US1834938A - Process of making spacing levers for typewriting machines - Google Patents

Description

Dec. 8, 1931. F. u. CONAFED 1,834,938

PROCESS 0F MAKING SPACING LEVERS FOR TYPEWRITING MACHINES Filed Feb. 16, 1929 Patented Dec. 8, 1931 UNITED STATES PATENT OFFICE FREDERICK U. German, or BRIDGEPORT, CONNECTICUT, ASSIGNOR TO UNDERWOOD ELLIOTT FISHER COMPANY, or NEW YORK, N. Y., A. CORPORATION OF DELAWARE PROCESS OF MAKING SPACING LEVERS FOR TYPEWRITING MACHINES Application filed February 16, 1929. Serial No. 340,533.

This invention. relates to improvements in process of making line-space levers for type writingmachines.

The levers may be formed by a cold proc- 6 ess of a single piece of metal, making them rugged, strongand durable. One of the ad vantages of this process lies in the fact that the levers can be made of metals not susceptible to heat treatment as the parts need not be heated to go through these operations. Another advantage of the process for manut acturing thelevers is the saving of metal used during this construction, so that the scrap metal is a minimum. The levers are also made of such a shape as tobe easily finished by polishing and plating, or otherwise. The levers have no oint-s, crevices or corners to 'retaindirt as they wouldhave if made of several separate pieces assembled together.

In this invention the left-hand platenknob occupies the usualposition with reference to the platen, but as this location is ordinarily occupied by the line-space lever in portable machines, the lever in this case has been bent upwardly and forwardly, forming an offset in whichspace formed thereby the knob may be located and where it is readily accessible by the operator. The lever in plan view may be substantially T-shaped, composed of a longitudinal long arm and a lateral short arm' across the end of the long a1'n1.-- The short arm extends both sides of the end of the long arm. One end of the short lateral arm is pivoted to the carriage, while the other-end is pivoted to and actuates the line-spacing mechanism of the platen. The free endcf the long, arm is provided with two integral lugs forming along with a pivotscrew, in part, a bearing fora finger-piece pivoted thereto and which is urged by a spring. towards a vertical position. The finger-piece is constructed so that it may be depressed. H I

Other features and advantages will hereina er pp a In the accompanying drawings,

Figure 1 is a perspective view of parts of a typewriter, having this invention embodied therein.

Figure 2 is a plan view of the spacing lever after it has been blanked out of sheet-metal.

Figure 3 is a side view of Figure 2.

Figure 4 is a "iew of the lever shown in Figures 1 and 2, after it has been twisted a one-quarter turn.

Figure 5 is a view of the lever shown in Figure 41, after it has been swedged in the forming die.

Figure 6 is a transverse section through Figure 5 and looking in the direction indieated by the arrows 66.

Figure 7 is a side View of the lever shown in Figure 5.

Figure 8 is a. view of the lever after the raw edges shown in Figure 5 have been trimmed. The raw edges or fins are shown in dotted lines.

Figure 9 is a side View of the lever shown in Figure 8,.

Figure 10 is a View of the lever after its arm has been offset.

Figure 11 is a perspective view of the lever in final form, ready to be assembled.

Figure 12 is a plan View of the assembled parts, as shown in Figure 1, illustrating the accessibility of the platen-knob.

Referring to the drawings, a platen 15 is rotatably mounted on a platen-shaft (not shown), journaled in the carriage 16 of the typewriter. ratchet-wheel 17 secured thereto, which is rotated by a pawl 18, pivotally attached to a slide-bar 19. The pawl 18 is normally disengaged from the ratchet-wheel by a seat secured to the frame of the carriage, so that when the slide 19 moves backward taking the pawl 18 with it, the latter drops into engage- The platen 15 has an associated one end to a screw 21, and the other end tothe carriage, whereby the parts are returned to their initial position, as shown in Figure 1. V

The slide-bar 19 is slidably mounted on the carriage 16, actuated by the lever 25, and has a lug 23,into whichis threaded the screw 21. The latter has a shank which forms a pivot for the arm 24 on the lever 25. Another arm 26 on the lever is pivoted on the shank ofi a screw 27,;whichis threaded, into a pivot=block 28 that is attached to the end frame of the carriage.

The arms 24- and-26, provided witlnbosses 29, and, 30 havinghholes 39 i and; 40, respectively, are (all integral. with the lever-arm31. "The latter is offset at 32 n is1u'e- 0,.- ie: n-approx ma e y parallel plane to that of the arms 24 and 26.

With reference to the process of making the lever 25 of one piece of metal, attention is called to the fact thatheretofore it has: not been'possible tosswedgej side extensions forminglugs similar to-"36 and 37 on "a'lever of this kind without using an excessive amount "off metal and even then it has only been possible to do (so, by a hot, forging process. In this invention thef lever 25 ism ade by a cold swedging' process, as; follows. The part that is'to become a-lever 25-is first punched out. of sheet metal,as a blank, which may have 1 a"thickness somewhat less than the width of the finished lugs 36, 37;. In the present embodiment of the invention the sheet metalisj'one-quarterofan inch thick,

' whilethe lugs36- and 37 are five-sixteenths of an inch at the bottom andt-apering 0E 'to-' ward'the top, as shown in Figurelll This invention is,however, applicable for making levers of many sizes and" shapes, and is not limited-to ian'ygivendimensions. The blank 4 -,'as-shownin Figure 2, in this punching operation, is formed with a side projectionor terminal' 45, Figure "2; at one end thereof, which is, later on inthe process, to form the lugs '36,= 37; The blank is made with the short arms 24, 26 forminga terminal at the other end; The blank 46-i's;formed"with' the portion between ,the terminals having a slight lateral curve 41 The'blank 46'may now be given a twist-throughninety degrees. between the terminals, as shown. at'51' in Figure 4. The curve 471111 the long arm 311s so formed theblank 46-"that when the blankistwisted, lts lower si'de 'willg lie approximately in a fiat'plan'e,see Figure 4. The twisted blank maynow be placed in a suitable swedging die, and," under heavy pressure applied thereit t( jtl 1e" .inet'alfofthe blank is forced into all of-the' mterstlces offthe die, seeFigures 5 andj6." The su'rpl us metal duringthe operai tronextrudes between the members of 7 the die,.' as af finv 48; which, later on, may bev tr mmedf to form' the edges of the lever as desired, as inF-igures 8' and 9. During the- "swedglng operationthe top of thelever is arched by the die to give it greater rigidity, and, when finished, this arched top 34, Figure 5, presents a pleasing appearance. The lever may be given several swedging operati ons in the die to harden the metal and make the lever stiller. The'lug on the end of the long arm 31, thus formed, may be milled across to form two lugs 36 and 37, which form, in part, the hinge for the finger-piece 43. Both lugs 36 and 37 are drilled,and one lug tapped to receive the screw 38, forming the l pivot upon which the finger-piece 43- rocks. The finger-piece is providedwith two cars 42. A spiralv spring 44 onthe pivot: screw" 38 tends'to retain'thefinger-piece '43 in its vertical position, shown in Figural.

Y The spring 44; yields upon the cover of the case (not shown) being closed upon the finger-piece-y43, makingit rock downwardly To operate the'lever' disclosed. herein forline-spacing, after the cover of-the case has been removed and the'finger-plece has assumed its vertical position, as shown in Figure 1', the finger 'of the operator engages the curved finger-piece 43 and presses it to the right. This swings the lever 25 on the'pivot-screw 27 and moves the short arm 24mmwardly. The latter moves the reciprocating slide-barj19 with it, and 1 alsothe pawl 18 pivoted thereto, During the first part of thismotion the pawl 18 -slides off-the seat 50 and engages one of the teeth of the ratchetwheel 17 moving the same through the desired letter-space distance. Continued pres.- sure against the finger-piece 43 moves the carriage to the right. of the machine, ready for typing another line. Upon removing the finger .from the finger-piece' 43,the lever 25 returns, by reason of the pull of the spring 20, to its initial position, taking the slide bar 19 and the pawl 18 with it, until finally the pawl 18' again engages the seat, 50', and

is. raised therebyv out; of engagement with the ratchet-wheel' 17, thus permitting the free rotation of the platen in eitherdirection by hand, if so desired. Y

Variations may. be resorted to within the scope'of the invention, and portionsof' the improvements may be used-without others. Having thus described my invention, I' claim: f

The herein-described process of making levers for typewriting machines and the like, which consists in cutting a blank form from sheet metal, determined in form by the amount of metal required by the parts of the completed lever, then twisting the blank to properly distribute the metal, then applying pressure upon the twisted blank in a forming die to change it to the desired form, then trimming the edges according to the outline desired, and then bending the lever to form an offset-space for the platen-knob.

FREDERICK U. CONARD.

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