting the plaster in the vicinity of the crack so that the crack will be freed of all loose portions or particles of plaster rendering it in condition to be pointed up or patched.

By having the edges II and i2 of the hood or casing shaped as specified will permit the hood or casing to be readily rocked or brought into various angular positions with respect to the wall or ceiling so that the cutters or blades may be made to vary their depth of cut in the plaster. The guard l5 being yieldably supported as well as pivotally mounted, will remain in contact with the Wall or ceiling during the movement of the hood or casing into its several angular positions with respect to the wall or ceiling consequently remaining in a position to catch all plaster that will be removed by the cutting blades for directing said out plaster into the hook or casing for gravitation into the collection receptacle I8.

The side walls of the guard ID ar provided with slots 24 to receive one of the shafts I9 so that the latter will not interfere with the pivotal move ment of the guard on the hood or casing.

The outward movement of the guard from the chamber 9 is limited by a stop 24 operating in a slot 25' formed in the hood. The stop is carried by the guard. An adjustable stop 28 is adjustably secured on the hood by set screws 21 and operates in the chamber 9 for varying the distance the guard may move in said chamber,

While I have shown and described the preferred embodiment of my invention, it will be understood that minor changes in construction, combination and arrangement of parts may be made without departing from the spirit and scope of the invention as claimed.

Having thus described my invention, what I claim is:

1. In a device of the character'described, a hood having one side thereof open and a slot in one end, an endless cutter mounted in said hood and including a plurality of blades movable into and out of the hood and adapted to leave the latter by way of the slot and return into the hood by Way of the open side thereof, means for connecting the endless cutter to a power source, a guard pivotally and yieldably mounted on the hood through which the blades of the cutters may move and adapted to act in directing cut material into the hood.

2. In a device of the character described, a hood having one side thereof open and a slot in one end, an endless cutter mounted in said hood and including a plurality of blades movable into and out of the hood and adapted to leave the latter by way of the slot and return into the hood by way of the open side thereof, means for connecting the endless cutter to a power source, a guard pivotally and yieldably mounted on the hood through which the blades of the cutters may move and adapted to act in directing cut material into the hood, a discharge neck formed on the hood through which the cut material may pass, and a collection receptacle detachably secured to the neck.

3. In a device of the character described, a hood having one side thereof open and a slot in one end thereof, spaced shafts journaled in said hood, means for connecting one of said shafts to a power source, drive means connecting said shafts, an endless belt supported by said drive means and adapted to travel over the shafts, cutting blades carried by said belt and movable out of said hood by way of the slot and into said hood by the open side thereof, said hood having a chamber formed in the walls thereof, a spring influenced guard pivotally mounted on the hood and movable into and out of the chamber to coact with the open side of the hood in engaging a wall or ceiling and permitting the hood to be moved towards and from the wall or ceiling while the guard remains in contact therewith to catch material removed by the blades and direct said material into the hood, and a discharge neck formed on the hood.

WILLIAM J. SMITH.

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3793784 *Jul 21, 1971Feb 26, 1974Fritz JetztProtective device for cutting machines
US3840987 *Nov 28, 1973Oct 15, 1974Thomas & Betts CorpProtective device for a power tool
US5588213 *Mar 7, 1995Dec 31, 1996Swanberg; Alan M.Circular saw with dust trapper
Classifications
U.S. Classification30/124, 30/276, 30/272.1
International ClassificationE04F21/16, E04F21/02
Cooperative ClassificationE04F21/16
European ClassificationE04F21/16