US2111125A - Typewriting machine - Google Patents

Description

March 15, 1938. J. PETZ TYPEWRITING MACHINE 2 Sheets-Sheet 1 Filed Sept. 19, 1936 ATZI'ORNEY March 15, 1938. J. PETZ TYPEWRITING MACHINE Filed Sept. 19, 1936 2 Sheets-Sheet 2 ATTORNEY Patented Mar. 15, 1938 UNITED. STATES PATENT OFFICE Application September 19, 1930, Serial No. 101,543

g 6 Claims. This invention relates typewriting machines in general and more specifically to the frame:

- fixed rod 23. This rod also serves as apivot for work. I

The object of the invention is to provide an improved framework for supporting such parts as the key levers and sublevers.

An object is to provide a support frame which is light and cheap to manufacture. yet is rigid 1 and'sturdy and maintains the parts supported,

such "as the sub-levers, accurately and permsnently centered with respect toother parts of a typewriting machine.

Another object is to provide a support frame which does not require for its manufacture the use of complex tools, such'asgang milling cutters and intricate fixtures.

An object is to provide a supporting frame, the

principal parts of which may be made by simple stamping or drawing operations. Various other objects, advantages, and features will be pointed out in the following description and claims, or will be apparent from a study of the description, claims, and accompanying drawings.

In the drawings:

Fig. 1 is a vertical section through a power type bar operating'mechanism incorporating the frame comprising the present invention.

Fig. 2 is an enlarged view of certain parts shown in Fig. '1.

Fig. 31s a plan view of the frame comprising the present invention. f

vFig. 4 is a perspective view of the frame formerly used.

5 The presentinvention has been shown as applied to the well-known Internatlonal" electric writing machine which was formerly knownin the art as the Electromatic." In this machine there is provided the paper carriage I3, in which 40 is mounted the usual platen I i for supporting the work sheet, which carriage is mounted by means of anti-friction bearings i2 on the usual grooved guide rails l3. The escapement mechanism, generally designated i4, controls letter spacing move- 45 ment of carriage Ill in writing upon the work sheet supported by platen I i.

The type bars i5 are pivotally mounted in the wire segment i6 forming part of the type basket IT. A universal bar 18 in the form of an open 5 frame is arranged to be operated by movement of the type bars I 5 to printing position and'actuates the escapement mechanism by means of a link is and a lever 20. A toggle,- comprising a toggle lever 2i and a togglelink 22, connects 55 each of the type bars IS with a pivot rod 23 mounted in segment H. A link 24 connects each toggle lever 2| with a sub-lever 25 pivoted on a the controlling keys 2'! and for a key lever like 23 which is connected to and actuated by the 5 space bar '23. Each sub-lever 25 is mounted alongside the key 21 which corresponds to the type bar to whichthe sub-lever is connected.

The sub-levers 25 are operated in a well-known way by camunits 33 cooperating with a power 10 roller 3i which turns in the direction of the arrow inFlg. 1. Each cam unit is pivoted on a rod 32 and isconnected by a link 33 with a sublever 25. There is a cam unit 3llfor each key 21 and one forthe lever "associated with the 15 space bar.. 'Whena key is depressed, the associated-cam'unit is operatively' engaged with the power roller 3| causing the cam unit to rock on its pivot 32 in a direction to draw downwardly the proper link 33, thereby rocking the sub-lever 23, 0 connected to such link in a clockwise direction (Fig. 1).' The link 24'is thereby drawn to the right, bending the toggle 2|, 22 and operating the type bar corresponding to the key 21 which was depressed. The cam unit for the space bar 25 does not operate a type bar, but operates escape- .ment I 4 through'a train of connections not shown.

Heretofore it has been the practice to support the pivot wire on a frame very similar to the one shownin perspective in Fig. 4. This frame 'con- 30 sisted of two partsyamember 34' made from a flat strip of heavy gauge steel bent longitudinally to form an obtuse angle in transverse section, and

a member 35 consisting of a. second and considerably thinner strip bent to a U-shape in trans- 35 verse section and welded to both sides of member 34 along one edge thereof. The member 34 is slightly thicker-than the'pivot rod 26 and the bend in member 33 is the same in diameter as the thickness ofmember 34 and is spaced from 40 the welded edge of said member a distance sufilcient to allow the pivot rod to he slid freely into the space thus formed by members 34, 35. After the members 34, 35 have been welded a plurality of equally spaced slots 38 are. cut in both members as shown in Fig. 4, each slot being wide enough to accommodate one sub-lever 25 and its.correspond ing key 21. The composite frame 34, .36 is at its ends mounted on two posts like 31 (Fig. 3 formed in a sub-frame 38 which also supports the pivot wires 32 for the cam units 30. Two screws like 33 and a dowel pin like 40 (Fig. 3) at each end of theframe 34-35 secure the frame to said posts. The holes for i are also experienced in manufacturing the frame 34-35 these screws and dowel in Fig. 4.

The form of construction shown in Fig. 4 has been found by experience to be not completely satisfactory from a manufacturing standpoint due to the cost of maintaining accurate spacing of the slots and certain other difliculties encountered in the process of manufacture. In order to manufacture the frame at a reasonable cost it is necessary to mill the slots 36 by means of a gang cutter having a separate cutter for each of the slots, as it is too costly to make a one-piece cutter with a row of teeth for each slot and both costly and too slow to mill the slots one at a time. A rather expensive milling fixture is required to be used with the gang cutter in order to provide the necessary solid support for the material between the slots while they are being out. When the gang cutter becomes dull all the individual cutters must be sharpened to the same diameter to ensure uniformity in the depth of the slots. Due to the thinness of the material of which the frame 34-35 is made, heavy burrs are formed at the ends and to a certain extent at the sides of the slots 36 and theseburrs are difflcult, as well as expensive, to remove. Other difficulties pins are clearly shown as any one experienced in making small machine parts will readily appreciate.

It is desirable that the frame 34-35 be as light and compact as possible in order'to reduce the weight and size of the machine. At the same time, since the frame has to support at least 49 key levers and about the same number of sublevers, it is necessary that the frame be very rigid to resist deflection of the pivot rod due to the weight of parts supported by the frame and the deflection forces producedby the operation of the sub-levers by the cam units. necessary that the frame 34-35 be rigid enough to maintain the spacing of the rods 25, 32 as any appreciable variation in the spacing of these rods results in uneven impressions of the type bars.

In order to avoid the manufacturing difliculties and still retain the desirable features stated above, a novef support frame has been devised I which is shown in Figs. 1 to 3. This frame conthe triangle, the hangers sists of a main support member 4| and a plurality of hangers 42. The member 4| is stamped from sheet metal of somewhat lighter gauge than.

the member 34 in Fig. 4 and is mounted on the posts 31 in the same manner as frame 34, that is, by means of screws 39 and dowel pins 40, as shown in Fig. 3. In order to stiffen the member 4| longitudinally, a rib 43 (Fig. 2) is formed centrally of said member. The frame member 4| is further stiffened longitudinally by bending the'longer edges downwardly at right angles to the top surface. The edges of the flanges 44 thus formed are further bent outwardly away from the central rib toform two support flanges 45 for the hangers 42.

The hangers '42 have the general shape of an inverted oblique triangle with the vertices rounded and with the bases parallel with the top surface of member 4|. At each end of the base of 42 are so shaped as to provide hook-shaped lugs 46 which embrace the flanges 45 and are soldered or welded thereto. The hangers 42 are spaced equal distances along the member 4| and provided with holes to accommodate the pivot rod 26. While Fig. 3 shows only eight of these hangers or bearing supports,

washers i of washers, 41 are interposed between the right It is also it is obvious that the number used is purely arbitrary.

There is a group comprising seven key levers 21 and seven sub-levers (Fig. 3) between two adjacent hangers 42, each sub-lever 25 being mounted alongside the corresponding key lever 21, with the sub-levers of the adjacent key levers by a washer 41 of substantially the same thickness as the width of the material between the slots 36 in Fig. 4; The hangers 42 have a thickness approximately half the width of the material between the slots 36 in Fig. 4, therefore 48 of substantially half the thickness hand faces of the hangers and the adjacent sublever 25 in order to make the spacing of the groups of. key levers and sub-levers equal to the spacing of the slots 36 in Fig. 4.

The holes for screws 39 and dowel pins 40 in member 4| have the same spacing both with reference to each other and with reference to the pivot rod 26 as'in the frame 34-35 in Fig. 4 so that the frame assembly comprising members 4| and 42 is completely interchangeable with the frame 34-35.

It will be noted that none of the parts used in the frame shown in Figs. 1 to 3 require milling operations but are simple stamped parts not requiring elaborate dies, 'tools, or fixtures for their manufacture. Thus the frame may be 'made cheaply and yet be rigid enough and accurate enough to'support the keys and key levers. The thin washers 48 may be stamped from strip stock while the thick washers 41 may be turned from screw stock, both of which are cheap operations to perform on a quantity production basis. There is no problem of burr removal as the slight burrs that may be produced in making the parts of the frame can be easily removed by machine very cheaply.

While there has been shown and described and pointed out the fundamental novel features of the invention as applied to a single embodiment, it will be understood that various omissions and substitutions and changesin the form and details of the device illustrated and in its operation may be made by those skilled in the art without departing from the spirit of the invention. It is the intention therefore to be limited only as indicated by the scope of thefollowing claims.

What is claimed is as follows:

1. A supporting frame for typewriting machines, comprising a main elongated member gage the edges of the marginal flanges in the main member and extending at right angles to the longitudinal axis, of the main member, said hangers being provided with aligned openings for supporting a pivot.

2. A supporting frame for typewriting machines comprising a main support member which is elongated in shape and provided with longitudinal marginal stiffening flanges and a plurality of hangers secured to and interlocking with the edges of said flanges at spaced intervals longitudinally of the main member and provided with aligned pivot supporting holes.

3. A supporting frame for typewriting machines comprising a main support member which is elongated in shape and provided with longitudinal marginal stiffening flanges and a plurality of hangers secured to said flanges at spaced intervals longitudinally of the main member, said hangers comprising flat stampings having a roughly triangular shape extending at right angles to the main member and adapted to support a pivot at spaced intervals along the main member, said stampings having lugs formed therein interlocking with the edges of the flanges.

4. A support frame for the key levers and sublevers of a typewriting or other machine having typewriting mechanism, comprising an elongated main member formed from a single sheet metal blank and provided with longitudinal divergent marginal flanges, and a plurality of pivot supports secured to the divergent marginal flanges at spaced intervals longitudinally oi. the main member between which supports the key levers and sub-levers are supported.

5. A support frame for typewriting machines comprising a main frame member formed 0! a single strip of sheet metal with longitudinal marginal stiffening flanges extending in planes at an angle to the plane of the body of said member, said flanges being further provided with divergent longitudinal flanges, and a plurality oi. pivot supports secured to the divergent flanges at right angles to the longitudinal axis of the main memher.

6. A support frame for typewriting machines comprising an elongated main member provided with longitudinal flanges extending at an angle to the plane of the bulk of said member, said flanges being further provided with flanges extending parallel with the plane of the bulk 01' said member, and a series of pivot supports extending at right angles to the plane oi. the bulk of said member and secured to the second-named flanges.

JOHN L. PETZ.

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