US3472353A

US3472353A - Repeat carriage spacing mechanism for typewriters

Info

Publication number: US3472353A
Application number: US603642A
Authority: US
Inventors: Floyd H Canny; Peter A Doll
Original assignee: SCM Corp
Current assignee: SCM Corp
Priority date: 1966-12-21
Filing date: 1966-12-21
Publication date: 1969-10-14
Anticipated expiration: 1986-10-14

Description

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REPEAT CARRIAGE SPACING MECHANISM FOR TYPEWRITERS Filed Dec. 2l. 1966 2 Sheets-Sheet l INVENTORS FLOYD H. CANNY( PETER A. DOLL lBY AGENT 3,472,353 REPEAT CARRIAGE SPACING MECHANISM FOR TYPEWRITERS Filed Dec. 21. 196e OC. 14, 1969 F, H, CANNY ETAL 2 Shets-Sheet 2 vINVENTORS: FLOYD H. CAN NY PETERA-poLL lAGI-:NT

United States Patent O U.S. Cl. 197--82 5 Claims ABSTRACT OF TI-IlE DISCLOSURE A repeat escapement mechanism for automatically incrementally stepping a carriage of a manual typewriter. This mechanism is additional to and operable independent of a conventional escapement, The mechanism includes a pendulum action that -oscillates in a horizontal plane with a rubber member to control the rate of oscillation.

BACKGROUND OF THE INVENTION This invention relates to manual typewriters and more particularly to escapement feed mechanisms therefor.

The closest known prior art related to this invention is disclosed in copending application Ser. No. 437,504, filed on Mar. 5, 1965 and titled Escapement Mechanism for Typewriters, now Patent No. 3,312,322 issued Apr. 4, 1967 to Floyd H. Canny. The copending application discloses a typewriter carriage repeat spacing mechanism similar to the present invention but employing a vertical acting pendulum arm instead of a horizontal acting pendulum arm. The copending mechanism is designed for use in manual oice machines which have vertical confines that allow use of a vertical acting pendulum type of repeat escapement, whereas the present invention is designed for manual compact machines which do not have the vertical confines that would allow use of the vertical mechanism.

SUMMARY OF THE INVENTION The invention provides an automatic repetitive spacing mechanism for typewriters of the manual compact class which is efficient and low cost. It also provides a repeat mechanism wherein the operational noise and shock are greatly reduced.

These provisions are accomplished by employing an escapement mechanism that is of a pendulum operating type wherein the pendulum arm is oscillated in the horizontal plane under the influence of a rubber dampening member.

BRIEF DESCRIPTION OF THE DRAWING FIGURE 1 is a bottom perspective view showing a portion of the conventional escapement mechanism operatively connected to a carriage rack and showing the repeat escapement mechanism in a normal non-carriage control condition;

FIGURE 2 is a front elevational view of a shaft assembly of the repeat escapement mechanism; and

FIGURES 3 and 4 are bottom plan views showing the extreme positions of the pendulum arm during a repeat spacing operation.

DESCRIPTION OF THE PREFERRED EMBODIMENT The invention mainly consists of a repeat escapement mechanism 8 including a shaft assembly 1li that is mounted to a frame bracket 12 for pivotal and longitudinal movement and a frame mounted rubber member 14. The shaft assembly 16 is comprised of a starwheel engageable actuator 16 which is rigidly assembled to the shaft proper 18 and a pendulum arm 20 which is also ICC rigidly assembled to the shaft 18 in substantially a horizontal plane but spaced from the actuator 16. When the shaft assembly 10 is brought into engagement with a starwheel 22, and the conventional escapement is disengaged, the lstarwheel teeth 24 alternately cooperate with two

dogs

26 and 28 of the actuator 16 to pivotally oscillate the shaft assemby 10 about its axis. The rubber member 14 which is cradled by a U-shaped member 30 on the pendulum arm 20, dampens the oscillating action for provrding a smooth automatic repetitive stepping motion of the carriage 37.

More specifically, the starwheel `22 is pivotally mounted between frame members 32 and 34 by a shaft 33 and is gear engaged with a normally biased carriage rack 35 by way of a pinion gear 36. Rack 35 is carried by a carriage 37. The starwheel 22 is held against the biasing effect of the carriage spring motor 39 and cord 41 by a holding dog 38 that is pivotally mounted on a conventional rocker type escapement bracket 40 and is limited against a stop member 42.

Referring now to FIGURE 2, the shaft assembly 10 is mounted at its ends between two frame mounted bearings 44 for longitudinal and pivotal movement. The lower bearing 44 is threaded into its frame portion 46 and is retained by a circular jam nut 48 while the upper bearing 44 is snap-fit into its frame portion 50. A compression spring 52 is disposed between the upper bearing 44 and the actuator 16 which tends to bias the shaft assembly 10 downward but is normally held ineffective by a heavier biased finger 54 which contacts an extension lip 56 of pendulum arm 20.

The shaft assembly 16 lies in a plane that is parallel to and spaced from the starwheel shaft 33 whereupon the actuator 16 will be moved into the rotative path of the starwheel teeth 24 by compression spring 52 when the finger 54 is moved away from lip 56. The shaft assembly 1i) is limited as the lip 56 of arm 20 abuts the top surface 57 of the lower bearing 44. This limit is adjustable as the lower bearing 44 is externally threaded its entire length.

Referring again to FIGURE 1, nger S4 is a formed extension of a bellcrank 58 that is rigidly assembled to a frame mounted pivotal shaft 60 so the end of its other finger 62 underlies a holding dog extension 64. An actuating bellcrank 66 is also rigidly assembled to shaft 60 but toward its opposite end and has a keyboard operable pull link 68 connected to one of its lingers 70 while a margin release pull link 72 is connected to its other finger 74. A tension spring 76 biases the shaft assembly 58, 60, 66 clockwise about its axis to a limited position determined by the pendulum arm 20 abutting a bendably adjustable frame member lip 78.

It can be seen that when pull link 68 is moved in the direction of the arrow by depression of its associated key button, the holding dog 38 releases the starwheel 22 and the restrained shaft assembly 10 is released and spring 52 biases actuator 16 into the path of the biased starwheel 22. The bellcrank 58 is so constructed that the actuator 16 is positioned in the starwheel path just before the holding dog 38 is released from the starwheel 22.

The U-shaped member 30 is adjustably mounted on the pendulum arm 20 by having a guiding tab 21 formed from member 30 and extending through an elongated slot 23 in arm V20 and having an adjustable locking screw 25 extend through slot 23 and threaded into member 30 so that it may cradle the rubber member 14 at varied positions along its free end length. The rubber member 14 is of a dead rubber type and is slightly tapered toward its free end. The rubber member 14 is fixed to the frame 79 at its left end by a bracket 81 assemblled by screws 83 and a frame bracket barbed extension 80 which is forced into a suitable rubber member 14 and has its free end extending in a substantially horizontal plane. It can be seen that the dampening effect that the rubber member 14 has on the pendulum arm 20 regulates the rate of oscillation imparted thereto by varying the location of the U-shaped member 3f). The further the member 30 is adjusted toward the free end, the less the rubber member 14 resists deection which causes a greater oscillation motion resulting in a slower rate of carriage stepping movements. In the other condition when the member 30 is adjusted toward the rigid end, the oscillation motion is less resulting in a faster rate of carriage stepping movements.

A portion of the noise and vibration introduced into arm 20 by the starwheel teeth 24 repeatedly contacting

dogs

26 and 28 is dissipated into rubber member 14 resulting in a substantially guieter and smoother repetitive stepping action of the carriage 37 relative to like features on previous machines.

Referring now to FIGURES 3 and 4, the two actuator dogs 26 and 2S are so shaped that the rotating starwheel teeth 24 will alternately contact the dog cam surfaces 82. The camming action causes the oscillation of the shaft assembly while the U-shaped member 30 alternately contacts the opposite sides of the rubber member 14 and deflects the rubber member 14 which in turn offers resistance to the back and forth motion of the shaft assembly 10. The rubber member 14, because of its limited ability to restore to a relaxed condition, slows and cushions the oscillating action so a smooth automatic repetitive stepping action of the carriage 37 is achieved.

When the key button is released, spring 76 (FIG. l) through bellcrank 66 biases the shaft 60 clockwise and the mechanism is returned to its normal inoperative position. The actuator 16 is of sufficient thickness, compared to the thickness of holding dog 38, so the holding dog 38 is positioned in the starwheel path just before the actuator 16 is disengaged from the starwheel 22. Also, the rubber member 14 has enough recovery ability to return the shaft assembly 10 back to its normal neutral position regardless of its pivotal disengaged position.

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

1. A typewriter or the like having a carriage (37) biased in a letter feed direction, comprising:

(a) a toothed starwheel (22) connected to the carriage for controlling movement of the carriage and rotatable in a predetermined direction by the biasing effect on the carriage;

(b) a shaft (18) mounted for movement longitudinally along its axis and for pivotal movement about its axis;

(c) a pair of dogs (26, 28) rigidly carried on said shaft;

(d) means (52) for moving said shaft longitudinally along its axis to move said pair of dogs from a starwheel disengaged position to a starwheel engaging position;

(e) an elongated elastomeric member (14) having a rigid end and a free end, said free end being exibly oscillatable relative to said rigid end in a direction transverse to its length;

(f) an arm (20) having one end rigidly carried -on said shaft (18) and oscillated thereby about its pivoted axis when said pair of dogs is in engaging position with said starwheel and when said starwheel is under the biasing effect of the carriage; and

(g) means (30) connecting said arm to said elastomeric member intermediate said rigid end and said free end thereof for dampening the rate of oscillation of said arm thereby regulating the automatic repetitive incremental stepping movements of the carriage.

Z. A typewriter as defined in claim 1 wherein said last named means (30) includes a member (30) adjustable relative to said arm (20) for varying the location of the connection of said arm and said elastomeric member (14) to vary the dampening effect of the oscillation of said arm.

3. A typewriter as defined in claim 2 wherein said adjustable member (3ft) is supported on said arm (20).

4. A typewriter or the like having a carriage (37) based in a letter feed direction, comprising:

(a) a toothed member (22) connected to the carriage for controlling movement of the carriage and moveable in a predeterminal direction by the biasing effect on the carriage;

(b) a pair of dogs (26, 28) supported for movement from an ineffective position to an effective position and in said effective position being engageable with said toothed member for oscillatable movement by said toothed member when the toothed member is under the inffuence of the biased carriage;

(c) an elongated elastomeric member (14) supported in a manner having a rigid end and a free end, said free end being flexibly oscillatable relative to said rigid end in a direction transverse to its length;

(d) an arm (20) having one end rigidly connected to said pair of dogs and oscillated thereby when said pair of dogs are oscillated by said toothed member; and

(e) means (30) connecting said arm to said elastomeric member for oscillative movement in said transverse direction for dampening the rate of oscillation of said arm thereby regulating automatic repetitive incremental stepping movements of the carriage.

S. A typewriter as defined in claim 4 wherein said elastomeric member (14) is made from a non-metal material.

References Cited UNITED STATES PATENTS 626,936 6/1899 Shimer 197-85 744,424- ll/ 1903 Steiger 197-64 937,336 l0/l909 Stickney 197-82 944,794 12/1909 Latta 197-85 1,921,490 8/1933 Stickney 197-82 3,312,322 4/1967 Canny 197--82 ERNEST T. WRGHT, JR., Primary Examiner U.S. Cl. X.R. 197-64