US998758A - Pitman. - Google Patents

Description

H. EICHHORN. PITMAN.

APPLICATION FILED 0GT.`19, 1908.

Patented July 25, 1911 HERMANN EICHHORN, OF ELIZABETH, NEW JERSEY, ASSIGNR TO THE SINGER MANUFACTURING COMPANY, A CORPORATION F NEW' JERSEY. l

Piraten.

SpecificationV of Letters' Patent.

Patented; Jury 25, ieri.

Application led October 19,1968. Serial No. 458,360.

',and useful Improvements in Pitmen, ,of vwhich the following 1s a specification, re;t-

' erence being had therein to the accompany ing drawlngs.

This invention has for its object to( provide an effective and inexpensive construe tion for machine elements ofthat class 1nn volviing a stern with an eye or yoke adaptedv to-enibrace and afford an operative connec# tion with another relatively ,movable element disposed crosswise thereof as, for instance, a crank-and-pitman connection.

In certain light-running machines constructed to operate at comparatively high speeds, and containing pitmen connecting rapidly reciprocating arts, it is of great importance that theY pitmen be vconstructed of extreme lightness consistent with the requisite strength and stiilness for perform ing their functions', so as to vavoid pounding and consequent noisy action and lack of durability; and the present invention is designed to provide a pitman. with these' qualities at a cost not materially exceeding that involved in production by casting and considerably less than by drop-forging. By the foregoing methods of construction, lightness was sacrificed for 'reduction of cost in the casting processes, while a considcrable increase of production was involved in the drop-forging processes.

According to the present invention a. machine element of the character described is formed of a sheet metal blank comprising a stem and an integral cross-member, the lattcl' being bent with its face in crosswi'se relation with that of the stem and again in substantially the plane of the stem into the desired form, as ancye for embracing a rotating .crank-pin such as the connecting rod Z of the sewing machine loop-taker mechanism formingthe subject of the United States patent to P'. Diehl and A. Grieb, No. 663,696, oi December 11, 1900. In order to insure that the connected end ot' the eye shall be flush with the opposite face ofr the stem from. which such member projects, it is desirable to form the cross! member at opposite edges of the stem with notches of a depth substantially that of the thickness of the sheet metal7 in order that .the cross-member may be bent upon a line beyond theedge where it would other.- wise }o1n the stem; and the cross-member preferably projects farther from one edge than the other of the stem in order that when rolled into circular form with its yends turned outwaitdly to form spaced ears for a clamping and an 'adjusting screw, such ears will be disposed :laterally thereof rather than in alinement with the stem. v

In the. accompanying drawings, Figure 1 1s a face View oil a sheet metal blank suitable for producing apitmpn with eyes at opposite ends to embrace cylindrical pins upon relatively movable parts of a train of mechanism rwhich the pltman is designed to operatively connect. Fig. 2 is a similar view of said blank with the cross-members at the ends of the' stem bent at right angles to the latter, and Fig. 3 is an edge view of the blank in the same stage of its formation, with one end portion in section. Fig. 4 is a face view ol the blank with the cross- -transversely of the face of the stem and provided with lateral ears for application of clamp-screws Fig. 5 is a-perspective View of the pitman with the clamp-screws applied to its eyes or sockets.

The blank is stamped from sheet metal, and is thereforeA of uniform thickness throughout, and is composed of a stem l and a cross-member at each end comprising the longer arm 2 a-nd shorter arm 3, both having at their outer ends aperturesll for the clamp-screw or bolt 'in the inished article.y The cross-member is provided adjacent its junction with' the stem 1, and at opposite edges of the latter, with the cuts or notches 5 of a depth-corresponding substantially with the thickness ot' the blank.

In producing the iinished machine element, each end is first bent transversely of the face'of the stem l upon a line joining the inner ends of the notches 5, whereby the adjacent edge of such cross-member is permitted to assume a -flushrelation withthe face of the stem opposite which the body of the cross-member is bent. The cross-member is then 'rolled into cylindrical form in a plane parallel with that of the stem to form the eye 6, with the end portions of the parts 2 and 3 turned outwardly and spaced apart slightly to form the parallel ears 7 Whose apertnres are brought into alinement to receivethe clamping screw or bolt. As represented. in Fig. 5, a clamp-screw 8 is inserted through one of such apertures and tapped.

into the other to serve as the clamping and adjusting means for the eyeji.

It is evident that the comparative lengths of the parts 2 and 3 ofthe cross-member may be Yariedto suit the posit-ion for which the eleinent is designed, as also the shape into which the cross-member is rolled or bent, which is determined in practice by the use for which the article is designed. v

Having thus Yset forth the nature of thev invention, what l claim herein is A machine element 'composed of a flat sheet metal blank and comprising a flat stem with an integral cross-member extending laterallyfrom said stem in both directions and bent from one face thereof and at right' angles thereto and again at right angles to the rst bent portion and eoncentrically with a transverse axis to form asplit eye and then outwardly to form parallel spaced ears7 one extremity of said eye being flush with the face of the stem opposite that from which it projects, and means for drawing said ears together.

In testimony whereof, I have signed my name to this specification, in the presence et two subscribing witnesses.

rHERMANN EICHHORN.

,Witnesses 1 D. RBIRNIE, H. J. MILLER.

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