US 2853778 A
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P 30, 1958 w .J. PRATT ET AL 2,853,778
WALL PAPER EDGER-TRIMMERS Filed Nov. 16, 1955 I N V EN TORS.
WILLIAM J. PRATT DOUGLAS R BLAKELY gram/ y I United States Patent ice WALL PAPER EDGER-TRIMNIERS William J. Pratt, North Bellmore, and Douglas P. Blakely, Massapequa, N. Y.
Application November 16, 1955, Serial No. 547,278
1 Claim. (Cl. 30-294) The subject of this invention is a novel and valuable cutting tool particularly adapted for use as an edgertrnnmer of wall paper after the latter has been hung on a wall, and even (at the usually ideal time for trimming) while the paper is still in very if not sloppily wet condition from the water-laden paste wherewith it is attached tothe wall. Such trimming, as will be appreciated by those familiar with the hanging of wall paper, is required at the meeting line of each wall surface and a surface at an angle (usually a 90 angle) to said surface, as a side fakce of a door or window jamb, a panelling strip or the One of the various special objects of the invention is to provide a simple, effective, low-cost device, which incorporates its edger-trimmer cutting edge as a razor blade of a type which is so inexpensive as ordinarily to be discarded after merely one or very few uses by a user of it for shaving his heard, as, for example, a so-called singleedge blade.
Another object of the invention is to provide a new and highly utilitarian hand-tool satisfying all the characterizations aforesaid, and including a handle portion in general prolongation of its working head and shaped for easy and comfortable palm grip, while made of two wholly or substantially identical sections capable of being practicably produced at trifling cost, by high-speed mass production methods; all in combination with internal recesses and protuberances partially carried by one of said sections and complementarily carried by the other for in a special manner solidly locking the inserted razor blade in working position, and with means for quickly separating and for equally speedily recoupling said sections thereby to facilitate speedy removal of a dulled blade and the substitution of a new blade.
Still another object of the invention is to provide a handtool as above, wherein not only do said recesses and protuberances coact with familiar and standard portions of a single-edge razor blade for positively (and not merely frictionally and hence unreliably) holding the blade rigidly in place in cutting position, against accidental shift of any kind and to any extent in any direction, but also wherein the cutting edge of the blade is thus locked in its predetermined placement so as to be set at a special ideal cutting angle for edge-trimming very wet wall paper without any chance of ever starting a tear or otherwise acting disruptively of the paper sheet being trimmed.
A further object of the invention is to provide a handtool as above, wherein the head of said tool, at opposite sides of a plane including the flat of the inserted blade, is oppositely bevelled to a special extent, thereby to provide a pair of like faces both of which are substantially flat and capable of having a highly smooth surface finish, with said faces having the planes of their flats (these faces at the same time desirably if not essentially equally angularly spaced away from the opposite sides of the flat of the blade) converging toward the working edge of the head of the tool at an angle almost but not quite 90,
that is, an angle of substantially 90.
Various other objects, advantages and features of the invention will be expressly pointed out or become apparent in the course of the following detailed description of a now preferred but merely illustrative embodiment of the invention as shown in the accompanying drawing, in which- Fig. -1 is a side elevation of said embodiment, on a reduced scale;
Fig. 2, drawn to about full scale as a present preference for size is kept in mind, is a top plan view of said embodiment;
Fig. 3 is a side elevation showing one of the aforesaid two sections, looking toward the interior thereof;
Fig. 4 is a view similar to Fig. 3, but looking at the other of said two sections; and
Fig. 5 is a transverse sectional view, taken on the line 55 of Fig. 3.
Referring now in detail to the new hand-tool in the exemplifying embodiment thereof shown in said drawing, the said two sections are respectively designated 8 and 10, both largely hollow as respectively shown at 6 and 7.
The section 8 is formed interiorly thereof with a pair of well-like recesses or pits 12 and 14; and for interfitting entry into said pits the section 10 interiorly thereof carries a pair of small posts or pins 15 and 16.
The sections 8 and 10 are preferably, and are shown as, molded from a suitable plastic, with each section one single unitary piece. For quick coupling and uncoupling of the two sections, in the former case to complete assembly of the hand-tool as shown in Fig. l and in the latter case to open up the tool as shown in Figs. 3 and 4, embedded in the main wall of section 8 at the interior thereof is a nut 17, while a screw 18 is provided, for passage of its shank through a hole 19 in the main wall of the casing 10 and then for engagement of its thread with the thread in the nut; said hole being countersunk, for snugly receiving the head of the screw, as indicated at 20 in Fig. 4.
At 22 is illustrated an ordinary single-edge (as a Gem or Personna) razor blade. Such a blade, as is well known, carries locked thereon a backing strip 23, and is formed with a pair of aligned notches one in each of its ends, such as the one indicated at 24 in Fig. l; and said blade also, at a midpoint along its length, has an aperture (not shown; but indicated at 240 in Pig. 1) spaced rather well back from the cutting edge of the blade and elongated transversely of the blade and terminating at the inner end of said aperture close to the backing strip 23 of the blade.
As indicated most clearly in Fig. 5, the section 8 has at its upper left-hand portion as said section is seen in Fig. 3 a segment formed to constitute a plateau-like memher or block 25 the maximum height of which is equal to the thickness of the said section 8 at about the location and in the direction of the double-arrow-headed dot and dash line 6 in Fig. 2.
Said block 25 is shaped over its top area to include a depressed channel 27, a less deeply depressed and wider channel 28, and a small lug-like projection 29, as well also as a finger-like projection 30. The depth of the channel 27 is one-half the thickness of the razor blade at its backing strip 23, the depth of the channel 28 is one-half the thickness of the blade itself, and the height of the projection 30 is equal to the totality of the thickness of said blade. While it would perhaps be well to have the height of the projection 29 also equal to the totality of the thickness of the blade, as the hand-tool is shown in the drawing, the height of the projection 29 is half the height of the projection 30.
The section 10, at its upper right-hand portion as said section is seen in Fig. 4, has a block 32 corresponding in all respects to the block 25, except that the projection 30 is omitted, and there is also emitted a part corre- 3 sponding to the downhill ramp-extension 33 of the block that is, at the top of block 32 the channels 27 and 28' and the lug-like projection 29' are, respectively,
and tightened in the nut 17. (Reverting to the comment .madehereinabove that it might perhaps be Well to have the height of the projection 29 equal to the totality of .the thickness. of the blade, it will be understood that tin that case the projection 29 would be omitted .from
the block 32.)
.Then, with the blade 22 having been previously placed on.the..b1ock .25 sothat the backing strip 23 lies in the .channel,27, theblade itself lies. in the channel 28, the 'lug-like projection 29 engages in the end notch of the bladeopposite to the, notch 24 shown in Fig. 1, and the finger-like projection 30 engages the aperture in the blade the location of which aperture is as aforesaid in- ..dicated at 24a in Fig. l, the blade is positively immovably locked in place in the hand-tool with the blades .cutting edge projected as shown in Figs. 1 and 2.
I For. lightness, the section 10 is shown as hollowed out allover except at the block 32; and for a similar reason the section 8 is similarly hollowed out, except that in the section 8 material is left to establish the ramp 33 and also to give. full thickness to that section near the lower end of its handle portion, as indicated at 35; these ele- .ments. 33 and 35 being provided to give good depthto .the pits ,12.and 14.
In Fig. 3, a pair of converging dot and dash lines will-be noted. The one of said lines to the right is in general conformity to a substantially straightupper subdivision of the length of the working face or edge ofthe head of the hand-tool. Jdicative of the direction of extension of the cutting edge The other of .said .lines is inof .the blade 22. These lines form an angle indicated at 36 and which is shown as approximately of the order of 12-15 By actual test, this has been proved to be .an ideal angle, with the working edge of the head below said substantially straight subdivision thereof very slightly curved down along its length, to a point about opposite .the screw 18, to facilitate smooth drawing of the tool,
such a smooth drawing as to be almost tantamount to the action of a spinnable roller, along a line where the wall .paper is to be edge-trimmed while wet and with absolute surety against tearing the paper.
The head of the tool, at opposite sides of a plane including the flat of the razor blade 22, is oppositely bevelled .as shown in Figs. 1 and 2, these bevels constituting faces 37 and 38 of considerable width and absolutely flat; their relative angularity defining as indicated .in Fig. 2 an included angle of almost yet something less than 90, that is, an angle of substantially 90.
The feature of providing said faces 37 and 38, of a width equal almost to half their length, makes of the tool a right handed one and also a left handed one; that is, according as, for example, a door or Window jamb edge is to the right or to the left of the user of the tool as he faces the papered wall, he will have the face 38 or 37, respectively, lying flat against the wet wall paper as the tool is pulled downward by means of the handle H for a cutting stroke to act as an edger-trimmer of the margin of the wallpaper adjacentto said jamb edge or the like.
With the sections s and 10 molded from a plastic, or otherwise suitably fabricated and then finished, for example, with a-good hardenamel, the said faces 37 and 38 at trifling .cost can be made, glassy smooth, also an important aid in easy pull of the tool downward by way of its handle portion, thereby to take maximum advantage of the slightly longitudinally rounded working face, or rather working edge, ofthe head of the tool, and also of the oblique angle at which the cutting edge of the razorv blade projects from said Working edge .as shown in Fig. 1.
As will be understood, only one now preferred of the many possible embodiments of the invention hasbeen shown. This has been described with considerable particularity of detail, notfor purposes of limitation of course, but merely to illustrate the capabilities of the invention in one embodiment thereof. As will also be understood, variations and modifications are possible, and parts of the improvements may be used without The scopeof protection contemplated is to be taken fromthe appendedclaim, interpreted as broadly as is consistent with the priorxart if any.
A Wall paper corner trimmer comprising a head portion and a handle, portion, said head portion having a flat end portion, said handle portion adapted to be held in one hand, guide surfaces outstanding rearwardly from said end portion on the bottom of said head portion, said guide surfaces diverging. at the center plane ofssaid head portion and at an angle substantially said guide surfaces being wide enough to guide said trimmer along a 90 wall intersection, and means to hold a blade in fixed position in said center plane of said head portion at an angle to the intersection line of said diverging guide surfaces and, extending out of said head portion in front of said end portion downwardly and forwardly.
. References. Cited in the file of this v.patent UNITED STATES PATENTS 1,863,153 Chr-istopherson June 14, 1932 2,018,149 Randle et a1. Oct. 22, 1935 2,349,734 Jaume May 23, 1944 2,437,896 Rutledge Mar. 16, 1948 2,473,551 Stanley June 21, 1949 2,498,107 Ferguson "Feb. 21, 1950