Field of the Invention

[1] The present invention relates to sequential linear shifter for H-pattern gearbox retrofit. Background

[2] Linear gear change sequence shifting is preferred for racing applications. However, many vehicles comprise conventional H-pattern gearboxes, thereby requiring H-pattern gear shifting not being ideal for such racing applications.

[3] As opposed to replacing the entire gearbox with expensive customised linear shifting gearboxes, including problems associated with customising such linear shifting gearboxes for differing vehicle types, a need exists for a compact and reliable mechanical interface providing a linear shifting to H-pattern retrofittable interface.

Summary of the Disclosure

[4] There is provided herein a sequential linear shifter which retrofits to an H-pattern gearbox to offer linear gear change shifting ability, particularly suited for racing application wherein, for gear changing, the linear gear change shifting allows the driver to push/pull a gear lever so as to change up and/or down in gear sequence.

[5] The present sequential linear shifter allows for retrofit to vehicles comprising H-pattern-type gearboxes and comprises a mechanically compact and reliable construction utilising an incrementally rotating positive drive cam comprising appropriately configured X and Y vector component cam tracks on opposing surfaces which act on adjacent sliders such that, shifting of the gear lever causes the positive drive cam to incrementally rotate in either direction and wherein the cam tracks act on the sliders to convert the linear motion into an H pattern.

[6] As such, with the foregoing in mind, there is provided a sequential linear shifter for H-pattern gearbox retrofit, the shifter comprising: a linearly shifting gear lever; a dive cam rotatably coupled to the gear lever such that shifting the gear lever in a first direction causes the dive cam to rotate an incremental amount in a first direction and shifting the gear lever in a second opposite direction causes the dive cam to rotate the incremental amount in a second opposite direction and wherein the drive cam defines an upper cam track acting on a top slider, the top slider acting on an upper point of a selector shaft, and the drive cam defines a lower cam track acting on a bottom slider, the bottom slider acting on an lower point of the selector shaft such that a distal end of the selector shaft traces an H-pattern as the cam rotates through the incremental amounts. [7] The top slider may be orientated orthogonally with respect to the bottom slider such that the cam tracks each respectively define X,Y vector components of the H-pattern.

[8] The top cam track may be spiralled such that the positional offset of the top slider may be substantially proportional to the rotational offset of the cam.

[9] The sequential linear shifter may further comprise a top slider mount housing configured for slidably engaging the top slider therein.

[10] The top slider defines a downwards orientated cam follower for engagement within the top cam track.

[11] The bottom slider may comprise an upwards orientated cam follower for engaging within the bottom cam track.

[12] The sequential linear shifter may further comprise a support cartridge between the cam and the bottom slider and wherein the upwards orientated cam follower may be configured for extending through and elongate aperture of the support cartridge to engage the bottom cam track.

[13] The sequential linear shifter may further comprise an outer casing configured for fastening to the support cartridge to how may be the cam therein.

[14] The sequential linear shifter may further comprise a ratchet mechanism operably interfacing the shift lever and the cam.

[15] The ratchet mechanism may comprise a pinion fastened to the shift lever, and wherein a distal end of the pinion may be configured to act on a rack and slider mechanism causing a geared ratchet arm to rotate accordingly and wherein a distal end of the geared ratchet arm may comprise pawls for selectively engaging indentations of an inner face of the cam.

[16] The sequential linear shifter may further comprise a lower shift lever adjustment configured to adjust the orientation of the shift lever with respect to the pinion.

[17] The sequential linear shifter may further comprise shift lever return springs configured to bias the shift lever to a neutral position.

[18] The sequential linear shifter may further comprise a gear knob fastened to the gearlever by way of a gear knob adjuster configured to adjust the orientation of the gear knob with respect to the shift lever.

[19] The bottom slider seats the selector shaft.

[20] The sequential linear shifter may further comprise a spherical bearing for seating the selector shaft.

[21] Other aspects of the invention are also disclosed. Brief Description of the Drawings

[22] Notwithstanding any other forms which may fall within the scope of the present invention, a preferred embodiment / preferred embodiments of the disclosure will now be described, by way of example only, with reference to the accompanying drawings in which:

[23] Figure 1 shows a sequential linear shifter for H-pattern gearbox retrofit in accordance with an embodiment of the present disclosure;

[24] Figure 2 shows a bottom perspective view of a lower region of the shifter in accordance with an embodiment of the present disclosure;

[25] Figure 3 shows a top perspective view of the lower region of the shifter in accordance with an embodiment of the present disclosure;

[26] Figure 4 shows a top perspective view of lower componentry of a linear shifter in accordance with a further embodiment of the present disclosure;

[27] Figure 5 shows a top perspective view of upper componentry of a linear shifter in accordance with the further embodiment of the present disclosure;

[28] Figure 6 shows a top perspective view of remote shift kit componentry for remote separation of upper and lower componentry of a linear shifter in accordance with an embodiment;

[29] Figure 7 shows exemplary cam tracks in accordance with an embodiment.

Description of Embodiments

[30] For the purposes of promoting an understanding of the principles in accordance with the disclosure, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the disclosure is thereby intended. Any alterations and further modifications of the inventive features illustrated herein, and any additional applications of the principles of the disclosure as illustrated herein, which would normally occur to one skilled in the relevant art and having possession of this disclosure, are to be considered within the scope of the disclosure.

[31] Before the structures, systems and associated methods relating to the sequential linear shifter for H-pattern gearbox retrofit are disclosed and described, it is to be understood that this disclosure is not limited to the particular configurations, process steps, and materials disclosed herein as such may vary somewhat. It is also to be understood that the terminology employed herein is used for the purpose of describing particular embodiments only and is not intended to be limiting since the scope of the disclosure will be limited only by the claims and equivalents thereof.

[32] In describing and claiming the subject matter of the disclosure, the following terminology will be used in accordance with the definitions set out below. [33] It must be noted that, as used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

[34] As used herein, the terms "comprising," "including," "containing," "characterised by," and grammatical equivalents thereof are inclusive or open-ended terms that do not exclude additional, unrecited elements or method steps.

[35] It should be noted in the following description that like or the same reference numerals in different embodiments denote the same or similar features.

[36] Turning now to figure 1, there is shown a sequential linear shifter 44 for H-pattern gearbox retrofit. The linear shifter 44 is configured for retro fit to existing H-pattern gearboxes wherein the H- pattern gearlever is replaced with the linear shifter 44. In such a manner, gears may be rather changed in a sequential linear manner having particular application for racing vehicles.

[37] The shifter 44 comprises a gear knob 1 for grasping by the operator. The gear knob 1 is fastened to a shift lever 3. In embodiments, a gear knob adjuster 2 may be employed to adjust the angle of the gear knob 1 with respect to the shift lever 3. The shift lever 3 is pivotally mounted so as to allow for linear shifting in the manner described herein. In the embodiment shown, the shift lever 3 is pivotally mounted by way of gearlever pedestal 4 and shift lever adjustments 5, 6 which engage a shift lever pinion 7.

[38] The shifter 44 may comprise shift lever return springs 8, 9 to bias the shift lever 3 in an upright position. In this manner, once the shift lever 3 has been shifted, either forward or backwards, the shift lever return springs 8, 9 return the shift lever 3 to a substantially upright or neutral position.

[39] A distal end of the pinion 7 extends through a cutout of a pedestal mounting plate 10 and acts on a rack and slider 11. The rack and slider 11 is mounted between opposing rack slider bushes 12 so as to be able to transition linearly therebetween as the pinion 7 rotates.

[40] The rack and slider 11 is housed by a rack cover plate 13 and outer casing 14 to act on a gear ratchet arm 15. The gear ratchet arm comprises a ratchet spring and pawls 16 which selectively engage indentations of an inner face of a drive cam 21.

[41] The pedestal mounting plate 10 is bolted to the rim of the outer casing 14. As can be seen, the outer casing 14 comprises multiple bolt holes such that the pedestal mounting plate 10 can be bolted to the outer casing 14 at differing rotational offsets. In this manner, the operational angle of the shift lever 3 may be configured in accordance with left and right-hand drive configurations, user preference and the like. In embodiments, the outer case 14 has sufficient boltholes such that the pedestal mounting plate 12 may be mounted in up to 12 separate rotational offsets with respect to the outer casing 14. [42] As can be appreciated, the shifting of the shift lever 3 forwards and backwards causes the pinion 7 to rotate which transitions the rack and slider 11 laterally causing the gear ratchet arm 5 to rotate accordingly. The ratchet spring and pawls 16 selectively engage the indentations of the inner face of the drive cam 21. In this manner, shifting the gear knob 1 in a first direction causes the drive cam 21 to rotate an incremental amount in a first direction and shifting the gear knob in a second opposite direction causes the drive cam 21 to rotate the incremental amount in a second opposite direction.

[43] The shifter 44 further comprises a support cartridge 23 beneath the drive cam 21.

[44] The shifter 44 further comprises a top slider 19 slidably held within a top slider mount housing 17 by way of a top slider bushes 18. The shifter 44 further comprises a corresponding bottom slider 26 slidable between bottom slider bushes 27.

[45] Now, as will be described in further detail with reference to figures 2 and 3 below, the drive cam 21 defines an upper cam track 31 acting on the top slider 19 and wherein the top slider 19 acts on an upper point of the selector shaft 24. Furthermore, the drive cam 21 defines a lower cam track 30 acting on the bottom slider 26, the bottom slider 26 acting on a lower point of the selector shaft 24 such that a distal end of the selector shaft traces an H-pattern as the cam 21 rotates through the incremental amounts.

[46] The selector shaft 24 may comprise top and bottom pivot balls 20, 25.

[47] As such, in use, the shift lever 3 rests in a neutral position. In order to change up a gear, the operator would shift the shift lever 3 rearwards causing the distal end of the selector shaft 24 to move into a first position of the H-pattern. The shift lever 3 would return to the neutral position.

[48] To further change up a gear, the operator would shift the shift lever 3 rearwards again causing the distal end of the selector shaft 24 to move to a second position of the H-pattern and so on and so forth.

[49] Thereafter, to change down a gear, the operator would push the shift lever 3 forwards causing the distal end of the selector shaft 24 to return to the previous position of the H-pattern and so on and so forth.

[50] As can also be seen from figure 1, the shifter 44 may comprise a bottom cover plate 28 and an adapter plate 29. The adapter plate 29 may be bolted to the existing H-pattern gearbox.

[51] In embodiments, the shifting direction of the shifter 44 may be reversed. Specifically, whereas the embodiment described above illustrated changing up of gears by pushing the shift lever 3 forwards, in embodiments the mechanism may be reversed such that pushing the shift lever 3 forwards results in changing down of gears. [52] For example, when the gear change rack slider 11 is on one side of the ratchet arm 15, linearly displacing the rack slider 11 in a first direction will cause the ratchet arm 15 to rotate in a first direction. However, were the rack slider 11 to be rotated through 180° so as to locate on an opposite side of the ratchet arm 15, then displacing the rack slider 11 in the first direction will cause the ratchet arm 15 to rotate in an opposite direction. As such, the selective placement of the rack slider 11 may be adjusted to control gear change direction.

[53] Furthermore, in embodiments, an upper portion of the shifter 3 may be remotely located away from a lower portion of the shifter 44 by way of an actuator cable, suited for out of reach gearboxes of preferential location of the gear leaver 3 as is substantially shown in figure 6.

[54] Turning now to figures 2 and 3, there is shown the lower portion of the shifter 44 in further detail so as to further illustrate the slider mechanisms.

[55] Specifically, figure 2 shows a bottom perspective view of the lower region of the shifter 44 and figure 2 shows a top perspective view of the lower region of the shifter 44.

[56] Now, figure 3 especially shows a top face of the cam 21 comprising a top cam track 31. As can also be seen, the top slider 19 defines a protrusion extending downwardly into the top cam track 31.

[57] As such, as the cam 21 rotates with respect to the top slider mount housing 17, the top slider 19 transitions in accordance with the engagement of the protrusion within the top cam track 31.

[58] In embodiment, the top cam track 31 is spiralled such that the offset of the top slider 19 is approximately proportional to the rotational offset of the cam 21.

[59] Turning now to figure 2, there is a specially shown a lower face of the cam 21 comprising a bottom cam track 30. As can be seen, in a similar manner, the bottom slider 26 defines an upwardly orientated protrusion which extends through an aperture of the support cartridge 23 so as to be engaged within the bottom cam track 30.

[60] As can also be seen, the bottom slider 26 seats a spherical bearing 22 of the selector shaft 24.

[61] As such, as the drive cam 21 rotates with respect to the support cartridge 23 and the bottom slider 26, the bottom slider 26 transitions in accordance with the engagement of the bottom slider protrusion within the bottom cam track 30. As can be seen, the bottom cam track 30 takes on a more complex configuration than that of the spiral upper cam track 31.

[62] In embodiments, the top slider 19 may be orientated orthogonally with respect to the bottom slider 26. In this manner, the sliders 19, 26 are able to each define the X, Y vector components of the H-pattern.

[63] In the exemplary embodiment provided herein, the top cam track 31, being substantially spiralled, may define the X vector component proportional to the rotational offset of the cam 21 so as to transition the distal end of the selector shaft 24 horizontally across the H-pattern. Furthermore, the bottom slider track 30 may provide the Y vector component so as to transition the distal end of the selector shaft 24 vertically across the H-pattern.

[64] Turning now to figures 4 - 6, there is shown a shifter 43 in accordance with second embodiment with slight variations as opposed to the shifter 44 shown in figures 1 - 3.

[65] In accordance with the second embodiment, the shifter 43 yet utilises the incremental rotation positive drive cam 21 except in that the top and bottom cam tracks 31, 30 are now on opposite sides of the cam 21.

[66] Furthermore, figure 7 shows exemplary cam tracks wherein, figure 7A shows the top cam track 31, figure 7B shows a side elevation cross-sectional view of the cam 21 and tracks and figure 7C shows the bottom cam track 30.

[67] Furthermore, figure 7 shows the corresponding rotation angle gear positions given as reverse, neutral and gears 1 - 7.

[68] Furthermore, the shifter 43 comprises a position sensing switch block 33 configured to read rotationally offset magnetic rotation encoders 45 on the periphery of the cam 21. In this way, as the cam 21 rotates to each rotational position, the magnetic rotation encoders 45 located adjacent the switch block 33 for reading. The switch block 33 may comprise hall effect transducers or the like so as to be able to detect the pattern of the adjacent rotation encoder magnets 45.

[69] As is also evident from figure 5, the ratchet and pawl springs 16 have a differing configuration wherein the springs comprise compression springs as opposed to torsion springs for pushing the pawls outwardly.

[70] Furthermore, the top slider mount housing 17 comprises detent springs and balls 43 for engaging with the interior rotation position demarcation indentations 46 of the cam 21.

[71] Furthermore, the top slider 19 and bottom slider 26 comprise separable cam followers 44, 46.

[72] Additionally, the shifter 43 may comprise a pivot tube 36 terminating in a clamp block 37 for interfacing with the respective H-pattern gearbox componentry. As is shown in ghost view, the pivot tube 36 is orthogonally offsetable for differing configurations when required.

[73] Furthermore, the shifter 43 may comprise a separate sledge plate 47 and closing the underside of the outer casing 14 as opposed to the profile defined thereby being integrally formed by the casing 14 as per the first embodiment 44.

[74] Figure 5 shows the upper componentry of the shifter 43 in accordance with this second embodiment.

[75] As can be seen, the former shift lever adjustments 5, 6 and pinion 7 are replaced with a shift lever pivot shaft 38 and adjacent bearings 39 which engage within shift lever side caps 47 which are fastened to the shift lever 3. As the shift lever pivot shaft 38 rotates within the pedestal 44, the shift lever pinion 37, extending partially within an inferior aperture of the pivot shaft 38 is manipulated from side to side.

[76] Furthermore, the shift lever return springs 38 take the form of compressive springs acting on the shift lever pinion 7 as opposed to the former torsion springs of the first embodiment 44.

[77] Turning now to figure 6, there is shown a remote shift kit 47 allowing for the remote separation of the upper and lower componentry of the shifter by way of a flexible push pull cable 42.

[78] Specifically, there is shown the shift lever pedestal 4 modified such that the shift lever pinion 7 acts on a proximal end of the push/pull cable 42. The underside of the pedestal 4 may be enclosed utilising cover plate 40. The distal end of the push/pull cable 42 enters a remote top 42 so as to act on the gearchange rack slide 11 enclosed therein.

Interpretation

Embodiments:

[79] Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment, but may. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments.

[80] Similarly it should be appreciated that in the above description of example embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the Detailed Description of Specific Embodiments are hereby expressly incorporated into this Detailed Description of Specific Embodiments, with each claim standing on its own as a separate embodiment of this invention.

[81] Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form different embodiments, as would be understood by those in the art. For example, in the following claims, any of the claimed embodiments can be used in any combination.

Different Instances of Objects

[82] As used herein, unless otherwise specified the use of the ordinal adjectives "first", "second", "third", etc., to describe a common object, merely indicate that different instances of like objects are being referred to, and are not intended to imply that the objects so described must be in a given sequence, either temporally, spatially, in ranking, or in any other manner.

Specific Details

[83] In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the invention may be practiced without these specific details. In other instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description. Terminology

[84] In describing the preferred embodiment of the invention illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. However, the invention is not intended to be limited to the specific terms so selected, and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar technical purpose. Terms such as "forward", "rearward", "radially", "peripherally", "upwardly", "downwardly", and the like are used as words of convenience to provide reference points and are not to be construed as limiting terms.

Comprising and Including

[85] In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word "comprise" or variations such as "comprises" or "comprising" are used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.

[86] Any one of the terms: including or which includes or that includes as used herein is also an open term that also means including at least the elements/features that follow the term, but not excluding others. Thus, including is synonymous with and means comprising.

Scope of Invention

[87] Thus, while there has been described what are believed to be the preferred embodiments of the invention, those skilled in the art will recognize that other and further modifications may be made thereto without departing from the spirit of the invention, and it is intended to claim all such changes and modifications as fall within the scope of the invention. For example, any formulas given above are merely representative of procedures that may be used. Functionality may be added or deleted from the block diagrams and operations may be interchanged among functional blocks. Steps may be added or deleted to methods described within the scope of the present invention.

[88] Although the invention has been described with reference to specific examples, it will be appreciated by those skilled in the art that the invention may be embodied in many other forms.