US1979620A - Typewriting machine - Google Patents

Description

Nov. 6, 1934. r E a HES; 1,979,620

TYPEWRITING MACHINE Qriginal Filed Dec. 11, 1933 2 s eets-sheet 1 Edward fi fess,

Nov. 6, 1934. E. a. HESS TYPEWRIT ING MACHINE 2 Sheet sSheet 2 QIiginal Filed Dec. 11,1933

3 MW Edward E- Jzass,

Patented Nov. 6, 1934 PATENT QF'FICE TYPEWRITING MACHINE EdwardB. Hess, Orlando, Fla., assignor to Royal Typewriter Company, Inc., New York, N. Y., a corporation of New York Original application December 11, 1933, Serial No.

Divided and this application March 29, 1934, Serial No. 718,015

2 Claims. (Cl. 197-106) This invention relates to new and useful improvements in typewriting machines generally, although more particularly to a key lever construction thereof. 7

This application constitutes a division of my copending application Serial No. 701,893, filed Dec. 11, 1933, for improvements in typewriting machines and which is a continuation in part of the parent application Serial No. 669,611, filed May 5, 1933. i g

Among the several objects of this invention are to provide a key lever for the type action which is constructed to afford a cushion effect to the operator when thelever is depressed, and to provide a key lever which is simple in construction and durable in operation.

In the drawings:-

Figure 1 is a, detail vertical sectional view through a typewriting machine, and showing my improved type action in its normal position,

Figure 2 is a somewhat similar view showing the partsof the type action in different positions, and

Figure 3 is a perspective view of the key lever,

the fulcrum section, the spring, and the power section being shown in separated relation.

Referring to the accompanying drawings, there is shown a platen C, a shifting segment F, a type bar G, and a key lever H.

The type bars G are mounted in the usual slots in the segment F and are pivotally mounted at their heels in said segment by a pivot rod 5. These type bars are normally supported in rest position by a head rest 6. Each type bar comprises a type section '7 and a heel section 8, the former being provided with a type head 9. The outer end of the heel section 8 is pivotally connected to the type section by a hinge pin 12 and is normally held in longitudinal alinement therewith by a spring 17.

The key lever H which comprises a power section 19 and a fulcrum section 20, is fulcrumed on a shaft 21 which extends across the machine. The inner end of the power section 19 is provided with a longitudinally extending recess 22 for receiving the outer end of the fulcrum section 20. The recess 22 forms resultant walls 23, 23 and the outer end of the fulcrum section 20 is hingedly connected to said walls by a hinge pin 24. The power section 19 at the inner end of the recess 22 is beveled to form a V-shaped end 25 having upper and lower inclined faces. The outer end of the fulcrum section 20 is inwardly beveled to form an angular recess 26. The angle of the recess 26 is greater than the angle of the V-shaped end 25. The upper bevel of the end 25 normally engages the upper bevel of the seat 26 to retain the power section 19 against upward swinging movement relative to the fulcrum section 20. The lower bevel of the end 25 is normally spaced from the lower bevel of the seat 26 so as to permit a limited downward swinging movement of the power section 19 relative to the fulcrum section 20 immediately following the key lever reaching the lowermost limit of its depression movement. In order to yieldably retain the power section 19 from such pivotal movement, I have provided a U-shaped wire spring 2'7. This spring is disposed within the recess 22, one arm thereof resting against the bottom of the recess and the upper arm extending across the adjacent ends of the sections 19 and 20 and bearing against the lower edges thereof.

The type action includes connections between the type bar and the key lever. These connections include a front link 28 which is pivotally mounted in a radial slot located in the under face of a segmental supporting bracket 29 which isdisposed above the key lever H and in front of the platen C. A pull link 31 is pivotally connected at its front end to the rear end of the front link 28, and the rear end of said pull link 31 is pivotally connected as at 32 to the heel of the associated type bar at a point below the pivot thereof and in a substantially vertical plane therewith. A draw link 33 has its upper end pivotally connected to the front link 28 and its lower end pivotally connected to the fulcrum section 20 of the associated key lever H. The key lever H extends forwardly through the usual comb guide 34. The front link 28 is balanced by a coil spring 35 having its upper end connected to the forward end of the front link 28 and its lower end connected to the comb guide support, and this spring functions to return the type bar to its normal position of rest upon release of the key lever H.

Mounted on the segment F is an abutment 36, preferably metal, for each type bar G. This abutment is positioned so that when the type bar is swung upwardly said abutment will be engaged by the heel section 8 of the type bar at a point preferably substantially midway between the fulcrum 5 of the type bar and the hinge pin 12 which hingedly connects the type bar sections 7 and 8, to thereby cause the type section '7 to swing rearwardly about the hinge pin 12 and. against the tension of the spring 1'7 into printing contact with the platen C.

In the operation of my invention as thus far described, the operator depresses a key lever H and the associated front link 28 is swung downwardly from the full line position shown in Figure 1 to the dotted line position shown in Figure 2, the sections 19, 20 of the key lever remaining in longitudinal alinement. During this downward movement of the front link, the pull link 31 causes the type bar G to be swung upwardly from the full line position shown in Figure 1 to the first dotted line position shown in Figure 2, the sec tions '7, 8 of the bar remaining in longitudinal alinement. During this period of time the motion of the type bar is accelerated, and when the type bar reaches its dotted line position, as shown in Figure 2, it is in front of and in spaced relation to the platen and is at the end of its accelerated movement. At this time the pivot 32 of the pull link 31 is in alinement with the pivot 5 of the type bar and with the pivotal connection between the front end of the pull link 31 and the front link 28. Thus the connections form a toggle and are now in locked relation. 1 Furthermore, at this time the fulcrum section of the key lever has been depressed to its fullest extent.

The type bar then travels rearwardly' by momentum until the fulcrum section 8 engages the abutment 36 which causes the type section 7 to swing about the pivot 12 and against the tension of the spring 17 to thereby impact the platen. During this momentum period of movement of the type bar, the power section 19 of the key lever is depressed about the pivot 24 to the full line position shown in Figure 2.

A stop which is usually employed for limiting the downward movement of the key lever, is eliminated as the key lever cannot be moved downwardly after the toggle links have reached their locked positions. During the depression of the key lever both the power and fulcrum . sections 19, 20 are retained against relative pivotal movement, but just as soon as the lever reaches the lower limit of its movement, and while the type bar is moving in its momentum travel, the power section 20 will be swung downwardly for a limited extent to thereby function as acushion for the operators stroke and avoid the use of the rubber caps now employed on the fingerpieces of key levers.

I claim:-

1. A key lever comprising hingedly connected power and fulcrum sections arranged end to end in longitudinal alinement, the inner end of the power section being provided with a longitudinally extending recess to receive and house the inner end of the fulcrum section, cooperating stop shoulders on the meeting ends of said sections, to limit the swinging movement in one direction of the power section relative to the fulcrum section, said shoulders comprising a V- shaped projection on the end of one section and a correspondingly shaped recess in the end of the other section for receiving said projection, the angle of the recess being greater than the angle of the projection, and a spring housed within said longitudinally extending recess and directly cooperating with both sections to normally and yieldably retain the power section against swinging movement relative to the fulcrum section.

2. A key lever comprising power and fulcrum sections arranged end to end in longitudinal alinement, a housing secured to the end of the power section and including side walls and a bottom which overlap the adjacent end of the fulcrum section, the housing extending below the sections to form a space between the bottom of the housing and the lower faces of the sections, a horizontal pivotal connection between the walls of the housing and the fulcrum section, the meeting ends of the sections being formed with cooperating shoulders to limit the upward swinging movement of the power section relative to the fulcrum section, and a U-shaped spring located within the housing between the bottom thereof and the lower faces of the sections and directly contacting the latter, the ends of the spring having fixed engagements, with the bottom of the housing and with the lower face of the fulcrum section.

EDWARD B. HESS.

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