GB2133351A

GB2133351A - Keyboard

Info

Publication number: GB2133351A
Application number: GB08334302A
Authority: GB
Inventors: Iain Sinclair
Original assignee: Individual
Current assignee: Individual
Priority date: 1982-12-22
Filing date: 1983-12-22
Publication date: 1984-07-25
Also published as: GB2133351B; GB8334302D0

Abstract

A moulded plastics keyboard comprises a one-shot lower moulding 3 and a one-shot upper moulding 8, each comprising two key rows 14, 15 and 36, 37, Each key pad 17, 18 is cantilevered by an elongate stalk 23, 40 to a rear block 24, 46. A membrane switch pad underlies the mouldings as assembled and is actuated on key depression against cantilever resilience. Key depression is positive, reliable, pleasant and uniform over the whole keyboard which is simple and inexpensive to make relative to conventional keyboard designs. <IMAGE>

Description

SPECIFICATION Keyboard The invention relates to a keyboard for use as part of a typewriter or computer input keyboard or in similar hardware such as telex communication equipment.

Typewriter and similar keyboards have been the subject of considerable research effort over recent years. Original mechanical keyboards employed cantilevered keypads mechanically linked with stalks terminating at a print head carrying an indicium signified at the keypad. Developments in electronics have made this form of keyboard redundant and keyboards not generally comprise keypads whose depression activates electronics which actuate energization of a motor function which drives a print head such as a golf ball head or daisy wheel.

Keyboards of this type normally are made up of independent keys each of which has its own specific mounting assembly. Despite mass production economics of scale, keyboards of such design are relatively expensive to manufacture in terms of component manufacture and final assembly.

According to the invention, a keyboard assembly comprises at least one key set (e.g. a moulding or pressing) wherein the component keys each comprise an optionally integral keypad carried by an elongate, resilient cantilever stalk (e.g. of plastics or metallic material) originating from and normally integral with a cantilever supporting member and displaceable only by resilient deformation.

A key set may make up part only of the keyboard layout as a whole, and a key set so constituted is per se included within the scope of the invention.

Generally, each key set will comprise a plastics or other moulding (e.g. one-shot) or pressing, the component keys comprising in each case an elongate, resilient, e.g. plastics, cantilever stalk originating from an integral, e.g. plastics moulded, cantilever supporting member common to all said stalks of said set.

In an embodiment of this form of the invention, at least one plastics moulding comprises one or more rows of keypads each of which is carried at or proximate an extremity of an elongate resilient plastics cantilever stalk originating at an opposed extremity from a plastics moulded cantilever support block, said block being common to all stalks of said moulding and said stalks extending therefrom in parallel spaced apart relationship with respect to each other. The cantilever support block will normally comprise an outer wall member enclosing a cavity normally traversed by strengthening webs.

The plastics moulding just described may conveniently comprise two parallel rows of keypads with the keypads of each row spaced apart from each other and in parallel to the centilever support block. Conveniently, the two rows are disposed at different elevations each in a common plane inclined to the horizontal by 10 to 20 (e.g. 150). The stalks of all the keys in the two rows are conveniently in the same horizontal plane. A space bar may be provided in spaced apart parallel relationship with respect to the keypad rows and the cantilever support block.

Two plastics mouldings of any of the kinds referred to earlier may be provided to make up two key sets constituting a complete keyboard, a first usually overlying a second and the second usually including a space bar provided as referred to above, such normally forming a lowermost key level with keypad rows forming the remainder of the board as separate higher levels.

The space bar normally includes a space bar pad which is cantilevered to said support block by one or more resilient plastics cantilever stalks originating at said block, the space bar and its cantilever support means being an integral part of the moulding. Conveniently, the key row cantilevers occupy a first plane and said space bar key cantilevers occupy a second plane parallel thereto and to the horizontal.

In a particular embodiment of the invention, a keyboard comprises a first plastics moulding representing one portion of a complete keyboard layout and a second plastics moulding representing a remaining portion of approximately equal size in terms of keypad content, the mouldings each comprising two spaced apart parallel rows of keypads each carried at the extremity of an elongate, resilient plastics moulded cantilever stalk originating at a moulding cantilever support block with the cantilever stalks parallel one to another, separate such support blocks being provided one forming part of each moulding and the stalks common to one respective moulding occupying a common horizontal plane spaced from and parallel to that for the stalks common to the other moulding, the first moulding including a space bar key cantilevered to the first moulding support block and havings its keypad separate from the key rows of said first moulding, and the second moulding support block being seated upon and secure to the first.

The invention includes within its scope a plastics moulded key set comprising a plurality of keypads each carried by an elongate resilient cantilever key stalk originating from a cantilever support member. Conveniently in such a key set the keypads are disposed in at least two parallel rows spaced differentially from and parallel to the support member and with the keypads of each staggered with rospect to those of the other, the key stalks extending in parallel in not more than one horizontal plane for each row of keypads and each alpha-numeric key stalk being such as to exhibit identical tactile response at least to all other alpha-numeric key stalks.

The invention enables a complete keyboard to be manufactured and assembled more cheaply than is possible with conventional keyboard designs. A complete keyboard can, for example, be made by injection moulding an upper and lower moulding each in a one-shot operation using cost-effective thermoplastic materials, particularly acrylonitrile-butadiene-styrene copolymer resin (ABS), polystyrene, polypropylene, acetal polymer or nylon. Such mould7ngs can easily be combined in a simple manufacturing operation and a membrane switch pad provided for actuation of operating electronics. The natural spring of the centilever stalks provides a subjectively pleasing tactile response which is positive, reliable and capable of reproduction uniformly not only over an entire keyboard but over all units produced in a mass production operation.

The invention will now be described, by way of example only, reference being made to the accompanying drawings in which: Figure 1 is a fragmentary plan view of a typewriter keyboard assembly according to the invention; Figure 2 is a side view of the assembly shown in Figure 1 viewed from the direction of the arrow II; Figure 3 is a plan view of a lower keyboard moulding forming part of the assembly shown in Figure 1; Figure 4 is a fragmentary front view of the moulding shown in Figure 3 viewed from the direction of the arrow IV; Figure 5 is a cross-sectional view taken along the line V-V of Figure 3; Figure 6 is a side view of the moulding shown in Figure 3 viewed from the direction of the arrow VI; Figure 7 is a cross-sectional view of part of the moulding shown in Figure 3 taken along the line VIl-VIl;; Figure 8 is a plan view of an upper keyboard moulding forming part of the assembly shown in Figure 1; Figure 9 is a fragmentary front view of the moulding shown in Figure 8 viewed in the direction of the arrow IX; and Figure 10 is a side view of the moulding shown in Figure 7 viewed in the direction of the arrow X.

In the keyboard assembly shown in Figure 1, the lower moulding shown in Figure 3 is shown designated by reference numeral 3. The upper moulding shown in Figure 8 is seated upon the lower moulding 3, the upper moulding being designated by the reference numeral 8. The two mouldings are secured together by fasteners (not shown) which penetrate bores 11 of the upper moulding 8 and bores 12 of lower moulding 3, the two sets of bores being in register in the assembled keyboard. A membrane switch pad 13 (Figures 2 and 6) underlies the assembly with its membrane switches in circuit with operating electronics when assembled as part of a typewriter.

Lower moulding 3 is shown in Figure 1 partially cross-hatched for recognition purposes.

Lower moulding 3 is a one-shot injection moulding of ABS resin. The moulding comprises two rows of keys 14 and 15, row 14 comprising twelve keys and row 1 5 comprising fourteen keys.

The two key rows are disposed at different elevations, as shown in Figures 5 and 6, with key row 15 uppermost, and the component keys of each row are staggered with respect to those of the other. A space bar 1 6 is disposed forward of key row 14 and forms a third and lowermost key level, the three levels occupying an inclined plane shown in chain lines at Ill in Figure 2.

Each key comprises a hollow keypad 17 formed with a web 1 8 in its cavity. A foot 1 9 extends downwardly from the web 18 and is spaced a small distance (typically 3.5 mm) from the membrane switch pad 13 for contact therewith on key depression.

Space bar 1 6 is similarly formed with a cavity 2G, a web 21 extending across its narrow dimension. A foot 22 extends downwardly from web 21 and, as in the case of keypads 17, is spaced a small distance (typically 3.5 mm) from the membrane switch pad 13.

Each keypad 1 7 is disposed at the forward extremity of a resilient cantilever 23 originating from a hollow rear block shown generally at 24.

The cantilevers 23 are identically dimensioned so as to provide identical tactile response on key depression against cantilever resilience. The cantilevers of key row 14 originate forward of the cantilever origins of key row 1 5 to accommodate forward positioning of key row 14. The cantilevers of the two rows occupy the same plane.

Space bar 1 6 is similarly cantilevered resiliently from the rear block 24, the keypad of space bar 1 6 being integral with and forming a junction between elongate members 25 and 26 which extend perpendicularly toward each other from cantilevers 27 and 28, respectively. Cantilevers 27, 28 are of larger lateral dimension than cantilevers 23 so compensating for their greater length relative to cantilevers 23 such as essentially to provide identical tactile response on resilient depression of space bar 1 6. Cantilevers 27 and 28 occupy a lower plane than cantilevers 23.

Block 24 comprises an outer wall 30 a forward section 30a of which is of casteliated form when viewed in plan. Internal wall 31 partitions the space within the wall 30. A plurality of webs 32 extend between the partitioning internal wall 31 and the outer wall 30. A rear recessed portion 33 of block 24 provides a seat for upper moulding 8, the latter being locatable against a shoulder 34 formed by an upper section of partition wall 31.

The bores 12 referred to earlier are formed by tubular part-mouldings 35 which extend through the thickness of recessed portion 33 of block 24.

Upper moulding 8 is a one-shot injection moulding of the same plastics material as lower moulding 3. Upper moulding 8 comprises two rows of keys 36 and 37, row 36 comprising fourteen keys and row 37 comprising thirteen keys. As in the case of key rows 14 and 1 5 of lower moulding 3, the two key rows of upper moulding 8 are disposed at different elevations with key row 37 uppermost (Figure 10), and the component keys of each row are staggered with respect to those of the other row.

Each key of upper moulding 8 comprises a hollow keypad 38. Keypads 38 are identical with the keypads 1 7 of lower moulding 3 except that feet 39 of keypads 38 are sufficiently longer than feet 1 9 of keypads 1 7 to compensate for the higher elevation of upper moulding 8 in the assembled keyboard.

Keypads 38 are each disposed at the forward extremity of a resilient cantilever 40, cantilevers 40 being dimensioned identically to cantilevers 23 of lower moulding 3. Cantilevers 40 originate from a hollow rear block shown generally at 46, the cantilevers of rows 36 originating forward of the cantilever origins of key rows 37 to accommodate the forward positioning of key row 36. All cantilevers 40 occupy the same plane which in the assembled keyboard is above the plane occupied by cantilevers 23.

- Block 46 comprises an outer moulded wall 42.

A forward section 42a of wall 42 has a castellated form when viewed in plan so as to provide the forward origins of the cantilevers 40 of key row 36. A plurality of webs 43 extend laterally between the longitudinal sections of wall 42.

The bores 11 referred to earlier are formed by tubular part-mouldings 44 which extend through the thickness of block 46, the part-mouldings at each opposed end of upper moulding 3 being linked by web 45 to the short end section of wall 42.

In the assembled keyboard as shown in Figures 1 and 2, block 46 of upper moulding 8 as just described seats upon recessed portion 33 of lower moulding block 24. Block 46 is brought into abutment against shoulder 34 of block 24 and the two mouldings adjusted along their largest dimension until bores 11 and 12 are in register.

Fasteners are then passed through the bores and secured so that mouldings 3 and 8 are locked together. The so assembled keyboard can then be combined with membrane switch pad 13, operating electronics and a printer to form a complete typewriter. The base of feet 1 9, 1 9a and 39 occupy the same plane between and parallel to the plane of cantilevers 27, 28 and that of membrane switch pad 13 so that all key displacements are identical in keying operations.

Keying operations are found to be userconvenient, a reliable, positive and subjectively appealing tactile response being obtained uniformly over the whole board from the natural spring of the cantilevers. The whole keyboard assembly of lower and upper mouldings, providing a conventional OWERTY layout (or other desired format), can be made in a two-shot operation by uncomplicated injection moulding techniques using inexpensive widely available thermoplastic materials.

Suitable dimensions for the various components of the keyboard described with reference to the drawings are as follows:- Cantilevers 23: length 57 mm; depth 4 mm; thickness 2 mm Cantilevers 27, 28: length 83 mm; depth 4 mm; thickness 3.5 mm Key displacement 3.5 mm Centre-centre key row spacing 1 9 mm The plane Ill shown in Figure 2 may typically have a 1 50 inclination to horizontal.

The invention as described earlier without reference to the drawings may include any one or more of the features of the invention as described with reference to the drawings or referred to in the attached claims.

Claims

1. A keyboard comprising one or more key sets wherein the component keys each comprise a keypad carried by an elongate, resilient cantilever stalk originating from a cantilever supporting member.

2. A keyboard as claimed in Claim 1 wherein each key set is a plastics moulding, the component keys in each set comprising an elongate resilient plastics cantilever stalk originating from a plastics moulded cantilever supporting member common to said stalks.

3. A keyboard as claimed in Claim 2 wherein two such plastic mouldings are disposed with a first overlying a second to provide two key sets.

4. A keyboard as claimed in Claim 2 or Claim 3 wherein at least one plastic moulding comprises one or more rows of keypads each of which is carried at or proximate an extremity of an elongate resilient plastics cantilever stalk originating at an opposed extremity from a plastics moulded cantilever support means, said means being common to all stalks of said moulding and said stalks extending therefrom in parallel spaced apart relationship with respect to each other.

5. A keyboard as claimed in Claim 4 wherein said plastics moulding comprises two parallel rows of keypads with the keypads of each row spaced apart from each other and in parallel to the cantilever support means.

6. A keyboard as claimed in Claim 5 wherein the two key rows are disposed at different elevations.

7. A keyboard as claimed in Claim 5 or Claim 6 wherein the cantilever stalks of all the keys in the two rows are in the same essentially horizontal plane.

8. A keyboard as claimed in any one of Claims 5 to 7 wherein said keys in the two rows comprise alpha-numeric keys.

9. A keyboard as claimed in any one of Claims 5 to 8 wherein a space bar key is provided in spaced apart parallel relationship with respect to the keypad rows and the cantilever support means.

10. A keyboard as claimed in Claim 9 wherein said space bar key comprises a space bar pad which is cantilevered to said support means by one or more resilient plastics cantilever stalks originating at said means.

11. A keyboard as claimed in Claim 10 wherein said key row cantilevers occupy a first plane and said space bar key cantilevers occupy a second plane parallel thereto and to the horizontal.

12. A keyboard as claimed in any preceding claim and comprising a first plastics moulding representing one portion of a complete keyboard layout and a second plastics moulding representing a remaining portion of approximately equal size in terms of keypad content, the mouldings each comprising two spaced apart parallel rows of keypads each carried at the extremity of an elongate, resilient plastics moulded cantilever stalk originating at a moulding cantilever support means with the cantilever stalks parallel one to another, separate such support means being provided one forming part of each moulding and the stalks common to one respective moulding occupying a common horizontal plane spaced from and parallel to that for the stalks common to the other moulding, the first moulding including a space bar key cantiievered to the first moulding support means and having its keypad separate from the key rows of said first moulding, and the second moulding support means being seated upon and secured to the first.

13. A keyboard as claimed in any preceding claim wherein the key pad of each key of each key set includes a member for actuating contact with a switch of a membrane switch pad.

14. A keyboard substantially as hereinbefore described with reference to, and as illustrated in, the accompanying drawings.

1 5. A plastics moulded key set comprising a plurality of keypads each carried by an elongate resilient cantilever key stalk originating from a cantilever support member.

16. A key set as claimed in Claim 1 5 and comprising the keypads in at least two parallel rows spaced differentially from and parallel to the support member and with the keypads of each staggered with respect to those of the other, the key stalks extending in parallel in not more than one horizontal plane for each row of keypads and each alpha-numeric key stalk being such as to exhibit identical tactile response at least to all other alpha-numeric key stalks.

1 7. A key set substantially as hereinbefore described as either an upper or lower keyboard moulding with reference to, and as illustrated in, the accompanying drawings.

18. A key assembly comprising a key support and one or more keys each of which comprises a resilient stalk cantilevered from said support and displaceable by depression of a terminal keypad only by deformation of the stalk against stalk resilience.

19. A key assembly as claimed in Claim 18 in the form of a plastics or metallic material pressing or moulding of the support and stalk(s).

20. A key assembly as claimed in Claim 18 which has the structure of any of the plastics mouldings referred to hereinbefore and has its stalk(s) and support made either of a plastics material or a metallic material.

21. A key assembly as claimed in Claim 18 or 1 9 wherein the keys are sufficient in number to make up at least one row of a QWERTY-type keyboard and are so arranged.

22. A OWERTY-type keyboard comprising a plurality of key assemblies as claimed in any one of Claims 18 to 21.

23. A key assembly for a keyboard wherein support for one or more keypads is provided by one or more elongate stalks resiliently cantilevered from a stalk support member, the assembly being such that depression of a keypad when supported at an extremity of such a stalk remote from its origin at the stalk support member displaces the stalk downwardly against its resilience.

24. A key assembly as claimed in Claim 23 wherein the elongate stalks have a length of from 40 to 100 mm so that the keys on depression offer a tactile response which simulates vertical linear movement.

25. A key assembly as claimed in Claim 23 or Claim 24 wherein the elongate stalks have a length of from 50 to 90 mm.

26. A key assembly as claimed in any one of Claims 23 to 25 wherein the elongate stalks have a length of from 50 to 80 mm (e.g. about 75 mm).

27. A key assembly as claimed in any one of Claims 23 to 25 wherein the elongate stalks have alength of55 to 60 mm.

28. A key assembly as claimed in any one of Claims 23 to 27 and comprising a plurality of keypads arranged in one or more rows, each keypad terminating a respective cantilevered enlongate stalk.

29. A key assembly as claimed in Claim 28 and comprising a plurality of keypads arranged in two spaced apart parallel rows and each terminating a respective elongate stalk equal in length to the other such stalks, said stalks being disposed adjacent and parallel each one to another and arranged with stalks for a first of said two keypads rows alternating with those for a second such row.

30. A key assembly as claimed in Claim 29 and in the form of a first keyboard portion, a second such portion being disposed in relation to the first so that: (i) a complete set of alphanumeric keys is provided, (ii) the keys occupy four spaced apart parallel rows, (iii) the keys of a third and fourth row are provided by the second keyboard portion and are forward of the first and second rows, (iv) the stalks for each keypad of each row are of equal length and displacement resistance, (v) the stalks of the first and second rows occupy an upper plane and those of the third and fourth rows occupy a lower parallel plane, and (vi) the stalks of the upper plane overly stalk-tostalk spaces in the lower plane.

31. A key assembly as claimed in Claim 30 wherein the origins of the stalks in any one row are rearward of at least the keypad row immediately to the rear of said one row (preferably at least the two immediately rearward rows).

32. A key assembly as claimed in Claim 30 or Claim 31 wherein the origins of all the stalks are rearward of a hands-on area of the assembly.

33. A key assembly as claimed in Claim 30 or Claim 31 wherein a membrane switch pad is provided beneath keypads each of which includes a portion for actuating a switch thereof upon depression against stalk resilience and wherein the origins of all the key stalks are to the rear of all of said actuating portions of said keypads.

34. A key assembly as claimed in any one of Claims 23 to 33 wherein a plurality of keypads are arranged in two or more parallel spaced apart rows, the elongate stalks are essentially horizontal and each row of keypads is disposed at a different elevation to the or each other row.

35. A key assembly as claimed in any one of Claims 23 to 34 wherein a plurality of keypads are arranged in two or more parallel spaced apart rows and wherein the length of each elongate stalk is substantially the back-to-front dimensions of the hands-on area of the assembly.

36. A key assembly as claimed in any one of Claims 23 to 35 which comprises a plastics moulding as referred to in any one of Claims 2 to 13.

37. A QWERTY keyboard whose keys form an assembly as claimed in any one of Claims 23 to 26.