US3066725A

US3066725A - Apparatus for prefabricating coving

Info

Publication number: US3066725A
Application number: US741673A
Authority: US
Inventors: Gertrude M Schweitzer
Original assignee: Individual
Current assignee: Individual
Priority date: 1958-06-12
Filing date: 1958-06-12
Publication date: 1962-12-04
Anticipated expiration: 1979-12-04

Description

Dec. 4, 1962 c. A. SCHWEITZER 3,066,725

APPARATUS FOR PREFABRICATING COVING Filed June 12. 1958 3 Sheets-Sheet l INVENTOR /4 By (Mac's/4 Sam 07255056614560 far/Pun -M7 50 11 0065 (inane/X ATTORNEYS Dec. 4, 1962 c. A. SCHWEITZER 3,066,725

APPARATUS FOR PREFABRICATING COVING Filed June 12, 1958 3 Sheets-Sheet :2

ATTORNEYS Dec- 4, 196 c. A. SCHWEITZER 3,066,725

APPARATUS FOR PREFABRICATING COVING Filed June 12, 1958 3 Sheets-Sheet 3 ATTORNEYS llite dttes atcnt ffice Muted 3,066,725 AP?ARATU FUR PREFABRRCATENG CGWHNG @harles A. Schweitzer, deceased, late of Almont, Mich, by Gertrude M. Schweitzer, executrix, 194 W. Stone St, Aliment, Mich.

Filed time 12, was, er. No. 741,673 8 Claims. ((1. 156-538) This invention relates to novel prefabricated coving structure and to special apparatus and process for forming the same.

in practicing the invention the coving is made by selecting strips of hardboard, plasterboard or the like, which will be referred to generically herein as hardboard, of the type usually used for drywall construction in modern housing.

it is the major object of the invention to provide a novel prefabricated hardboard coving.

A further object is to provide a novel preformed laminated coving structure.

It is another object of the invention to provide novel apparatus and process for the manufacture of prefabricated coving.

A further object is to provide a novel apparatus and process for making prefabricated coving wherein laminated strips of hardboard surface bonded with incured adhesive are preformed in progressive steps to a final form where the adhesive is cured.

it is a further object of the invention to provide a novel apparatus and method for making prefabricated coring wherein laminated hardboard is subjected to successive independent forming operations and held in final form until it achieves a permanent set.

Further objects of the invention will appear as the description proceeds in connection with the appended claims and the annexed drawings wherein:

FIGURE 1 is an end elevation of the novel coving strip of the invention;

FEGURE 2 is a perspective view of a length of coving;

IGURE 3 is a side elevation partly in section showing apparatus according to a preferred embodiment of the invention and showing a glued strip in position to be formed;

FZGURE 4 is a fragmentary view in section showing the first forming step wherein the holder bar is lowered to clamp the inner edge of the strip;

FIGURE 5 is a similar fragmentary view showing the second forming step wherein the intermediate bar has been lowered upon the strip and imparted the first bend thereto;

HGURE 5 is a further fragmentary view showing the third forming step wherein the main bar has descended into contact with the strip to impart its final curvature; and

FIGURE 7 is a fragmentary front elevation showing the apparatus in further detail.

he novel coving strip of the invention, which may be made in any desired length, is shown best in FIGURES l and 2 and comprises a laminated structure consisting essentially of a front strip 11 and a thicker back strip 12 formed to a desired curvature with an interface 13 of adhesive between them. Strips Ill and 12 are of the sane width and length and are preferably lengths of so-called hard board which is a synthetic board made of compressed cellulosic fibres. This hard board is available under many different trade names and it comprises stiif slabs or strips of compressed fibrous material which may be sawed like wood and which may be preformed to a given curve as in practicing the invention. For example, the thiclter strip 12 may be made of Upson white board and the thinner strip ll of Upson all weather board, and equivalent materials of other manufacture are available.

it has been found in practicing the invention that the front concave surface 14 of coving made according to the invention is smooth and free of wrinkles as a result of the special novel process of making it hereinafter described.

When installed the coving is usually mounted in the corner formed by two intersecting room walls as at 15, 16 and a straight Wooden heel strip 17 is adhesively secured all along the back of the formed strip near one edge. This strip 17 is essentially of wedge shape with a surface 18 to lie fiat on the adjacent Wall, and a series of screw fasteners 19 along the strip attach it to the wall. The back of other edge of the strip bears flexibly against the wall 16 when screws 19 are tight, and the tops of screws 19 may be countersunk and filled with putty and painted over so that a smooth clean surface 1 5 appears at the room corners.

The forming apparatus comprises a suitable rigid support 211 upon which is mounted an arcuate fixed die n1ember 2'2 having a smooth front surface 23 conforming to the desired curvature of surface 14 of the coving. Preferably die member 22 is of sheet metal and its surface 23 is polished. Heaters 24 are mounted so as to be housed by the die member and are distributed to substantially uniformly heat surface 23 to a desired adhesive curing temperature as will appear. The foregoing provides a longitudinally straight heated fixed lower die surface.

The movable die members consist essentially of intermediate bar 25 and main bar which are mounted on the support above the fixed lower die member and adapted for independent movement toward the fixed die member.

The forming surface 27 of bar 25 has the same curvature as the adjacent steeper curved portion of fixed die surface 23, and the forming surface 28 of die bar 26 has the same curvature as the remainder of fixed die surface 23, and when both the intermediate and main bars are lowered to clamp a coving strip against surface 23, the

surfaces

27 and 28 are essentially continuations of each other. All elements of

surraces

23, 27 and 28 are parallel and perpendicular to the plane of the paper, and these surfaces are coextensive in length.

Intermediate bar 2:5 is a composite structure comprising a main portion 25 that has a smooth guide face 31 adapted to slide along the smooth flat fixed guide surface 32 or" a strip 33 on the support. At its inner corner the main portion 2? has a recess 34 in which is disposed a holder bar 35. The forming surface 36 of bar 35 is an effective continuation of surface 2'7 during the operation as will appear.

A series of pockets are formed in main member 29 opening into recess 34 to accommodate coil springs 39, and stems 41 extend freely through bores to terrni nate in enlarged heads 43. When the parts are as in FIGURE 3, the compression springs project holder bar 35 a short distance below the surface 2?, the amount of such projection being limited by heads 33.

A sturdy fixed guide block 44 extends the length of thesupport and it is formed with a plurality of bores slidably supporting a plurality of links 46 connected at their lower ends to the nain portion 29 of intermediate die bar 25. The upper ends of links 46 are connected pivotally at 4 to the ends of short crank arms d8 all fixed on a longitudinal shaft dil suitably rotata ly mounted on the support. Rocking of shaft 4? is controlled as by a crank 51 pivotally connected to a foot treadle operated arm 52.

Compressed between the main body portion 29 of die bar 25 and the fixed support block 44 are a series or".

s earer;

e.) owerful coil e sion surin s 53. rlGURh 3 these sp gs are shown under maximum compi this being accom' lisncd by the rvward ull of u as 45 p A upon ClOCiiv se rocking of cracks suitable latch on arm 52. maintains the parts in the e counterclockwise, as by release of the latched arm tb springs 53 all expand together to force the interinedia.-v die bar 25; toward the fixed die membe The die member as is mounted for movement parallel to die member 25 is fixed to the lower of a series of bars slide guided at 55, on the support 21 and formed with rack teeth 57 meshed with pinions 58 on a shaft 9 rotatably mounted on support 2 and provided with a handwheel 61.

In practicing the process of the i vention two fiat strips of hardboard are selected of de d size. The strips are of the same length and width but are pi fer-ably oi dii ferent thickness, with the inner strip being thinner. For example, for the usual housing construction strips hardboard if. and 12 are selected that are about twelve inches wide and some standard length such as fifteen feet. The strip ll may be about one-eighth inch thick and strip .l .ay be about three-sixteenths inch thick.

The strips are first coated over their entire interface area 13 with a suitabie liquid adhesive and placed in full surface area contact. The glue adhesive may be of any suitable type which doe not set or dry too quickly because it is important in the process that the adhesive not be set during the forming operations.

The fiat adhesive bonded assembly is now ready to be introduced into the press apparatus for forming and it is pushed in edgewise as shown in 3 until the longitudinal edge 7% abuts the llat smooth stop face 71 that extends along support 21. The intermediate and main die bars are in raised position at this time as shown in PEG- URE 3.

Now the treadle bar 52 is unlatched and the intermediate die bar 2-5 descends mainly under the influence of springs 53. This descent may be aided or at least start d by a positive rocking of shaft 43 by the treadie bar to exert a downward push on die 25.

Fir the extended holding bar 35 contacts the la nated hardboard assembly all along its inner edge over a width of about an inch or two. This clamps the noted hardboard strip edge tightly against the under fixed die surface 23 and prevents any outward movement of the strip away from stop face 7i during subsequent forming. This is shown in FIGURE 4.

' ic member 25 continues to descend under the pressure of springs until forming face 2'7 contacts and bends the hardboard assembly over the adjacent surface 23. During this action the entire holding bar 35 is displaced into recess 3 because the total force of springs 39 is much less than that of springs 53. Finally the parts reach the position shown in 5 wherein holding bar 35 becomes essentially part of the intermediate and surfaces 27 and 36 are substantial continuations of each other.

Now the forming of the steeper curved portion of the coviug is complete and about a third of the coving is tightly clamped in the press. The springs exert t heavy clamping pressure and this arrangement perrr the forming of a wide range of thicknesses of mater without resorting to adjustments.

The operator now turns handwheel iii to rotate shaft 58 and pinions 59 so that the rack bars 5% are simultaneously displaced to move main bar 26 down until forming surface 28 engages and bends the laminated hardboard assembly to conform to the fixed curvature of surface 23 as shown in EGURE 6.

During the forming operations wherein surfaces 2-"! and are engaging the upper surface of the laminated strip, slight re ive sliding movement occurs between the trips it and is: outwardly of the clamped edge as per- ,e do

4 ed, by the still wet glue interface which acts as a la so that after the apparatus parts assume the position shown in PEGURE 6 the thinner strip 11 extends past the outer edge of strip a small distance, say about a quarter of an inch. This occurs since the inner edge is tightly clamped by the holding After the parts assume the position of QURE 6, the ediate and main die memi ers are maintained in po n for a suflicient length of time to allow the glue adhesive to set and permanently bond strip" and 12 to ethcr in the formed condition. This setting or curing oi the adhesive is speeded and promoted by heat 5 which impart the necessary temperature to die surface When the adhesive has been set the press is released by raising e intermediate and nvin dies to the open 1B 3 and the for .ed caving remove 1 5 1p 17 may be adhcsively attached in another strip, if needed, and the edge where the strips overlap is "iinrned back to remove the overlap. The coving is new early to use and may be cut to desired leng A curved coving strip formed in accord with the foreng has a smoothly curved non-wrinkled concave face is, and this is attributed mainly to the provision for relative sliding of the strips and i2 during forming. By thinner more flexible inner strip the tendency is even further reduced.

The invention may be embodied in other specific forms without departing from the spirit or essential characteris tics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by United States Letters Patent is:

1. Apparatus for prefabricating coving comprising a support, means defining an edge positioning surface on said support, a fixed die member on said support having a continuous surface extending away from said edge positioning surface and conforming to the desired coving shape, an intermediate die member movably mounted on said support for displacement toward and from said fixed die surface and having a forming surface corresponding to one part of said fixed die surface, a holding member resiliently and movably mounted on said intermediate die member adjacent said edge positioning surface, and a main die member movably mounted on said support independently of said intermediate die member for displacement toward and from said fixed die surface and having a forming surface corresponding to another part of said fixed die surface, and means for independ- .ently moving said movable die members toward said fixed die member, said holding member being so mounted on said intermediate member that upon movement of said intermediate member toward said fixed die member the holding member will engage and clamp the edge of a coving strip held against said positioning surface before said coving strip is engaged by said intermediate member.

2. Apparatus for prefabricating coving comprising a support, means deining an edge positioning surface on said support, a fixed die member on said support having a continuous surface extending away from said edge oning surface and conforming to the desired coving shape, an intermed ate die member slidably mounted on said support for dis lacement toward and from said fixed die surface and having a forming surface corresponding to one part of said fixed die surface, a holding member slidably and resiliently mounted on said intermediate die member adjacent said edge positioning surface, and a main die member siidably mounted on said support in dependently of said intermediate die member for dispiacement toward an from said fixed die surface and mitted, and eve having a forming surface corresponding to another part of said fixed die surface, and means for independently moving said movable die members toward said fixed die member, said resilient mounting for said holding member urging said holding member toward said fixed die member in advance of the intermediate die member so that when said intermediate die member is moved toward the fixed die member the holding member will engage and clamp the edge of a coving strip held against said positioning surface before said coving strip is engaged by said intermediate die member.

3. In the apparatus defined in claim 2, resilient means stronger than the resilient mounting of said holding member and compressed by separational movement of the intermediate die member from the fixed die member adapted for urging said intermediate die member toward said fixed die member with sufiicient coving strip forming pressure.

4. In the apparatus defined in claim 3, cooperating rack and pinion means on the support and fixed die member for moving said main die member with respect to said fixed die member.

5. Apparatus for prefabricating coving comprising a support, means defining an edge positioning surface on said support, a fixed die member on said support having a surface extending away from said edge positioning surface and conforming to the desired coving shape, an intermediate die member movably mounted on said support for displacement toward and from said fixed die surface and having a forming surface corresponding to one part of said fixed die surface, a holding member movably mounted on said intermediate die member adjacent said edge positioning surface, and a main die member movably mounted on said support for displacement toward and from said fixed die surface and having a forming surface corersponding to another part of said fixed die surface, and means for independently moving said movable die members toward said fixed die memher said holding member being resiliently mounted in a recess in said intermediate die member and adapted to be withdrawn into said recess when said intermediate die member has been moved to engage a coving strip to be formed between said surfaces.

6. Apparatus for prefabricating coving comprising a support, means defining an edge positioning surface on said support, a fixed die member on said support having a surface extending away from said edge positioning surface and conforming to the desired coving shape, an intermediate die member movably mounted on said support for displacement toward and from said fixed die surface and having a forming surface corresponding to one part of said fixed die surface, a holding member movably mounted on said intermediate die member adjacent said edge positioning surface, and a main die member movably mounted on said support for displacement toward and from said fixed die surface and having a forming surface corresponding to another part of said fixed die surface, and means for independently moving said movable die members toward said fixed die member, said holding member being resiliently mounted in a recess in said intermediate die member and adapted to be withdrawn into said recess when said intermediate die member has been moved to engage a coving strip to be formed between said surfaces, and said holding member comprising a bar having a surface that is a substantial continuation of the surface of said intermediate die member in said withdrawn condition.

7. Apparatus for prefabricating coving comprising a support, means defining an edge positioning surface on said support, a fixed die member on said support having a surface extending away from said edge positioning surface and conforming to the desired coving shape, an intermediate die member movably mounted on said support for displacement toward and from said fixed die surface and having a forming surface corresponding to one part of said fixed die surface, a holding member movably mounted on said intermediate die member adjacent said edge positioning surface, and a main die member movably mounted on said support for displacement toward and from said fixed die surface and having a forming surface corresponding to another part of said fixed die surface, means for independently moving said movable die members toward said fixed die member, and resilient means reacting between said intermediate die member and the support and compressed by separation of the intermediate die member from the fixed die member for urging said intermediate die member toward said fixed die member.

8. Apparatus for prefabricating coving comprising a support, means defining an edge positioning surface on said support, a fixed die member on said support having a surface extending away from said edge positioning surface and conforming to the desired coving shape, an intermediate die member movably mounted on said support for displacement toward and from said fixed die surface and having a forming surface corresponding to one part of said fixed die surface, a holding member movably mounted on said intermediate die member adjacent said edge positioning surface, and a main die member movably mounted on said support for displacement toward and from said fixed die surface and having a forming surface corresponding to another part of said fixed die surface, means for independently moving said movable die members toward said fixed die member, said holding member being resiliently mounted in a recess in said intermediate die member and adapted to be withdrawn into said recess when said intermediate die member has been moved to engage a coving strip to be formed between said surfaces, and resilient means cooperating with said intermediate member of sufficient strength to exert a coving forming pressure so positioned relative to said intermediate die member and said holding member as to transmit a coving holding pressure through said intermediate die member to said holding member.

References Cited in the file of this patent UNITED STATES PATENTS 92,187 Hann July 6, 1869 1,488,504 Keyes Apr. 1, 1924 1,775,762 Harvey Sept. 16, 1930 1,872,482 Messing Aug. 16, 1932 2,009,265 Hirschfield July 23, 1935 2,350,915 Miller June 6, 1944 2,380,573 Baesecker July 31, 1945 2,640,517 De Mello June 2, 1953 2,682,908 Schultz July 6, 1954 2,744,850 Schofield May 8, 1956 2,781,570 Seymour Feb. 19, 1957 2,812,001 Mannisto Nov. 5, 1957