CA1091089A

CA1091089A - Print head

Info

Publication number: CA1091089A
Application number: CA256,898A
Authority: CA
Inventors: Robert M. Pabodie
Original assignee: Monarch Marking Systems Inc
Current assignee: Avery Dennison Retail Information Services LLC
Priority date: 1975-07-24
Filing date: 1976-07-13
Publication date: 1980-12-09
Also published as: DE2633279C3; GB1554939A; DE2633279B2; DE2633279A1

Abstract

PRINT HEAD
Abstract of the Disclosure There is disclosed a print head having drive wheels and support wheels and printing bands extending under tension about the respective drive and support wheels. The printing bands are configured to have relatively long printing blocks connected by relatively short sections. The printing blocks have printing characters and the sections have human readable characters. The support wheels have at least four sides and the corners of the wheels are truncated. The printing blocks are supported one-at-a-time by the side of the wheel at a printing zone.

Description

- --"' 1091089 Docket M-304 PRINT HEAD
~ackground of the Invention Field of the Invention This invention relates to print heads for printing apparatus.
Brief Description of the Prior Art Prior art printing bands of the type shown in Canadian patents Nos. 6S3,495 to Frederic L. Rieger, dated -~ -December 4, 1962 and 964,926 to Robert M. Pabodie, dated March 25, 1975 illustrate a printing band having printing sections and human readable sections approximately the same length as the printing section. The human readable section enables the user to determine the printing character on the band which is in supported relation with the support~ --wheel at the printing zone by viewing a human readable character on the band at a location remote from the printing zone. While -~
such printing bands have been widely accepted commercially, the length of the band is at least twice as long as the length of the printing blocks. Such commercial bands have blank portions in that it is sometimes desired to compose a line having fewer characters than the total number of bands. In bands having blanks, therefore, less than fifty percent of the length of the bands is useable to print indicia.
i~ Attempts have been made to position human readable characters between printing characters on print wheels as evidenced by U.S. patents Nos. 984,588 to Merrick, dated February 21, 1911; 1,868,997 to Speicher, dated July 2~, 1932;

2,249t627 to Drucker et al, dated July 15, 1941; and 2,943,559 to Rothmann, dated July 5, 1960.

.

Docket M-304 Summa~ of the Invention The purpose of the invention is to provide a print head having drive and support wheels and printing bands passinq under tension about the respective drive and support wheels in which the useable length of the band is greatly increased over prior art printing bands, while at the same time retaining the feature of human readability of the printing characters at the printing zone. This is accomplished by providing a printing band which has relatively long printing blocks or sections with printing characters and relatively short sections with human readable characters joining the printing blocks. The printing blocks are substantially longer than the relatively short sections.
Such a band is useable with a support wheel havinq generally equal sides, but with the corners of the wheel beinq truncated.
The combined lenqths of the truncations are substantially less than the remaining length of the respective side. The wheel is adapted to support one printinq block at a time.
More specifically, it is preferred that each support wheel have four and only four pairs of qenerally parallel sides, with the sides of two of the pairs being relatively lonq and the sides of the remaininq two pairs beinq relatively short in the rotational plane of the wheel. It is also preferred to have notches at the outer peripheries of the drive and support wheels.
With respect to the support wheel, it is preferred that only the relatively long sides have notches. ~he printing band preferably has luqs on its underside that can cooperate with the notches in the drive and support wh~els. It is preferred that th~e lugs be equally spaced apart and that the undersides of the relatively short sides of the support wheel be free of any lugs.

lO9iO89 Docket M-304 Brief Description of the Drawings FIGURE 1 is a perspective view of a print head in accordance with the invention;
FIGURE 2 is an enlarged side elevational view of the . 5 print head shown in FIGURE l;
FIGURE 3 is an enlarged fragmentary side elevational view of the print head;
FIGURE 4 is a fragmentary sectional view of a support wheel;
FIGURE 5 is a perspective view of the printing band shown in FIGURES 1, 2 and 3;
FIGURE 6 is a side elevational view of one end of the printing band;
. FIGURE 7 is a side elevational view showing one side of the printing band;
FIGURE 8 is a side elevational view showing the end , of the printing band opposite the end shown in FIGURE 6; and ,~ FIGURE 9 is a side elevational view showing the side jl of the printing band opposite the side shown in FIGURE 7.
Detailed Description of the Preferred Embodiment With reference to FIGURE l there is shown a print head generally indicated at 10. The print head is shown to comprise support structure in the form of a series of generally annular drive wheels 11 which are suitably individually rotatably mounted for rotation about an axis A, a series of support wheels 12 which are individually; rotatably mounted on a shaft 13, and printing bands generally indicated at 14. The wheels ~1 are selectively and individually driven by a selector 15 which is shiftable along the axis A to selectively couple with any one of ~091089 Docket M-304 the wheels 11. Rotation of the selector 15 will cause the selected wheel 11 to rotate, thereby driving the selected printing band and causing rotation of the respective wheel 12.
The wheels 11 and 12 are provided with respective notches 16 and 17 at their outer peripheries. A detent mechanism generally indicated at 18 and shown only in FIGURE 2 has a spring urged detent element individual to each wheel 12 so that each wheel 12 is detented in the printing position.
; One of the printing bands 14 is shown in considerable detail in FIGURES 5 through 8. The printing band 14 is shown to be of the integral, molded, endless type. The printing band 14 comprises printing blocks 20 which are relatively long in ~ the direction of extent of the band. Each printing block 20 is I shown to have one bar-shaped printing character 2i and some of ¦ 15 the printing blocks additionally have alpha or numeric-shaped ' printing characters 22. The printing blocks 20 are shown to be connected by relatively -~hort sections 23. The sections 23 have human readable characters or indicia 24. It is preferred that the human readable characters 24 have a lower elevation than the printing characters 21. The printing band 14 is also shown to have two blank sections 25. The underside of each printing block and blank 25 is provided with three equally spaced-apart lugs 14'.
The relatively short sections 23 are free of any lug on their undersides. All the lugs 14' on the underside of the printing band are shown to be equally spaced apart.
It is noted that the wheels 11 are identical to each other, and the wheels 12 are identical to each other.~ With i reference to FIGURE 3, for example, it is apparent that the wheel 12 has eight sides 26, 27, 28, 29, 30, 31, 32 and 33. The sides ) .
_5_ Doc~et M-304 26 and 30 are parallel to each other, the sides 28 and 32 9 are parallel to each other, the sides 27 and 31 are parallel to each other and the sides 29 and 33 are parallel to each other. The sides 26, 28, 30 and 32 are substantially equal in length, and the sides 27, 29, 31 and 33 are substantially equal in length. The length of one of the sides 31 is indicated at S in FIGURE 4, and the lengths of the sides 30 and 32 are indicated at Sl in FIGURE 4. The lengths of the sides 27, 29, 31 and 33 are shown to be substantially greater than the sides 26, 28, 30 and 32. Stating the relationship of the sides 27, 29, 31 and 33 to each other in a different way, the wheel 12 is considered to be truncated at the ccrners and the length of the truncation is indicated at T. Considering one of the sides, - side 31 for example, the length S is substantially longer than the combined lengths of the two respective truncations T.
As shown in the drawings, the side 26 is disposed at an obtuse angle of 135 to each of the sides 27 and 33, the side 28 is shown at an obtuse angle of 135 to each of the sides 27 and 29, the side 30 is shown at an obtuse angle of 135 to each of the sides 29 and 31, and the side 32 is shown at an obtuse ; angle of 135 to each of the sides 31 and 33. The 135 obtuse angle between the sides 31 and 32 is shown at _ in FIGURE 4.
Although it is preferred that the sides 26 and 30 be parallel to each other and that the sides 28 and 32 be parallel to each other and thus act to support the printing band, it is within the scope of the inventio~ to relieve the sides 26, 28, 30 and 32 so that there is minimal or no contact of the s~ctions 23 with the wheel 12. It is apparent from FIGURE 2 that the 1(~91089 ~ocket M-304 printing character 21 is opposite a platen 34 at a printing zone Z. When the print head 10 and the platen 34 are moved relatively toward each other, contact of the inked printing element 21 with the record R will cause an impression to be made on the record. The user will note the nature of the printing elements 21 at the printing zone by viewing the corresponding human readable character through a window or ; aperture 35 or by means of a pointer (not shown). When a ; selected wheel 11 is driven the printing band 14 is advanced to bring the selected printing character to the printing zone Z and thereupon the corresponding human readable character will appear at the window 35 so that the user will always be apprised . of the nature of the printing character being presented at the printing zone Z even though the user is viewing the corresponding , 15 human readable indicium 24 at a location remote from the printing ~! .
zone Z.
While the wheels 12 are shown to have two pairs of parallel relatively long sides 27 and 31, and 29 and 33, and two pairs of parallel relatively short sides 26 and 30, and 28 and 32, it can have more than two pairs of each, for example there can be three pairs of parallel relatively long sides and three pairs of parallel relatively short sides, but .
the number of pairs of relatively long sides should equal the number of pairs of relatively short sides.
The priniing blocks 20 are shown to be generally the ., '~ same length as the relatively long sides 27, 29, 31 and 33, ; although due to the slight overhang the printing bloc~ 20 are slightly longer than the distance S. The relatively short _ 7 _ .

~09~089 Docket M-304 sections 23 are about the same length as the length of the relatively short sides, indicated by the distance Sl.
It is preferred that the printing blocks 20 be at least about twenty percent longer than the sections 23, that the printing blocks occupy at least about sixty percent of the band length, and that the sections 23 occupy less than about thirty percent of the band length. By way of example, not limLtation, the printing blocks 20 and the blanks 25 are about 0.875 inch in length and the sections 23 are about 0.285 inch in length; the distance S is equal to about 0.9 inch, the distance T is about 0.15 inch, and the distance Sl is about 0.22 inch.
Other embodiments and modifications of this invention will suggest themselves to those skilled in the art, and all such of these as come within the spirit of this invention are included within its scope as best defined by the appended claims.

. -8-.

Claims

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

1. A print head, comprising a first rotatable wheel having at least four pairs of generally parallel sides, the sides of at least two of the pairs being relatively long and the sides of at least two of the pairs being relatively short in the rotational plane of the first wheel, the number of pairs of relatively long sides equal the number of pairs of relatively short sides, each relatively short side being adjacent two relatively long sides, a second rotatably mounted wheel, an integral, molded, endless printing band extending under tension about the first and second wheels, the printing band having relatively long printing blocks and at least one blank section disposed along its extent, one of the relatively long sides supporting a relatively long printing block at a printing zone, the printing blocks having a set of different printing characters, relatively short sections joining adjacent relatively long printing blocks in an alternating pattern, and human readable indicia on the relatively short sections corresponding to the different printing characters and disposed such that the human readable indicium corresponding to the printing character at the printing zone is remote from the printing zone, the relatively long printing blocks, the relatively short sections and the blank section or sections together occupying substantially the entire length of the printing band.

2. A print head as defined in claim 1, wherein the relatively long printing blocks are at least about twenty percent longer than the relatively short sections.

3. A print head as defined in claim 1, wherein the printing blocks occupy at least about sixty percent of the band length.

4. A print head as defined in claim 1, wherein relatively short sections occupy less than about thirty percent of the bend length.

5. A print head as defined in claim 1, including notches at the outer peripheries of the first and second wheels, and equally spaced-apart lugs at the underside of the printing band for cooperation with the notches, the undersides of the relatively short sections being free of any lugs.

6. A print head as defined in claim 1, including notches at the outer peripheries of the first and second wheels, and equally spaced-apart lugs at the underside of the printing band for cooperation with the notches, the under-sides of the relatively short sections being free of any lugs, the outer peripheries of the relatively short sides being free of any notches.

7. A print head as defined in claim 1, wherein the first wheel has four and only four relatively long sides and four and only four relatively short sides.

8. A print head, comprising: a first rotatably mounted wheel having at least four sides, the corners of the wheel being truncated, a second rotatably mounted wheel, an integral, molded, endless printing band extending under tension about the first and second wheels, the printing band having relatively long printing blocks and at least one blank section disposed along its extent, one of the sides supporting a relatively long printing block at a printing zone, the relatively long printing blocks corresponding generally in length to the length of a side of the wheel, the printing blocks having a set of different printing characters, relatively short sections joining adjacent relatively long printing blocks in an alternating pattern, and human readable indicia on the relatively short sections corresponding to the different printing characters and disposed such that the human readable indicium corresponding to the printing character at the printing zone is remote from the printing zone, the relatively long printing blocks, the relatively short sections and the blank section or sections together occupying substantially the entire length of the printing band.

9. A print head as defined in claim 8, wherein the relatively long printing blocks are at least about twenty percent longter than the relatively short sections.

10. A print head as defined in claim 8, wherein the printing blocks occupy at least about sixty percent of the band length.

11. A print head as defined in claim 8, wherein relatively short sections occupy less than about thirty percent of the band length.

12. A print head as defined in claim 8, including notches at the outer periphery of the sides of the wheel, equally spaced-apart lugs at the underside of the printing band for cooperation with the notches, the undersides of the relatively short sections being free of any lugs.