US2826287A - Control for a decelerating mechanism - Google Patents

Description

M r 11,1958 R. D. DODGE 2,826,287

I CONTROL FOR A'DECELERATING MECHANISM 2 Shee'ts-Shet Filed Dec. 30, 1954 INVENTOR. RONALD o. DODGE Isa Q monk- ATTORNEY March 11, 1958 R. DODGE 2,826,287

CONTROL FOR A DECELERATING MECHANISM Filed Dec. 50, 1954 FIG. 2

2 Sheets-Sheet 2 INVENTOR. RONALD 0.00005 M 6am? ATTORNEY United States Patent CONTROL son A DECELERATING MECHANISM Ronald D. Dodge, Poughkeepsie, N. Y., assignor to International Business Machines Corporation, New York, N. Y., a corporation of New York Application December 30, 1954, Serial No. 478,634 7 Claims. (Cl. 197-183) This invention relates to movable carriage business machines and more particularly to an improved decelerating mechanism for absorbing shock while stopping a business machine carriage after afree or power driven run. One form of such decelerating mechanism is shown in my copending application Serial No. 479,444, filedDecemher 29, 1954.

It is well recognized in the business machine art, particularly with typewriters, that some sort of shock reduction means must be employed to reduce the noise and shock of the carriage when it is returned to its left hand margin position; or set free during a tabulation run. The art is replete with examples of snubbers and air cushions which operate to reduce shock and noise during these carriage functions, but there is still need in the art for an improved speed sensitive decelerating mechanism, that is, one which exerts a decelerating force that. is proportional to the speed of the carriage at the time the decelerating force is applied.

pointed out in the following description and claims and illustrated in the accompanying drawings, which disclose, by way of example, the principle of the invention and the best mode which has been contemplated of applying that principle.

In thedrawings: Fig. 1 is a perspective view of the rear of'the-well fknownlBM typewriter, showing a linkage mechanism for actuating a decelerator.

Fig: 2 is a side elevation of the decelerating mechanism used during a carriage return.

Fig. 3 isa plan view of aportion of'the carr'iage'r'eturn decelerating mechanism.

Fig.4 is a side elevation of the mechanism employed to decelerate the carriage after a tabulation run. 'Br-iefly'this invention relates to a decelerator for a typewriter or business machine carriage wherein a decelerating cam is selectively interconnected with a power driving means that will act to limit the movement of the cam; The cam is connected through various linkages to the carriage of the business machine and during a tabulation or carriage return run, the linkage system is actuated tending to move the cam. The interengagement of the cam with the power driving means however limits the rate of movement of the cam and consequently'deceler-ates the business machine carriage.

Referring to the drawings and particularly to Fig. 1 a typewriter carriageis illustrated as having a margin rack-2, carrying a margin stop 4 with the margin rack being movable with the carriage transversely relative to rails 6 one or which is shown.

Patented Mar. 11, 1958 In conventional typewriter installations as more particularly shown in copending application Serial No. 469,870, filed November 19, 1954, the typewriter is provided with a margin control lever or check 8 which is slidable within fixed limits (slots 9) relative to supporting studs 10 which'are secured to the typewriter frame. 'i he sliding of themar'gin check 8 is employed to rock a margin bell crank iz which is pivotally supported by the stud carried'bythe typewriter frame. More specifically as the margin stop 4is driven toward the margin cheek -8 due to the carriage being returned to its left hand margin position, a blocking shoulder 16 of the margin stop 4 engagesa corresponding shoulder 18 of the margin check 8, thereby sliding the latter to the left (as viewed in- Fig'.- 1) relative to the studs 10, to rotate the margin bell crank 12 counterclockwise about its stud 14.

Conventional typewriters, as more particularly described in U. S. Patent No. 1,935,436, to Dodge, are further provided with a-tabulating'system wherein a tab lever 20 is positionedon the typewriter frame for pivotal movementabout an axis indicated by the dot dash line 22. The pivotal movement is in response to the operation of a tabulating power device (not shown) which acts to rock: a bellcrank 24 counterclockwise about a pivot pin 26 thereby pushing on the right hand end of the tab lever 2b to rock it counterclockwise about the axis 22 so that its lefthand end 28 will push a tab check lever 30 out from behind a bracket 32 freeing the check lever 30 for movement to the left relative. to the tab lever within the limits of the slots 33. The tab check lever 30, is con- I nected to a crank arm 38 via a link 34.

The tab check lever Stl, when set in a checking position, is more particularly shown in U. S. Patent 1,935,436,

is engageable with a conventional tabulation stop of the "479,444, filed- December 29, 1954. When the carriage is actually stopped, the margin check 30 willhavebeen recocked to a rest position behind a shoulder (not shown.)

but carried by bracket 32.

The actionsof the rocking ofthe 'marginlever 12 about its pivot 14; and the movement of thetab check 30 first to the left as the tab ,key of the typewriter is-operated,

and. then to the right and back to the position shown in 'Fig. 1 as the tab. stop hits. the tab checkare employed respectively in conjunction witha corresponding.deceleratmg mechanism to slow down therate of carriage travel at the. end of either a t-abulating run or a carriage return operation.

Carriage return. decelerator The basic stiuctureof both'the carriage return decelerator and-'the tabnlating decelerator is substantially identicah Specifically, these deceleratorshave segments or cams 44,: 46 respectively whichfare supported coaxially about shafts 43, 50 respectively which in turnare supported by brackets SZ, 54' respectively withthe brackets being pivotally supported about pin shafts -56, -S respectively. The pin shafts'56, 58 are carried by supporting' brackets 60, 62 respectively, which are mounted on the typewriter frame. The arms 52, 54 carry integral stops 64,"68respectively'which are en-gageable with set screws 70, 72. With this structure the shafts 48, 50 are pivotal about the pinshafts 56,58 from a position wherein the stop arms 64, 63 are engageablewiththe screws-70, '72 to a counterclockwise limitwherein the peripheries of sectors'44, 46 areinengagement with the continuously rotating power (In Figs. 2 and 4 the sectors are carried in turn by brackets 92, 94 which are secured to the typewriter frame. Links 80, 82 respectively are provided with springs 81, 83 which are attached to the frame to bias the pins 76, 78, and consequently the sectors 44, 46 clockwise about their supporting shafts 48, 50.

As viewed in Figs. 2 and 4 the links 80, 82 are adjustably connected to the bell cranks 84, 86 through adjustable bearings 96, 98 which are movable in slots 100, 102 thereby varying the throw of the links 80, 82 depending upon the radius of the bearings 96, 98 with respect to the pin shafts 88, 90.

In both the cafriage return and tabulating decelerator, a spring 104, 166 respectively is employed to rock the arms 52, 54 to the clockwise limit into engagement with the adjustable set screws 70, 72 thereby biasing the peripheries of segments 44, 46 normally out of engagement with the power roll 74. The springs 104, 106 are normally tensioned but can be collapsed to remove the clockwise rocking force on the arms 52, 54. If either sector 44 or 46 is rotated counterclockwise as viewed in Figs. 2 and 4 with the springs 104 and106 under tension, then the sectors will simply rotate about their pin shafts 48, 59 and remain clear of the constantly rotating power roll 74. Such a rotation will be produced by a force applied to the sectors 44, 46 through the links 80, 82 respectively. If the tension in the springs 104, 106 has been relaxed however, then any force applied to the sectors 44, 46 through the links 80, 82 will first rock the corresponding pin shafts 48, 50 counterclockwise about their axes 56, 58 until the peripheral surfaces of the cams 44, 46 are individually brought into engagement with the peripheral surface of the power roll 74. The geometry of the. structure, then, once the sectors 44, 46 are brought into engagement with the power roll, is such that so long as a force is continually applied through the link 80 or 82 the corresponding sector will remain in engagement with the power roll irrespective of the restoration of normal tension to the springs 104, 106 respectively.

Based on this operating principle, and in order to utilize the action for the decelerators, the tension in springs 104, 106 must first be collapsed and then the corresponding bell cranks 84, 86 must be rocked counterclockwise about the supporting pins 88, 90 through forces applied by the links 108, 110 to bring the sectors 44, 46 respectively into engagement with the power roll. Then because of the frictional engagement between the peripheral surfaces of the sectors and the power roll, the sectors will not be able to rotate counterclockwise about their supporting shafts 48, 50 any faster than the peripheral speed of the power roll 74 will permit. This relationship limits the rate of counterclockwise rocking of the bell cranks 84, 86 and accordingly by connecting the links 108, 110 to the bell cranks 38, 12 respectively, a mechanism is provided to slow down the carriage after either carriage return operation or a tabulating operatlon.

In order to release the tension on spring 104 to initiate a decelerating action for a carriage return operation, the spring 104 is interconnected between the bracket 52 and a bell crank 114 which is pivotally supported about a pin 116 carried by the typewriter frame. The bell crank is normally biased counterclockwise by a spring 118 which is secured to a portion of the typewriter frame, but during a power carriage return operation, as more particularly explained in copending application Serial No. 469,870, filed November 19, 1954, a pull is exerted on a link 120 by the carriage return cam thus rocking the bell crank 114 clockwise about its pivot 116. It is also explained in the copending application that the clockwise rocking of hell crank 114 is utilized through the action of the link 122 to lift the escapement pawls out of the escapement rack during a carriage return operation. It is obvious that since spring 104 is connected at the outer end of the bell crank 114, rocking the bell crank 114 clockwise about its pivot 116, will collapse the spring 104 to relieve the tension on it. Accordingly it can be observed that during a powered carriage return operation when the operator depresses the well known carriage return button the link 120 will first be pulled by the carriage return cam to rock the bell crank 114 clockwise about its supporting pin 116 thereby lifting the pawls out of the escapement rack as heretofore mentioned, and, as the carriage return cam continues to rotate, the tension in spring 104 will be collapsed. It is well understood in the art that during a carriage return motion, -a tension tape (not shown) is employed and driven through a friction clutch to pull the carriage into its left hand margin position. As the carriage goes into its left hand margin position, with further reference to Fig. 1, the margin stop 4 engages the margin check 8 thereby rocking the bell crank 12 counterclockwise about its supporting pin Fig. 2 the raising of link 108 will rock the bell crank 84 counterclockwise about its support pin 88 thereby exerting a force on the link and since the tension in spring 104 has been collapsed by bell crank 114 sector 44 will be brought into engagement with the periphery of the power roll 74 whereupon the continued counterclockwise movement of bell crank 84 as caused by the counterclockwise rocking of the bell crank 12 (as viewed in Fig. 1) drives the sector 44 through a peripheral contact cycle with the power roll 74. The peripheral speed of the power roll 74 limits the rate of rotation of the sector 44 and also the rate of rotation of the bell crank 84 and consequently the rate of rotation of the bell crank 12. Since bell crank 12 is positively connected with the carriage through a predetermined movement thereof (margin stop 4 driving margin check 8) the interengagement of sector 44 and power roll 74 acts to decelerate the carriage.

Tabulation decelerator With respect to the tabulating mechanism the bell crank 86 is provided with an integral arm 128 and the spring 106 is interconnected between the outer end of arm 128 and the bracket 54. Furthermore, the bell crank 86 is shown rotated to its clockwise limit, which action will release the tension in spring 106. When the bell crank 86 is rocked counterclockwise about its supporting pin 90 the arm 128 will be rocked counterclockwise about supporting pin 90 thereby putting tension in the spring 106 to pull the bracket 54 to its clockwise limit into engagement with the set screw 72.

It can be appreciated that the decelerator for the tab mechanism would be operated somewhat differently from that for the carriage return operation. More specifically, it will be recognized that, in the carriage return operation, .the bell crank 12 is simply moved counterclockwise as driven by the interengagement of the margin stop 4 and the margin check 8. However, in the tabulation operation the tab check lever 30 is first moved to the left under the control of the tab operation when the tab lever 20 is rocked counterclockwise about its axis 22. Then with the tab check 30 in the tab stop engaging position the carriage will be free in flight until one of the stops (not shown) which has been set in the tab check engaging position engages the tab check to drive it to the right from its Fig. 1 position to a normal position where the left hand ends of the slots 33 are driven into engagedecelerator as viewed in Fig. 4 is in its cocked position,

and in its normal position the sector 46 will have been rotated approximately 90 counterclockwise through a peripheral contact cycle thus lifting the link 110 to rock the bell crank 38 clockwise about its supporting stud 40 so that the hell crank 38 acting through the link 34 allows the tab check lever 30 to return to its normal position.

In operation of the tabulation decelerator then, the tab mechanism is first operated to release tab check lever 30 to its Fig. 1 position. This action rocks bell crank 38 counterclockwise to cock the tabulation decelerator by pushing down on link 110 to rock bell crank 86 to its Fig. 4 position. As heretofore mentioned, this action will release the tension in spring 106 and'thus condition the decelerating mechanism to slow down the carriage after a tabulation run.

When the tab stop hits the tab check 30, link 82 acting through pin 78 rocks pin shaft 50 about shaft 58 to bring sector 46 into peripheral contact with power roll 74: Thereafter the rate of rotation of the power roll controls the rate of rotation of sector 46 and hence the rate at which tab check 30 can be moved from Fig. 1 position to its normal position.

With this structure, there is a direct driving relationship between the carriage during a portion of a tabulating run and the decelerator. Hence the carriage will be slowed down after a tabulation run with a minimum of noise and shock. Furthermore, in both the tabulating decelerator and the carriage return decelerator the stopping force will be no greater than necessary to stop thecarriage.

While there have been shown and described and pointed out the fundamental novel features of the invention as applied to a preferred embodiment, it will be understood that various omissions and substitutions and changes in 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 the following claims.

What is claimed is:

1. In a power driven typewriter having power means and a carriage movable across a printing position under the influence of a power imparting means, a device for decelerating said carriage as it travels through a predetermined distance comprising a cam, an arm supporting the same for angular motion through an engaging cycle with said typewriter power means between a start and finish position wherein the angular motion of said cam is limited by said power means, means mounting said arm for pivotal movement from an inactive limit wherein said cam cannot engage said power means to an active limit wherein said cam is engageable with said power means, and linkage means interconnecting said cam and said carriage during movement of the latter through said predetermined distance to correspondingly move said cam from its start to finish position as said carriage moves through said predetermined distance whereby said carriage acting through said linkage will drive said cam into engagement with said power means thereby limiting the rate of movement of said cam from its start to finish position and consequently limiting the rate of movement of said carriage through said predetermined distance.

2. In a power driven typewriter having power means and a carriage movable across a printing position under the influence of a power imparting means, a device for decelerating said carriage as it travels through a predetermined distance comprising a cam, an arm supporting the same for angular motion through an engaging cycle with said typewriter power means between a start and finish position wherein the angular motion of said cam is 6 limited by said power'means, means *mountingsaid arm for pivotal movement from an inactive limit wherein said cam cannot engage said power meansto' an active limit wherein said cam is engageable with 'said power means, spring means biasing said arm normally to its inactive position, means responsive to the institution of a carriage movement under its powerimparting means for collapsing said spring means to relieve its tension and thereby permit movement of said arm to its active position, and linkage means interconnecting'said cam and said carriage during movement of thelatter thr'oughsaid predetermined distance to correspondingly move said cam from its start to finish position as said carriage moves through said predetermined distance whereby after said spring means has been collapsed by the institution of a carriage movement said carriage acting through said linkage will drive said cam into engagement with said power means thereby limiting the rate of movement of said cam from its start to finish position and consequently limiting the rate of movement of said carriage through said predetermined distance.

3. In a power driven typewriter having a power roll and a carriage movable across a printing position under the influence of a power imparting means, a device for decelerating said carriage as it travels through a predetermined distance comprising a cam of constant radius, an arm supporting the same for angular motion through a peripheral contact cycle with said power roll from a start to a finish position wherein the angular motion of said cam is limited by said power roll, means mounting said arm for pivotal movement from an inactive limit wherein said cam cannot engage said power roll to an active limit wherein said cam can pass through said peripheral contact cycle with said power roll, and linkage means interconnecting said cam and said carriage during movement of the latter through said predetermined distance to corr'espondingly move said cam from its start to finish position as said carriage moves through said predetermined distance whereby said carriageacting through said linkage will drive said cam intoengageinent with said power roll to limit the rate of movement of said cam from its start to finish position and consequently to limit the rate of movement of said carriage through said predetermined distance.

4. In a power driven typewriter having power means and a carriage movable across a printing position under the influence of a power imparting means, a device for decelerating said carriage as it travels through a predetermined distance comprising a cam of constant radius, an arm supporting the same for angular motion through an engaging cycle with said typewriter power means between a start and finish position wherein the angular motion of said cam is limited by said power means, means mounting said arm for pivotal movement from an inactive limit wherein said cam cannot engage said power means to an active limit wherein said cam is engageable with said power means, spring means biasing said arm normally to its inactive position, means responsive to the institution of a carriage movement under its power imparting means for collapsing said spring means to relieve its tension and thereby permit movement of said arm to its active position, and linkage means interconnecting said cam and said carriage during movement of the latter through said predetermined distance to correspondingly move said cam from its start to finish position as said carriage moves through said predetermined distance whereby after said spring means has been collapsed by the institution of a carriage movement said carriage acting through said linkage will drive said cam into engagement with said power means to limit the rate of movement of said cam from its start to finish position and consequently limit the rate of movement of said carriage through said predetermined distance.

5. In a power driven typewriter having a power roll and a carriage movable across a printing position under the influence of a power imparting means, a device for decelerating said carriage as it travels through a predetermined distance comprising a cam, an arm supporting the same for angular motion through a peripheral contact cycle with said power roll from a start to a finish position wherein the angular motion of said cam is limited by said power roll, means mounting said arm for pivotal movement from an inactive limit wherein said cam cannot engage said power roll to an active limit wherein said cam can pass through said peripheral contact cycle with said power roll, and linkage means interconnecting said cam and said carriage during movement of the latter through said predetermined distance to correspondingly move said cam from its start to finish position as said carriage moves through said predetermined distance whereby said carriage acting through said linkage will drive said cam into engagement with said power roll to limit the rate of movement of said cam from its start to finish position and consequently to limit the rate of movement of said carriage through said predetermined distance.

6. In a power driven typewriter having a power roll and a carriage movable across a printing position under the influence of a power imparting means, a device for decelerating said carriage as it travels through a predetermined distance comprising a cam of constant radius, an arm supporting the same for angular motion through a peripheral contact cycle with said power roll from a start to a finish position wherein the angular motion of said cam is limited by said power roll, means mounting said arm for pivotal movement from an inactive limit wherein said cam cannot engage said power roll to an active limit wherein said cam can pass through said peripheral contact cycle with said power roll, spring means biasing said arm normally to its inactive position, means responsive to the institution of a carriage movement under the influence of its power imparting means for collapsing said spring means to relieve its tension and thereby permit movement of said arm to its active position, and linkage means interconnecting said cam and said carriage during movement of the latter through said predetermined distance to correspondingly move said cam from its start to finish position as said carriage moves through said predetermined distance, whereby after said spring means has been collapsed by the institution of a carriage movement said carriage acting through said linkage will drive said cam into engagement with said power roll to limit the rate of movement of said cam from its start to finish position and consequently limit the rate of movement of said carriage through said predetermined distance.

7. In a power driven typewriter having a power roll and a carriage movable across a printing position under the influence of a power imparting means, a device for decelerating said carriage as it travels through a predetermined distance comprising 'a cam, an arm supporting the same for angular motion through a peripheral contact cycle with said power roll from a start to a finish position wherein the angular motion of said cam is limited by said power roll, means mounting said arm for pivotal movement from an inactive limit wherein said cam cannot engage said power roll to an active limit wherein said cam can pass through said peripheral contact cycle with said power roll, spring means biasing said arm normally to its inactive position, means responsive to the institution of a carriage movement under the influence of its power imparting means for collapsing said spring means to relieve its tension and thereby permit movement of said arm to its active position, and linkage means interconnecting said cam and said carriage during movement of the latter through said predetermined distance to correspondingly move said cam from its start to finish position as said carriage moves through said predetermined distance whereby after said spring means has been collapsed by the institution of a carriage movement said carriage acting through said linkage will drive said cam into engagement with said power roll to limit the rate of movement of said cam from its start to finish position and consequently limit the rate of movement of said carriage through said predetermined distance.

References Cited in the file of this patent UNITED STATES PATENTS

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