US2202053A - Adjustment device - Google Patents

Description

May 28, 1940. w. F. HELMOND I 2, ADJUSTMENT DEVICE Filed June 11', 1938 INVEN OR WILLIAM F. HELMDND ,ATTQRN EY Patented May 28, 1940 PATENT OFFICE ADJUSTMENT DEVICE William F. Helmond, West Hartford, 001111., as-

signor to Underwood Elliott Fisher Company, New York, N. Y., a corporation of Delaware Application June 11, 1938, Serial No. 213,226

6 Claims.

This invention relates to an adjustment device and more particularly to an adjustment device having provision for selective adjustment of a multiplicity of parts to govern the operation of a series of spaced independently movable members. Although the invention may be of somewhat general application it has a particularly important relation to typewriting mechanism and more specifically therein to the adjustment of the throw-off timing for the various type bar actuators of a power-driven typewriter.

One reason for the special application of this invention to typewriting mechanism is its incidental or secondary advantage in reducing the noise of impact when the power drive unit throws an actuator into contact with the adjustment device as the latter is serving to effect disconnection between the actuator and the power drive unit.

vIn a power-driven typewriter it is highly desirable that the mechanism controlling the throw of the type bars be disconnected at a definite time relative to the position of the type head in its arc of travel to the platen. Owing to link and lever connections conventionally employed in typewriter type actions and the power operating devices therefor, it is necessary to have individual adjustment for each type action whereby the point of disconnection from the power unit may be adjusted to suit, and it is also desirable that when this adjustment has been made no unintended change shall take place as might be due to vibration or other causes.

The present invention has, therefore, as its principal object the provision of an adjustment device which shall be rigid. simple in construction, and inexpensive to manufacture. and in which the adjustment may be quickly and conveniently made and is assuredly maintained- The present invention further relates to a simple and inexpensive method of making an adjustment device for use in a typewriter or other machine involving a series of spaced related operating parts.

In the drawing wherein is illustrated one of various possible embodiments of the invention and wherein the method of making such a device is also indicated:

Fig. l is a diagrammatic view of the type action and platen of a power-driven typewriter in which the present invention is serving as a throw-off stop for the power-driven actuator.

Fig. 2 is a View showing the component parts of the invention in partial disassembly.

'tively soft resilient pieces l5 are provided prefer- Fig. 3 is a view in cross section of the invention as shown in Fig. 2 with the parts assembled and the method completed. The section is taken transversely through the median of one of the adjusting screws.

Referring now more particularly to the drawing, a channel member preferably of metal is indicated atv Ill. At spaced points along the center line of the base of the channel member tapped holes I I are provided. Into each of these 10 holes a screw I3 is threaded until a substantial portion of its threaded shank lies between opposite side walls M of the channel member. Relato rubber such reference is intended to embrace any other material having similar characteristics of plasticity and resilience so that it may be pressed into frictional engagement with the surfaces of the threads of the screw and will serve to retard the rotation thereof.

The molded rubber pieces l5 are fitted into the spaces between the channel side walls and the screw shanks with the groove I6 in position to fit around the screw shanks. When in such po sition the side walls M are pressed toward each other and set in that position as shown in Fig. 3. This forces the rubber into the thread spaces as indicated at I! in Fig. 3 except for a slight distance along the screw shanks where 4 the pieces l5 do not meetas indicated at I 8 in Fig. 3. The rubber strips are held in the channel against displacement by the pressing in of the side walls M.

The screws [3 may be screw-slotted for appli- 46 cation of an instrument for rotation of the screw, either at the top or bottom. In the present preferred embodiment such slot is provided in the bottom of the screw as indicated at l9.

In Fig. 1 of the drawing a typewriter key lever is shown at 20 fulcrumed at 2| and held in its upper position against a stop 22 by a return spring 23. One type bar of a conventional series is shown .at 24 pivoted at .25 and adapted for a movement to a platen 26 under control of a sublever 27 pivoted at 28.

Each sublever has an actuator 28' pivoted on it at 29 and held upwardly with its forward end 30 against a stop bar 3| by a spring 32. Each actuator carries a pivoted pawl 33 adapted to be engaged by the teeth of a toothed roller 34 which latter extends transversely of the typewriter and is journaled in the frame thereof and ordinarily continuously driven by an electric motor.

The adjusting device heretofore described is indicated in its operative position in Fig. 1 at 35 and is used there to provide selectively variable points for the throw-off of the actuators 28. As each key lever 20 is depressed a hook 36 overlying a lug 3'! on the actuator 28' pulls the actuator down around the pivot 29 and engages the toothed pawl 33 with the drive roller 34. This advances the actuator forwardly until a cam face 38 contacts the head of screw l3 whereupon further continued forward movement of the actuator lifts it to disengage the pawl teeth and allow spring 32 to restore it upwardly.

The temporary engagement of an actuator with the drive roller causes a throw of a related type bar to the platen. Obviously the force of impact is variable in accordance with the length of time or distance that the actuator is maintained in engagement with the drive roller. Variation in these factors causes variation in the typing stroke and consequently one letter may appear sharp and another may appear weak just as is frequently noted in the operation of manually struck types.

If such condition is noted in a typewriter -equipped with the present invention the duration of the engagement between the pawl 33 and the fluted roller may be varied at will by rotating the appropriate screw I3 in one direction or the other.

Having once made such an adjustment it is desirable to maintain it during subsequent operation of the machine. The friction grip of he rubber on opposite sides of the screw and over the area of the threads is suificient to hold the screw against rotation under normal use conditions, and sound vibrations from impact of the actuator are absorbed to a large extent by the rubber between the screw shank and the channel member.

What is claimed is:

l. A row of spaced adjustment screws and a mounting therefor including a channel-shaped metal member through the base of which the screws are threaded with the screw shanks between the channel side walls, a rubber strip along each opposite wall of the channel and clamped by said walls into frictional engagement with the thread surface of the screws.

2. A row of spaced adjustment screws and a mounting therefor including a channel member through the base of which the screws are threaded with the screw shank between the channel side walls, a rubber strip along each channel wall having spaced transverse grooves to fit the screws and being under pressure from the wall which forces the rubber into engagement with a substantial area of the thread surface.

3. An adjustment device for engagement by separately operable parts in a typewriting mechanism, comprising a channel member adapted to be fixed to a supporting frame, a row of spaced screws threaded into the base of the channel and having their threaded shanks lying between the channel side-walls, a soft-vulcanized rubber strip on each side of the row of screws, held by the side walls in pressure engagement with all the screws to the extent that the rubber of the strips is forced into the screw thread spaces.

4. In a power-driven typewriter having a type action system including a series of type bar actuators and a power roller cooperative therewith, an adjustable throw-off device adapted for engagement by the actuators and comprising an elongate channel fixedly mounted, a series of throw-off screws carried by said channel, and a body of resilient material compressed within said channel and embracing said screws to dampen impact of the actuators thereon and frictionally lock said screws in adjusted positions.

5. In a power-driven typewriter having a type action system including a series of type bar actuators and a power roller cooperative therewith, an adjustable throw-off device adapted for engagement by the actuators and comprising a fixedly mounted elongate channel having a base and side walls, a series of throw-off screws threadedly carried in said channel base and projecting substantially between the side walls thereof, and a pair of rubber strips, each disposed between a channel side wall and said screws, said strips frictionally engaging said screws to resist rotation thereof and dampen impact of the actuators thereon.

6. In a power-driven typewriter having a type action system including a series of type bar actuators and a power roller cooperative therewith, an adjustable throw-off device adapted for engagement by the actuators and comprising a fixedly mounted elongate channel having a base and side walls, a series of throw-off screws having threaded shanks threadedly carried in said channel base and projecting substantially between the side walls, and a pair of rubber strips having transverse grooves accommodating the screw shanks, said strips being disposed at opposite sides of said screw shanks and compressed within said channel to frictionally lock said screws against rotation and dampen impact of the actuators thereon.

WILLIAM F. HELMOND.

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