US3722654A - Repeat spacing mechanism for typewriters - Google Patents

Abstract

A repeat spacing mechanism for typewriters wherein there are rotatably mounted a feed pawl and a hold pawl on a pawl shaft coaxially therewith; normally the hold pawl engages a toothed wheel rotatably urged by a spring drum for moving a carriage in the letter feed direction. Further provided is an elastic member made of piano wire which is operated by a repeat space key, said member being provided with a weight at its free end. During depression of the repeat space key, the elastic member acts on the feed pawl, thereby causing the feed and hold pawls to be alternately engaged with and disengaged from the toothed wheel and the carriage to perform a continuous repeat spacing movement in the letter feed direction at a speed controlled by said weight.

Description

United States Patent 1 91 Watanabe et al.

[ Mar. 27, 1973 REPEAT SPACING MECHANISM FOR TYPEWRITERS [75] Inventors: Tomoyoshi Watanabe, Minato-ku,

Nagoya; Masao Jozuka, Hekikaigun,

Aichi, both of Japan [73] Assignee: Brother Kogyo 'Kabushiki Kaisha, A

Mizuho-ku, Nagoya-shi, Japan 22 Filed 061. 23, 1970 21] Appl. No.: 83,589

[30] Foreign Application Priority Data Oct. 24, 1969 Japan ..44/l0l043 [52] US. Cl. ..l97/82 [51] .Int. Cl. ..B4lj 19/00 [58] 'Field'of Search ..l97/64, 82, 84, 84 A, 84 B,

[56] References Cited UNITED STATES PATENTS 3,417,848 12/1968 Gallant .....197/82 744,424 11/1903 Steiger ...197/64 937,336- 10/1909 Stickney ....l97/82 2,037,178 4/1936 Roh rer ..197/82 2,728,436 12 1955 Kupper ..197 s2 2,896,767 7 1959 Barkdoll.... .....197 s2 3,028,942 4/1962 Page ..197 ss 3,258,101 1966 Decker... ....197 ss x 3,312,322 4/1967 Canny ..197 s2 3,472,353 10 1969 Canny et al. ..197 s2 Primary Examiner-Ernest T. Wright, Jr. Attorney-Flynn & Frishauf [5 7] ABSTRACT A repeat spacing mechanism for typewriters wherein there are rotatably mounted a feed pawl and a hold pawl on a pawl shaft coaxially therewith; normally the hold pawl engages a toothed wheel rotatably urged by a spring drum for moving a carriage in the letter feed direction. Further provided is an elastic member made of piano wire which is operated by a repeat space key, said member being provided with a weight at its free end. During depression of the repeat space key, the elastic memberacts on the feed pawl, thereby causing the feed and hold pawls to be alternately engaged with and disengaged from the toothed wheel and the carriage to perform a continuous repeat spacing movement in the letter feed direction at a speed controlled by said weight.

7 Claims, 11 Drawing Figures PAIEmEumwm 3,722,654

SHEET l [1F 4 FIG. 8

FIG. i0 FIG. H

semiautomatic typewriter.

REPEAT SPACING MECHANISM FOR TYPEWRITERS BACKGROUND OF THE INVENTION The present invention :relates to a repeat spacing mechanism for typewriters which causes the carriage of a typewriter, particularly :a manualor semiautomatic typewriter to make arepeat spacing movement continuously. I Where a typewriter, particularly, a manual or semiautomatic typewriter is desired to start printing at a point'defined by skipping the carriage several letter spaces from a given printing position, there maybe applied any of three processes of depressing a tabulating key,-operating a carriage release lever mounted on the carriage and repeatedly depressing a space bar.

While the first process offers convenience where a printing column is fixed, as in the case of tabulation, it has the disadvantage that where it is desired to skip the carriage from one printing position to another, the

setting and clearing of a tabulator stop'has to be conducted frequently, which is very troublesome. .With the second process, a typist is required to take his hands off the keyboard each time the carriage is to be skipped, resulting in not only the derangement of the typing rhythm but also loss of time. Generally, therefore, there is often used a third process in which the typist depresses the space bar repeatedly until the following printing position is set, though he need not take his hands off the keyboard. Accordingly, this third process I SUMMARY OF THE INVENTION An object of the present invention is to provide a durable repeat spacing mechanism for typewriters of sufficiently simple construction to facilitate manufacture which, during depression of a repeat space key, enables a carriage continuously to conduct a repeat spacing movement at a prescribed speed travelling one exact letter space each time and, upon depression of a type key orspace bar, to perform a single step movement smoothly without being affected byan inertia increasing member or weight. I

Another object of the present invention is to provide an inexpensive repeat spacing mechanism of simple. construction for typewriters wherein oscillation means having an elastic member made of, for example, piano wire, stainless steel wire or plastic material and spacing movement by the spring force of the elastic member itself.

The'present invention can be more fully understood from the following detailed description when taken in connection with the accompanying drawing.

ing mechanism, showing the condition in which the BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a bottom view of the repeat spacing mechanism of the present invention;

FIG. 2 is a sectional view along line IIII of FIG. 1;

FIG. 3 is a sectional view along line IIIIII of FIG. 1; FIG. 4 is a sectional view along line lVIV of FIG. 1, indicating an oscillation means and a repeat space key and its related members; I

5 is the bottom view of a part of the repeat spacfeed .pawl engages 'anescapement wheel when an operation member is operated; 7

FIG. 6 is the bottom view of the same part of the repeat spacing mechanism as shown in FIG. 5, indicating the condition in which the feed .pawl engages the escapement wheel during depression of the repeat space key;

FIG 7 is the sectional view along line IV-IV of FIG. 1, indicating the condition of the oscillation means in which a feed pawl engages the wheel during depression of'a repeat space key;

FIG. 8 shows the manner in which the elastic member is pushed back by a cam action between the feed arm of the feed pawl and the tooth of the wheel during depression of .the repeat space key;

FIG. 9 is a front view of a modification 'of the oscillation means; i

FIG. 10 is a side view of the oscillation meansin FIG. 9; and

FIG. 11 is a front view of still another modification of the oscillation means. 7

DETAILED DESCRIPTION OF THE INVENTION Referring to FIGS. '1 to 6,'numeral 11 denotes a base plate, to which there is fixed a bearing sleeve 13 by a lock nut 12 so as to penetrate said base plate ll.'A wheel shaft 14 is inserted into the bearing sleeve 13 (FIG. 2) and fitted with a space pinion 15 at the upper end and a toothed member or an escapement wheel 16,

for example, a saw-toothed wheel at'the lower end. In

FIG. 1, below the base plate 11 is disposed apawl shaft 17 in parallel with the wheel shaft 14. With the. pawl shaft 17 are rotatably engaged a feed pawl 18 and hold pawl l9 both bent at the center in such' a manner that they are superposed on each other at said bend. Substantially at the center of a feed. arm 18a constituting one end of the feed pawl 18 is provided a perpendicular arm 18b substantially at right angles thereto. At the free end of the perpendicular arm 18b is formed an en gaging portion facing the wheel 16. The other end of the feed pawl 18 constitutes a driven arm 18d. Between a projection l8e formed on the central portion of the feed pawl 18 and a spring holder 20 provided on the base plate 11 is stretched strong spring means, for example, a tension spring 21.- This tension register with the wheel 16 at points several pitches and a half apart from each other. At the other end of the hold pawl 19 is formed a disengagement arm 19c in a manner to be superposed on the feed arm 18a of the feed pawl 18. Between the perpendicular arm 18!) of the feed pawl 18 and the hold arm 19a of the hold pawl 19 is stretched a weak spring 23 which draws the hold pawl 19 toward the perpendicular arm 18b and causes the disengagement arm 19c continuously to contact the stopper 18f, thereby allowing the hold pawl 19 to turn substantially jointly with the feed pawl 18 about the shaft 17. Under this condition, the engaging portion 180 of the feed pawl 18 and the engaging portion 19a of the hold pawl 19 are so designed that when one of them enters the rotating field of the wheel 16, the other is removed therefrom. An operation member 24 is rotatably mounted on a pivotal shaft 25 which is pivoted on the base plate 11. This operation member 24 comprises a contact roller 26 for urging the driven arm 18d of the feed pawl 18 against the force of the tension spring 21, a portion 27 located between the wheel shaft 14 and pivotal shaft 25 and an arcuate elongated hole 28 perforated near the contact roller 26. There is provided another member 29 which is positioned between the wheel shaft 14 and pivotal shaft 25 and rotatably connected to a horizontal shaft 30. This member 29 has a push arm 31 contacting and pressing portion 27 of the operation member 24 and a pin-like receiving member 32. The operation member 24 is located in the triangular area defined by the pivot shaft 25, wheel shaft 14 and paw] shaft 17.

Carriage urging means or a spring drum 33 normally urges a carriage 34 having a platen (not shown) rotatably mounted thereon in the letter feed direction indicated by the arrow D of FIG. 1 through a connecting strap 35. A rack 36 is connected to the carriage 34 and engaged with the space pinion 15. The wheel 16 is urged clockwise as viewed from FIG. 1 by the tension of the spring drum 33 through the rack 36 and space pinion 15. Operation of a release lever (36a) connected to one end of the rack 36 causes the rack 36 to rotate counterclockwise as viewed from FIG. 2 so as to be disengaged from the space pinion 15.

A universal plate 37 advances and retracts in the direction of the arrows B and C of FIG. 3 respectively in response to the reciprocation of a type key (not shown). When the universal plate 37 is urged forward in the direction of the arrow B the operation member 24 is rotated clockwise in FIG. 1 through the aforementioned member 29 against the force of the tension spring 21.

Referring to FIG. 1, a lever 38 has its pivotal part rotatably connected to a shaft 39 mounted on a frame (not shown). To one end of the lever 38 is connected one end of a connecting rod 40, the other end of which engages the elongated idle hole 28 of the operation member 24, and to the other end of said lever 38 is connected one end of a second connecting rod 41. The other end of said second connecting rod 41 is rotatably connected to the extended end 4211 of a third connecting rod 42 through a shaft 43. One end of said third connecting rod 42 is fixed to a member 44 having an L- shaped cross section which is rotatably mounted on the frame and the other end of said third connecting rod 42 is fixed to a space bar 45 positioned on a keyboard (not shown). Depression and release of the space bar 45 cause the member 44 to reciprocate through the third connecting rod 42. This reciprocation is converted to the rocking motion of the lever 38 through the second connecting rod 41. This rocking motion in turn causes the operation member 24 to rock through the first connecting rod 40.

Referring to FIG. 4, numeral 46 represents an elastic rod member, for example, a piano wire disposed perpendicularly to and closely behind the feed arm 18a of the feed pawl 18. This elastic rod member 46 may be made of, for example, stainless steel, beryllium-copper alloy, phosphor copper or other similar elastic materials. The intermediate part of the elastic rod member 46 is rotatably mounted on a shaft 48 fixed to a supporting member 47 connected to the base plate 11. The upper free end of said elastic rod member 46 is fitted with an inertia increasing member or a weight 49. The aforementioned elastic rod member 46 and inertia increasing member 49 jointly constitute oscillation means acting on the feed arm 18a.

There is further provided a fourth connecting rod 50, one end of which is connected to the lower end of the elastic rod member 46 and the other end of which is connected to a repeat space key lever 52 through a fifth connecting rod 51. The repeat space key lever 52 constitutes a crank in the embodiment of FIG. 4 and has its central part rotatably connected to a frame 54 through a shaft 53. To the other end of the repeat space key lever 52 is fixed a repeat space key 55 which constitutes a manual operation member and is arranged parallel with the space bar 45.

The fourth connecting rod 50 is normally biased by a spring 56 or the like in the direction opposite to the direction of the arrow A of FIGS. 1 and 4. Depression of the repeat space key 55 causes the repeat space key lever 52 to rotate clockwise as viewed from FIG. 4, and in consequence the fourth connecting rod 50 to move in the direction of the arrow A of FIGS. 1 and 4 through the fifth connecting rod 51, thereby allowing the elastic rod member 46 to rotate clockwise as viewed from FIG. 4 (or downward in FIG. 1). As a result, the feed arm 18a of the feed pawl 18 is urged by the elastic rod member 46 to rotate counterclockwise as viewed from FIG. 1.

In FIG. 4, a lever stop 57 is disposed on the counterclockwise side of the upper portion of the repeat space key lever 52 and, when the repeat space key 55 is not depressed, keeps it at a prescribed position against the tension ofa spring 56. At this time, the upper portion of the repeat space key lever 52 contacts the lever stop There will now be described the operation of a repeat spacing mechanism according to the present invention. When the universal plate 37 retracts in the direction of the arrow C of FIG. 3, the feed pawl 18 has its engaging portion disengaged from the wheel 16 and the hold pawl 19 has its engaging portion 19b engaged therewith by the force of the tension springs 21 and 23 respectively as shown in FIG. 1, preventing the carriage 34 from moving in the letter feed direction. When the universal plate 37 advances in the direction of the arrow B of FIG. 3 by the printing operation of the type key (not shown), the aforesaid member 29 is urged to rotate the operation member 24 clockwise in FIG. 1 and the contact roller 26 pushes the driven arm 18d to rotate the feed pawl 18 counterclockwise about 7 the shaft 17 against the force of the tension spring 21, thereby bringing the engaging portion 18c into an engaging field with the wheel 16as shown in FIG. 5. At the same time, the stopper l8frotates the hold pawl 19 in the same direction as the feed pawl 18 to release the engaging portion 19b from the wheel 16 (FIG. 5). As the result, the wheel 16 rotates for a peripheral length corresponding to half a pitch of the carriage 34 until it engages the engaging portion 18c, causing, as shown in FIG. 5, the engaging portion 180 to be engaged with the wheel 16 and the engaging portion 19b to be disengaged therefrom. When the universal plate 37 is retracted in the direction of the arrow C by releasing the type key, both the feed pawl 18 and the hold pawl 19 are'rotated clockwise. The hold pawl 19 is brought into the rotation field of the wheel 16 and the feed pawl 18 is disengaged therefrom as shown in FIG. 1. The wheel 16 rotates clockwise for a peripheral length equal to another half pitch of the carriage 34.

Each cycle of depressing and releasing the type key causes the feed pawl 18 and hold pawl 19 to be alternately engaged with and disengaged from the wheel 16, allowing the carriage 34 to move one pitch each time, namely, make a single step movement. Upon depression of the space bar 45, the carriage 34 performs substantially the same movement. Depression of the space bar 45 causes the lever 38 to rotate clockwise as viewed from FIG. 1 through the connecting rod 42, member 44 and connecting rod 41 in turn, and the operation member 24 to rotate clockwise as viewed from FIG. 1 through the connecting rod 40 Accordingly, as shown in FIG. 5, the engaging portion 18c of the feed pawl 18 is engaged with the wheel 16 and the engaging portion 19b of the hold pawl 19 is disengaged therefrom, causing the carriage 34 to move half a pitch in the letter feed direction.

Return of the space bar 45 to its original positio causes the lever 38 and operation member 24 to rotate counterclockwise as viewed from FIG. 1, allowing the engaging portion 180 of the feed pawl 18 to be disengaged from the wheel 16 and the engaging portion 19b of the hold pawl 19 to be engaged therewith and in consequence the carriage 34 to move half a pitch in the letter feed direction. Thus each cycle of depressing and releasing the space bar 45 permits the carriage 34 to make a single step movement of one pitch.

Referring now to FIG. 1, depression of the repeat space key 55 causes the elastic rod member 46 to rotate clockwise as viewed from FIGS. 4, 7 and 8 (or downward in FIGS. 1 and 6) through the repeat space key lever 52 and connecting rods 51 and 50in turn, and in consequence the feed arm 18a of the feed pawl 18 to be urged to the right hand side as shown in FIG. 7 (or downward in FIGS. 1' and 6). The feed pawl 18 rotates counterclockwise against the force of the tension spring 21, bringing the engaging portion 180 thereof into an engaging field with the wheel 16. On the other-- hand, the hold pawl 19 is urged by the stopper 18f to rotate in the same direction as the feed pawl 18, caus ing the engaging portion 19b to be disengaged from the wheel 16. As the result, the wheel 16 rotates for a peripheral length corresponding to half a pitch of the carriage 34 until it engages the engaging portion 180 of the wheel 16. Thus the wheel the feed pawl 18 allowing, as shown in FIG. 6, the engaging portion 18c to be engaged with the wheel 16 and the engaging portion 19b to be disengaged therefrom.

Under the condition of FIG. 6, a force for moving the carriage 34 in the letter feed direction urges the wheel 16 to rotate clockwise through the rack 36 and space pinion 15 (FIG. 1), so that the engaging portion 18c of the feed pawl 18 undergoes a cam action ex ertedby that tooth of the wheel 16 which engages said engaging portion 186. As the result, the feed pawl 18 rotates clockwise, i.e. in the biasing direction of the tension spring 21, thereby bending the elastic rod member 46 in the direction opposite to the direction in which the elastic rod member 46 urges the feed arm 18a of the feed pawl 18 so as to disengage the engaging portion 18c of the feed pawl 18 from the wheel 16. At this time the hold pawl 19 is made to rotate with the feed pawl 18 by the tension spring 23 to bring the engaging portion 19b of the hold pawl 19 into an engaging field with 16 rotates for a peripheral length corresponding to half a pitch of the carriage 34 until it engages the engaging portion 19b. In this condition, the engaging portion of the feed 'pawl 18 is disengaged from the wheel 16 and the engaging portion '19b of the hold pawl 19 is engaged therewith.

Whilethe repeat space key 55 is depressed under such condition, the elastic ro d member 46 urges, as shown in FIG. 8, the-feed arm 18a of the feed pawl 18 against the force of the tension spring 21 to rotate said pawl 18 counterclockwise in FIG. 6. Thus the engaging portion 180 is again engaged with the wheel 16 and the engaging portion 19b is disengaged therefrom.

As mentioned above, depression of the repeat space key 55 causes the engaging portion 180 of the feed pawl 18 and the engaging portion 19b of the hold pawl 19 to be alternately engaged with and disengaged from the,

wheel 16 due to the elasticity of the elastic rod member 46, the force applied to the engaging portion 180 of the feed pawl 18 so as to allow the carriage 34 to move the letter feed direction, the cam action conducted by the teeth of the wheel 16 and the urging force of the tension spring 23 and 21 respectively, thereby allowingthe carriage 34 to make a continuous repeat spacing movement at a prescribed speed.

The inertia increasing member or weight 49 mounte on the upper end of the elastic rod member 46 rocks in response to the alternate engagement with and disengagement from the wheel 16 of the two engaging portions 18c and 19b.'The inertia of said weight 49 acting on the feed pawl 18 restricts the rotation of the wheel 16 resulting from the elasticity of the elastic rod member 46 urging the feed pawl '18 and the cam action performed by the engaging portion 180 jointly with the teeth of the wheel 16, thereby permitting the carriage 34 to make continuous repeat spacing movement at a proper speed, travelling one exactletter space each time.

Upon release of the repeat space key 55, the elastic rod member 46 rotates counterclockwise as viewed from FIGS. 7 and 8 back to the condition shown in FIGS. 4 and l and ceases to urge the feed pawl 18. Now, the tension spring 21 acts on the feed pawl 18, causing,,as shown in FIG. 1, the engaging portion 18c to be disengaged from the wheel 16 and the engaging portion 19b to be engaged therewith, so that the wheel 16 stops rotation and in consequence the carriage 34 ceases to make a repeat spacing movement.

When, under such condition, the type key or space bar 45 is depressed to cause the operation member 24 to rotate and the engaging portion 18c of the feed pawl 18 to be engaged with the wheel 16, then the driven arm 18d of the feed pawl 18 is contacted by the contact roller 26 of the operation member 24 to relieve the carriage 34 of a force to urge it in the letter feed direction and prevent the rotation of the feed pawl 18 and in consequence the aforementioned cam action. Accordingly, the engaging portion 18c of the feed pawl 18 is not disengaged from the wheel 16 until the type key or space bar 45 is released to return the operation member 24 to its original position.

As is apparent from the aforementioned construction, even if the repeat space key 55 is operated during depression of the type key or space bar 45, the rotation of the escapement wheel 16 is already restricted by the feed pawl 18 through the contact roller 26 of the operation member 24, thus offering the advantage that the cam action is not applied to the feed pawl 18, thus preventing the carriage 34 from performing a repeat spacing movement.

FIGS. 9 and illustrate a modification of the oscillation means according to the present invention. Throughout FIGS. 9 and 10, the parts are designated by numerals of the order of hundreds as well as suffixes. The same parts of FIGS. 9 and 10 as those of the oscillation means of FIGS. 7 and 8 are indicated by the same digits of the last two places and suffixes. The modification of FIGS. 9 and 10 is different from the oscillation means of FIGS. 7 and 8 in that the free end of an elastic rod member 146 consists of a vertical portion 146a and horizontal portion 14-6b bent at right angles thereto. The horizontal portion 146b is positioned perpendicular to the direction in which the elastic rod member 146 oscillates. An inertia increasing member or a weight plate 149 assumes the form of a rectangular or square plate, and its two adjacent sides have lugs 149a and 14% to be connected to the the vertical and horizontal portions 146a and 14612 respectively.'The weight plate 149 is substantially integrally fixed to the upper portion of the elastic rod member 146 by the lugs 149a and l49b. The lower portion of elastic rod member 146 is wound around a shaft 148 which is similar to the shaft 48 in the embodiment of FIGS. 4, 7 and 8.

In the modification of FIGS. 9 and 10, depression of the repeat space key 55 causes a connecting rod 150 to move in the direction of the arrow A and in consequence the feed pawl 18 and hold pawl 19 to be alternately engaged with and disengaged from the wheel 16, and the oscillation means to rock in response thereto. Accordingly, the weight plate 149 rocks with the elastic rod member 146, and its surfaces undergo air resistance. The oscillation means of FIGS. 9 and 10, therefore, offers substantially the same effect as when the elastic rod member 146 is fitted with a heavier weight at its free end, thereby retarding the speed with which the feed and hold pawls l8 and 19 engage the wheel 16, so that even with a light weight plate 149, the carriage 34 can make a continuous repeat spacing movement with a proper speed travelling one exact letter space each time. The modification of FIGS. 9 and 10 is the same as the embodiment of FIGS. 1 to 8 in other respects.

A feed arm 118a and a shaft 148 are respectively arranged and operated in the same manner as the feed arm 18a and the shaft 48 of the embodiment of FIGS. 4, 7 and 8.

FIG. 11 presents still another modification of the oscillation means according to the present invention. The oscillation means of FIG. 11 consists of an inertia increasing member or weight 249 and elastic rod member 246 which are made of plastic material and integrally formed with each other, and is rotatably connected to a shaft 248 mounted on the base plate 11. A feed arm 218a and a shaft 248 are respectively arranged and operated in the same manner as the feed arm 18a and the shaft 48 of the embodiment of FIGS. 4, 7 and 8. Upon depression of the repeat spacing key 55, a connecting rod 250 is moved in the direction of the arrow A to make the feed pawl 18 and the hold pawl 19 alternately engaged with and disengaged from the escapement wheel 16 to produce the rocking motion of said oscillation means. Since said oscillation means has the same operation and mechanism as those of FIGS. 1 to 8 and FIGS. 10 and 11, description thereof is omitted to avoid duplication.

As is apparent from the foregoing description, the elastic rod member of the oscillation means may be formed of not only piano wire, but also stainless steel, beryllium copper alloy, phosphor copper and other similar metal wire. Further, it is possible to fabricate the inertia increasing member or weight and elastic rod member integrally from plastic material, rubber or other similar material.

As described above, the present invention provides a repeat spacing mechanism for typewriters of simple construction and excellent function and capable of inexpensive manufacture wherein there is provided oscillation means which does not actuate the feed and hold pawls in the ordinary single step movement of the carriage, but acts thereon only when the carriage is desired to make a continuous repeat spacing movement.

What we claim is:

1. A repeatspacing mechanism for typewriters having a frame, a carriage movably mounted on said frame, carriage urging means provided between said frame and saidcarriage for urging said carriage in a letter feed direction, and a space bar located on said frame, comprising:

a. a base plate positioned under said carriage and fixed to said frame;

a wheel shaft vertically and pivotally mounted on the base plate, an upper portion of said wheel shaft operatively connected with said carriage so as to be rotated in one direction by the urging force of said carriage urging means;

c. a toothed escapement wheel secured to a lower portion of said wheel shaft;

d. a pawl shaft mounted on said base plate substantially parallel to said wheel shaft;

e. a feed pawl and a hold pawl rockably mounted on said pawl shaft in a plane parallel with said toothed wheel and selectively engageable with said toothed f. a first spring means coupled between said feed pawl and said base plate for biasing said feed pawl to rotate about said pawl shaft in a first direction in which said feed pawl is normally disengaged from said toothed wheel;

. a second spring means coupled between said feed pawl and said hold pawl for biasing said hold pawl to rotate about said pawl shaft in said first direction to a position in which said hold pawl is normally engaged with said toothed wheel;

. connecting means for connecting said feed pawl to said hold pawl by the bias of said second spring means for effecting rotation of said hold pawl together with the feed pawl in a second direction opposite to said first direction against the bias of said first spring means upon each depression of said space bar, so that said feed pawl is engaged with said toothed wheel and said hold pawl is disengaged from said toothed wheel;

i. a repeat space key lever having a repeat space key connected thereto at an upper end thereof, said repeat space key lever being pivotally mounted on the frame and coupled to said repeat space key so as to-be operated upon depression of said repeat space key;

j. a rod member of elastic material vertically disposed under said carriage, said rod member having a lower end connected to said repeat space key through a connecting rod and said repeat space key lever, an intermediate part pivoted on a supporting shaft mounted on said base plate, and I space key, in a direction away from said feed pawl until said feed pawl is disengaged from said toothed wheel by the joint bias force of said first spring means, said carriage urging means and a camming action exerted between said feed pawl and said toothed wheel while said repeat space key remains depressed, and said rod member then flexing back towards said feed pawl in a swinging motion of said rod member to again cause said feed pawl to engage with said toothed wheel, so that said feed pawl and said hold pawl are alternately and cyclically engaged with and disengaged from said toothed wheel to effect rotation of said toothed wheel so as to cause said carriage to make a repeat spacing movement in the letter feed direction only while said repeat space key is held depressed.

2. The repeat spacing mechanism according to claim 1, wherein said weight and said rod member are formed as an integral unit. r

3. The repeat spacing mechanism according to claim 1, wherein said swinging motion of said rod member repeatedly and cyclically continues during continued depression of said repeat space key.

. The repeat spacing mechanism according to claim 1, wherein said camming action exerted between said feed pawl and said toothed wheel occurs while said feed pawl contacts the crest surfaces and the trailing edge surfaces, as determined with respect to the direction of rotation of said toothed wheel, of the respective teeth of said toothed wheel.

5. The repeat spacing mechanism according to claim 1, wherein said first spring means comprises a first tension spring stretched between said feed pawl and said base plate.

6. The repeat spacing mechanism according to claim 1, wherein said second spring means is a tension spring stretched between said feed pawl and said hold pawl.

7. The repeat spacing mechanism according to claim 1, wherein said connecting means includes an arm extending from said hold pawl and means on said feed pawl for engaging said extending arm.

Claims (7)

1. A repeat spacing mechanism for typewriters having a frame, a carriage movably mounted on said frame, carriage urging means provided between said frame and said carriage for urging said carriage in a letter feed direction, and a space bar located on said frame, comprising: a. a base plate positioned under said carriage and fixed to said frame; b. a wheel shaft vertically and pivotally mounted on the base plate, an upper portion of said wheel shaft operatively connected with said carriage so As to be rotated in one direction by the urging force of said carriage urging means; c. a toothed escapement wheel secured to a lower portion of said wheel shaft; d. a pawl shaft mounted on said base plate substantially parallel to said wheel shaft; e. a feed pawl and a hold pawl rockably mounted on said pawl shaft in a plane parallel with said toothed wheel and selectively engageable with said toothed wheel for normally causing a single step movement of the carriage in the letter feed direction; f. a first spring means coupled between said feed pawl and said base plate for biasing said feed pawl to rotate about said pawl shaft in a first direction in which said feed pawl is normally disengaged from said toothed wheel; g. a second spring means coupled between said feed pawl and said hold pawl for biasing said hold pawl to rotate about said pawl shaft in said first direction to a position in which said hold pawl is normally engaged with said toothed wheel; h. connecting means for connecting said feed pawl to said hold pawl by the bias of said second spring means for effecting rotation of said hold pawl together with the feed pawl in a second direction opposite to said first direction against the bias of said first spring means upon each depression of said space bar, so that said feed pawl is engaged with said toothed wheel and said hold pawl is disengaged from said toothed wheel; i. a repeat space key lever having a repeat space key connected thereto at an upper end thereof, said repeat space key lever being pivotally mounted on the frame and coupled to said repeat space key so as to be operated upon depression of said repeat space key; j. a rod member of elastic material vertically disposed under said carriage, said rod member having a lower end connected to said repeat space key through a connecting rod and said repeat space key lever, an intermediate part pivoted on a supporting shaft mounted on said base plate, and an upper portion normally disposed close to and perpendicular to said feed pawl and extending above said feed pawl, said rod member rotating about said supporting shaft against the bias of said first spring means upon depression of the repeat space key; k. a weight fixed to the top of said rod member, for increasing the inertia of said rod member when it is moving with a swinging motion; and l. said upper portion of said rod member being flexed, during continued depression of said repeat space key, in a direction away from said feed pawl until said feed pawl is disengaged from said toothed wheel by the joint bias force of said first spring means, said carriage urging means and a camming action exerted between said feed pawl and said toothed wheel while said repeat space key remains depressed, and said rod member then flexing back towards said feed pawl in a swinging motion of said rod member to again cause said feed pawl to engage with said toothed wheel, so that said feed pawl and said hold pawl are alternately and cyclically engaged with and disengaged from said toothed wheel to effect rotation of said toothed wheel so as to cause said carriage to make a repeat spacing movement in the letter feed direction only while said repeat space key is held depressed.

2. The repeat spacing mechanism according to claim 1, wherein said weight and said rod member are formed as an integral unit.

3. The repeat spacing mechanism according to claim 1, wherein said swinging motion of said rod member repeatedly and cyclically continues during continued depression of said repeat space key.

4. The repeat spacing mechanism according to claim 1, wherein said camming action exerted between said feed pawl and said toothed wheel occurs while said feed pawl contacts the crest surfaces and the trailing edge surfaces, as determined with respect to the direction of rotation of said toothed wheel, of the respective teeth of said toothed wheel.

5. The repeat spacing mechanism according to claim 1, wherein said first spring Means comprises a first tension spring stretched between said feed pawl and said base plate.

6. The repeat spacing mechanism according to claim 1, wherein said second spring means is a tension spring stretched between said feed pawl and said hold pawl.

7. The repeat spacing mechanism according to claim 1, wherein said connecting means includes an arm extending from said hold pawl and means on said feed pawl for engaging said extending arm.

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