US 3382695 A
Description (OCR text may contain errors)
y 14, 8 R. A. G. CAPE 3,382,695
WEB BENDER Filed Dec. 10, 1965 5 Sheets- Sheet 1 /NVENTOR RAG. CAPE ATTORNEYS R. A. G. CAPE May 14, 1968 WEB BENDER S Sheets-Sheet 2 Filed Dec. 10, 1965 IN'VENTOR R. A. 6. 0A PE z A rroR/ve y s R. A. G. CAPE WEB BENDER May 14, 1968 5 Sheets-Sheet 5 Filed Dec. 10, 1965 lNVENTOR RAG. CA PE A T TORNEyS United States Patent 3,382,695 WEB BENDER Richard Allan Gordon Cape, Lachine, Quebec, Canada,
assignor to Dominion Bridge Company, Limited, Quebec, Quebec, Canada Filed Dec. 10, 1965, Ser. No. 512,920 6 Claims. (Cl. 72190) ABSTRACT OF THE DISCLOSURE A web bender in which a strip of material is fed into a central zone between a pair of travelling link tracks to form a web of Warren type configuration. Each link of the tracks is equipped with an arm which is movable outwards into the central zone under the control of a cam associated with each track. Anvil members on each link bear against the web material to straighten the material between bends as the formed web passes through the central zone. One of the tracks is in a fixed location while the other track is adjustable relative to the fixed track whereby the depth of the web to be formed can be varied within predetermined limits without changing the links or arms of the tracks.
This invention relates to web benders used in the fabrication of light weight truss construction.
The web bender hereinafter described is an improvement on my Patent No. 3,158,731 issued November 24, 1964, and copending application Serial No. 412,693 filed November 20, 1964, now Patent No. 3,352,330 in which a strip of thin material is bent to form shapes of approximately Warren type web configuration.
The web bender of this invention is similar in effect to a pair of mating gears both having infinitely large radii between which material is bent to form shapes of approximately Warren type web configuration. In such a comparison, each gear is replaced by a pair of tracks which, in plan view, may be considered to be straight on adjacent sides, straight or curved on opposite sides and rounded at both ends. Around each track a series of joined links may be rotated. Each link contains a centrally located tongue (representing a gear tooth) which may move normal to the link in its centreline plane, but whose axial movements are controlled by bearing at its inner end against a cam above each track. The outer ends of the tongues contact the web material which bends reversely around each consecutive tongue when the links are in motion. Associated with each of the links and with the tongues are a pair of anvil members which bear against the 'web material as it is bent around the ends of the tongues, the anvil members straightening the web material between adjacent bends. The invention is further characterized in that one of the tracks has a fixed location in the web bending machine while the other track is adjustable relative to the fixed track to increase or decrease the spacing between the adjacent straight sides in order to enable webs of varying depth to be produced on the same machine without changing the links and tongues. For this purpose, the individual tongues are adjustable in their links in order that the outer ends of the links, about which the web material is bent, will travel in a line coincident with the pivot axis of the links passing between the adjacent straight sides of the tracks and in particular, that the ends of the tongues associated with the links travelling about the adjustable track will always travel in a straight line or fixed datum line which is coincident with the line of travel of the pivot axis of the links associated with the fixed track while travelling on a straight line between the adjacent straight sides of the tracks. The invention is still further characterized in that each track is provided with a ice replacable cam located ahead of the adjacent straight sides of the tracks, the cams being contoured to project the ends of the tongues outwardly of the tracks, at the commencement of the web bending operation, to grip and bend the web material to a definite length coincident with the length of diagonal between bands in the finished bent web formed by the machine as defined by the adjusted spacing-between the adjacent straight sides of the tracks.
The object of the invention is to provide a web of light weight material having maximum strength and rigidity for use in the manufacture of Warren type trusses.
A further object of the invention is to provide a web bender which can readily be adjusted to form webs of various depths.
A fu'ther object of the invention is to provide a web bender having tongues adjustable in their associated links to permit the ends of the tongues to travel in a fixed straight datum line through the centre Zone of the machine.
A further object of the invention is to provide pairs of anvils associated with the web forming tongues, the said anvils straightening the diagonals of the web between adjacent bends.
These and other objects of the invention will be apparent from the following detailed specification and the accompanying drawings, in which:
FIG. 1 is a plan view of the web bender according to the present invention.
FIG. 2 is a vertical elevation taken on the line 22 of FIG. 1 showing a section through one link only.
FIG. 3 is an end elevation taken on the line 33 of FIG. 1 with the links and tongues removed and showing the means for adjusting the position of one track relative to the other.
FIG. 4 is a partial side elevation of one track element and a link and tongue assembly.
FIG. 5 is a vertical end elevation of a link and tongue assembly, partly in section to show the means for adjusting the length of the tongue.
FIG. 6 is a plan view of the link and tongue assembly shown in FIG. 5.
FIG. 7 is a vertical elevation of one form of anvil havin g more than one anvil surface.
FIG. 8 is a cross section of the anvil taken on the line 8-8 of FIG. 7.
FIG. 9 is a cross section of the anvil taken on the line 99 of FIG. 7.
FIG. 10 is a diagram illustrating'the adjusted positions of the ends of one set of tongues relative to a fixed datum line of travel of the ends of the other set of tongues for different depths of web.
Referring to the drawings the web bender consists essentially of a fixed track assembly 5, mounted on a base 6, and a second track assembly 7, also mounted on the base 6, but adjustable relative to the fixed track assembly 5.
Both track assemblies 5 and 7 have recessed continuous tracks 8 and S, which are straight and parallel with each other at 9 and 9 in the web forming position of the ma chine. The remaining portions of the tracks 8 and 8 are curved at the entrance and exit of the web forming portion of the machine and the opposite sides of the tracks may be straight or curved.
Located above and in a plane parallel with the plane of the tracks 8 and 8' are the earns 10 and 10" each of which have straight portions 11 and 11' facing each other and parallel with their associated straight portion of tracks 9 and 9. Each cam 10 and 10 has a replaceable cam 12 and 12' located at the entrance of the web forming portion of the machine, the purpose of which will be explained later.
Two chains of links 13 are located to travel about the tracks '8 and '8' and cams and 10. The links 13 are joined together by the pivot pins 14, each of which is projected downwardly past the tracks 8 and 8 and carry a roller 15 adapted to run in the tracks (FIGS. 2 and 4). Each link is provided with a roller 16 adapted to run on the top surface 17 of the track assemblies 5 and 7 to maintain the links level. The chain of links 13 associated with the fixed track 8 is driven directly by the drive 18 and sprocket 19 engaging with the heads 20 of the pivot pins 14.
Each link 13 is slotted on its top surface at 21 to receive a tongue 22 disposed at right angles to a line passing through the axis of the pins 14 joining the links together. Each tongue 22 has its vertical sides grooved at 23 to receive the guide rollers 24 mounted on the top surface of the links 13. A cam follower 25 is mounted on the top surface of each tongue 22 adjacent its outer end for engagement with the surface 26 of the oppositely disposed cam 10 or 10.
The projection outwards of the end of the tongue 22 from its supporting link in the direction of the oppositely disposed cam 10 and 10' is adjustable by means of a replaceable collar 27 held in place by the web engaging member 28. Collars of varying thickness are used for various adjustments of the tongues 22. This web engaging member 28 has a clevis type head 29 carrying a pin 30 and a shank 31 projecting into the bore 32 in the tongue 22. A U-shaped member 33 is mounted on the top of the member 28 and is engaged by a continuous elastic member (not shown) which may be in the form of a coil spring. This continuous elastic member when engaging all of the U-shaped members 33 associated with one chain of links 13 maintains the cam rollers 25 in contact with the opposing cam surface 26 of the cams 10 and 10.
Mounted on the top surface of each of the links 13 are a pair of anvils 34 whose peripheral surface straightens the diagonal portions of the formed web between bends, as will be explained later. In FIG. 1 these anvils 34 are shown as being circular. However, it is preferable that each anvil have a flattened surface 35 located parallel with and in contact with the straight diagonal portions of the web between bends. A suitable key 36 holds the anvil with its flattened surface 35 in a set position on the link 13.
Due to the fact that the straight diagonal portions of the formed web will take a slightly different angular position in webs of diflerent depth, the anvils 34 will have to be replaced by other anvils having a slightly different depth and setting of the flattened surfaces 35.
In FIGS. 7, 8 and 9 there is shown a modified type of anvil 37 having three flattened surfaces 38, 39 and 40 (FIG. 9) all tangent to varying radii from the vertical axis of the anvil. The three flat surfaces 41 (FIG. 8) are all tangent to an equal radius from the vertical axis of the anvil for the purpose of locking the anvil by the key 36 against rotation on the links 13.
As previously mentioned the track assembly 5 is fixed while the track asembly 7 is adjustable relative to the track member 5. The track assembly 5 is secured to the base 42 by the stud bolts 43. A pair of guide rods 44 project horizontally from the base 6 of the track assembly 5 and pass through bores 45 in the base '6 of the track assembly 7. A threaded shaft 46 is held captive but rotatable in the base 6 and is threaded through the threaded bore 47 in the base 6' of the track assembly 7.
The cams 10 and 10 are held in spaced relation above their respective tracks -8 by the spacer blocks 49 and are secured in place by the stud bolts 50.
In the operation of this invention, the machine is designed to form four primary depths of web. For instance, the primary sizes contemplated may be 2 /2," 3% 4" and 6". For each primary size, the projected length of the tongues are varied. For the smallest depth of Web the collars 27 are dispensed with, and for webs of 3 1", 4" and 4 6" depth, collars 27 of different thickness are used. Alternatively, different lengths of tongues could be used, in which case the spacing lengthwise of the tongue of the cam roller 25 would vary with respect to the pin 30.
Having decided on a depth of web to be formed in the machine, in addition to setting the proper length of tongue for that operation, the proper anvils 34 must be selected and fitted in place on the links 13, making up the chain B. The track assembly 7 is located relative to the track assembly 5 so that the axis of the pins 30 coincide with the straight line passing through the axis of the pins 14 joining the links 13 making up the chain A as they pass between the straight and parallel surfaces 11 and 11 of the cams 10 and 10". The straight line C therefore forms the datum line from which all adjustments of the machine are made and the pins 30 on the tongues in the chain B must, at all times coincide with this datum line C for any adjusted position of the track assembly 7.
With the machine set in motion, the sprocket 19 drives the chain A through contact with the heads 20. As the material 51 is fed into the machine in the direction of the arrow 52 in FIGURE 1 and is threaded about the pins 30 on successive tongues 22, it is bent to form the shape of a Warren type web configuration, with the pins 30 in the tongues 22 of the chain B forming the bends D at a radius centered on the datum line C. The anvils 34 straighten out the diagonal portions 53 of the web adjacent the bends D.
The drive of the chain B is transmitted from the chain A through the formed web as in a pair of gears.
The location of the pins 30a and 30b relative to each other at the entrance to the machine is such that a precise length of web material is measured olf, ensuring that there will be little or no slack in the material between bends as the web is formed in the straight portion of the machine. The earns 12 and 12 control this precise measuring-otf of the material. These cams 12 and 12' are replaced by other cams when the track assembly 7 is moved relative to the track assembly 5 for the forming of a different depth of web.
In FIG. 10 there is shown in diagrammatic form what adjustments are made in the formation of webs of various depth. The pins 30E represent the pins 30 in FIG. 1 associated with the chain A and are set on their respective tongues 22 at a distance E from the datum line C. As the pins 30E are spaced equally apart from a centreline G passing through the pin 30F representing one of the pins 30' in FIG. 1 associated with the chain B the diagonal portions 53 of the wire web will lie at a fixed angle with respect to the centerline G. The anvils 34a are set on their respective links to straighten out the wire so that the wire is straight between bends D.
If a depth of web H is to be formed on the same machine the track assembly 7 is moved away from the track assembly 5 the desired distance and the tongues on both chains A and B are adjusted accordingly. It is essential that the pins 30 on the tongues of the chain B be always centred on the datum line C. With this adjustment made the pins 3013 will move away from the datum line C to take up the position on the line H. The portions 53' of the wire web will take up a ditferent angular position with respect to the centreline G and the anvils 34a will have to be reset in order to straighten the portions 53 of the wire to the new angle. This can be done by replacing the anvils or by adjusting the type of anvil shown in FIGS. 7, 8 and 9.
Similarly, if the web is to have a depth J the pins 30E will be moved away from the datum line C to take up a position on the line 1.
Within each adjustment of depths E, H and J an overlap of web depth can be obtained in which the anvils will function to straighten out the diagonal portions 53 of the wire suflicient to maintain the degree of rigidity required in the bent wire web to ensure the formation of a truss having the desired resistance to collapse.
The following is a typical example of the variations which can be obtained in a machine having four basic tongue lengths combined with adjustment of the track assembly 7 with respect to the fixed track assembly 5.
In a machine above described, a wide variety of web depths can be obtained merely by adjusting certain ele ments of the machine which are accessible from the upper face of the machine all without the necessity of dismantling the machine. The change over from one web depth to another can be accomplished in a minimum of shutdown time.
What I claim is:
1. A web bender for forming a continuous V-contoured web comprising means to feed a straight wire web into the web bender, two co-planar closed tracks in said web bender, one of said tracks being fixed and the other adjustable with respect to the fixed track for the formation of different sizes of web, a set of endlessly connecting links riding on each track, a web engaging tongue mounted on each link perpendicular thereto and longitudinally slidable with respect to the link, the effective length of the said tongues being adjustable for each adjusted position of the said tracks relative to each other, means to turn the said links around the said tracks in unison, said facing sides of said tracks defining a central zone wherein the said tongues are advanced with the tongues of one set alternating with the tongues of the other set, a cam on each of said tracks, and a cam 01- lower on each tongue, the said cams having their sides adjacent the said central zone straight and parallel with the facing sides of said tracks.
2. A web bender as set forth in claim 1 in which the connecting links associated with the fixed track form a datum line through the said central zone and the tongues associated with the links on the opposite track are adjusted to the said datum line on adjustment of one track relative to the other.
3. A web bender as set forth in claim 1 in which each of said tongues include a pin about which the said wire web is bent, and a pair of anvils on the adjacent opposite links straighten the diagonals 0f the bent web during the bending operation.
4. A web bender as set forth in claim 3 in which the said anvils are adjustable to straighten the diagonals of the bent web on change of angle of the diagonals with change of adjusted length of the said tongues.
5. A web bender as set forth in claim 1 in which a replaceable cam on each of said first mentioned cams, move the said tongues at the entrance to the said central zone to contact and measure off a fixed length of wire at the commencement of the Web bending operation.
6. A web bender as set forth in claim 5 in which the said replacable cams are each contoured to adjust the stroke of the said tongues in agreement with the adjusted length of the tongues.
References Cited UNITED STATES PATENTS 3,199,175 8/1965 Wogerbauer 72l90 3,158,731 11/1964 Cape 72190 2,963,048 12/1960 Smith 14071 CHARLES W. LANHAM, Primary Examiner.
L. A. LARSON, Assistant Examiner.