US2028200A

US2028200A - Typewriting machine

Info

Publication number: US2028200A
Application number: US746949A
Authority: US
Inventors: Gabrielson Carl
Original assignee: LC Smith and Corona Typewriters Inc
Current assignee: SCM Corp
Priority date: 1934-10-05
Filing date: 1934-10-05
Publication date: 1936-01-21
Anticipated expiration: 1953-01-21

Description

Jan. 21, 1936. c, GABRIELSON TYPEWRITING MACHINE 5 0 s w mm 2 M r. Wm M 92W 1! w w d 23 .M 4 x J ATTORN EYS Patented Jan. 21, 1936 I UNITED STATES PATENT OFFICE TYPEWRI'IING MACIHNE.

Carl G'abriel'son, Syracuse, N. Y1, assignor to L O; Smith & Corona Typewriters, Inc., Syracuse, N. Y., a corporation of New York Application October 5, 1934, Serial No. 746,949

Claims. (01. 197-74) machine parts and to the operatorsfinger when the. shift key is violently actuated.

To the foregoing ends, andother ends which 1'5 will appear from. the following description of the preferred embodiment of theinvention shown in the: accompanying drawing, the invention consists of the combinations of? elements, arrangements of" parts, and. features of construction. 20: pointed out in the appended claims and hereinafter described. In the drawing:

Fig. 1 is a fragmentaryfront view, with certain parts broken away, showing so much. of the ma- 2'6 chine as is necessary for an understanding of the present invention; and

Fig; 2 is a fragmentary vertical longitudinal sectional view taken medially of the machine.

The type bar supporting segment It carries in 30' a known manner the. pivoted type bars, one of which is shown at l I in Fig. 2; andsaid segment is supported in a known manner in the main frame [2 of the machine. is supported in an upwardly and rearwardly in- 353 clined plane to shift down and up in said plane,

the supporting means for the segment comprising raceways I3 at the ends of the segment, race-- ways [4 on the main frame opposedto raceways l3, a pair of ball bearings l 5, one in each pair of opposed raceways l3l4, a pair of rigidarms l6 spaced apart transversely of the. machine and extending downward and forward from the lower edge of the medial portion of the segment, a horizontal rock shaft ll extending transverselyof the machine and journalled on a pair of bear ing screws I8 carriediby the main frame, a pair. of rock arms. l9 extending forward fromthe rock shaft and connected attheir forward ends to. the lower ends of arms I6of the segment by horizontal pivots 20, aforwardly extending rock arm 2| onthe rock shaft at one end of the shaft and having a lateral and downward extension 21 and a return pull spring 2'2 for the segment, which spring is'anchored atits rear end to the lower end-of extensionZWandisanchored at its for- As shown, the segment ward end tothe main frame at 23 to normally shift the segment upward and hold it up in. its normal lower case printing position.

The machine has the usual roller platen 24 supported on the usual carriage (not shown) mounted on the main frame. The type barsare actuated in the usualmanner' by key levers (not shown) to strike to a common printing. point on the platen, each type bar carrying as usual a lower case type 25 and an upper case type 26. -0:

The improvements will now be described.

A stud bolt 21, threaded? intotthe. lower edge of the segment midway the. ends of the segment, extends downward and forward from the segment in the plane of case shift movement. of the 5.

segment. This stud bolt? is provided with: an upper case stop in the form ofa collar 28 on the. bolt having over its lower face a sound-deadening and vibration absorbing cushion. in. the form of a rubber washer 29:- on. the bolt; Said stud bolt is also provided with a lower case stop-J in. the form of-a nut 30 which is screwed on the bolt and has over its upper face a sound-deadening and vibration absorbing. cushion in the formofa rubber washer 3| on the bolt.

The stops 28 -49 and 30.3l coact with. aframe stop consisting of a slightly resilient sheet! metal bar or strap 32. Bar 32 is relatively long and extends flatwise transversely of the machine below the segment a substantial distance'to both the right and left of the stud bolt 21; The. bar 32 is bolted to the main frame at each end of the bar by means of two bolts 33 provided with. clamping nuts 34. The bar 32 is supported out of contact With the main frame by vibrationabsorbing and 35 sound-deadening rubber washers 35: which are mounted on bolts 33 and are clamped" between the main frame and the underface of the bar 32. Midway its ends the bar ispermanently bent upward to provide a relatively stiflmedial yoke-like bar portion 32 'the cross-element of which is tilted to lie in a plane perpendicular to the stud bolt 21 and is provided with an aperture through which said bolt loosely extends.

The stop 30-3l normally abuts the lower face of said cross-element of said yoke-like medial shifting the segment downward into its lower case printing position, and said improved means will now be described.

A shift key lever, 36 carrying a shift key 31 at its forward end is fulcrumed at its rear end at 3'8 on the main frame and is normally held rocked upward against a suitable stop 39 on the main frame by a key lever return spring 40 which is anchored to the key lever and to the main frame. A pendent pull link 4!, which is pivoted at its upper end by pivot 42 to the forward end of the arm 2i of the rock shaft IT, has a yieldable connection at its lower end with the shift key lever 36 between the fulcrum of said lever and the shift key 31.

This yielding connection comprises a three-arm lever located at one side of key lever 36 and piv0ted thereon by a horizontal pivot 43 which extends transversely of the machine. The three arms of said three-arm lever extend from its pivot, one arm 44 extending rearwardly, an arm 45 extending forwardly, and an arm 46 extending up wardly, from the pivot 43. Arm 44 has thereon a laterally extending pin 41 pivotally engaged with the lower end of link'4l, preferably by being engaged in the lower end of a vertical slot 48 in said link. Arm 45 is a stop arm coactive with an overhanging stop 49 fixedly held or riveted at 50 to the key lever 36, said stop arm preferably having an adjustable up-and-down extending stop screw 5! threaded therethrough to, engage with its upper end under the overhanging stop 49. A look nut 52 is preferably threaded on the stop screw to engage the under face of the lever arm 45. To yieldingly hold the stop armengaged by means of the upper end of screw 5i under the stop 49, said stop 49 is provided with an upstanding lug 53 through a suitable aperture in which is loosely slidable the forward portion of a foreand-aft extending plunger 54 which is pivoted at its rear end to the upper end of arm 46 of the three-arm lever by a horizontal pivot 56 which extends transversely of the machine, about which plunger is coiled a compression spring 55 which abuts at its forward end the rear face of lug 53 and abuts at its rear end shoulders formed by;

enlargement of the rear end portion of the plunger.

Upward movement of the segment by return spring 22 is arrested by engagement of stop 3ll--3l under frame stop 3232 as shown in Figs. 1 and 2. The strength of spring 22 is such that said spring is not strong enough to hold the slightly resilient bar il232 bowed or flexed, and the segment will, therefore, instantly come to rest in its proper lower case printing position upon impact of stop 30-3l with said bar. Cushion 3| of stop 3U3l and the slightly resilient frame stop 32-42 silently and accurately bring the segment to rest in its normal elevated lower case printing position. The sheet metal stop 32-32 has a different period of vibration from that of the cast metal main frame andthe cast metal segment and is, furthermore, supported on the rubber pads 35, so that vibrations due to shock incident to arrest of the upward movement of the segment produce substantially no audible sound.

To shiftthe segment downward to its upper case printing position the shift key 31 is depressed to rock the rock shaft ll through the arm 2 l, link 4|, and the yielding connection between said link and the key lever 36. The segment, upon depression of the shift key to the position shown in dotted lines in Fig. 2 ,'is silently'arrested in its upper case printing position by engagement of stop 2829 with stop bar 32-32 If excessive down thrust is coninued on the shift key after stop 28-29 engages bar 32-32 spring 55 will be compressed and the key lever may continue its downward movement until arrested by engagement of said key lever with a stop 5'! on the main frame. Spring 55 is not strong enough to permit the stop bar to be held bowed or flexed by pressure whichcan be exerted on the shift key to compress spring 55. The segment, therefore, will instantly come to rest in its proper upper case printing position upon impact of stop 2829 with bar 32--32 even when the key lever is carried down against stop 5? by a violent blow on the shift key or by an .excessive pressure maintained on the key after stop 28-49 abuts bar 32-322". Bar

3232 while sufficiently resilient to vibrate minutely under impact of stops 2829 and 3'll3 l, is sufficiently stiff relatively to

springs

22 and 55 to practically instantaneously resume a neutral nonflexed position after impact of either of said stops thereagainst. By the improvements described, provision is made for shifting the segment to predetermined case positions at which it is arrested both silently and accurately.

What I claim is: l

1. A typewriting machine having a main frame, a support mounted in the main frame for shifting movement from one to the other of two positions to condition the machine for printing upper and lower case characters, two spaced stops movable with said support, and a resilient metal strap held at its opposite ends to the main frame with the strap free from contact with the main frame intermediate its held ends for engagement of said stops with the opposite faces of said strap substantially midway between the ends of the strap to arrest the support in said two positions.

2. A typewriting machine, as claimed in claim 1, wherein each of said stops has a strap-engaging face of vibration-absorbing and sound-deadening material, such as rubber.

3. A typewriting machine as claimed in claim 1, wherein pads of sound-deadening and vibrationabsorbing material, such as rubber, are interposed between the held ends of the strap and the main frame, and each of the two spaced stops has its strap-engaging face covered with a pad of sound-deadening and vibration-absorbing material, such as rubber.

4. A typewriting machine having a main frame, a support shiftable in the main frame to condition the machine for upper and lower case printing, a pair of spaced stops shiftable with the support, a slightly resilient sheet metal stop held to the main frame and interposed between said pair of spaced stops for engagement of said spaced stops alternately with said sheet metal stop, a return spring connecting said support and frame to shift the support to and normally hold it in a lower case printing position in which said sheet metal stop is abutted by one of said spaced stops, a shift key lever fulcrumed on the main frame, and means forming a yieldable connection between said key lever and support for shifting said support into an upper case printing position in which said sheet metal stop is abutted by the other one of said spaced stops, said resilient sheet metal stop being sufficiently stiff to assume a non-flexed position while either of the said spaced for engagement of the spaced stops with opposite faces of said strap substantially midway the ends of the strap.

6. A typewriting machine, as claimed in claim 4, wherein the sheet metal stop is a strap of sheet metal which is spaced from the main frame between the ends of the strap and is held only at its ends tothe main frame, sound-deadening pads are interposed between the held ends of the strap and the main frame, and said strap is held to the main frame for engagement of said spaced stops with the opposite faces of the strap substantially midway the ends of the strap.

7. A typewriting machine having a main frame, a type bar supporting segment mounted in the main frame to shift in an up-and-down direction for case-changing purposes, key-controlled means for shifting the segment between upper and lower case printing positions, a rigid stop carrier depending from said segment substantially midway the ends of the segment, upper and lower case stops carried by said carrier and spaced apart longitudinally of the carrier, and a resilient metal strap extending transversely of said carrier and having an aperture therein substantially midway its ends through which said carrier is slidable when the segment is shifted, said strap being secured at its ends to the main frame with the strap out of contact with the frame intermediate the secured ends of the strap for abutment of one of said stops with the upper face of the strap to arrest the segment in one of said case printing posi- 5 tions and for abutment of the other one of said stops with the lower face of the strap to arrest the segment in the other one of the case printing positions of the segment.

8. A typewriting machine as claimed in claim 7, characterized in that said key-controlled means for shifting the segment comprises a key lever fulcrumed on the main frame, a frame shaft journalled on the main frame and connected to the segment to shift the segment, and means forming a yieldably extensible operating connection between said key lever and rock shaft for rocking the shaft.

i 9. A typewriting machine as claimed in claim 7, characterized in that sound-deadening pads are interposed between the main frame and the two ends of said strap.

10. A typewriting machine as claimed in claim '7, characterized in that the segment is shifted in both directions by yieldable means.

CARL GABRIELSON.