US1427470A - Platen-carriage mechanism for typewriters - Google Patents

Description

0. A. HOKANSON. PLATEN CARRIAGE MECHANISM FOR TYFEWR ITERS.

APPLICATION FILED JUNE I2, 1922?.

.Patented Aug. 29, 1922.

2 SHEETSSHEET I.

0. A. HOKANSON.

- PLATEN CARRIAGE MECHANISM FOR TYPEWRITERS.

. APPLICATION FILED JUNE 2. 1920 IAQZQYU.

Patented Aug. 29,

2 SHEET SS HEET 2.

UNITED STATES PATENT omen.

OTTO A. HOKANSON, OF WOODSTOCK, ILLINOIS, ASSIGNOR TO WOODSTOCK TYPE- WRITER. COMPANY, OF WOODSTOCK, ILLINOIS, A CORPORATION OF ILLINOIS.

fi 4227g470:

Application filed June 12,

To all whom it may concern:

Be it known that I, O'r'ro A. HOKANSON, a citizen of the United States, residing at Woodstock,.in the county ofMcHenry and State of Illinois, have invented certain new and useful Improvements in Platen-Carriage Mechanism for Typewriters, of wh1ch the following is a specification. I

This invention relates to platen carriage mechanism and especiall to an anti-creeping device for the carriage bearing balls, and has for its object the provision of a mechanism of the character named which shall be of improved construction and operation.

The invention is exemplified in the combination and arrangements of parts shown in the accompanying drawings and described in the following specificatmn, and 1t 1s more particularly pointed out in the appended claims.

In the drawings,

Fig. 1 is a top plan view of an anti-creeping ball retainer frame forming a part of the resent invention;

Fig. 2 is an elevation of the frame shown in Fig. 1; I

Fig. 3 is a transverse sectional view of a platen carriage having the present invention applied thereto; and

Fig. 4 is a vertical section substant1ally on line 4-4 of Fig. 3.

In the form of platen carriage illustrated in Figs. 3 and 4, the numeral 10 designates the bed plate of the latch carriage provided with V-ways 11 at t e front and rear edges thereof. The platen carriage comprises a movable plate 12 having V-ways 13 arranged to cooperate with the ways 11 and between the ways 11 and 13 hearing balls 14 are 1nterposed. The carriage plate 12 may be made in two sections adjustably connected together 0 cap screws 15 which permits of easy assem ling and also provides for an adjustment of the bearings on the balls 14 A ball retainer frame 16, shown in detail in Figs. 1 and 2, is provided for holding the balls 14 in proper position in the ways 11 and 13 and is arranged to travelbetween the bed plate 10 and the carria e plate 12. When the carriage 12 is move along the bed 10 it is apparent that the linear movement of the balls 14 will normally be half as great as that of the carriage but in practice there is a tendency for the balls to creep Specification of Letters Patent.

Patented Aug. 29, 1922.

1920. Serial No. 388,420.

or work toward one end or the other of the ways 11 during continued movement of the carriage back and forth upon its ways. In order to prevent a creeping movement of th1s kind, the frame 16 is provided with a projection 17 on which a toothed wheel 18 is journaled in position to engage a rack 19 secured to the carriage bed plate 10, as shown in Figs. 1 and 4. A similar rack 20 is secured to the platen carriage plate 12 so that when the carriage is moved back and forth upon its bed, the toothed wheel 18 will travel between the two relatively movable parts at a speed equal to half. the speed of the carriage upon 1ts bed plate. Since the wheel 18 is journaled on the frame 16, it is apparent that the frame will be constrained to move in unison with the wheel thus imparting to the balls 14 the correct speed relatlve to the movement of the ways 11 and 13. e

The platen carriage is moved by the usual form of spring drum or by any well known and approved mechanism and is controlled by an escapeme'nt wheel 21 having apinion 22 which meshes with a rack, not shown but connected with the movable carriage. Stops 23 and 24 are provided for limiting the movement of the carriage on its bed, thus preventing the balls 14 from being carried beyond the ends of the ways 11 .and 13.

As will be seen from the drawings, the frame 16 may be stamped from sheet metal with cross bars 25 having reinforcing ribs 26 formed thereon. The balls 14 are held in circular openings in upright flanges 27 bent downwardly from the front and rear bars 28 and 29 respectively of the frame 16. It will be seen that the frame is, simple and of light construction and that it fits between the parts of the platen carriage without inter fering with the working mechanism of the carriage and without requiring additional space.

I claim:

1. In a typewriter, a platen carriage support comprising a frame plate having laterally projecting guideways at the opposite edges thereof, a platen carriage comprising a plate arranged parallel with said frame plate and having laterally projecting guideways overlapping the guideways on said frame plate and forming ball races therewith, a ball retainer comprising a sheet metal frame interposed between said plates supported by said parallel plates, and a gear Wheel for engaging said racks journaled on said sheet metal frame and arranged parallel with the roller engaging flanges thereof so that therollers in said ball races will be constrained to travel a distance equal to half the relative movement between said parallel plates.

2. In a typewriter, a platen carnage frame comprising a horizontally disposed plate having upstanding flanges at opposite edges thereof, said flanges being bent into V-shape to form guideways at their sides, a platen carriage comprising a plate arranged parallel with said frame plate and having downwardly extending flanges at the edges thereof overlapping the flanges on said frame plate and cooperating therewith to form raeeways for roller bearings, a hearing retainer comprising a sheet metal frame positioned between said parallel plates and adf'aeent the uppermost one thereof, said frame laving downwardly bent flanges extending between the parts of the raceways, roller bearings in said raceways engaged by said downwardly bent flanges, racks secured to said parallel plates, an ear extending down wardly from said sheet metal frame, and a pinionjournaled on said ear in a plane substantially parallel with said bearing engaging flanges, said pinion meshing with said racks for controlllng the movement of said bearing rollers.

In testimony whereof I have signed my name to this specification on this 1st day of June A. D. 1920.

OTTO A. HOKANSON.

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