US3700086A

US3700086A - Typewriter for use with a drafting straight edge

Info

Publication number: US3700086A
Application number: US886308A
Authority: US
Inventors: David P Jones
Original assignee: Individual
Current assignee: Individual
Priority date: 1969-12-18
Filing date: 1969-12-18
Publication date: 1972-10-24
Anticipated expiration: 1989-10-24

Abstract

A printing assembly including a support means supporting a rack and adapted to be attached to a drafting straight edge. The rack extends through a head assembly and is engaged by a pinion gear for moving the head assembly along the rack. The head assembly is connected through links to a carriage which supports two longitudinally extending rows of type characters. The head means is moved between a raised position and a lowered position and includes a hammer pin for engaging one of the type characters to cause it to print when in the lowered position. Normally the head means prints the characters in one row but includes a handle on the links interconnecting the head means and the carriage to shift the position of the links so that upon movement of the head means to the lowered position, a character in the other row will be printed.

Description

United States Patent Jones 1 Oct. 24, 1972 [54] TYPEWRITER FOR USE WITH A DRAFTING STRAIGHT EDGE 221 Filed: Dec. 18,1969

211 App]. No.: 886,308

[52] U.S. Cl. ..197/2, 197/187, 197/190, 197/60 [51] Int. Cl. ..B4lj 3/38 [58] FieldofSearch ..l97/2,6.1,6,6.7,1;l01/18, 101/35,42,44,45

2,428,378 10/1947 Mossbach ..197/2 2,367,313 l/l945 Reynolds et a1. ..197/2 481,855 8/1892 English ..197/2 X 479,085 7/1892 Beauregard et a1 ..197/2 Primary ExaminerRobert E. Pulfrey Assistant Examiner-Ralph T. Rader Att0rneyMcGlynn, Reising, Milton & Ethington [57] ABSTRACT A printing assembly including a support means supporting a rack and adapted to be attached to a drafting straight edge. The rack extends through a head assembly and is engaged by a pinion gear for moving the head assembly along the rack. The head assembly is connected through links to a carriage which supports two longitudinally extending rows of type characters. The head means is moved between a raised position and a lowered position and includes a hammer pin for engaging one of the type characters to cause it to print when in the lowered position. Normally the head means prints the characters in one row but includes a handle on the links interconnecting the head means and the carriage to shift the position of the links so that upon movement of .the head means to the lowered position, a character in the other row will be printed.

15 Claims, 13 Drawing Figures PATENTEUBBI 24 m .3. 700,086

SHEET 3 BF 3 I 5429.2] INVENTOR' TO R NEYS TYPEWRITER FOR USE A DRAFIING STRAIGHT EDGE This invention relates to a printing assembly of the type suitable for use on a drafting table for printing various characters onto the surface of a sheet drawings.

Practically without exception in all drafting situations, the draftsman is required to utilize lettering on any drawing. It is not uncommon that although'a draftsman may make beautiful drawings, his lettering capabilities are very poor.

Accordingly, it is an object and .feature of this invention to provide a printing assembly which may be positioned over the surface of a sheet of drawings for printing the necessary characters thereon.

' In correlation with the foregoing object and feature, it is another object and featureof this invention to provide a printing assembly which includes a support means for positioning the assembly over a surface to be printed with carriage means for resting on the surface and supporting first and second longitudinally extending rows of type characters and head means operatively interconnecting the support means and the carriage means for shifting the carriage means in a direction transversely of the rows of type characters to move the rows into and out of position for printing while simultaneously moving a type character in the row in position for printing into printing engagement with the surface.

In correlation with the foregoing objects and features, it is another object and feature of this invention to provide such a printing assembly wherein the first and second rows of type characters are adjustable longitudinally of the carriage means and wherein there is included indexing means operatively interconnecting the support means and the head means for adjusting the position of the head means and the carriage means longitudinally of the support means.

Other objects and attendant advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

FIG. 1 is a plan view of a preferred embodiment of the instant invention shown attached to a drafting straight edge;

FIG. 2 is a plan view of the carriage means with the linkage means for connection to the head means being shown in cross section;

FIG. 3 is a fragmentary cross sectional view of the carriage means of FIG. 2 to show the interior thereof;

FIG. 4 is a fragmentary cross sectional view taken substantially along line 4-4 of FIG. 1;

FIG. 5 is a side view of the preferred embodiment of the instant invention and showing the head means in the raised or non-printing position;

FIG. 6 is a view taken substantially along line 6-6 of FIG. 1 and is a view similar to FIG. 5 but showing the head means in the lowered or printing position;

FIG. 7 is a view similar to FIG. 5 but showing the linkage means interconnecting the head means and the carriage means in a different position;

FIG. 8 is a view similar to FIG. 6 but like FIG. 7 shows the linkage means in a different position to effect the printing of a character in a different row than 2 printed when the assembly is in the position illustrated in FIG. 6;

FIG. 9 is an enlarged fragmentary cross sectional view taken substantially along line 9-9 of FIG. 1;

FIG. 10 is a fragmentary cross sectional view of reduced scale taken substantially along line 1010 of FIG. 9;

FIG. 11 is a fragmentary cross sectional view of reduced scale taken substantially along line 1111 of FIG. 9;

FIG. 12 is a fragmentary cross sectional view taken substantially along line 12-12 of FIG. 1 and showing a stylus in position for adjusting the position of the type characters; and

FIG. 13 is a side view of the stylus utilized to select a character for printing.

Referring now to the drawings wherein like numerals indicate like or corresponding parts throughout the several views, a printing assembly constructed in ac cordance with the instant invention is generally shown at 20.

The printing assembly 20 includes a support means for positioning the assembly 20 over a surface 22 to be printed. The support means includes the bracket 24 with extensions 26 bolted thereto and extending forwardly therefrom. The support means also includes means comprising a generally U-shaped member 28 for attachment to a drafting straight edge 30. The U- shaped member 28 is preferably made of a yieldable plastic for snapping into clamping engagement with opposite extremities of the straight edge 30, as illustrated in FIGS. 5 through 8. It will be appreciated that the U- shaped yieldable member 28 may take various configurations depending upon the configuration of the drafting straight edge 30, there being inuse approximately four or five cross sectional configurations of straight edges which are used in the drafting profession. A portion of the U-shaped member 28 extends through a slot in the bracket 24 and has a bore extending therethrough through which a pin 32 is inserted to retain the bracket 24 to the U-shaped member 30.

The printing assembly 20 also includes a carriage means, generally indicated at 34, for resting on the surface 22 and supporting first andsecond longitudinally extending parallel rows of type characters, the rows being indicated at 36 and 38, respectively, in FIGS. 3, 9, and 12.

The assembly 20 also includes head means, generally indicated at 40, operatively interconnecting the support means and the carriage means 34 for shifting the carriage means 34 in a direction transversely of the

rows

36 and 38 to move the

rows

36 and 38 into and out of position for printing and for moving a type character in the row in position for printing into printing engagement with the surface 22. In other words, the carriage means 34, along with the

rows

36 and 38 which it carries, moves or shifts in a direction which is transverse to the longitudinal extent of the

rows

36 and 38. 1 An indexing means, generally shown at,42 in FIG. 10, operatively interconnects the head means 40 and the support means for moving the head means 40 and the carriage means 34 relative to the support means in a direction parallel to the

rows

36 and 38. The indexing means 42 includes a rack 44 having round pins 46 extending from the ends thereof so as to be rotatably supported by the extensions 26, of the support means. Thus,.the indexing means 42 is rotatably supported by the support means for rotation relative to the support means about the axis of the pins 46. The axis of the pins 46 is parallel to the

rows

36 and 38 so that the head means 40 may be rotated about the axis of the pins 46 between the printing position illustrated in FIGS. 1, 4, 6, 8, and 9 and the non-printing position illustrated in FIGS. and 7.

The head means 40 includes the housing defined by the upper and lower

interconnected plates

48 and 50. The

plates

48 and 50 are interconnected by bolts 51. The rack 44 is retained in and extends through the housing. The indexing means further includes a pinion gear 52 having a shaft extending from either side thereof and into the

respective plates

48 and 50 of the housing so as to be rotatably supported by the housing. The pinion gear 52 engages and coacts with the rack 44. The indexing means also includes actuation means comprising a drive gear 54, a shaft 56, and a knob 58, for manually rotating the pinion gear 52 to move the head means 40 along the rack 44. The drive gear 54 is rotatably supported by the housing and the shaft 56 extends from the drive gear 54 and through the plate-48 of the housing and the knob 58 is disposed on the distal end of the shaft 56 for rotating the latter.

The head means 40 also includes linkage means, defined by the first link means 60 and the second link means 62, operatively interconnecting the housing of the head means 40 and the carriage means 34 for performing the shifting of the carriage means 34 as the head means 40 moves between the printing and nonprinting positions. The first link means 60 is pivotally connected at a first extremity to the housing by a pin 64 which extends through flanges 65 of the upper plate 48 of the housing. The second link means 62 comprises a pair of spaced links each pivotally connected at a first extremity to the carriage means 34 by pins 66 which extend through bifurcated ends and through coupling members 67 which extend upwardly from the carriage means 34. The links of the second link means 62 are pivotally'connected at the second extremities thereof by the pins 68 to the second extremities of the link means 60. The extremities of the link means 60-and 62 are best illustrated descriptively when viewed in side elevation as in FIGS. 5, 6, 7 and 8. In actual construction, however, the link means 60 comprises an integral member having downturned ends to be received by the bifurcated second extremities of the link means 62 and through which the pins 68 extend. The member defining link means 60 then extends inwardly toward the head means40 and then through an upward bend to extend upwardly to receive the pin 64 and then across the upper portion of the head means 40, as best illustrated in FIG. 4. The link means 60 includes a handle portion 60, and consequently the handle 69, in a direction away '7 to the printing position illustrated in FIG. 8, the axis of the pins 68 will move about the axis of the pins 46 and will, consequently, cause the carriage means 34 to shift downwardly as is best illustrated by comparing FIGS. 7 and 8 since the axis of the pins 64 are at a lower position as viewed in FIG. 8 than as viewed in FIG. 7. As will become more clear upon completion of the total description, the movement of the head means 40 from the position illustratedin FIG. 7 to the position illustrated in FIG. 8 will affect the printing of a character in the row 36. If it is desired, however, to affect-the printing of a character in the row 38, the handle 69 is grasped along with the knob 58 to move the first link means to the position illustrated in FIG. 5 so that when the head means 40 is rotated to the printing position illustrated in FIG. 6 a character in the row 38 is printed. When the handle 69 is moved to the position illustrated in FIG. 5 the axis of the pins 68 is positioned closer to the axis of the pins 46 when in the printing position illustrated in FIG. 6 so that the carriage means 34 is shifted a greater distance upwardly. Thus the handle 69 defines an actuatable means movable between first and second positions for aligning a type character in one of the

rows

36 and 38 for printing when in a first position (such as that shown in FIG. 8) and for aligning a type character in the other of the

rows

36 and 38 when in a second position (such as that shown'in FIG. 6).

The head means 40 includes a hammer comprising the pin 74 for engaging and moving one of the type characters in one of the

rows

36 and 38 as the head means 40 moves to the printing position illustrated in FIGS. 6 and 8. The pin 74 is yieldably supported by the housing for yielding while engaging one of the type characters of the

rows

36 and 38. The pin 74 is-slidably supported in the plate 50 of the housing and a band spring 76 reacts between the pin 74 and the. housing to yieldably urge the pin 74 out of the housing. In this manner, a relatively constant force is applied to a type character in one of the

rows

36 and 38 by the spring 76.

Thus, the hammer pin 74 will engage a type character in either

row

36 or 38 as the knob 58 is grasped to move the head means 40 from the non-printing position to the printing position depending upon the position of the first link means 60, i.e., whether the handle 69 is grasped and moved while moving the head means 40 to the printing position. As illustrated in FIG.

9 the head means is in the printing position and-the handle 69 has been grasped to move the first link means 60 to the position illustrated in FIG. 6 so that hammer pin 74 engages and has moved a type character in the row 38 into printing engagement with the surface 22.

There is also included a detent means coacting with the pinion gear 52 for releasably retaining the pinion gear 52 in rotary positions along the rack 44 which correspond to the distance between immediately adjacent type characters as they are printed (i.e. character spacing). The detent means includes a cylindrical member or roller 80 which engages the periphery of the pinion gear 52. The roller 80 is supported on a detent plate 82 by a pin, rivet, or the like. The detent plate 82 is slidably supported in a recession 84 in the lower plate 50 above the pinion gear 52 and the drive gear 54. The detent plate 82 has an elongated slot 86 therein surrounding the shaft extending from the pinion 52 and the shaft 56 to allow movement of the detent plate 82. The detent plate 82 has an upturned flange portion 88 at the forward end thereof and a biasing means comprising the .spring 90 and reacts between the upper plate 48 of the housing and the detent plate 82 to urge the roller 80 into engagement with the periphery of the pinion gear. Thus, as the knob 58 is rotated to rotate the drive gear 54, which in turn rotates the pinion 52, the roller 80 will snap into engagement between adjacent teeth. The distance the head means 40 moves as the roller 80 moves from between two teeth to the next position, is a distance equal to the distance between characters to be printed on the surface 22. It will be noted that the pinion gear 52 engages half of the rack 44 with the other half of the pinion gear 52 being exposed for engagement with the roller 80 of the detent means.

The carriage means 34 includes a casing defined by the lower member 92 and the upper member 94. The upper and

lower members

92 and 94 are connected together as by the fastening elements 95. As best illustrated in FIGS. 9 and 12, the lower member 92 has a raised central portion 96.

The carriage means 34 also includes a slide 97 supporting the rows of

type characters

36 and 38. The slide 97 is slidably supported by the upper and

lower members

92 and 94 of the casing for movement relative thereto in a direction parallel to the

rows

36 and 38 to selectively position the type characters in a position for printing.

The casing has a slot 98 extending therealong and the slide 97 has a selector portion 99 disposed in the slot 98 and exposed to the exterior of the casing. The selector portion 99 has rows of characters thereon corresponding to the type characters on the

rows

36 and 38. The casing also has a pointer 100 as illustrated in FIG. 2 adjacent the slide 97 for indicating the characters on the selector portion 99 corresponding to the type characters disposed in position for printing. There are a series of holes 101 disposed along the selector portion 99 of the slide 97 and aligned with the characters thereon. A receiving means in the casing defined by the hole 102 in the offset portion 96 of the lower member 92, as illustrated in FIG. 9, is disposed immediately below the selector portion 99 for receiving a stylus 103 which extends through one of the holes 101 for positioning the desired type character for printing thereof. In other words, a stylus 103 is inserted into one of the holes 101 adjacent the character desired and the slide 97 is moved to the proper position by the stylus 103 where the end of the stylus 103 will drop into the hole 102, which could be a dimple. Thus the stylus 103 is manually utilized to select the desired character and is removed from the assembly during the printing of that character, i.e., the stylus 103 is completely independent of the printing assembly 20.

Thereis also included means comprising the leaf spring 104 to coact with serrations 105 in the slide 97 for aligning and retaining the slide 97 in the selected position at least during movement of the head means 40 to the printing position. As an alternative, the slide 97 may contain notches aligned with the characters and into which a wedge tooth or the like extending from the head means 40 may pass to precisely align the type character desired. The casing of the carriage means 34 also includes an opening 107 in the lower plate 92 and above the surface 22 to be printed for allowing movement of a type character therethrough by the hammer pin 74, as illustrated in FIG. 9. The casing also includes another opening 108 centrally thereof and in the upper member 94 for receiving and allowing the hammer pin 74 to extend therethrough to engage a type character in one of the

rows

36 and 38.

The casing of the carriage means 34 also includes an indicator'means generally indicated at 110 for indicating the area on the surface 22 to be printed when the head means 40 is in the non-printing position as illustrated in FIG. 5 and 7. In other words, the indicator means 110 is normally disposed over the line being printed when the head means 40 is in the non-printing position and as the head means 40 is moved to the printing position, the indicator means 110 shifts downwardly or away from the support means and the letter to be printed is printed in the area previously shown in the slot between the pointers of the indicator means 110.

The rows of

type characters

36 and 38 are secured at the ends thereof to the slide 97 and are preferably made of a material impregnated with ink with the characters disposed on the side facing the surface 22. Preferably, brass backing strips are disposed on the opposite side of the

rows

36 and 38 and are engaged and flexed by the hammer pin 74. Also, and in the preferred embodiment, a lubricant strip is disposed between the

rows

36 and 38 to facilitate relative movement therebetween. Preferably the

rows

36 and 38 containing the type characters are of the material sold under the trademark PORLON by Johnson's Wax Company.

As an alternative, an elongated belt having type characters thereon with an associated ink reservoir adjacent the opening 107 may be utilized in substitution for the

rows

36 and 38.

The lower member 92 of the carriage means 34 includes dimples 1 15 as illustrated in FIG. 4 for maintaining the lower plate a very small distance above the surface 22 to prevent smearing as the carriage means 34 is shifted between the printing and non-printing positions.

In brief review, the operation of the printing assembly is that it is attached to a drafting straight edge 30 and assumes the non-use position illustrated in F IG. 7. The indicating means 110 is aligned on the line wherein characters are to be printed on the surface 22. The stylus 103 is inserted into one of the holes 101 adjacent the character desired to be printed. The stylus is then moved to move the slide 97 in the direction wherein the desired character is moved beneath the indicator 100 at which point the stylus 103 will fall into the opening 102. The spring 104 will retain the slide 97 in the selected position. The two rows of characters on the selector portion 99 of the slide 97 correspond to the type characters on the

rows

36 and 38. If it is desired to print a characterin the row 36, the knob 58 is grasped without grasping the handle 69, and the head means 40 is rotated from the non-printing position illustrated in FIG. 7 to the printing position illustrated in FIG. 8 wherein the hammer pin 74 engages a character in the row 36 to move the type character into engagement with the surface 22. If it is desired to print a character in the row 38, the handle 69 is grasped at the same time that the knob 58 is grasped to move the handle 69 toward the knob 58; thus, moving the axis of the pin 68 closer to the axis of the pin 46 so that when the head means 40 is rotated from the non-printing position illustrated in FIG. to the printing position illustrated in FIG. 6, the hammer pin 74 will engage a type character in the row 38., After the character is printed on the surface 22, the knob 58 is rotated to move the head means 40 and the carriage means 34 into position for printing the next character.

If it is desired to rapidly shift the head and carriage a considerable distance, such may be accomplished without rotating the knob 58 by merely manually moving the detent plate 82 to move the cylindrical roller out of engagement with the periphery of the pinion gear 52.

It will also be noticed that the entire assembly is symmetrical about a center line passing transversely therethrough so that it is identical to the right or left of that center line as viewed in FIG. 1 so that the assembly may be operated very satisfactorily by either a righthanded or left-handed person.

The invention has been described in an illustrative manner, and it is to be understood that the terminology which has been used is intended to be in the nature of words of description rather than of limitation.

Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

l. a A printing assembly comprising; support means for positioning the assembly over a surface to be printed; carriage means including a casing for resting on the surface and a slide supporting at least one longitudinally extending row of type characters; said slide being slidably supported by said casing for movement relative thereto in a direction parallel to said row to position a type character therein for printing; and head means operatively interconnecting said support means and said carriage means for shifting said carriage means toward and away from said support means by sliding it over the surface in a direction which is transverse to the longitudinal extent of said row shifting of said carriage away from said support means thereby moving said row from' a first nonprinting position to a second printing position, and including means for moving a type character in said row into printing engagement with the surface said row being shiftable to said first non-printing position after the printing of each character.

'2. An assembly as set forth in claim 1 including indexing means operatively interconnecting said head means and said support means for moving said head meansand said carriage means relative to said support means in a direction parallel to said row.

3. An assembly as set forth in claim 2 wherein said indexing means supports said head means for movement relative to said support means between printing and non-printing positions.

4. An assembly as set forth in claim 3 wherein said head means includes linkage means operatively connected to said carriage means for performing said shifting of said carriage means as said head means moves between said printing and non-printing positions.

5. An. assembly as set forth in in claim 4 including indicator means on said casing for indicating the area on the surface to be printed when said head means is in said non-printing position.

6. An assembly as set forth in claim 4 wherein said head means includes a housing; and said linkage means includes first link meanspivotally connected at a'first extremity to said housing, and second link means pivotally connected at a first extremity to said carriage means and at a second extremity to the second extremity of said first link means.

7. An assembly as set forth in claim 6 wherein said indexing means is rotatably supported by said support means for rotation relative thereto about an axis parallel to said rows so that said housing may be rotated about said axis between said printing and non-printing positions.

8. An assembly as set forth in claim 7 wherein said head means includes a hammer for engaging and moving one of said type characters as said housing moves to said printing position.

9. An assembly as set forth in claim 8 wherein said hammer is yieldably supported by said housing for yielding while engaging one of said type characters.

10. An assemblyias set forth in claim 9 wherein said casing has a slot extending therealong and said slide has a selector portion disposed in said slot and exposed to the exterior of said casing, said selector portion having at least one row of characters thereon corresponding to said type characters, said casing having an opening therein above the surface to be printed for allowing movement of a type character therethrough by said hammer, said casing having a pointer adjacent said slide for indicating characters thereon corresponding to type characters disposed over said opening at the various positions of said slide.

11. An assembly as set forth in claim 10 including indicator means on said casing for indicating the area on the surface to be printed when said head means is in said non-printing position.

12. An assembly as set forth in claim 1 1 wherein said support means includes means for attachment to a straight edge.

13. An assembly as set forth in claim 11 wherein said indexing means includes a rack rotatably supported by said support means and extending through said housing, a pinion gear rotatably supported by said housing and engaging said rack, and actuation means for manually rotating said pinion gear to move said head means along said rack.

14. An assembly as set forth in claim 13 including detent means coacting with said pinion gear for releaseably retaining said pinion gear in rotary positions along said rack which correspond to the distance between immediately adjacent type characters.

15. An assembly as set forth in claim 14 wherein; said actuation means includes a drive gear rotatably supplate to urge said cylindrical member into engagement with the periphery of said pinion gear; said hammer comprises a pin slidably supported by said housing, and a band spring reacting between said pin and said housing to yieldably urge said pin out of said housing; said first link means includes a handle extending from said first extremity thereof and adjacent said knob so that said first link means may be pivoted thereby; and including stop means disposed on said housing for limiting movement of said first link means, first spring means urging said first link means and said handle away from said knob, second spring means urging said second extremity of said second link means away from said carriage means, a series of holes along said selector portion of said slide and aligned with said characters thereon, a receiving means in said casing immediately below said selector portion for receiving a stylus extending through one of said holes for positioning the desired type character over said opening in said casing, and means for aligning and retaining said slide in the selected position at least during movement of said head means to said printing position.

Claims

1. A printing assembly comprising; support means for positioning tHe assembly over a surface to be printed; carriage means including a casing for resting on the surface and a slide supporting at least one longitudinally extending row of type characters; said slide being slidably supported by said casing for movement relative thereto in a direction parallel to said row to position a type character therein for printing; and head means operatively interconnecting said support means and said carriage means for shifting said carriage means toward and away from said support means by sliding it over the surface in a direction which is transverse to the longitudinal extent of said row shifting of said carriage away from said support means thereby moving said row from a first nonprinting position to a second printing position, and including means for moving a type character in said row into printing engagement with the surface said row being shiftable to said first non-printing position after the printing of each character.

2. An assembly as set forth in claim 1 including indexing means operatively interconnecting said head means and said support means for moving said head means and said carriage means relative to said support means in a direction parallel to said row.

5. An assembly as set forth in in claim 4 including indicator means on said casing for indicating the area on the surface to be printed when said head means is in said non-printing position.

6. An assembly as set forth in claim 4 wherein said head means includes a housing; and said linkage means includes first link means pivotally connected at a first extremity to said housing, and second link means pivotally connected at a first extremity to said carriage means and at a second extremity to the second extremity of said first link means.

10. An assembly as set forth in claim 9 wherein said casing has a slot extending therealong and said slide has a selector portion disposed in said slot and exposed to the exterior of said casing, said selector portion having at least one row of characters thereon corresponding to said type characters, said casing having an opening therein above the surface to be printed for allowing movement of a type character therethrough by said hammer, said casing having a pointer adjacent said slide for indicating characters thereon corresponding to type characters disposed over said opening at the various positions of said slide.

12. An assembly as set forth in claim 11 wherein said support means includes means for attachment to a straight edge.

15. An assembly as set forth in claim 14 wherein; said actuation means includes a drive gear rotatably supported by said housing, a shaft extending from said drive gear, a knob disposed on the end of said shaft for rotating the latter; said detent means includes a cylindrical member engaging the periphery of said pinion gear, a detent plate slidably supported by said housing and supporting said cylindrical member, and biasing means reacting between said housing and said detent plate to urge said cylindrical member into engagement with the periphery of said pinion gear; said hammer comprises a pin slidably supported by said housing, and a band spring reacting between said pin and said housing to yieldably urge said pin out of said housing; said first link means includes a handle extending from said first extremity thereof and adjacent said knob so that said first link means may be pivoted thereby; and including stop means disposed on said housing for limiting movement of said first link means, first spring means urging said first link means and said handle away from said knob, second spring means urging said second extremity of said second link means away from said carriage means, a series of holes along said selector portion of said slide and aligned with said characters thereon, a receiving means in said casing immediately below said selector portion for receiving a stylus extending through one of said holes for positioning the desired type character over said opening in said casing, and means for aligning and retaining said slide in the selected position at least during movement of said head means to said printing position.