US2159784A

US2159784A - Apparatus for use in forming pittsburgh joints

Info

Publication number: US2159784A
Application number: US156096A
Authority: US
Inventors: Demmin George Edwin
Original assignee: Individual
Current assignee: Individual
Priority date: 1937-07-28
Filing date: 1937-07-28
Publication date: 1939-05-23
Anticipated expiration: 1956-05-23

Description

y 1939- G. E DEMMIN 2,159,784

APPARATUS FOR USE J IN FORMING PITTSBURGH JOINTS Filed July 28, 1937 Patented May 23, 1939 UNITED STATES PATENT OFFICE APPARATUS FOR USE IN FORMING Prr'rs- BURGH JOINTS George Edwin Demmin, Peoria, n1.

8 Claims.

ing so called Pittsburgh joints, said invention contemplating a special machine constructed for the named purpose, or an attachment to the well known brakef employed in sheet-metal-benda ing operations.

.The main object of the invention is to pro- "wvide an apparatus for sheet metal bending by,

zti while, reducing many laborious handling opera- That the invention may be fully understood the appended drawing is provided wherein;

(Figure 1 is a transverse sectional elevation of gg parts of an apparatus involving my invention showing an inserted sheet metal part asthe work to .be acted upon.

Figure 1 shows in perspective part of an abutment member illustrated in Figurel. "36"?" Figure 2 is a simil'ar to Figure 1 showing one f theparts of, the apparatus in a different position-ffor acting upon the insertedwork.

igures corresponds to the earlier figures, particularly Figure 1 wherein a part of the, appara- 1 3o tus involved in the invention is shownas having been manipulated for acting upon the work. .,Figure 4 corresponds to Figure 1 with the work infa"different position after being acted upon for applying pressure thereto as a finishing operaon. i

Figures 5, 6 and 7 show the various forms of the work resulting from operationsthereon and treated shown in Figures 2, 3 and4 respective- Figural; illustrates in perspective a sheet metal elbow merely to best give an understanding of F i the use of the type of joint herein named.

Sheet metal workers are familiar with the 50 many tedious operations necessary in forming a joint by hand and the more or less imperfectjlyrfinished product, aswell as the considerable fwork. Q

Itis with this view that the apparatus now This invention relates to apparatus for 'formbending rail 2. rail 2 and the surface 8' of the member is spaced 5* correspond in the order given with the work as amount of time required to turn out a given piece Application July 28, 1937, Serial No. 156,096

to be described has been provided whereby the joint may be quickly, easily and perfectly provided.

In order to make the invention readily understood the' essential parts of a brake of any 5- ordinary type are herein illustrated, the same being shown in transverse section, wherein I designates a support such as a part of a bench or table to receive upon its top surface the work to be acted upon indicated at A, 2 representing 10 a member known as a bending rail, this usually lying at an angle of substantially 45 to the top surface of said bench I which by means of suitable guides and operating means not shown,

is raised and lowered as employed to clamp work upon said bench.

At 4 is a bending leaf or apron hingedly attached to the bench at 5 and when suspended as shown in Figures 1, 3 and 4 having one of its surfaces 6 flush with the top surface of said bench, I being the usual weighted balancing arm for the said bending leaf or apron.

Hingedly mounted upon the front face of the bending rail 2, as the novel part herein, in a machine for the purpose of forming joints, is a bar 8 which shall be termed herein an abutment member, this being of any length desired, the form thereof in cross section being substantially as illustrated in the figures, part of said member likewise being shown in perspective in Figure 1 0 1 The mounting for said member may be, for example, one or more hinges one of which is indicated at 9 by which it may be mounted upon said The point of the hinge 9 at the a short distance from the plane of the bench top, being in this instance a distance about equal to the thickness of the apron 4 plus the thickness of the work A, said member being spaced from the rail 2 a distance, also, slightly greater than a double thickness of said work as will be understood later.

The member 8 is formed with an operating handle Land a suitable spring friction device at u maybe ailixed'to the rail 2to engage the handle to maintain the member normally in the position shown in Figures 1, 2 and 4.

To form a Pittsburgh joint it is required, of course, that a metal sheet at its edge must be twice folded upon itself in the form of a Z, and

this usually somewhat diflicult operation is quite simply produced on the machine or apparatus as herein appointed.

In the practical operation the work is clamped upon the bench l by the named bending rail 2 with sufficient stock projecting across and beyond the apron i to provide the final result. The work having been properly adjusted and clamped the projecting portion is now acted upon by upwardly swinging the apron s, Figure 2, whereupon, the work is given an arcuate angular bend b over the margin of the rail 2, and said apron then reaching a position at right angles to the plane of said rail 2, and at the same operation by crowding the work between itself and the abutment member 8 bends said work to form the extension 0, the said member 8 thus constituting an abutment for the purpose. The apron may now be returned to its normal pendant position, whereupon the member 8 is' swung forward to substantially the position shown in Figure 3, its end surface 8' carrying the said extension over upon the initial bend b, any portion, as d, extending beyond the said initial bend I) being forced upon the face of the apron l and, caused to take up a slight angle to said extension 0.

It is now apparent that the abutment member 8 if spaced sufficiently from the rail 2 will admit of two thicknesses of the Work to lie between said member and said rail and the spacing may be more or less as desired, sufficient space being perfrom the clamping arrangement the extension (2 mitted, however, to admit of the entrance of companion member between I) and c employed in creating a conduit within an elbow, see Figures 7 and 8, or other forms.

Having created the single fold shown in Figures 3 and 6 the work is now placed between suitable clamping devices such, for example, as the rail 2 and table i, see Figure 4, and the whole collapsed into the Z form. And upon removal of the work will take up a slightly angular position with respect to 0, see Figure 7, and act as a guide for the named companion portions of the said elbow or other conduit structure to be created.

It is' noted that the extension d is bent at a slight angle to b, c in producing the folded portion in Figure 3 by being forced upon the apron 4, retaining that relation even under pressure of the rail 2 in Figure 4 as evidenced in Figure '7.

"That is to say, the pressure of the rail in collapsing the folds b, 0 does not necessarily occasion any change in the angle of d, that portion springing back to its angular position after pressure is removed.

Figure 8 illustrates part of a conduit in the form of an elbow, in line with the last above, wherein the parts A each operated upon as herein described at each of its edges and afterward bent into curved form for elbow purposes, not new herein, and receive side members B, B forming a complete conduit structure.

While the plane of the working face of the bending rail 2 may have any other angle with respect to the top surface of the bench i an obtuse angle such as shown is preferable since the work in the form shown in Figures 3 and 6, whose bends b and 0 lie at an acute angle to the bench surface is in better position to receive pressure thereon for collapsing purposes, it being always "preferable, of course, that the work approach as much as possible a Z-form in order that pressure may be more easily applied thereto.

Again, the various elements of the machine structure may have positions, relatively, other than those shown as long as the several operations upon the work provide the results required upon such work in producing the final completed forms shown.

While the invention contemplates a type of apparatus wherein the apron is hingedly mounted as herein, said apron may perhaps be otherwise disposed and operated while free to crown the work into the angle formed at the working faces of the rail and abutment member. Thus it is not the purpose to be confined to the exact means shown for operating upon the work.

I claim:

1. In apparatus for bending sheet metal in forming Pittsburgh joints including a support to receive the work, means to clamp the work upon said support, including arail to receive upon a face thereof part of the work, an apron hingedly mounted adjacent the support, and an abutment member hingedly mounted adjacent the face of the said rail adapted toswing between two positions with respect thereto and having a face adapted to lie normally substantially at right angles to the plane of said face of the rail, said apron in its hinging action adapted to bend the work toward and against the named faces of the said abutment member and said rail and together with said work fit into the angle made by said faces, said abutment member in a hinging action thereof adapted upon removal of the apron from said angle to engage the work and double said work upon itself.

2. In apparatus for bending sheet metal in forming Pittsburgh joints including a support to receive the work, means to clamp the work upon said support, including a rail to receive upon a face thereof part of the work, an apron hingedly mounted adjacent the support and having a work engaging surface substantially flush with the work receiving surface of the support, and an abutment member hingedly mounted adjacent the face of the rail and normally substantially paralleling the latter, a face of the member having spaced relation to the plane of the work engaging face of the apron and that of the support and lying substantially at right angles to the said face of the said rail, said apron adapted in a swing thereof to lie within the angle formed by said face of the member and that of said rail and to force into said angle an extension of work mounting on the support, said member adapted in a hinging action thereof to engage the said extension of the work and double it upon itself while abutting upon said rail.

3. Apparatus for bending sheet metal in forming Pittsburgh joints including in its construction a support, a member thereon for receiving a sheet of metal against it, a hingedly mounted bending apron on the support adapted to engage and bend the metal to carry a part thereof upon said member, and an abutment member lying adjacent such member and hingedly mounted thereon and having a face to receive that part of the metal against it, bent up by said apron, said face of the abutment member in the hinging action of said abutment member adapted to double said part of the metal upon that part so bent upon the described first member by said apron.

4. Apparatus for bending sheet metal in forming Pittsburgh joints including in its construction a member to fix a sheet of metal in position to be worked upon and for receiving the metal against it, a hingedly mounted bending apron adapted to engage and bend the metal to carry a part thereof against said member, and a hingedly mounted abutment member lying at the first member and having a face disposed adjacent the work receiving face of said first member, and also adapted to receive part of the metal against its said face, said face of said abutment member adapted in a hinging action of the latter to double the said part of the metal upon that part lying upon said first member.

I Apparatus of the nature and for the purpose [angle to the plane of the metal to be processed,

if [a bending apron mounted to. swing about the rail and to engage and bend part of the metal over upon the said rail, an abutment portion at said rail mounted to swing and to'receive against it an extension of said part of the metal so placed at the said rail, said abutment member having a face adapted to engage and fold the said extenffsion upon and substantially paralleling said part so positioned upon said rail.

1 6. Apparatus of the nature and for the purpose l described including in combination with a support having a surface for receiving upon it work to: be processed, a bending rail lying adjacent the said surface of the support and also having a working surface, the same being inclined at an acute angle to said surface of the support, and

a bending apron adjaicent both the surfaces adapted in a movement thereof to engage and bend the work at an acute angle towardthe said surface of the rail, an abutment member hingedly mounted adjacent the-said surface of the rail and itself having a working face lying normally at an angle to the rails said surface, said member adapted to receive an extension of the work against its working face in the named action of e the-apron, and said member adapted in a hinging action thereof to engage and bend said extension ed, a rail at the support having a surface inclined at an angle to the said surface of the support, a member hinged at the support having a surface substantially paralleling the said surface of the same, said member adapted to fold part of the metal distant from the margin thereof upon the inclined surface of the rail, a hingedly mounted member at said rail, the same having a surface lying normally at an angle to the surface of the, rail and also receiving part of the thus folded metal against it in the action of the first named member, said surface in a hinging action of said member adapted to fold the metal lying thereagainst upon that portion of said metal abutting the inclined surface of the rail and to force a free marginal portion of the metal upon the first named member in the normal position of that member.

8. In an apparatus for use in forming joints, the combination with a support, a rail cooperating therewith for clamping sheet metal work thereon and having a working surface lying at at obtuse angle to the working surface of the support, and a bending apron hinged to said support having an operating work engaging surface, of an abutment member hingedly mounted in close proximity to said surface of said rail and having a surface disposed in spaced relation to both the hinge line of said apron and the working surface of said support, said surface of said abutment member adapted in the hinging action of the said apron to receive against it a part of the sheet metal work carried by said apron, the latter also carrying'part of the work upon the rail adjacent the abutment member, and said surface of said abutment member in the hinging action of that member adapted to be carried to a position substantially parallel to the named surface of the rail to fold the work upon itself at said rail.

GEORGE EDWIN DEMMIN.