US3444976A - Typewriter carriage decelerator - Google Patents

Description

y 969 c. P. ANDERSON 3,444,976

TYPEWRITER GARRI AGE DECELERATOR Filed Oct. 10, 1967 INVENTOR.

CARL F. ANDERSON WLAI AGENT United States Patent 3,444,976 TYPEWRITER CARRIAGE DECELERATOR Carl P. Anderson, Homer, N.Y., assignor to SCM Corporation, organized under the laws of New York Filed Oct. 10, 1967, Ser. No. 674,308 Int. Cl. B413 19/02, 29/10, 19/04 US. Cl. 197-64 5 Claims ABSTRACT OF DISCLOSURE A carriage decelerator for typewriters having a mechanism for accelerating a speed responsive centrifugal governor. The mechanism includes a counterstop slide operable by a carriage supported margin stop, a lever pivotally mounted on the slide, a sector gear connected to the lever and to the governor and a rigid plate having a curved surface engageable by the lever in a manner to cause the lever to pivot about its axis at an accelerating rate which accelerates the governor for decelerating the carriage.

Background of the invention The present invention includes a lever which interconnects the counterstop slide and the governor driving sector gear. When the carriage margin stop contacts and moves the slide toward the end of the carriage return run, the lever, which is pivotally mounted on the slide, is moved against a rigid curved surface for causing an accelerated pivoting of the lever. This motion is imparted to the governor by way of the sector gear and the braking force is imparted back through the mechanism to decelerate the carriage.

Description of the drawing FIGURE 1 is a perspective view illustrating the mechanism in its rest position and the carriage left margin stop in a position just prior to contacting the counterstop slide; and

FIGURE 2 is a front elevational view of the lever and the curved surface of the rigid plate and illustrating four different positions of the lever during a deceleration operation.

Description of the preferred embodiment Referring to the drawing and particularly to FIGURE 1, the counterstop slide is mounted on a rigid frame shaft 12 for movement along the shaft. The slide 10 is limited for leftward movement by a left shaft support bracket 14 while it is limited for rightward movement by a rubber abutment 16. The slide 10 is normall biased against the left limit 14 by a tension spring 18 and has a lower extension 20 with the lever 22 pivotally mounted thereon by way of a stud 24. The sector gear 26 is pivotally mounted on a frame bracket 28 by a stud 30 and is connected to the lever 22 by way of a link 32 in a manner whereby a counterclockwise motion of the lever 22 would cause a clockwise motion of the sector gear 26.

3,444,976 Patented May 20, 1969 "ice The teeth 34 of sector gear 26 mesh with teeth of a governor driving pinion 36 which is rigidly mounted on the upper end of a governor shaft 38 of a governor 39. The shaft 38 is pivotally mounted within the governor housing 40 and provides a means for-rigidly supporting a pair of centrifugal dog retainer plates 42. The retainer plates 42 are rigidly mounted to each other by a pair of pins 44 and straddle a pair of centrifugal dogs 46 which pivot about the pins 44 upon rotation of the governor shaft 38. Each dog 46 has a friction pad 50 carried thereby that contacts the side wall 48 of the housing 40 to resist the rotation of shaft 38 which, in turn, resists the motion of the remaining mechanism for decelerating the carriage. The governor 39 is rigidly mounted on a frame member 52 by screws 53 and the governor 39 is responsive in offering more frictional resistance to the mechanism the faster the governor 39 is rotated.

A plate 54 which is rigidly mounted to the rear frame 56 by screws 58 has a curved surface portion 60 against which the upper portion of the lever 22 acts. The lever 22 is normally biased clockwise about its pivot stud 24 through link 32 and sector gear 26 by a tension spring 62 so the upper end of the lever 22 is in contact with surface 60 of the plate 54.

When the carriage is returned, the carriage margin stop 64 contacts the slide upper extension 66 near the end of the carriage run and drives the slide 10 to the right and the plate 54 causes the lever 22 to pivot counterclockwise as the pivot center of the lever 22 moves in a substantially horizontal line. As the lever 22 is pivoted, the sector gear 26 is moved in a clockwise direction and the governor shaft 38 is thereby rotated in a counterclockwise direction whereupon the centrifugal dog friction pads 50 are pressed against the governor housing 40 to affect a braking force on the carriage.

The deceleration of the carriage is accomplished by pivoting the lever 22 at an accelerated rate. More specifically, referring to FIGURE 2, the curved shape of the plate surface 60 provides a variable fulcrum for the lever 22 as stud 24 moves to the right. By varying the fulcrum above stud 24 as the lever 22 moves to the right, the lower portion of the lever 22, which is operatively connected to the governor shaft 38, is actuated with an increased linear velocity. This is illustrated diagrammatically by the different lever lower portion linear distances 68 and 70. The distance 70 for a given movement of stud 24 at the end of the lever working movement is greater than the distance 68 for the same stud 24 movement at the beginning of the lever working movement. This accelerated linear velocity of the link 32 effects an accelerated rotation of the governor shaft 38 which acts upon the carriage through the mechanism and decelerates the carriage until the slide 10 is finally arrested by the rubber abutment 16.

It can now be seen that the mechanism just described provides a typewriter carriage decelerating means for reducing noise and shock at the end of a carriage return run and is of a simple and economical construction.

What is claimed and desired to be secured by Letters Patent is:

1. In a typewriter having a power driven carriage mounted for movement across a printing position and a device for decelerating the carriage as it travels through a predetermined distance of power driven movement comprising:

(a) a member (10) mounted for sliding movement in response to movement of the carriage when the carriage travels through said predetermined distance;

(b) a lever (22) operable by the movement of said slideable member;

(c) an energy absorber (39);

(d) means (26, 32) interconnecting said energy ab- 4 sorber (39) and said lever (22); and

(e) a rigid plate (54) having a curved surface (60) engageable by said lever for pivoting said lever at an accelerated rate as said slideable member is moved by the carriage to actuate said energy absorber thereby decelerating the carriage during said predetermined distance.

2. A typewriter as defined in claim 1 wherein said en- 4 center (24) of said lever (22)-moves in a substantially horizontal line, said interconnecting means (26, 32) being "connected to said lever on one side of said pivot center and said rigid plate (54) acts on said lever on the opposite side of said pivot center. v

References Cited v UNITED STATES PATENTS:

2,829,754 4/1958 Norcross; 2,854,124 9/1958 Dodge et a1. 2,926,769 3/1960 Toeppen. 2,958,409 11/1960 Dodge et al.

' ERNESTT. wRiGHT, 111., Primary amt-"6;.

US. Cl. X.R.

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