CA1162787A - Print head assembly and method of making same - Google Patents
Print head assembly and method of making sameInfo
- Publication number
- CA1162787A CA1162787A CA000401998A CA401998A CA1162787A CA 1162787 A CA1162787 A CA 1162787A CA 000401998 A CA000401998 A CA 000401998A CA 401998 A CA401998 A CA 401998A CA 1162787 A CA1162787 A CA 1162787A
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- providing
- drive wheels
- series
- side plate
- mounting
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Abstract
Docket M-391 PRINT HEAD ASSEMBLY AND METHOD OF MAKING SAME
Abstract of the Disclosure There is disclosed a method of making a print head assembly and a print head assembly. The print head assembly is comprised of one or more subassemblies. Each subassembly is made up of relatively few parts including a mounting block having a concave mounting surface, a series of drive wheels supported at their outer peripheries on the mounting surface, and a series of printing bands with which the drive wheels are engaged. The subassemblies can be readily assembled on a fixture. Thereafter, each subassembly is oriented relative to side plates to make a print head assembly.
Abstract of the Disclosure There is disclosed a method of making a print head assembly and a print head assembly. The print head assembly is comprised of one or more subassemblies. Each subassembly is made up of relatively few parts including a mounting block having a concave mounting surface, a series of drive wheels supported at their outer peripheries on the mounting surface, and a series of printing bands with which the drive wheels are engaged. The subassemblies can be readily assembled on a fixture. Thereafter, each subassembly is oriented relative to side plates to make a print head assembly.
Description
~ 162787 Docket M-391 PRINT HEAD ASSEMBLY AND ~IET~OD OF l`~AKING SA~lE
__ _ _ Background of the Invention Field of the Invention This invention relates to a method of making print head assemblies and to print head assemblies.
Brief Description of the Prior Art Various embodiments of a prior art print head as-sembly are disclosed in U. S. Patent No. 3,968,7~5 to Paul ~.
Hamisch, Jr. granted July 13, 1976. One embodiment has a lo single mounting block with a concave mounting surface for mounting drive wheels and support means. Printing bands are trained about the drive wheels and the support means. The mounting block is formed integrally with the support means and one side plate. There is a second side plate connected to the mounting block and a selector for engaging any drive wheel in its central hole to advance any selected printing band. The selector extends through an opening in the second side plate. The selector is assembled onto the side plate before the second side plate is connected to the mounting
__ _ _ Background of the Invention Field of the Invention This invention relates to a method of making print head assemblies and to print head assemblies.
Brief Description of the Prior Art Various embodiments of a prior art print head as-sembly are disclosed in U. S. Patent No. 3,968,7~5 to Paul ~.
Hamisch, Jr. granted July 13, 1976. One embodiment has a lo single mounting block with a concave mounting surface for mounting drive wheels and support means. Printing bands are trained about the drive wheels and the support means. The mounting block is formed integrally with the support means and one side plate. There is a second side plate connected to the mounting block and a selector for engaging any drive wheel in its central hole to advance any selected printing band. The selector extends through an opening in the second side plate. The selector is assembled onto the side plate before the second side plate is connected to the mounting
2~ block. In another embodiment suited for multi-line printing there are two such mounting blocks, two series of drive wheels and two series of printing bands and an integral side plate. There is a second side plate connected to the mounting blocks and there is a selector for each series of wheels. The print head assembly is assembled similarly to the manner described with respect to the previously mentioned embodiment .
~ ~2~8~
~ocket M-391 2 1 In applicant's prior art print head assemblv accordin~
to U. S. Patent No. 3,968r745, on~ of the side plates is molded integrally with the mounting block and the parting line is taken along that side plate. This requires the mold for the mounting block and the integral support means to be pro-vided with a certain draft angle from side-to-side to enable the resultant molded structure to be removed from the mold. Moreover, the molding of the side plate integrally with the mounting block an~ support means has at times 10 caused the resultant structure to be warped.
The goal of high quality printing may not be achieved when the print head components are warped or when molding draft is other than negligibleO Iligh quality printing is required when printing machine readable codes such as the OCR code or various types of bar codes.
U. S. Patent No. 3,796,152 to Eugene ~. Finke and Paul H. ~Iamisch, Jr. granted March 12, 1974 discloses a print head assembly having a mounting block with side plates. The side plates mount the shaft which in turn mounts the multi-20 sided side-by-side wheels.
Summary of the Invention The invention relates to a low cost, compact, modular, print head assembly having relatively few components, which components are readily accurately molded using moldable plastics material, and the molded components are easy to assemble.
In molding the mounting block of the present invention, the parting line is preferably midway between the sides so the draft angle is about one half as large as 30 the draft angle for the mounting block in Patent No. 3,96~,7~5.
Moreover, by molding the mounting block separate from the side plates, the mounting block is less likely to be warped.
This is due mainly to the fact that the mounting bloc~ according ~ 162'787 ocket M-391 3 1 to tle present invention can be made of relatively unifor~
section without abrupt changes in section.
It is one feature of the invention to make the print head assembly by first assembling one or more sub-assemblies, each subassembly including a printing block having a concave mounting surface, drive wheels mounted at their outer peripheries on the concave mounting surface, supporting means, and printing bands trained about the drive wheels and the supporting means. The invention utilizes 10 drive wheels having holes into which the selector extends.
The wheels are preferably small so that the size of the print head can be small. It is preferred that the subas-sembly or subassemblies which form part of the print head assembly be assembled while the mounting block and support means are on a fixture. Thereafter the side plates and the selector assembled onto the subassembly or subassemblies. An important feature is that the subassembly be a modular unit which is easy-to-assemble and is easy-to-handle as a subassembly. It is preferred to have the supporting means integrally molded 20 with the concave surface.
In making a print head assembly for printing two or more lines of data, it is preferred to have the lines close together without duplicating the number of parts. For example, a two-line print head assembly according to the inven-tion can be made by orienting one print head subassembly in one way and orienting another identical print head subassembly the oth~r way. This can be accomplished by having the supporting means of each subassembly close together and positioning the subassemblies at an angle with respect to 30 each other while the supporting means support the lines of printing elements in a common plane. A line passing through the axis of the drive wheels and center of the supporting means intersects the plane at an angle with respect to the perpendicu-lar. ~ach subassembly is inclined at the same angle with respect to a centerline perpendicular to the supporting plane, considering that the centerline passes between the sub-assemblies.
~ 162'~7 )ocket M-391 4 1 Brief Des~ ption of the Drawin~s FIGURE 1 is a partially exploded perspective view of a print head assembly in accordance wi~h the invention;
FIGURE 2 is an snd view showing two subassemblies and a side plate;
FIGURE 3 is a ~ectional view taken along line 3--3 of FIGU~E 2;
FIGURE 4 i5 a sectional view taken along line 4--4 of FIGURE 2;
FIGURE 5 is a fragmentary diagrammatic view showing how the subassemblies are oriented;
FIGURE 6 is an exploded perspective view showing how subassemblies can be assembled using a fixture; and FIGURE 7 is a fragmen~ary perspective view of a suba~sembly assembled on the fixture.
Detailed Description of the Pre~erred Embodiment With reference initially to FIGURE 1, there is disclosed, in partially exploded form, a print head assembly generally indicated at 10. The assembly 10 is shown to 20 include two subassemblies 11 and 12, ~ide plates 13 and 14 and shiftable and rotatable selectors 15 and 16.
Referring now also to FIGURES 2 through 4, the subassemblies 11 and 12 are shown to be identical, and hence the same reference characters will be used to denote like components. The subassemblies 11 and 12 have flexible printing bands 17 arranged to print a plurality of lines. Each sub-assembly includes a series of printing bands arranged to print a single line. Each printing band has a printing portion 17 and a human readable portion 17~. Each prin~ing band 17 i8 30 engaged ~ith a drive wheel 18 which is rotatably mounted or supported at its outer p~riphery on an arcuate concave mounting surface 19. The concave mounting ~urfa~e 19 cradle~ the respective series of wheels 18. The mounting ~urface 19 is illustrated to be part of a mounting block 20. ~t is preferred that a support 21 be formed integrally as part of the mounting block as oppo~ed to having separate idler wheel~ which are well known in the art so that manufacturing costs can be kept to a minimum. The printing band~ 17 o~ each subassembly are trained ~ 162787 ~ocket M-391 5 1 about the respective wheels 18 and the support 21 and are under a slight amount of tension to insure good traction between lugs 22 on the underside of the printing band and lugs 23 at the outer peripheries of the wheels 18. The outer surfaces of the printing bands ~7 are provided with a series of different printing elements 24 along the printing portion 17' for printing selectcd indicia on a record. As best sho~n in FIGURE 5, the supports 21 each support a plurality of printing elernents 24 at a printing zone Z in a common flat plane P. The subassemblies 11 and 12 are shown to be disposed at predetermined angles so that the printing elements 24 are in fact in the common plane r and yet the subassemblies 11 and 12 are identical. This is accomplished by having the subassemblies 11 and 12 in reverse positions as best illustrated in FIGUR~S 3 and 4. It is readily apparent from these FIGURES that the integral mounting blocks 20 and their respective supports 21 are integral asym-metrical parts. The side plate 14 has a pair of projections or lugs 25 and 26 which are received in cavities 27 and 2S. The projections 25 and 26 are offset from each other so that the 20 subassembly 12 can be connected to the side plates 13 and 14 in only one position as is evident from FIGUR~ 3 and the sub-assembly 11 can be connected to the side plates 13 and 14 only in the opposite position as indicated in FIGUX~ 4.
The side plate 14 has a plurality of rectangular sockets or recesses 29 for receiving respective keys or locators 30. The side plate 13 also has a plurality of sockets or recesses 29 for receiving keys or locators 30. The recesses 29 and keys 30 fit precisely and accurately locate the side plate with respect to the integral mounting ~lock 20 and the 30 support 21 of each subassembly. Threaded fasteners 31 pass through holes 32 in the respective side plates 13 and 14 and are threadably received in holes 33 in the mounting block 20 to hold the subassemblies 11 and 12 and the side plates 13 and 14 accurately in assembled relationship.
l 1627B7 Docket M-3~1 6 1 The selectors 15 and 16 have respective knobs 34 and 35 and respective selector shafts 36 and 37. Each selector shaft (only shaft 36 being shown in detail) has a plurality of lugs 38 ~or engaging in respective recesses 18' at the inner periphery of respective wheels 18. Further details of the selector are best shown in U. S. Patent No. 3,968,745.
Each selector 15 and 16 also includes a detent element 39 also best shown in U. 5. Patent No. 3,968,745. The detent element 39 releasably holds the respec~ive selector in any selec~ed lo position. Selectors 15 and 16 further include respective indicators 40 and 41 which are mounted for sliding movement by guides 42 and 43, and 44 and 450 The indica~ors 40 and 41 have pointers 40' are aligned with the lugs 38 to indicate the wheel 18 which is being engaged. Each selector 15 and 16 is provided with a respective re~ainer 47 and 48 for holding the selectors 15 and 16 assembled with the side plate 13.
With reference to FIGURE 6, there is shown a fixture generally indicated at 50. It is apparent that the fixture 50 is similar to the structure of the side plate 14 except that 20 the sockets 29 and the spacers 49 associated with each sub-assembly are spaced relatively widely apart. This wide spacing as shown in FIGURE 6 facilitates assembly of the wheels 18 and printing bands 17 onto the unting block 20 and the support 21 because there is adequate working space around each mounting block 20 and its support 21. The mounting blocks 20 are plugged into the fixture 50 as indicated. Thereafter, each wheel and its respective printing band 17 is moun~ed onto the respective mounting block. This is accomplished by placing the gear in mesh with several lugs 22, thereafter positioning 30 one of the printing blocks at the printing zone Z as shown in FIGURE 7 and thereafter manually tensioning the print band and sliding the wheel onto the concave mounting surface 19.
The printing band 17 and its respective wheel 18 are manually pushed along until the printing bands and wheels are stacked in a series, a partial series being ~hown in FIGURE 7. With the arrangement shown in FIGURES 6 and 7, the subassemblies 11 and 12 and the subassemblies 11 and 12 can be stacked or ~ ~62'7~7 ~ocket Mo391 7 1 conveniently stored until ready to be ~ssembled with the remaining componentæ o~ the print head assembly. The con~truc tion o~ the subassemblies 11 and 12 ls economically accom-plished because the m~unting blocks and the supports 21 are integral. Both suba~semblies 11 and 12 are easy to handle and therefore with respect to this feature it is not necessary that the mounting blook 20 and the support 21 be integral. With respect to this fea~ure it is only necessary that once the wheels 18 and bands 17 have been assembled lo onto the mounting block 20 and the support 21 that the resultant unit be of a subassembly which can be easily handled to facilitate final assembly, and the subassemblies form Lmportant parts of the print head assembly. In the prior art device according to United States Patent No. 3,796,152, where wheels are used, there is no easy-to-handle subassembly because the shaft for the idler wheels is not supported ~r mounted by the subassembly itself but rather by side plates.
It is another feature of the invention to provide means that render it impossible to assemble the modular sub-20 assemblies 11 and 12 incorrectly because the rectangulax keys30 have sides 30' that extend parallel to a centerline C and if the positions of the subassemblies 11 and 12 were interchanged, it would be readily apparent to the assembler that the supports 21 would be too far apartO As indicated in FIGURES 2 and 5, the supports are close together so that the lines of printing on the record will be close. Also, the projections 25 and 26 make misorienta~ion of the suba~semblies 11 and 12 impossible.
As is evident, the axes of the two series of wheels 18 are more widely spaced apart than the supports 21. As illus-30 trated, a reference line RF drawn through the axis of thewheels 18 and the center of the support 21 of subassembly 11 exists at an angle A with respect to the centerline C.
Similarly, a reference line RF' drawn through the axis of the wheels 18 and the center of the support 21 of subassembiy 12 makes an angle A' with the centerline C. The centerline C is perpendicular to the plane P and is disposed between the respective subassemblies 11 and 12. The angles A and A' are equal to each other so it is readily apparent tha~ is it only 27~7 ,cket M-391 8 1 necessary to reverse the positions of the subassemblies 11 and 12 in order to be able to assemble the subassemblies 11 and 12 properly wi~h respect to the side plates 13 and 14.
In assembling the print head assembly 10, it is preferred to key the subassemblies 11 and 12 to the side plate 14 by means of the locators 30 extending into sockets 29 and thereupon pass the threaded fasteners 31 through holes 32 and into the mounting blocks 20. It is apparent that the side plate 14 is devoid of posts which would interfere with 10 the connection of the subassemblies 11 and 12 and the sicle plate 14. Thereupon the selector shafts 36 and 37 are insertec' through openings 51 in the side plate 13 and then retainers 47 and 4~ are connected to the respective shafts 36 and 37 to hold the selectors 15 and 16 in assembled relationship with respect to side plate 13. The indicators 40 and 41 are inserted into guided relationship with respect to respective guides 4Z and 43, and 44 and 45. The guides 42 through A5 are part of posts 52, 53 and 54 and there are additional posts 55 (only a fragment of which is shown) and 56. The posts 52 through 20 56 have respective keys or locators 57 received in respective sockets or holes 58. Once the selectors 15 and 16 have been assembled onto the side plate 13, the outer portion of the selector shafts 36 and 37 are inserted into the holes 18' in the wheels 18 and the locators 57 are inserted into the sockets 58. Thereupon the threaded fasteners 31 associated ~lith the side plates 13 and 14 can be passed through respective holes 32 and into the mounting blocks 20.
Other embodiments and modifications of this invention will suggest themselves to those skilled in the art, and all 30such of these as come within the spirit of this invention are included within its scope as best defined by the appended claims.
~ ~2~8~
~ocket M-391 2 1 In applicant's prior art print head assemblv accordin~
to U. S. Patent No. 3,968r745, on~ of the side plates is molded integrally with the mounting block and the parting line is taken along that side plate. This requires the mold for the mounting block and the integral support means to be pro-vided with a certain draft angle from side-to-side to enable the resultant molded structure to be removed from the mold. Moreover, the molding of the side plate integrally with the mounting block an~ support means has at times 10 caused the resultant structure to be warped.
The goal of high quality printing may not be achieved when the print head components are warped or when molding draft is other than negligibleO Iligh quality printing is required when printing machine readable codes such as the OCR code or various types of bar codes.
U. S. Patent No. 3,796,152 to Eugene ~. Finke and Paul H. ~Iamisch, Jr. granted March 12, 1974 discloses a print head assembly having a mounting block with side plates. The side plates mount the shaft which in turn mounts the multi-20 sided side-by-side wheels.
Summary of the Invention The invention relates to a low cost, compact, modular, print head assembly having relatively few components, which components are readily accurately molded using moldable plastics material, and the molded components are easy to assemble.
In molding the mounting block of the present invention, the parting line is preferably midway between the sides so the draft angle is about one half as large as 30 the draft angle for the mounting block in Patent No. 3,96~,7~5.
Moreover, by molding the mounting block separate from the side plates, the mounting block is less likely to be warped.
This is due mainly to the fact that the mounting bloc~ according ~ 162'787 ocket M-391 3 1 to tle present invention can be made of relatively unifor~
section without abrupt changes in section.
It is one feature of the invention to make the print head assembly by first assembling one or more sub-assemblies, each subassembly including a printing block having a concave mounting surface, drive wheels mounted at their outer peripheries on the concave mounting surface, supporting means, and printing bands trained about the drive wheels and the supporting means. The invention utilizes 10 drive wheels having holes into which the selector extends.
The wheels are preferably small so that the size of the print head can be small. It is preferred that the subas-sembly or subassemblies which form part of the print head assembly be assembled while the mounting block and support means are on a fixture. Thereafter the side plates and the selector assembled onto the subassembly or subassemblies. An important feature is that the subassembly be a modular unit which is easy-to-assemble and is easy-to-handle as a subassembly. It is preferred to have the supporting means integrally molded 20 with the concave surface.
In making a print head assembly for printing two or more lines of data, it is preferred to have the lines close together without duplicating the number of parts. For example, a two-line print head assembly according to the inven-tion can be made by orienting one print head subassembly in one way and orienting another identical print head subassembly the oth~r way. This can be accomplished by having the supporting means of each subassembly close together and positioning the subassemblies at an angle with respect to 30 each other while the supporting means support the lines of printing elements in a common plane. A line passing through the axis of the drive wheels and center of the supporting means intersects the plane at an angle with respect to the perpendicu-lar. ~ach subassembly is inclined at the same angle with respect to a centerline perpendicular to the supporting plane, considering that the centerline passes between the sub-assemblies.
~ 162'~7 )ocket M-391 4 1 Brief Des~ ption of the Drawin~s FIGURE 1 is a partially exploded perspective view of a print head assembly in accordance wi~h the invention;
FIGURE 2 is an snd view showing two subassemblies and a side plate;
FIGURE 3 is a ~ectional view taken along line 3--3 of FIGU~E 2;
FIGURE 4 i5 a sectional view taken along line 4--4 of FIGURE 2;
FIGURE 5 is a fragmentary diagrammatic view showing how the subassemblies are oriented;
FIGURE 6 is an exploded perspective view showing how subassemblies can be assembled using a fixture; and FIGURE 7 is a fragmen~ary perspective view of a suba~sembly assembled on the fixture.
Detailed Description of the Pre~erred Embodiment With reference initially to FIGURE 1, there is disclosed, in partially exploded form, a print head assembly generally indicated at 10. The assembly 10 is shown to 20 include two subassemblies 11 and 12, ~ide plates 13 and 14 and shiftable and rotatable selectors 15 and 16.
Referring now also to FIGURES 2 through 4, the subassemblies 11 and 12 are shown to be identical, and hence the same reference characters will be used to denote like components. The subassemblies 11 and 12 have flexible printing bands 17 arranged to print a plurality of lines. Each sub-assembly includes a series of printing bands arranged to print a single line. Each printing band has a printing portion 17 and a human readable portion 17~. Each prin~ing band 17 i8 30 engaged ~ith a drive wheel 18 which is rotatably mounted or supported at its outer p~riphery on an arcuate concave mounting surface 19. The concave mounting ~urfa~e 19 cradle~ the respective series of wheels 18. The mounting ~urface 19 is illustrated to be part of a mounting block 20. ~t is preferred that a support 21 be formed integrally as part of the mounting block as oppo~ed to having separate idler wheel~ which are well known in the art so that manufacturing costs can be kept to a minimum. The printing band~ 17 o~ each subassembly are trained ~ 162787 ~ocket M-391 5 1 about the respective wheels 18 and the support 21 and are under a slight amount of tension to insure good traction between lugs 22 on the underside of the printing band and lugs 23 at the outer peripheries of the wheels 18. The outer surfaces of the printing bands ~7 are provided with a series of different printing elements 24 along the printing portion 17' for printing selectcd indicia on a record. As best sho~n in FIGURE 5, the supports 21 each support a plurality of printing elernents 24 at a printing zone Z in a common flat plane P. The subassemblies 11 and 12 are shown to be disposed at predetermined angles so that the printing elements 24 are in fact in the common plane r and yet the subassemblies 11 and 12 are identical. This is accomplished by having the subassemblies 11 and 12 in reverse positions as best illustrated in FIGUR~S 3 and 4. It is readily apparent from these FIGURES that the integral mounting blocks 20 and their respective supports 21 are integral asym-metrical parts. The side plate 14 has a pair of projections or lugs 25 and 26 which are received in cavities 27 and 2S. The projections 25 and 26 are offset from each other so that the 20 subassembly 12 can be connected to the side plates 13 and 14 in only one position as is evident from FIGUR~ 3 and the sub-assembly 11 can be connected to the side plates 13 and 14 only in the opposite position as indicated in FIGUX~ 4.
The side plate 14 has a plurality of rectangular sockets or recesses 29 for receiving respective keys or locators 30. The side plate 13 also has a plurality of sockets or recesses 29 for receiving keys or locators 30. The recesses 29 and keys 30 fit precisely and accurately locate the side plate with respect to the integral mounting ~lock 20 and the 30 support 21 of each subassembly. Threaded fasteners 31 pass through holes 32 in the respective side plates 13 and 14 and are threadably received in holes 33 in the mounting block 20 to hold the subassemblies 11 and 12 and the side plates 13 and 14 accurately in assembled relationship.
l 1627B7 Docket M-3~1 6 1 The selectors 15 and 16 have respective knobs 34 and 35 and respective selector shafts 36 and 37. Each selector shaft (only shaft 36 being shown in detail) has a plurality of lugs 38 ~or engaging in respective recesses 18' at the inner periphery of respective wheels 18. Further details of the selector are best shown in U. S. Patent No. 3,968,745.
Each selector 15 and 16 also includes a detent element 39 also best shown in U. 5. Patent No. 3,968,745. The detent element 39 releasably holds the respec~ive selector in any selec~ed lo position. Selectors 15 and 16 further include respective indicators 40 and 41 which are mounted for sliding movement by guides 42 and 43, and 44 and 450 The indica~ors 40 and 41 have pointers 40' are aligned with the lugs 38 to indicate the wheel 18 which is being engaged. Each selector 15 and 16 is provided with a respective re~ainer 47 and 48 for holding the selectors 15 and 16 assembled with the side plate 13.
With reference to FIGURE 6, there is shown a fixture generally indicated at 50. It is apparent that the fixture 50 is similar to the structure of the side plate 14 except that 20 the sockets 29 and the spacers 49 associated with each sub-assembly are spaced relatively widely apart. This wide spacing as shown in FIGURE 6 facilitates assembly of the wheels 18 and printing bands 17 onto the unting block 20 and the support 21 because there is adequate working space around each mounting block 20 and its support 21. The mounting blocks 20 are plugged into the fixture 50 as indicated. Thereafter, each wheel and its respective printing band 17 is moun~ed onto the respective mounting block. This is accomplished by placing the gear in mesh with several lugs 22, thereafter positioning 30 one of the printing blocks at the printing zone Z as shown in FIGURE 7 and thereafter manually tensioning the print band and sliding the wheel onto the concave mounting surface 19.
The printing band 17 and its respective wheel 18 are manually pushed along until the printing bands and wheels are stacked in a series, a partial series being ~hown in FIGURE 7. With the arrangement shown in FIGURES 6 and 7, the subassemblies 11 and 12 and the subassemblies 11 and 12 can be stacked or ~ ~62'7~7 ~ocket Mo391 7 1 conveniently stored until ready to be ~ssembled with the remaining componentæ o~ the print head assembly. The con~truc tion o~ the subassemblies 11 and 12 ls economically accom-plished because the m~unting blocks and the supports 21 are integral. Both suba~semblies 11 and 12 are easy to handle and therefore with respect to this feature it is not necessary that the mounting blook 20 and the support 21 be integral. With respect to this fea~ure it is only necessary that once the wheels 18 and bands 17 have been assembled lo onto the mounting block 20 and the support 21 that the resultant unit be of a subassembly which can be easily handled to facilitate final assembly, and the subassemblies form Lmportant parts of the print head assembly. In the prior art device according to United States Patent No. 3,796,152, where wheels are used, there is no easy-to-handle subassembly because the shaft for the idler wheels is not supported ~r mounted by the subassembly itself but rather by side plates.
It is another feature of the invention to provide means that render it impossible to assemble the modular sub-20 assemblies 11 and 12 incorrectly because the rectangulax keys30 have sides 30' that extend parallel to a centerline C and if the positions of the subassemblies 11 and 12 were interchanged, it would be readily apparent to the assembler that the supports 21 would be too far apartO As indicated in FIGURES 2 and 5, the supports are close together so that the lines of printing on the record will be close. Also, the projections 25 and 26 make misorienta~ion of the suba~semblies 11 and 12 impossible.
As is evident, the axes of the two series of wheels 18 are more widely spaced apart than the supports 21. As illus-30 trated, a reference line RF drawn through the axis of thewheels 18 and the center of the support 21 of subassembly 11 exists at an angle A with respect to the centerline C.
Similarly, a reference line RF' drawn through the axis of the wheels 18 and the center of the support 21 of subassembiy 12 makes an angle A' with the centerline C. The centerline C is perpendicular to the plane P and is disposed between the respective subassemblies 11 and 12. The angles A and A' are equal to each other so it is readily apparent tha~ is it only 27~7 ,cket M-391 8 1 necessary to reverse the positions of the subassemblies 11 and 12 in order to be able to assemble the subassemblies 11 and 12 properly wi~h respect to the side plates 13 and 14.
In assembling the print head assembly 10, it is preferred to key the subassemblies 11 and 12 to the side plate 14 by means of the locators 30 extending into sockets 29 and thereupon pass the threaded fasteners 31 through holes 32 and into the mounting blocks 20. It is apparent that the side plate 14 is devoid of posts which would interfere with 10 the connection of the subassemblies 11 and 12 and the sicle plate 14. Thereupon the selector shafts 36 and 37 are insertec' through openings 51 in the side plate 13 and then retainers 47 and 4~ are connected to the respective shafts 36 and 37 to hold the selectors 15 and 16 in assembled relationship with respect to side plate 13. The indicators 40 and 41 are inserted into guided relationship with respect to respective guides 4Z and 43, and 44 and 45. The guides 42 through A5 are part of posts 52, 53 and 54 and there are additional posts 55 (only a fragment of which is shown) and 56. The posts 52 through 20 56 have respective keys or locators 57 received in respective sockets or holes 58. Once the selectors 15 and 16 have been assembled onto the side plate 13, the outer portion of the selector shafts 36 and 37 are inserted into the holes 18' in the wheels 18 and the locators 57 are inserted into the sockets 58. Thereupon the threaded fasteners 31 associated ~lith the side plates 13 and 14 can be passed through respective holes 32 and into the mounting blocks 20.
Other embodiments and modifications of this invention will suggest themselves to those skilled in the art, and all 30such of these as come within the spirit of this invention are included within its scope as best defined by the appended claims.
Claims (34)
1. Method of making a print head assembly, comprising the steps of: providing mounting means having a concave mounting surface, providing supporting means disposed opposite the concave mounting surface, providing a series of drive wheels having holes, providing a series of printing bands each having a plurality of different printing elements, pro-viding a selector, providing a pair of first and second side plates with the second side plate having an opening, assembling the drive wheels and the respective printing bands onto the mounting means so that the drive wheels are rotatably supported on the concave mounting surface with their holes in general alignment and with the printing bands being trained about the respective drive wheels and the supporting means to provide a subassembly, and connecting the first and second side plates to opposite sides of the subassembly in precise orientation with the selector extending through the opening in the second side plate and into the holes to engage any selected wheel to provide an assembly.
2. Method of making a print head assembly, comprising the steps of: providing mounting means having a concave mounting surface, providing supporting means disposed opposite the concave mounting surface, providing a series of drive wheels having holes, providing a series of printing bands each having a plurality of different printing elements, providing a selector, providing a pair of first and second side plates with the second side plate having an opening, assembling the drive wheels and the respective printing bands onto the mounting means so that the drive wheels are rotatably supported on the concave mounting surface with their holes in general alignment and with the printing bands being trained about the respective drive wheels and the supporting means to provide a subassembly, positioning the first and second side plates at opposite sides of the sub-assembly in precise orientation, the selector extending through the opening in the second side plate and into the holes in the wheels, and securing the first and second side plates to the mounting means in said precise orientation to provide an assembly.
Docket M-391-C-l
Docket M-391-C-l
3. Method of making a print head assembly, comprising the steps of: providing a mounting block having a concave mounting surface, providing supporting means disposed opposite the concave mounting surface, providing a series of drive wheels having holes, providing a series of printing bands having a plurality of different printing elements, providing a selector, providing a pair of first and second side plates with the second side plate having an opening, assembling the drive wheels and respective printing bands onto the mounting block so that the drive wheels are rotatably mounted on the concave mounting surface with their holes in general alignment and with the printing bands being trained about the respective drive wheels and the supporting means to provide a subassembly, positioning the first side plate against one side of the subassembly, securing the first side plate to the subassembly, inserting the selector through the opening in the second side plate, inserting the selector into the holes in the wheels, positioning the second side plate against the other side of the subassembly with the end portion of the selector inserted into the holes in the wheels, and securing the second side plate to the mounting block to provide an assembly.
4. Method of making a print head assembly, comprising the steps of: molding a one-piece mounting block having a concave mounting surface and a support disposed opposite the concave mounting surface from moldable plastics material, providing a series of drive wheels having holes, providing a series of printing bands each having a plurality of different printing elements, providing a selector, providing a pair of first and second side plates with the second side plate having an opening, assembling the drive wheels and the respective printing bands onto the mounting block so that the drive wheels are rotatably supported on the concave mounting surface with their holes in general alignment and with the printing bands being trained about the respective drive wheels and the supporting means to provide a subassembly, and connecting Docket M-391-C-l the first and second side plates to opposite sides of the subassembly in precise orientation with the selector extending through the opening in the second side plate into the holes to engage any selected wheel to provide an assembly.
5. Method of making a print head assembly, comprising the steps of: molding a one-piece mounting block having a concave mounting surface and a support disposed opposite the concave mounting surface from moldable plastics material, providing a series of drive wheels having holes, providing a series of printing bands each having a plurality of different printing elements, providing a selector, providing a pair of first and second side plates with the second side plate having an opening, assembling the drive wheels and the respective printing bands onto the mounting block so that the drive wheels are rotatably supported on the concave mounting surface with their holes in general alignment and with the printing bands being trained about the respective drive wheels and the supporting means to provide a subassembly, positioning the first and second side plates at opposite sides of the subassembly in precise orientation, the selector extending through the opening in the second side plate and into the holes in the wheels, and securing the first and second side plates to the mounting block in said precise orientation to provide an assembly.
6. Method of making a print head assembly, comprising the steps of: molding a one-piece mounting block having a concave mounting surface and a support disposed opposite the concave mounting surface from moldable plastics material, providing a series of drive wheels having holes, providing a series of printing bands having a plurality of different printing elements, providing a selector, providing a pair of first and second side plates with the second side plate having an opening, assembling the drive wheels and respective printing bands onto the mounting block so that the drive wheels are rotatably mounted on the concave mounting surface with their holes in general alignment and with the printing bands being trained about the respective drive wheels and the supporting means to provide a subassembly, positioning the Docket M-391-C-l first side plate against one side of the subassembly, securing the the first side plate to the mounting block, inserting the selector through the opening in the second side plate, positioning the second side plate against the other side of the subassembly with the end portion of the selector inserted into the holes in the wheels, and securing the second side plate to the mounting block to provide an assembly.
7. Method of making a print head assembly, comprising the steps of: providing mounting means having a concave mounting surface, providing supporting means disposed opposite the concave mounting surface, providing a series of drive wheels having holes, providing a series of printing bands each having a plurality of different printing elements, pro-viding a selector, providing a pair of first and second side plates with the second side plate having an opening, assembling the drive wheels and the respective printing bands onto the mounting means so that the drive wheels are rotatably supported on the concave mounting surface with their holes in general alignment and with the printing bands being trained about the respective drive wheels and the supporting means to provide a subassembly, and keying the first and second side plates to opposite sides of the subassembly in precise orientation with the selector extending through the opening in the second side plate into the holes to engage any selected wheel to provide an assembly.
8. Method of making a print head assembly for printing at least two lines of data, making at least two subassemblies having substantially identical parts, each subassembly being made by molding a one-piece mounting block having a concave mounting surface and a support disposed opposite the concave mounting surface from moldable plastics material, providing a series of drive wheels having holes for receiving a selector, providing a series of printing bands each having a plurality of different printing elements, assembling the drive wheels and the respective printing bands onto the mounting block so that the drive wheels are rotatably supported on the concave surface with their holes in general alignment with the printing bands being Docket M-391-C-l trained about the respective drive wheels and the supporting means to provide a subassembly, the support supporting a printing element in a plane which is inclined from the perpendicular relative to a reference line passing through the center of a drive wheel and the support;
orienting the subassemblies so that the supports are disposed close together in the same plane and the reference lines are inclined with respect to each other.
orienting the subassemblies so that the supports are disposed close together in the same plane and the reference lines are inclined with respect to each other.
9. Method of making a print head assembly for printing at least two lines of data, making at least two identical subassemblies, each subassembly being made by molding a one-piece mounting block having a concave mounting surface and a support disposed opposite the concave mounting surface from moldable plastics material, providing a series of drive wheels having holes for receiving a selector, providing a series of printing bands each having a plurality of different printing elements, assembling the drive wheels and the respective printing bands onto the mounting block so that the drive wheels are rotatably supported on the concave surface with their holes in general alignment with the printing bands being trained about the respective drive wheels and the supporting means to provide a subassembly, the support supporting a printing element at a printing position in a plane which is inclined from the perpendicular relative to a reference line passing through the center of a drive wheel and the support;
orienting the subassemblies so that both sub-assemblies are equally and oppositely inclined with respect to a line extending between the subassemblies and intersecting the plane of the supports at a right angle and so that the printing elements at the printing position are in the same plane.
orienting the subassemblies so that both sub-assemblies are equally and oppositely inclined with respect to a line extending between the subassemblies and intersecting the plane of the supports at a right angle and so that the printing elements at the printing position are in the same plane.
10. Method of making a print head assembly, comprising the steps of: providing mounting means having a concave mounting surface, providing supporting means disposed opposite the concave mounting surface, providing a series of drive wheels having holes, providing a series of printing bands each having a plurality of different printing elements, pro-viding a selector, providing a pair of first and second side Docke-t M-391-C-l plates with the second side plate having an opening, placing the mounting means and supporting means in a fixture, assembling the drive wheels and the respective printing bands onto the mounting means so that the drive wheels are rotatably supported on the concave mounting surface with their holes in general alignment and with the printing bands being trained about the respective drive wheels and the supporting means to provide a subassembly, removing the subassembly from the fixture, and connecting the first and second side plates to opposite sides of the subassembly in precise orientation with the selector extending through the opening in the second side plate and into the holes to engage any selected wheel to provide an assembly.
11. A print head assembly, comprising: mounting means having a concave mounting surface, a series of drive wheels rotatably mounted at their outer peripheries on the concave mounting surface, the drive wheels having holes in general alignment with each other, supporting means disposed opposite the concave mounting surface, a series of printing bands each having a plurality of different printing elements, the printing bands being trained about the respective drive wheels and the supporting means to provide a subassembly, a selector for selectively setting any wheel to advance a selected printing band, first and second side plates with the second side plate having an opening for receiving the selector, and means connecting the first and second side plates to opposite sides of the subassembly in precise orientation with the selector extending through the opening in the second side plate and into the holes in the wheels to provide an assembly.
12. A print head assembly as defined in claim 11, wherein the connecting means includes means for keying the first side plate to the mounting means and means for keying the second side plate to the mounting means.
13. A print head assembly as defined in claim ll, wherein the connecting means includes means for keying the first side plate to the mounting means, means for keying the second side plate to the mounting means, and means securing the first and second side plates in keyed relationship to the mounting means.
Docket M-391-C-l
Docket M-391-C-l
14. A print head as defined in any one of claims 11, 12 or 13, wherein the mounting means is molded from moldable plastics material.
15. A print head as defined in any one of claims 11, 12 or 13, wherein the mounting means and the supporting means are molded in one piece of moldable plastics material.
16. A print head as defined in any one of claims 11, 12 or 13, wherein the mounting means is molded of moldable plastics material.
17. A print head as defined in claim 11, wherein the connecting means includes threaded fasteners.
18. A print head assembly, comprising: at least two identical subassemblies, each subassembly having a one-piece mounting block having a concave mounting surface and a support disposed opposite the concave mounting surface and composed of moldable plastics material, a series of drive wheels rotatably mounted at the outer peripheries on the concave mounting surface, a selector, the drive wheels having aligned holes for receiving the selector, a series of printing elements each having a plurality of different printing elements, the printing bands being trained about the respective drive wheels and the support, the support supporting a printing element in a flat plane which is inclined from the perpendicular relative to a reference line passing through the center of a drive wheel and the support, and means for holding the subassemblies so that both subassemblies are equally and oppositely inclined with respect to a centerline extending between the subassemblies and intersecting the of the supports at a right angle and so that the printing elements at the printing portion are in the same plane.
19. Apparatus as defined in claim 18, wherein the subassemblies are asymetrical and cooperable with at least one of the side plates to enable the subassemblies to be assembled only with their respective supports disposed in the same plane.
20. Apparatus as defined in claim 18, including means for preventing the subassemblies from being assembled with their respective supports out of the plane.
Docket M-391-C-l
Docket M-391-C-l
21. A print head assembly, comprising: at least two identical subassemblies, each subassembly having a one-piece mounting block having a concave mounting surface and a support disposed opposite the concave mounting surface and composed of moldable plastics material, a series of drive wheels rotatably mounted at the outer peripheries on the concave mounting surface, a selector, the drive wheels having aligned holes for receiving the selector, a series of printing elements each having a plurality of different printing elements, the printing bands being trained about the respective drive wheels and the support, the support supporting a printing element in a flat plane which is inclined from the perpendicular relative to a reference line passing through the center of a drive wheel and the support, and means for holding the subassemblies so that both supports are disposed close together in the same plane and the reference lines are inclined with respect to each other.
22. Apparatus as defined in claim 20, wherein the subassemblies are asymmetrical and cooperable with one of the side plates to enable the subassemblies to be assembled only with their respective supports disposed in the same plane.
23. Apparatus as defined in claim 21, including means for preventing the subassemblies from being assembled with their respective supports out of the plane.
24. Method of making a print head assembly, comprising the steps of: providing a pair of separate, molded mounting blocks composed of plastics material each having a substantially constant profile with an elongate concave mounting surface, there being means opposite the concave mounting surface for supporting printing bands, providing for each of the mounting blocks a series of drive wheels having central holes defining a continuous opening, providing a series of printing bands for each mounting block with each band having a plurality of different printing elements, providing a pair of band selectors, providing a pair of separate first and second molded side plates composed of plastics material with the second side plate having openings, assembling a series of drive wheels and a series of printing bands on each of the mounting blocks with the drive Docket M-391-C-1 wheels rotatably supported on the concave mounting surface with the printing bands trained about the respective drive wheels and the band supporting means, providing a locator and a cooperating locator-receiving recess for the first side plate and for one side portion of each mounting block, locating the pair of mounting blocks in side-by-side, oriented relationship with respect to each other and with respect to the first side plate using the respective cooperating locators and locator-receiving recesses to present the printing elements at the band supporting means in a common plane, providing a locator and a cooperating locator-receiving recess for the second side plate and for the other side portion of each mounting block, each band selector being positioned in the continuous opening of the respective series of drive wheels with a portion of the band selector projecting through the respective opening in the second side plate, and locating the second side plate with respect to the pair of mounting blocks using the respective cooperating locators and locator-receiving recesses.
25. Method of making a print head assembly, comprising the steps of: providing a pair of separate and identical molded mounting blocks composed of plastics material with each mounting block having means providing a concave mounting surface, there being means opposite the concave surface providing a band support, providing for each of the mounting blocks a series of drive wheels having central holes defining a continuous opening, providing a series of printing bands for each mounting block with each band having a plurality of different printing elements, providing a pair of band selectors providing a pair of first and second molded side plates composed of plastics material with the second side plate having openings, assembling a series of drive wheels and a series of printing bands on each of the mounting blocks with the drive wheels rotatably supported by the support surface and with the printing bands trained about the respective drive wheels and band support means, providing the mounting blocks and at least one side plate with cooperating means enabling the mounting blocks to be positioned in only Docket M-391-C-l opposite orientations with respect to each other, positioning the mounting blocks in opposite orientations with a centerline through one series of wheels and its respective band support means and another centerline through the other series of wheels and the other band support means being equally and oppositely angularly inclined with respect to a common intervening line perpendicular to a plane provided by the band support means with each band selector being positioned in the continuous opening of the respective series of drive wheels with a portion of the band selector projecting through the respective opening in the second side plate and with the first and second side plates secured to both mounting blocks for maintaining the positioned relationship of the mounting blocks and the first and second side plates relative to each other.
26. Method of making a print head assembly, comprising the steps of: providing a pair of mounting means each having a concave mounting surface, there being band supporting means disposed opposite each concave mounting surface, providing for each mounting means a series of drive wheels having holes, providing for each mounting means a series of printing bands each having a plurality of different printing elements, providing a pair of selectors, providing a pair of first and second side plates with the second side plate having openings, placing the pair of mounting means and supporting means in a fixture, assembling the drive wheels and the respective printing bands onto the mounting means so that the drive wheels are rotatably supported on the concave mounting surface with their holes in general alignment and with the printing bands being trained about the respective drive wheels and the supporting means to provide a pair of subassemblies, removing the subassemblies from the fixture, and connecting the first and second side plates to opposite sides of the subassembly in a predetermined orientation with the selectors extending through the openings in the second side plate and into the holes to engage any selected wheel to provide an assembly.
Docket M-391-C-1
Docket M-391-C-1
27. Method of making a print head assembly, comprising the steps of: providing a pair of separate and identical molded mounting blocks composed of plastics material with each mounting block having means providing a concave mounting surface, there being means opposite the mounting surface providing a band support, providing for each of the mounting blocks a series of drive wheels having central holes defining a continuous opening, providing a series of printing bands for each mounting block with each band having a plurality of different printing elements, providing a pair of band selectors, providing a pair of first and second molded side plates composed of plastics material with the second side plate having openings, assembling a series of drive wheels and a series of printing bands on each of the mounting blocks with the drive wheels rotatably supported on the mounting surface and with the printing bands trained about the respective drive wheels and band support means, positioning the mounting blocks in opposite orientations with a centerline through one series of wheels and its respective band support means and another centerline through the other series of wheels and its respective band support means being equally and oppositely angularly inclined with respect to a common intervening line perpendicular to a plane provided by the band support means, wherein the positioning step includes providing a locator and a cooperating locator-receiving recess for the first side plate and for one side portion of each mounting block, locating the pair of mounting blocks in side-by-side, oriented relationship with respect to each other and with respect to the first side plate using the cooperating locator and locator-receiving recesses to present the printing elements at the band supporting means in a common plane, and providing a locator and a cooperating locator-receiving recess for the second side plate and for the other side portion of at least one of the mounting blocks, locating the second side plate with respect to the mounting blocks, and securing the first and second side plates to the mounting blocks with the mounting blocks disposed in Docket M-391-C-l side-by-side oppositely oriented relationship with respect to each other with each band selector being positioned in the continuous opening of the respective series of drive wheels with a portion of the band selector projecting through the respective opening in the second side plate.
28. Method of making a print head assembly, comprising the steps of: providing a pair of separate molded mounting blocks composed of plastics material with each mounting block having means providing a concave support surface, there being means opposite the mounting surface providing a band support, providing for each of the mounting blocks a series of drive wheels having central holes defining a continuous opening, providing a series of printing bands for each mounting block with each band having a plurality of plates composed of plastics material with the first side plate being devoid of structure that would interfere with the connection of the mounting blocks to the first side plate and with the second side plate having openings, assembling a series of drive wheels and a series of printing bands on each of the mounting blocks with the drive wheels rotatably supported on the mounting surface and with the printing bands trained about the respective drive wheels and band support means, and positioning the mounting blocks in opposite orientations with a centerline through one series of wheels and its respective band support means and another centerline through the other series of wheels and its respective band support means being equally and opposite angularly inclined with respect to a common intervening line perpendicular to a plane provided by the band support means, wherein the positioning step includes providing a locator and a cooperating locator-receiving recess for the first side plate and for one side portion of each mounting block, locating the pair of mounting blocks in side-by-side, oriented relationship with respect to each other and with respect to the first side plate using the cooperating locator and locator-receiving recesses to present the printing elements at the band supporting means in a common plane, and providing a locator and a cooperating locator-Docket M-391-C-1 receiving recess for the second side plate and for the other side portion of at least one of the mounting blocks, and locating the second side plate with respect to the mounting blocks.
29. Method of making a print head assembly, comprising the steps of: providing a pair of separate, molded mounting blocks composed of plastics material each having means providing an elongate concave mounting surface, there being means opposite the mounting surface for supporting printing bands, providing for each of the mounting blocks a series of drive wheels having central holes defining a continuous opening, providing a series of printing bands for each mounting block with each band having a plurality of different printing elements, providing a pair of band selectors, providing a pair of first and second molded side plates composed of plastics material with the second side plate having openings, assembling a series of drive wheels and a series of printing bands on each of the mounting blocks with the drive wheels rotatably supported on the concave mounting surface with the printing bands trained about the respective drive wheels and the band supporting means to provide a pair of subassemblies, thereafter locating the pair of subassemblies in side-by-side, oriented relationship with respect to each other and with respect to the first side plate using locators and cooperating locator-receiving recesses, with each band selector being positioned in the continuous opening of the respective series of drive wheels with a portion of the band selector projecting through the respective opening in the second side plate, and thereafter locating the second side plate with respect to the pair of mounting blocks to provide an assembly.
30. Method of making a print head assembly, comprising the steps of: providing a pair of separate, molded mounting blocks from plastics material each having means providing an elongate concave mounting surface, there being means opposite the mounting surface for supporting a printing band, providing for each of the mounting blocks a series of drive wheels having central holes defining a Docket M-391-C-l continuous opening, providing a series of printing bands for each mounting block with each band having a plurality of different printing elements, providing a pair of band selectors, providing a pair of first and second molded side plates composed of plastics material with the second side plate having openings, assembling a series of drive wheels and a series of printing bands on each of the mounting blocks with the drive wheels rotatably supported on the mounting surface with the printing bands trained about the respective drive wheels and the band supporting means to provide a pair of subassemblies, wherein the steps of providing the molded mounting blocks and the first and second molded side plates include providing cooperating first locator means for the first side plate and for one side portion of each mounting block and second locator means for the second side plate and for the other side portion of each mounting block, locating the pair of subassemblies in side-by-side, oriented relationship with respect to each other and with respect to the first side plate using the first locator means, with each band selector being positioned in the continuous opening of the respective series of drive wheels with a portion of the band selector projecting through the respective opening in the second side plate, and thereafter locating the second side plate with respect to the pair of mounting blocks using the second locator means.
31. A print head assembly, comprising: a pair of separate and identical mounting blocks composed of plastics material with each mounting block having means providing a concave mounting surface, means opposite the concave surface providing a band support, a series of drive wheels for each mounting block, the drive wheels of each series having central holes defining a continuous opening, a series of printing bands for each mounting block with each band having a plurality of different printing elements, a pair of band selectors, a pair of first and second side plates composed of plastics material with the second side plate having openings, a series of the drive wheels and a series of the printing bands being assembled Docket M-391-C-l on each of the mounting blocks with the drive wheels rotatably supported by the support surface and with the printing bands trained about the respective drive wheels and band support means, the mounting blocks and at least one side plate having cooperating means enabling the mounting blocks to be positioned in only opposite orientations with respect to each other, the mounting blocks being positioned in opposite orientations with a centerline through one series of wheels and its respective band support means and another centerline through the other series of wheels and the other band support means being equally and oppositely angularly inclined with respect to a common intervening line perpendicular to a plane provided by the band support means with each band selector being positioned in the continuous opening of the respective series of drive wheels with a portion of the band selector projecting through the respective opening in the second side plate and with the first and second side plates secured to both mounting blocks for maintaining the positioned relationship of the mounting blocks and the first and second side plates relative to each other.
32. A print head assembly, comprising: a pair of separate and identical mounting blocks composed of plastics material with each mounting block having means providing a concave mounting surface, means opposite the mounting surface providing a band support, a series of drive wheels for each mounting block, the drive wheels of each series having central holes defining a continuous opening, a series of printing bands for each mounting block with each band having a plurality of different printing elements, a pair of band selectors, a pair of first and second side plates composed of plastics material with the second side plate having openings, a series of the drive wheels and a series of the printing bands being assembled on each of the mounting blocks with the drive wheels rotatably supported on the mounting surface and with the printing bands trained about the respective drive wheels and band support means, the mounting blocks being positioned in opposite orientations with a centerline through one series of wheels and its respective band support means and another centerline through the other series of wheels and its respective band support means being equally and oppositely angularly inclined with respect to a common intervening line perpendicular Docket M-391-C-l to a plane provided by the band support means, a locator and a cooperating locator-receiving recess for the first side plate and for one side portion of each mounting block for locating the pair of mounting blocks in side-by-side, oriented relation-ship with respect to each other and with respect to the first side plate to cause the printing elements to be presented at the band supporting means in a common plane, a locator and a cooperating locator-receiving recess for the second side plate and for the other side portion of at least one of the mounting blocks for locating the second side plate with respect to the mounting blocks, and means for securing the first and second side plates to the mounting blocks with the mounting blocks disposed in side-by-side oppositely oriented relationship with respect to each other, with each band selector being positioned in the continuous opening of the respective series of drive wheels and with a portion of the band selector projecting through the respective opening in the second side plate.
33. A print head assembly, comprising a pair of separate mounting blocks composed of plastics material with each mounting block having means providing a concave support surface, means opposite each mounting surface providing a band support, a series of drive wheels for each mounting block, the drive wheels of each series having central holes defining a continuous opening, a series of printing bands for each mounting block with each band having a plurality of different printing elements, a pair of band selectors, a pair of first and second side plates composed from plastics material and with the second side plate having openings, a series of the drive wheels and a series of the printing bands being assembled on each of the mounting blocks with the drive wheels rotatably supported on the mounting surface and with the printing bands trained about the respective drive wheels and band support means, the mounting blocks being positioned in opposite orientations with a centerline through one series of wheels and its respective band support means and another centerline through the other series of wheels and its respective band support means being equally and opposite angularly inclined with respect to a common intervening Docket M-391-C-l line perpendicular to a plane provided by the band support means, a locator and a cooperating locator-receiving recess for the first side plate and for one side portion of each mounting block for locating the pair of mounting blocks in side-by-side, oriented relationship with respect to each other and with respect to the first side plate to cause the printing elements to be presented at the band supporting means in a common plane, and a locator and a cooperating locator-receiving recess for the second side plate and for the other side portion of at least one of the mounting blocks.
34. A print head assembly, comprising: a pair of separate mounting blocks composed of plastics material each having means providing an elongate concave mounting surface, means opposite the mounting surface for supporting a printing band, a series of drive wheels for each mounting block, the drive wheels of each series having central holes defining a continuous opening, a series of printing bands for each mounting block with each band having a plurality of different printing elements, providing a pair of band selectors, a pair of first and second side plates composed of plastics material with the second side plate having openings, a series of the drive wheels being rotatably supported on the mounting surface with the printing bands trained about the respective drive wheels and the band supporting means to provide a pair of subassemblies, first locating means for the first side plate and for one side portion of each mounting block for locating the subassemblies in side-by-side, oriented relationship with respect to each other and with respect to the first side plate, second locating means for the second side plate and for the other side portion of each mounting block for locating the second side plate with respect to the pair of mounting blocks, each band selector being positioned in the continuous opening of the respective series of drive wheels with a portion of the band selector projecting through the respective opening in the second side plate.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000401998A CA1162787A (en) | 1979-08-23 | 1982-04-29 | Print head assembly and method of making same |
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US06/069,217 US4283832A (en) | 1979-08-23 | 1979-08-23 | Method of making print head assembly |
| US069,217 | 1979-08-23 | ||
| CA356,931A CA1124133A (en) | 1979-08-23 | 1980-07-24 | Print head assembly and method of making same |
| CA000401998A CA1162787A (en) | 1979-08-23 | 1982-04-29 | Print head assembly and method of making same |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1162787A true CA1162787A (en) | 1984-02-28 |
Family
ID=27166766
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000401998A Expired CA1162787A (en) | 1979-08-23 | 1982-04-29 | Print head assembly and method of making same |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1162787A (en) |
-
1982
- 1982-04-29 CA CA000401998A patent/CA1162787A/en not_active Expired
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| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |