US1549082A - Back spacer for typewriters - Google Patents

Description

Aug. 11, 1925. 1,549,082

0. A. HOKANSON BACK SPACER FOR TYPEIRII'BRS Filed July 17. 1920 2 Sheets-Sheet 1 Aug'. 11, l 925.

1 v 08 O. A. HOKANSON J01 BACK SPACER FOR TYPEWRITERS Filed July 17.;1920

Patented Aug. 11, 1925.

OTTO A. HOKANSON, OF WOODSTOCK,

ILLINOIS, Assrenon To WOODSTOCK 'rrrnwnrrnn COMPANY, OF WOODSTOCK, ILLINOIS, A. CORPORATION OF ILLINOIS.

BACK SPACER FOR- TYPEWRITERS.

Application filed. July 1'7,

1 0 all whom it may concern:

Be it known that I, O'r'ro A. HoKANsoN, a. citizen of the United States, residing at Woodstock, in the county of McHenry and State of Illinois, have invented certain new and useful Improvements in Back Spacers for Typewriters, of which the following is a specification.

This invention relates to that portion of typewriter mechanism by which the platen carriage may be fed in a reverse direction with a step by step movement corresponding to the letter spacing on the typewritten sheet, and has for its object the provision of mechanism of the character named which shall be of improved construction and operation.

The invention is exemplified in the combination and arrangement of parts shown in the accompanying drawings and described in the following specification, and it is more particularly pointed out in the appended claims.

In the drawings Fig. 1 is a fragmentary vertical sectional view of a portion of a typewriter having one embodiment of the present invention applied thereto;

Fig. 2 is a horizontal section substantially on line 22 of Fig. 1; and

Fig. 3 is a vertical section substantially on line 3-3 of Fig.2.

In the embodiment of the invention shown in the drawings, the numeral 10 designates a base or main frame of a typewriter having a platen carriage frame 11 supported by arms 12 which are pivotally mounted at 13 on the main frame 10. The arms 12 are arranged to swing about their pivotal supports 13 to move the platen carriage into operative position, as shown in Fig. 3, and also into a folded or inoperative position, in which the platen carriage is swung to the right on its pivotal supports approximately 180 degrees from the position shown in Fig. 3. The platen carriage frame 11 is provided with a platen carriage 14 arranged to slide along ways 15 on the carriage frame. The movement of the carriage 14- is controlled by a rack 16 meshing with a pinion 17 which is connected with an escapement wheel 18 journaled on the platen frame 11.. Any usual and approved form of escapement 1920. Serial No. 396,887.

mechanism may be usedfor controlling the operation of the escapement wheel 18.

The main frame 10 of the typewriter is provided with a rear plate 19 having laterally bent flanges 20 and 21 on which a bar 22 is mounted for longitudinal sliding move. ment. A slot 23 is formed in one end of the bar 22 and a screw 24: passes through the slot into the flange 20 to hold the bar in place and to limit the longitudinal movement thereof. A second slot '25 isprovided in the opposite end of the bar and is arranged at an angle to the longitudinal axis of the bar, as shown in Fig. 2. A screw 26 passes through the slot and is provided with an extension 27 to which is secured one end of a spring 28. The opposite end of the spring 28 is attached to a lug 29 extending downwardly from the bar 22 so that the bar is normally drawn to the right, as viewed in Figs. 1 and 2. The end of the. bar 22 adjacent the slot 25 carries an upwardly projecting flange 30 having a dog 31 pivotally mounted at 32 thereon.- A. spring 33 surrounds the pivot 32 and tends to rotate the dog 31 in a clockwise direction, as viewed inFig. 1. A stop 3Pis formed on the dog to strike the bar 22 and limitthe movement of the dog under the influence. of the spring 33.

An arm 35 is out from the plate 19 of the typewriterframe and bent upwardly and rearwardly, as shown in Figs. 1 and 2, to form a stop for engaging a lug36 on the dog 31. The spring 28 jection 36 against the stop 35 so that the dog 31 is rotated against the tension of the spring 33 into the position shown in Fig. 1. The dog 31 is provided with an acting face 37 positioned adjacent the escapement wheel 18 and when the bar 22 is shifted to the left against the tension of the spring 28 by mechanism to be described, the projection 36 will be released from the stop 35 and the spring 33 will swing the acting face 37 upwardly into the plane of the escapement wheel 18 so that as the bar 22 continues to move .to the left the face 37 of the dog 31 will engage one of the teeth of the escapement wheel 18 and rotate the escapement wheel in a backward direction an amount corresponding to one of the spaces between theteeth of the wheel. The escapement wheelwill, of course,

normally presses the probe retained in its new postion b the dogs by which it is controlled. The lange 30 is provided with an upwardly extending tooth 3 arranged so that when the bar 22 1s moved to actuate the dog 31 and rotate the escapement wheel, the tooth 30 will be moved into a position in the rear of one of the teeth on the escapement wheel to prevent any danger of overthrow of the escapement wheel under the force of the backspacing dog. Since the escapement wheel is connected with the pinion 1? which meshes withthe rack 16 the reverse movement of the escapement wheel will move the platen carriage backwardly an amount corresponding to a letter space. By successively vibrating the bar 22 the platen carriage may be fed backwardly by a step by step move ment any amount desired.

For moving the bar 22 the typewriter is provided with a back-spacing key lever 38 having an upwardly projecting arm 39. WVhen the platen carriage is in operating position the arm 39 engages a bell crank lever 40 pivotally supported on a lug 41 extending downwardly from the lower face of the platen carriage frame 11. A spring 42 is carried on the lug 41 and normally holds the bell crank 40 in engagement with the arm39. The upper end of the arm 39 isbeveled, as shown at 43, so that when the platen carriage frame 11 moves downwardly into operating position the bell crank 40 will be guided by the beveled surface 43 into position in front of the arm 39. A link 44 is pivotally mounted at 45 on the bell crank 40 and is provided with a slot 46 at its opposite end slidably supported on a suspension pin 47 extending downwardly from the frame 11. The link 44 is provided with an opening 48 arranged to engage a spur 49 bent upwardly from the bar 22. The opening 48 is of a greater width than the thickness of the spur 49 and the upper end of the spur is beveled to guide the spur into position in the opening 48 when the platen carriage frame moves into operating position. Operation of the back spacing key lever 38 will move the bell crank 40 and cause the link 44 to shift the bar 22 against the tension of the spring 38 which operation first releases the dog 31 until it swings into the plane of the escapement wheel 18. Further movement of the backspacing key lover will cause the end of the bar 22 to travel in the direction of the slot 25, thus bringing the operating face 37 of the dog 31 into contact with one of the teeth of'the escapement wheel 18 and rotate the escapement wheel to shift the platen carriage one space. hen the back spacing key is released the spring 42 will restore the link 44 to its original position, thus permitting the bar 22 and the dog 31 to return to the position shown in Fig. 1.

The operation may, of course, be repeated as many times as desired. hen the backspacing mechanism is inactive the dog 31 is held in the position shown in Fig. 1 by the stop 35 so that it does not interfere with the rotation of the escapement wheel for controlling the forward movement of the platen carriage. Since the operating dog 31, together with its actuating bar 22 are mounted on the stationary portion of the typewriter frame, the dog will always be in position to be brought into operative engagement with the escapement wheel whenever the platen carriage frame is moved to its operating position. The movement of the platen carriage frame to operating position will also automatically establish connection between the back-spacing key lever 39 and the actuating bar 22 through the medium of the bell crank 40 and link 44 mounted on the platen carriage frame. When the platen carriage frame is swung to its folded position the bell crank 40 and link 44 will be disconnected from the back-spacing key lever and the bar 22, respectively, thus disengaging the backspacing key lever from the mechanism for engaging the escapement wheel. The operating connection is automatically restored upon return of the platen carriage frame to its operating position, as previous ly explained. claim 1. In combination, a typewriter having a base frame and a platen carriage frame mounted thereon for movement into and out of operating position, an escapement wheel carried by said platen carriage frame and movable therewith, and backspacing mechanism comprising a part mounted on said base frame in position to engage said escape ment wheel whensaid platen carriage frame is in its operating position.

2. In combination, a typewriter comprising a base frame, a platen carriage frame mounted on said base frame and movable into and out of operating position, a platen carriage movably mounted on said platen carriage frame, an escapement wheel on said platen carriage frame for controlling the movement of said carriage, and mechanism mounted on said base frame for engaging said esoapement wheel for imparting a back spacing movement to said platen carriage said escapement wheel being movable into and out of operative relation with said engaging mechanism when said platen carriage frame is moved into and out of operating position.

3. In combination, a typewriter comprising a main frame, a platen carriage frame having a platen carriage movably mounted thereon, means for supporting said platen carriage frame for movement into and out of operating position, escapement mechanism mounted on said platen carriage frame for controlling the movement of said platen carriage, and a back-spacing dog mounted on said main frame in position to cooperate with said escapement mechanism, whensaiol platen carriage frame is in operating position, to impart a back-spacing movement to said platen carriage.

4. In combination, a typewriter comprising a main frame, a platen carriage frame mounted on said main frame and movable into and out of operating position, a platen carriage movably mounted on said platen carriage frame, escapement mechanism mounted on said platen carriage frame for controlling the movement of said platen carriage, back-spacing mechanism comprising an oscillatory member mounted on said main frame and having a. dog pivotally mounted thereon in position to cooperate with said escapement mechanism when said platen carriage frame is in operating position, means for hOlCliIlg said dog out of the path of movement of said escapement mechanism when said oscillatory member is in one position, and resilient means for automatically moving said dog into position to engage said escapement mechanism when said oscillatory member is actuated to perform a back-spacing operation.

5. A typewriter comprising a main frame, a platen carriage frame mounted on said main frame for movement into and out of operating position, a platen carriage on said platen carriage frame, back-spacing mechanism comprising a part mounted on said main frame and arranged to impart a backspacing movement to said platen carriage when said platen carriage frame is in operating position, a back spacer key mounted on said main frame and means for automatically rendering said back-spacing mechanism inoperative when said platen carriage frame is moved out of operating position, said means comprising a connection for operatively connecting said key and'said beforementioned part when said platen carriage frame is in operative position.

6. A typewriter comprising a main frame, a platen carriage frame mounted on said main frame for movement into and out of operating position, a platen carriage on said platen carriage frame, backspacing mechanism comprising a part mounted on said main frame, a back-spacing key on said main frame, and means on said platen carriage frame for connecting said back-spacing key with the said part of said back-spacing mechanism when said plat-en carriage frame is in operating position.

7. In a typewriter, a main frame, a platen carriage frame mounted thereon for move-- ment into and out of operating position, a platen carriage on said platen carriage frame, back-spacing mechanism comprising a part mounted on said main frame and arranged to impart a back-spacing movement to said platen carriage when said platen carriage frame is in operating position, a backspacing key on said main frame, and means on said platen carriage frame for connecting said back-spacing key with said part of said back-spacing mechanism, said means being movable with said platen carriage frame and arranged to automatically connect said key and back-spacing mechanism part when said platen carriage frame is moved into operating position and to disconnect said key and back-spacing mechanism part when said platen carriage frame is moved out of operating position.

8. A typewriter comprising a main frame and a platen carriage frame mounted thereon for movement into and out of operating position, back-spacing mechanism comprising a part mounted on said main frame, a back-spacing key on said main frame, and connecting means for said key and part, said connecting means being carried by said platen carriage frame and movable therewith to automatically disconnect said key and back-spacing part when said platen carriage frame is moved out of operating position. a

9. In a typewriter", a platen carriage, an escapement wheel for controlling said carriage, back-spacing mechanism for engaging said escapement wheel to impart a backward movement to said carriage, said mechanism comprising an oscillatory member 100 mounted for sliding movement in a direction parallel to the plane of said wheel and having a dog pivotally mounted thereon and movable about its pivot in a plane trans verse to the plane of movement of said es- 105 capement wheel, means for holding said dog out of operating position when said oscillatory member is in one position, and resilient means for holding said oscillatory member in said position.

10. A typewriter comprising a main frame, a platen carriage frame mounted thereon for movement into and out of operating position, a platen carriage movably mounted on said platen carriage frame, an 115 escapement wheel for controlling the movement of said carriage on said frame, backspacing mechanism comprising an oscillatory member mounted on said main frame,

a dog pivotally mounted on said oscillatory 120 member, resilient means for moving said oscillatory member in one direction, a stop for engaging said dog, when said oscillatory member is drawn by said resilient means to the limit of its movement, to hold said dog 125 out of the plane of said escapement wheel, a spring for automatically moving said' dog into posit-ion to engage said escapement wheel when said oscillatory member is moved in the opposite direction, a back-spac- Eng key lever mounted on said main frame, ated by said key lever when said platen car a bell crank mounted on said platen carriage riage frame is in operating position.

frame and arranged to engage said key ievel' In testimony whereof I have signed my 10 when said platen carriage frame is in opername to this specification on this 21st day ating positiom and means for connecting of J une, A. D. 1920.

said bell crank with said oscillatory member to permit said oscillatory member to be oper- OTTO A. HOKANSON.

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