US1366671A - Method of forming the rim members of sheet-metal pulleys - Google Patents

Description

E. G. LARSON AND J. T. SDERSTRM. METHOD OF FORMING THE RIM MMBERS OF SHEET METAL PULLEYS.

Patented Jan. 25, 1921;

2 SHEETS-SHEET h E. G. LARSON AND u. SDERSTROM. METHOD or rommc THE mm MEMBERS or SHEET mam PuLLYs. APPLICATION FILED 16.21, 1919.;

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UNETED STATE QEFICE.

EEIK answer LABSON, or GOTTENBORG, AND JOHAN rnonon SDERSTRM, OF nnrnrnnnomr, SWEDEN, nssronons ro AKTIEBOLAGET SVENSKA KULLAGER- FABRIKEN, or sorrnmone, sw'nnnn, e oenronerron or SWEDEN.

METHOD OF OEMING THE BIM MEMBERS OF SHEET-METL PULLEYS.

To call 7,071 om it may cancer 17,:

Be it known that we, Earn GUs'rAr LAR- soN and JOHAN Tronoi lonnsrnn, subjects ot' the Kin ot' Sweden, residing, respeciivelm at (i ottenborg, Sweden, and at Katrineholm, Sweden, have iuvented a new and useful `Improvement in Methods of ,Formin' the Bim l'enibers of Sheet-Metal Pulleys, of' which the 'following is a speciication. i

The present inventon relates to a method of produeing a eonvex or eurved profile oi' the rim member of sheet metal pulleys. The face or periphery of .pu lleys hasas e rule a convex profile in order to prevent the belt from slipping oi. The present invention relates to a simple method of producng such convex profile of the :face or periphery of sheet metal pulleys in which the rim niember consists of a sheet metal band placed around a spider or spoke member.

The .present method is broadly `characterized by this that the band which is to form the rini, is introdneed between a punch 'and a corresponding die and is pressed and successively fed between said punch end said die so that owing to the pressing the band obtains the desi red conyex profile. tic'e the said pressing may be performed on rini members the ends of which are buttjointed as well as on rim members which are provided at the joint with flanges bent inward for seem-ing the rim member to the spider or spoke member. ;in the first named instance 'the .metal band is first bent so that it obtains the :proper curvature corresponding to the diameter of ,the pulley, which bending may be eiiected 'for instance in a rolling apparatus having three rolls the upper oneof which is adjnstable. The band is afterward fed between the punch and the die for producing the convex profile. the other hand, if the rim member is provided wLith jointing fianges bent inward, it is suitable, before the rim member is pressed to conyex profile to corrugate or slit the said fianges so that they permit the portions oi' said fianges 'to the rini ?member adjacent Ti the jontng acqnire the conyex profile.

flanges are plaited or eorrugated and thns not slitted this operation will produce a certain arching of the rim member in the Via-inity of the fianges Whenlthe jonting fianges have been made corrngated the sheet metal Specificaton of Letters Petent.

Tn prac-' Pzitented J an. 25, 1921.

Application filed August 21, 1919. Serial No. 3185393.

'the metal into approximetely the segment of a cyliuder preferably after such formation of .the fianges; and finally pressing the conte): portion of the rini member to mpart to it a profile which is conveX in a plane Coincident with the axis around which the pulley is to turn.

The means 'or pressing the rim member to the desired convex profile consists principally of a punch and a corresponding die the working surfaces of which punoh and die hare the seine curvatures inthe central plane of sherim member as the inner and' outer suraces of the mounted rim member, while in the axial plane they have greater curvatures than the desired COnVBX profile of the rim inember. This latter feature is necessary since after the pressing the rim member always fiattens out somewhat owing to the elasticity of the material. The means for plaiting or' corrugating the jointing fianges `consists suitably in similar manner of a p nch and e die one of which is pro- `vided with one or more preferebly Wedgeshaped projections and 'the other of which is provided with one or more correspondingly sheped grooves. y

The aeeompanying drawings llustrate by way oi' example one embodiment of the firstmentioned means and one embodiment of ;the last mentioned means. Figure 1 shows a side View of the means for produeing the convex profile of the rinrniember, and 2 shows an edge View of the said means. Fg. shows a'side View of the means for producing the corrugatiens.

The means for producng the eenvex profile consists of the punch 'l and the .corresponding die 2 The `punch l is provided with a groove 3 in order to provide against pressing down of guidng knobswhich are preferably provided in the rim member for guiding said member on the spider'or spoke member. Otherwise the punch has the shape of two cones the bases of which abut. The curvatures ofthe punch and of the die in the central plane of the rim member are equal to the desired curvatures of the nner and outer surfaces of the rim member 4:, whereas the concave angle between the bounding lines in the axial plane of the rim member is slightly smaller than the desired angle, in view of the elasticity of thematerial.

'If desired, the punch 1 may, of course, be shaped in such manner that the section of the punch in a plane through the axis of the 'rim member is bounded by a circular curve instead of two straight lnes, as shown in Fig. 2. The radius of said circular curve shall in such case be somewhatsmaller than the radius of the final curvature.

The means for corrugating shown in Fig. 3 consists of a punch 5 and a die 6. The punch 5 is adjustable in lateral direction and is provided in the working surface directed toward the die with a semi-circular or wedgeshaped projection 7, which is largest at the bottom and tapers into a point at the upper edge ofth'e working surface. The die 6 is provided with a groove 8 corresponding to the proj'ection 7. The punch 5 is Secured to a reciprocating slide-block 9 which is guided in a guide 10. The movement of the slide block toward the die is produced by means of a wedge ll which is movable in vertical direction and bears against a roller 12 ournaled in the slide block. A coil spring l is inserted between the slide-block 9 and the portion 13 of the guide 10 supporting the die 6, which spring becomes compressed when the slide block is moved against the die and moves the slide-block back to initial position when the wedge 11 moves upward.

The rim member 15 is placed over the portion 13 so that its fiange 16 covers the work ing surface of the die 6. W hen the punch is moved against the fiange the desired corrugation is formed in said fiange, and, simultaneonsly, the portion of the rim member adjacent the flange obtains a slightly conveX or arched shape. `When the fiange has been corrugated the rim member is bent to the proper curvature and is finally pressed with the apparatus shown in 'l and 2, so that it obtains the desired convex shape.

It will be understood that the punch 5 may also be provided with several projections 7 adjacent one another and the die 6 with a correspondng number of slots 8, so 'that several plaits or corrugations are formed in the ointng flanges. i

e claim i 1. The method of forming the rim member of sheet metal pulleys which consists in turning up the ends of metal bands to form jointing flanges, and convexing the intervening portions of the bands by repeated pressure between a' punch and die having at their junction a conveX profile, such pro-` file being a segment of a circle in the plane of the pulley, and being of convex' section in planes coinciding with the axis of the pulley.

2. The method of forming the rim member of sheet metal pulleys which consists in convexing a metal band having its ends bent to form jointng fianges by subjecting it between such flanges to pressure between a punch and-die having at their junction a convex profile, such profile being a segment of a circle in the plane of the pulley, and being of convex section in planes coinciding with the axis of thevpulley, such pressur being applied repeatedly to different portions of the band.

3. The method of forming the rim member of sheet metalpulleys which consists in tnrning up the ends OI" `a metal band to form jointing flanges, shaping such fianges so as to not oppose the convexing of the contiguous portions of the band in a transverse plane, and then convexing the intervening portions of the band by pressure between a punch and die having at their junction a convex profile, such profile* being a segment of a circle in the plane of the pnlley, and being of convex section'in planes coinciding with the axis of the pulley, such pressure being applied repeatedly to difierent portions of the band.

4:. The method of forming the rim meinber of sheet'metal pulleys which consists in turning'up the endsof a metal band to form jointing fianges,` then co rrugating such fianges so that they will not oppose the convexing of the contiguous portions of the band in a transverse plane, and then convexing the intervening portions of the band by pressure between a punch and die having at thei-r junction a convex` profile, such profile being a segment of a circle in the plane of the pnlley, and being of conveX section in planes coinciding with the axis of the pulley, such pressure *being'applied repeatedly to different portions of the band.

5. In the forming' of the rim member of sheet metal pulleys by first turning up the ends of a metal band to form jointing fianges, and then convexing the intervening portions of the band, the step of corrugating such llanges by pressing them between corrugatng dies adapted to crimp the flanges to a depth continually increasing from the bend to the end of each flange. i

rem GUSTA?, Larsen( jOHAN TEODGR snrksmem.

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