ARRANGEMENT FOR ADJUSTING THE INCLINATION OF A KEYBOARD

Abstract: The inclination adjusting arrangement (11) is applied to a keyboard having a base structure (13) in which a plurality of keys is mounted. The keybard is provided in its lower portion with fixed front support feet and rear support feet (18). The rear feet (18) can project by varying amounts from the bottom (16) of the base structure (13) in such a way that the angle of inclination of the plane of the keys is variable with respect to the desk top. For the purposes of adjusting the degree of projection, the rear feet (18) are pivoted and movable along their own axis by means of a slot (31) which co-operates with a fixed pivot pin (21) on the base structure (13). Each rear foot (18) comprises a positioning tooth (23) which is disposed opposite a support surface (22) and which is capable of selectively engaging with a seat of a series of seats (24, 26,27) of the base structure (13). Resilient means (28) which co-operate with the pin (21) hold the positioning tooth (23) engaged with one of the seats. The seats (24, 26 and 27) are disposed on a circular arc substantially coaxial with the fixed pin (21), in different angular positions for varying the distance of the support surfaces (22) from the plane of the keys. The resilient means comprises a resilient blade (28) which is bent and curved in such a way that its free end (33) engages the fixed pin (21).

Description: The present invention relates to an arrangement for adjusting the inclination of a keyboard having a base structure in which there is mounted a plurality of keys and which is provided in its lower portion with feet by means of which it can be supported on a support surface referred to herein as a desk top, and in which the feet can project by varying amounts from the bottom of the base structure in such a way that the angle of inclination of the plane of the keys is variable with respect to the desk top. In an arrangement for adjusting the inclination of a keyboard, of known type, the keyboard is provided with a pair of rear feet comprising two cams mounted eccentrically on a shaft in the base structure. A gear mechanism transmits the movement as between the shaft on the base structure and a control shaft having a knurled knob at one end. The user of the arrangement, by rotating the knurled knob in a clockwise or anticlockwise direction, by means of the control shaft and the gear mechanism, causes rotary movement of the shaft bearing the two cams and can thus vary the angle of inclination as between the plane of the keys and the support surface. That arrangement suffers from the disadvantage of being fairly expensive. The object of the present invention is to provide an arrangement for adjusting the inclination of a keyboard, which is simple, reliable, and aesthetically acceptable and which is at the same time easy and quick to use and which finally is inexpensive. Accordingly, the arrangement for adjusting the inclination of a keyboard, according to the invention, is characterised in the manner set out in claim 1. A preferred embodiment of the invention is set forth in the following description which is given by way of non-limiting example, with reference to the accompanying drawings in which: Figure 1 is a side view of a keyboard with the inclination adjusting arrangement according to the invention, in a first operating position, Figure 2 is a side view of the keyboard with the arrangement shown in Figure 1, in a second operating position, Figure 3 is a side view of the keyboard with the arrangement of Figure 1, in a third operating position, Figure 4 is a view of part of the bottom of the structure of the keyboard with the arrangement to the invention as shown in Figure 3, on an enlarged scale, Figure 5 is a side view in partial section of the keyboard with the arrangement as shown in Figure 1, on an enlarged scale, and Figure 6 is a partial section of details of the arrangement shown in Figure 5, in an operating position. Referring to Figure 1, the arrangement for adjusting the inclination of a keyboard is generally indicated by reference numeral 11 and is applied to a keyboard 12 having a base structure 13 of substantially parallelepipedic shape, in which a plurality of keys 14 is mounted. The base structure 13 comprises a bottom 16 provided with front fixed support legs or feet 17 and rear support legs or feet 18 which can project by variable distances from the bottom 16 in such a way that the angle of inclination of the plane of the keys 14 is variable selectively according to the preference of the operator, with respect to a support surface 19, as shown by way of non-limiting example in Figures 1, 2 and 3. The front support feet 17 and the rear support feet 18 can be in groups of two or more according to the dimensions of the keyboard 12. Since the invention relates only to the rear support feet 18 which are the same as each other and for the purposes of simplification of the description, only one of the rear support feet 18 will be described hereinafter, being referred to for the sake of simplicity as the foot 18. In particular, the inclination adjusting arrangement 11 (Figure 5 comprises the foot 18 which is pivoted and which moves axially with respect to a fixed pivot pin 21 of the base structure 13. The foot 18 is of substantially parallelepipedic shape and has a support surface 22 by means of which it is supported on the support surface 19, a positioning tooth 23 which is disposed at the opposite end to the support surface 22 and which is capable of selectively engaging a series of seats 24, 26 and 27 of the base structure 13, and a resilient blade 28 which is arranged always to be engaged with the fixed pin 21 to hold the positioning tooth 23 always in a condition of engagement with the selected seat 24, 26 or 27. The seats 24, 26 and 27 are disposed on a circular arc which is coaxial with the fixed pin 21 but they are at various angular positions in such a way as to permit the plane of the keys 14 (Figure 1) to be inclined with respect to the support surface 19. In Figure 5, the positioning tooth 23 is shown in solid lines in the position of engagement with the seat 24, it is shown in dash-­ dotted lines in the condition of engagement with the seat 26, corresponding to Figure 2, and it is shown in double-dotted-dashed lines in a condition of engagement with the seat 27, corresponding to Figure 3. The foot 18 (see Figure 5) which is of elongate shape comprises, in an intermediate portion thereof, a hook-shaped element 29 which defines a slot 31 and an inclined surface 32 which partially delimits the slot 31. The foot 18 is pivoted and moves axially with respect to the fixed pivot pin 21 by means of the slot 31, as will be described in greater detail hereinafter. The element 29 is disposed adjacent to the resilient blade 28 which in turn is adjacent to the positioning tooth 23. The resilient blade 28 is bent and curved in such a way that the free edge 33 thereof is always engaged with the fixed pivot pin 21. The foot 18 also comprises, on mutually oppositely disposed side surfaces thereof, two shoulders 36 (see Figure 4) and 37 which are disposed adjacent to the rigid element 29 (see Figure 5), two series of ribs (see Figure 4) and 39 which are disposed adjacent to and at the sides of the support surface 22, and a projecting edge 41 which is disposed on the continuation of the support surface 22. The foot 18 is of plastics material and is produced in one piece with the support surface 22 (see Figure 5), the positioning tooth 23, the resilient blade 28, the element 29, the shoulders 36 (Figure 4) and 37, the series of ribs 38 and 39 and the projecting edge 41. The bottom 16 of the keyboard 12 comprises a housing 42 for accommodating the part of the foot 18 opposite to the surface 22, and two fixed abutments 43 and 44 which are co-operable with the shoulders 36 and 37, as described hereinafter. The seats 24 (see Figure 5), 26 and 27 provided in the base structure 13. The seats 27 and 26 comprise an inclined surface 46 and 47 respectively for assisting with the movement of the positioning tooth 23 from a position of minimum inclination in which the tooth 23 is engaged with the seat 27, as shown in Figure 3, to a second inter­ mediate position in which the positioning tooth 23 is engaged with the tooth 26, as shown in Figure 2, to a third position of maximum inclination in which the positioning tooth 23 is engaged with the seat 24, as shown in Figure 1, as described hereinafter. The mode of operation of the inclination adjusting arrangement 11 is as follows: It will be assumed that the foot 18 is in the first position in which the positioning tooth 23 is engaged with the seat 27, corresponding to Figure 3, and the keyboard is set at the position of minimum inclination. Using a finger, the operator applies a force to the projecting edge 41 and causes the foot 18 to begin to rotate in an anticlockwise direction about the fixed pin 21. Due to the force of the resilient blade 28, the positioning tooth 23 engages and slides over the inclined surface 46 and the foot 18 rotates easily with a low manual pressure which loads the blade 28 until the positioning tooth 23 is aligned with the seat 26. At that point, the resilient blade 28, by virtue of the stress thereof, urges the tooth 23 upwardly and causes it to engage and holds it in an engaged condition with the seat 26. The foot 18 is now in its second position corresponding to that shown in Figure 2. If the angle of inclination of the plane of the keys 14 with respect to the support surface 19 is still not sufficient, the operator, still by means of the projecting edge 41, causes the foot 18 to rotate further in the anticlockwise direction about the fixed pin 21, again loading the blade 28. The positioning tooth 23 engages and slides over the inclined surface 47 while the foot 18 continues to rotate easily with a low manual pressure. When the positioning tooth 23 is in a position of alignment with the seat 24, the stress of the resilient blade 28 causes the tooth 23 to be urged upwardly and causes it to engage with the seat 24 and holds it in the engaged condition therein. The foot 18 will then be in the third position thereof, corresponding to the position shown in Figure 1. In that position, the shoulders 36 (Figure 4) and 37 engage and are blocked against the fixed abutments 43 and 44 which act as travel-limiting elements. If the operator should try accidentally to continue the rotary movement in the anticlockwise direction, such movement would be prevented insofar as the foot 18 is locked with the positioning tooth 23 housed in the seat 24 and with the shoulders 36 and 37 in a condition of abutting against the fixed abutments 43 and 44. That eliminates the possibility of parts of the arrangement being broken. Each of the three positions shown in Figures 1, 2 and 3 in stable insofar as the force of the resilient blade 28 is such as to hold the positioning tooth 23 always in a condition of engagement with the respective seat 27, 26 and 24. Any force applied to the keyboard 12 in a direction towards the surface 19 only causes the condition of engagement as between the tooth 23 and the seats 27, 26 and 24 to be maintained. If the operator is to move the foot 18 from the third position shown in Figure 1 to the second position shown in Figure 2 or from the second position to the first position shown in Figure 3, the user operates the arrangement in the following manner: Using two fingers, the operator grips the ribs 38 (see Figure 4) and 39 and then pulls the foot 18 along the axis thereof outwardly of the base structure 13, causing the slot 31 to slide on the fixed pin 21 against the force of the resilient blade 28. When the closed end of the slot 31 (see Figure 6) is in a position of being blocked against the fixed pin 21, the positioning tooth 23 is already disengaged from the seat 24 or the seat 26. The operator then rotates the foot 18 in a clockwise direction until the positioning tooth 23 is in alignment with the second seat 26 or with the first seat 27. As soon as the operator ceases to pull on the foot 18, the resilient blade 28 causes the positioning tooth 23 immediately to come into engagement with the second seat 26 or the first seat 27. As shown in Figure 5, the foot 18 is mounted to the base structure 13 in a very easy and simple fashion. Indeed, it is only necessary to position the foot 18 in a slightly inclined position against the bottom of the housing 42,with the slot 31 in line with the fixed pin 21. By applying a slight manual pressure to the outside edge of the positioning tooth 23, the foot 18 is moved towards the rearward part of the bottom 16 (towards the left in Figure 5), the element 29 bends slightly, permitting the fixed pin 21 to be received in the slot 31, and the free edge 33 of the resilient blade 28 engages the fixed pin 21 and causes the foot 18 to assume its first position, that is to say, the position shown in doubled-dotted-dash line as shown in Figure 3. It will be apparent therefore that the force of the resilient blade 28 holds the foot 18 in a stably engaged condition, with the positioning tooth 23 engaged with the respective seat 24, 26 and 27. In addition, a straightforward manual pressure is sufficient to overcome the force of the resilient blade 28 and to vary the angle of inclination of the plane of the keys 14. It will be appreciated that the inclination adjusting arrangement 11 as described hereinbefore may be the subject of various modifications and various addition of parts, without departing from the scope of the present invention. In particular, in place of the two series of ribs 38 and 39 on the foot 18, it is possible to provide two circular seats or recessed rings in the foot 18, for example to make it easier for the operator to grip the foot 18 manually. In addition the three seats 24, 26 and 27 are not limitative as described hereinbefore, and there may be a larger number thereof, thereby limiting the magnitude of the angular movement from one seat to another, thus providing a wider range of options in regard to varying the angles of inclination of the plane of the keys 14 with respect to the support surface 19.

Claims: 1. An arrangement for adjusting the inclination of a keyboard (12) having a base structure (13) in which a plurality of keys (14) is mounted and which is provided in its lower portion with adjustable support feet (18) which can project by variable amounts from the bottom of the base structure to vary the inclination of the plane of the keys with respect to a deck top, characterised in that the adjustable feet (18) are pivoted and movable with respect to a fixed pivot pin (21) of the base structure, each of the adjustable feet comprising a support surface (22), a positioning tooth (23) which is disposed opposite to the support surface and which is capable of selectively engaging a seat of a series of seats (24, 26, 27) of the base structure (13), which are disposed on a circular arc coaxial with the fixed pin and which are at different angular positions, and resilient means (28) for urging the positioning tooth to stay engaged with a seat of the series of seats, the distance of the support surfaces (22) of the feet (18) from the plane of the keys depending upon which seat of the series is engaged, so permitting variable angles of inclination of the plane of the keys with respect to the desk top. 2. An arrangement according to claim 1, characterised by a pin-­ slot assembly (21, 31) comprising an element (29) of the foot (18), which delimits the slot, and the fixed pin (21). 3. An arrangement according to claim 2, characterised in that the said element (29) projects from the foot (18) and the slot (31) houses the fixed pin (21) to permit the foot to pivot and to move axially with respect to the fixed pin, and in that the resilient means (28) comprise a resilient blade disposed adjacent to the said element and having a portion (33) adapted to stay always engaged with the fixed pin. 4. An arrangement according to any of the preceding claims, characterised in that each of the adjustable feet (18) is of a substantially parallelepipedic shape provided on a side thereof of smaller size with the support surface (22) and on the opposite side with the positioning tooth (23). 5. An arrangement according to claims 3 and 4, characterised in that each of the feet (18) comprises on a side of larger size both the element (29) having the slot (31) and the resilient blade (28) and in that this element and resilient blade are adjacent to the positioning tooth (23). 6. An arrangement according to claim 2, 3 or 5, characterised in that the said element (29) is of a hooked configuration and comprises an inclined surface (32) which delimits the slot (31), and in that the resilient blade (28) is bent and curved in such a way that the free end (33) always engages the fixed pin (21). 7. An arrangement according to any of claims 2, 3 5 and 6, characterised in that each of the feet (18) is provided on the mutually opposite side surfaces thereof with two shoulders (36, 37) which are disposed adjacent to the said element (29) and two series of ribs (39) which project from the respective sides and which are disposed adjacent to the support surface (22) and which facilitate axial displacement of the feet. 8. An arrangement according to any of the preceding claims, characterised in that the series of seats comprise three seats (27,, 26, 24) capable of being selectively engaged by the positioning tooth (23) to define three positions of inclination of the plane of the keys with respect to the desk top. 9. An arrangement according to claims 7 and 8, characterised in that the first and second seats (27, 26) corresponding to the position of minimum inclination and the position of intermediate inclination of the plane of the keys with respect to the desk top each have an inclined surface (46, 47) for assisting with positioning of the positioning tooth (23) from the first position corresponding to the first seat to the second position corresponding to the second seat and to the third position corresponding to the third seat and to the condition of maximum inclination of the plane of the keys with respect to the desk top, and in that the base structure (13) comprises two fixed abutments (43) co-operable with the two shoulders (36, 37) of the respective foot when the foot is in the third position to prevent possible breaking as between the parts of the arrangement if the foot were to be forced beyond the third position. 10. An arrangement according to any of the preceding claims, characterised in that the base structure (13) comprises a series of housings for accommodating respective feet (18) and in that each foot is adjustable and has a projecting edge (41) adjacent to the support surface (22), to permit gripping thereof to facilitate positioning of the foot in one of the three seats (24, 26, 27). 11. An arrangement according to claims 6 and 9, characterised in that, when the adjustable foot (18) is in the third position or in the second position, to be positioned in the second position or the first position, the adjustable foot must be gripped on the ribs (39), must be pulled axially outwardly of the base structure (13) against the force of the resilient blade (28) and must then be turned about the fixed pin (21) to position the positioning tooth (23) in the second seat (26) or in the first seat (27) and then finally released, whereupon the resilient blade causes the positioning tooth rapidly to engage with the second seat or with the first seat. 12. An arrangement according to claim 11, characterised in that each foot (18) of is plastics material in one piece with the support surface (22), the positioning tooth (23), the resilient blade (28), the element (29) having the slot (31), the two shoulders (36, 37), the two series of ribs (39) and the projecting edge (41). 13. An arrangement according to any of the preceding claims, chgaracterised in that the said circular arc is about an axis parallel to the transverse axis of the base structure (13) of the keyboard. 14. An arrangement according to any of the preceding claims characterised in that, for mounting the foot (18) to the base structure (13), the foot is disposed in a position of being slightly inclined against the bottom of the housing with the slot (31) aligned with the fixed pin (21), a pressing force is applied to the outside edge of the positioning tooth (23), urging the foot towards the rear part of the base structure so as slightly to bend the element (29) which defines the slot, permitting the fixed pin to be housed in the slot and permitting the free edge of the resilient blade (28) to engage the fixed pin, thereby to cause the foot to occupy its first position.

Inventors: FACCO, GASTONE
Applicants: ING. C. OLIVETTI & C., S.P.A.
Application year: 1986
Main classification: B41J5
IPC codes: B41J29, B41J5, G06F3, F16M11