CA1147168A - Transmission ratio selecting mechanism - Google Patents
Transmission ratio selecting mechanismInfo
- Publication number
- CA1147168A CA1147168A CA000356098A CA356098A CA1147168A CA 1147168 A CA1147168 A CA 1147168A CA 000356098 A CA000356098 A CA 000356098A CA 356098 A CA356098 A CA 356098A CA 1147168 A CA1147168 A CA 1147168A
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- CA
- Canada
- Prior art keywords
- ratio
- cam
- gear
- coupling
- selector
- Prior art date
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- Automobile Manufacture Line, Endless Track Vehicle, Trailer (AREA)
- Transmissions By Endless Flexible Members (AREA)
Abstract
ABSTRACT
A vehicle transmission with parallel input, output and idler shafts each provided with first and second gear wheels. The first gear wheels on the input and output shafts are in constant mesh and the first gear wheel on the idler shaft meshes with the input shaft first gear wheel alone, while the second gear wheels on the input and output shaft are in constant mesh and the second gear wheel on the idler shaft meshes with the output shaft second gear wheel alone. A synchromesh clutch unit selectively connects the input shaft first and second gear wheels with the input shaft and a non-synchromesh clutch unit selectively connects the output shaft first and second gear wheels with the output shaft to obtain a number of different output shaft ratios. The control means for the transmission is arranged to ensure that the non-synchromesh clutch unit is engaged before the synchromesh clutch unit on the selection of each output shaft ratio.
A vehicle transmission with parallel input, output and idler shafts each provided with first and second gear wheels. The first gear wheels on the input and output shafts are in constant mesh and the first gear wheel on the idler shaft meshes with the input shaft first gear wheel alone, while the second gear wheels on the input and output shaft are in constant mesh and the second gear wheel on the idler shaft meshes with the output shaft second gear wheel alone. A synchromesh clutch unit selectively connects the input shaft first and second gear wheels with the input shaft and a non-synchromesh clutch unit selectively connects the output shaft first and second gear wheels with the output shaft to obtain a number of different output shaft ratios. The control means for the transmission is arranged to ensure that the non-synchromesh clutch unit is engaged before the synchromesh clutch unit on the selection of each output shaft ratio.
Description
This invention relates to transmissions and in particular to transmission ratio selecting mechanisms.
In such fields as, for example, tractors and fork-lift trucks there is a requirement for transmissions which provide several ratios in the forward and reverse drive directions and a mutual forward/reverse shuttle facility.
Problems arise with ratio selecting mechanisms for use with transmissions of the type in which the selection of a given ratio involves the movement of more than one ratio coupling member (typically an axially movable sleeve or collar by a single ratio selector member (typically a gear selector lever).
An example of a transmission of the type referred to in the preceding paragraph is described and claimed in the Applicants recently allowed U.K. Patent No. 2055162 in which six gear wheels mounted on three shafts provide two forward and two reverse drive ratios. The constructional details of the six gear wheel transmission assembly of U.K. Patent No.
2055162 are described in the present application to provide a better understanding of the construction and operation o~
the selecting mechanism of the present invention.
It is an object of the present invention to provide an improved form of ratio selecting mechanism which is compact and which is suitable for use with transmission assemblies of, for example, tye type described and claimed in the Applicant's previously referred to U.K. Patent No. 2055162.
According to the present invention there is provided a transmission ratio selecting mechanism including a ratio selector means, first and second ratio coupling members . .
movable to couple associated gear wheels with first and second shafts respectively to select a number of ratios of an associated transmission, and linkage means for moving the ratio coupling members in response to movement of the ratio selector means, the linkage means including disconnecting means for disconnecting one of the ratio coupling members from the selector means during selection of at least one of the transmission ratios, the selecting mechanism being arranged so that for the selection of said at least one ratio both the gear coupling members are initially moved axially of their respective shafts in synchronism in the same direction by the selector means so that one coupling member couples one of the associated gear wheels with one of the shafts thus completing the first part of the selection of said at least one ratio, the disconnecting means is then operated, and selection of said at least one ratio is completed by further movement of only the other coupling member axially of its respective shaft in the opposite direction in response to further movement of the selector means to couple another of the associated gear wheels with the other shaft, the selector means being arranged to return the ratio coupling members to synchronism on movement of the selector means to select another ratio.
A selecting mechanism of the form described in the preceding paragraph is particularly suitable for use in selecting the ratios of the transmission assembly of the APplicants ~reviously referred to U.K. Patent.
The linkage means may include a member which is angularly movable in response to movements of the selector means with first and second cam members arranged to be moved by the angularly movable member to move said first and second ratio coupling members respectively, and the disconnecting means arranged to disconnect the angularly movable member from one L7~
of the cam members during selection of said at least one ratio.
Conveniently the disconnecting means includes a toggle linkage connected with the selector means for displacing the angularly movable member in a direction generally parallel to its axis of angular movement to disconnect drive from said one cam member.
The ~irst ratio engaging member may comprise a coupling sleeve forming part of a non-synchromesh clutch unit and the second ratio engaging member may comprise a coupling sleeve forming part of a synchromesh clutch unit of the type specified, the linkage means ensuring that the non-synchromesh coupling sleeve is brought into engagement first during the selection of each ratio of the associated transmission.
Reference throughout this specification to synchromesh units or clutch units of the type specified refer to units which include a coupling member (for example a sleeve) axially slidable relative to the shaft for coupling a gear.to said shaft, the coupling member being slidable from a non-engaged position in which said gear is not coupled to the shaft, through a synchronising position in which clutch members in the synchromesh unit are in frictional contact to synchronise the rotational speeds of said gear and shaft to a fully engaged position in which said gear is coupled to said shaft and axial movement of the coupling member is completed.
In a further form of the invention the linkage means includes a selecting mechanism having tw~ generally parallel shift rails one of each ratio coupling member, and a selector member connected with the ratio selector means, the ratio selector member having a formation engageable with _ .. _ .. _ _ _ . . . _ _ . ...
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co-operating formations associated with the two rails, the formation on the selector member being movable in directions generally parallel to the direction of extension of the rails to move said rails and also being movable during the selection of said at least one ratio in directions generally perpendicularly to said directions of extension in order to disconnect the formation on the selector means from its co-operating rail formation, thus connecting the associated ratio coupling member from the ratio selector means.
Where the selecting mechanism is used in the control of synchromesh clutch unit of the type specified using cam members as described above the cam member associated with the synchromesh sleeve preEerably has three zones, a first zone contacted by the follower during movement of the coupling member towards the synchronising position, a second zone contacted by the follower during synchronisation and a third zone contacted by the follower after synchronisation has taken place and as the coupling member is moved towards the fully engaged position, the first, second and third zones being shaped so that a tangent to the cam surface at the point of contact with the follower during synchronisation makes a smaller angle with the direction of movement of the cam member than tangents drawn to points of contact with the first and third zones of the cam surface, so that for a given selection force applied to the cam member a larger ratio engagement force is applied to the follower during synchonisation than when the follower is in contact with the first and third zones.
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The invention will no~ be described~ by way of exan)ple only~
with re~erence to the accornpanying drawings in ~hich:-Figure 1 is a vertical section through an agricul-tural tractor transrnission embodying the invention;
Figure 2 is a diagrammatic reprcsentation of part of an input gear set Z of the transmission part of which is not visible in Figure l;
Figure 3 shows the provision of an additional plane-tary gear to-double the number of ratios provided by the transmission.
Figure ~ shows the speed selection gate of the trans-mission;
Figure 5 shows the sequence of movement of the syn-chronising devices of a main change speed gear set X of the transmission;
Figure 6 shows the cam groove used to control the synchronising devices of the main change speed gear set X;
Figure 7 shows diagrammatically the manner in which the cam having the groove o~ Figure 6 is rotated;
Figure 8 shows in plan the manner in which the input set cam and auxiliary output set cam are sequenced relati~e to each other;
Figure 9 is a sectional view on the line A-A of Fi~ure 8;
~ Figure 10 shows the cam grooves which control the auxiliary output set Y and the non-synchromesh coupler of the input gear set Z
Figure 11 shows a side view in the direction of arrow B of Figure 8 of the upper half of the cam arrange-ment shows in Figure 8;
Figure 12 shows the range selection gate of the transmission;
Figure 13 shows the cam groove which controls the synchromesh coupler of the input gear set Z;
Figure 14 shows the sequence of movem~nts of the synchromesh coupler of thc input gear set;
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Figure 15 shows graphically the ground speeds obtainable (in Kilometres/hour) in each ratio o~ a typical transmission in accordance with the invention at selected engine speeds.
Figure 16 shows the sequence of movements oE the couplers of the auxiliary output gear set Y and the non-synchromesh coupler of the input gear set Z;
Figure 17 and 18 show in tabular form the ~ear wheels used to obtaion each transmission ratio;
Figure 19 shows part of the cam groove of Figure 13 on an enlarged scale;
Figure 20 is a simplified representation of the geometry of the cam follower and groove shown in Figure 19;
Figure 21 shows a vertical section through an alternative ratio selection arrangement for input gear set Z and main change speed gear set X, and Figure 22 shows schematically the plate-type cam member used in the arrangement of Figure 21.
The basic transmission construction is shown ;n Figure 1.
It comprises a main four speed chanye speed gear set ~, a two speed auxiliary output gear set Y, and a constant mesh input gear set Z capable of providing two forward speeds and two re~erse speeds. Input gear set Z is the subject of the Applicants previously referred to UK Patent No. 2055162.
The main change speed set X comprises four gears 10,11,12 and 13 which are splined onto a lay shaft 14 and four constant mesh gears 15,16,17 and 18 which are rotatably mounted on the two portions 19 and 20 of the transmission output shaft.
The gears 15 and 16 are associated with clutch means in the form of a first synchronising unit 21 while the gears 17 and 18 are associated with further clutch means in the form of a second synchronising unit 22.
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As will be appreciated, a first ratio is provided in the main change speed set X by sliding the sleeve 21a of the synchronising unit 21 to the left so that power is transmitted from the shaft 19 through gears 15 and 10 onto the lay shaft 14 and ~ack to portion 20 of the output shaft via the auxiliary output train Y. In a similar fashion a second ratio is obtained by sliding the sleeve 21a to the right thus transmitting power from the shaft portion 19 via gears 16 and 11 to the lay shaft 14 and hence to the output shaft poxtion 20 via the output set Y.
Similarly, two further ratios can be obtained by sliding the second sleeve 22aof the synchronising unit 22 to the left and right respectively.
The output gear set Y comprises a gear 23 slidable on splines 24 provided on the output shaft portion 20.
This gear 23 is engageable with a gear 25 which rotates with the lay shaft 14 to provide a low auxiliary output train ratio . By sliding the gear 23 on the splines 24 teeth 26 on the gear 23 can be meshed with co-operating teeth 27 on the gear 18 thus locking the gear 18 to the shaft portion 20 and providing a higher output train ratio via gears 13 and 18.
The input gear set Z comprises gears 28 and 29 which are rotatably mounted on an input shaft 30. These two gears are in constant mesh with gears 31 and 32 which are in turn rotatably mounted on the output shaft portion 19.
Mounted behind the gears 28, 29, 21 and 32 as viewed in Figure 1, are two idl.er gears 33 and 34 shown diagrammati-cally in Figure 2 which mesh with gears 32 and 28 respect-ively. The idler gears rotate with a common shaft 35.
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~7~68 ~3 Associ.ated with the gears 28 and 29 is a further clutch means in the form of a third synchronising unit 36 whose sleeve 36b can be used to couple either the gear 28 or the gear 29 to the inpu~ shaft 3~. The clutch means for coupling either the gear 31 or 32 to the output shaft 19 comprises a simple sliding collar 37 which is coupled with shaft 19 and engageable with teeth 31a and 32a provided on gears 31 and 32 respectively.
The input gear set Z can be arranged to provide a high forward ratio by moving the sleeve 36b to the left to couple the gear 28 to the input shaft 30 and also sliding the collar 37 to the left to contact the gear 31 with the shaft portion 19. A low forward ratio can be provided by engaging the sleeve 36b with the gear 29 and sliding the collar 37 to the right to couple the gear 32 with the shaft portion 19.
A first reverse ratio is obtained from the input set Z when the sleeve 36_ couples the gear 28 to the input shaft 30 and the collar 37 couples the gear 32 to the shaft portion 19. With the synchronising sleeve and the collar in these positions drive passes from the input shaft 30 via gear 28, gear 34, shaft 35, gear 33 and gear 32 to the shaft portion 19. A further reverse ratio is obtained by engaging the synchronising sleeve 36_ with the gear 29 and moving the collar 37 to couple the gear 31 w.ith the shaft portion 19. In this condition drive is transmitted from the input shaft 30 via gear 29, g~ar 32, gear 33, shaft 35, gear 34, gear 28 and gear 31 to the shaft portion 19.
Thus the input set Z, is capable of providiny two forward speec~and two reverse speeds which enable the whole transmission to provide, if required, sixteen forward speeds and sixteen reverse speeds.
~7~613 Since, as described below, the collar 37 is always arranged to couple either the gear 31 or 32 to the output shaft portion 19 before the synchronising sleeve 36b couples either the gear 28 or~29 to the input shaft 30, tke collar 37, when coupling the gear 31 or 32 to the shaft portion 19, only has to overcome the re~tively low rotational inertia of the ~ears of input train Z since the higher inertia ~tems~such as the shaft 30 and the associated clutch parts (not shown) are not at that time coupled by the synchronising device 36. This makes it possible to use a simple sliding collar 37 rather than another synchronisin~
unit thus making input set Z significantly cheaper and also more compact than if another synchronising unit was ~used in place of collar 37. In this later regard it will be noted that the maximum radial dimension of collar 37 is signifi-cantly less than that of sleeve 36b thus allowing shafts 30 and 19 to be appreciably closer together than if collar 37 were to be replaced by another synchronising unit. This allows the whole transmission to be of a more compact design.
If desired, the speed range can be further increased by the addition of a two speed planetary gear on the input end of the transmission as shown in Figure 3. The planetary gear includes a sun wheel 38 formed integrally on an input shaft extension 39, planet gears 40 mounted on a planet carrier 41, and an annulus gear 42 which is held fixed.
A slidable sleeve 43 can occupy the position shown in Figure 3 in which it couples the planet carrier 41 with the previously described input shaft 30 to provide a first planetary ratio or can be slid axially to engage teeth 44 formed on the input shaft extension 39 to d;rectly couple the input shaft extension to the shaft 30 thus locking out ~L3 47~613 the planetary gear to provide a second ratio.
It will be appreciated that mechanical coupling of the two speed planetary gear using the sleeve 43 can be re-placea by a hyd~aulically operated clutch arrange~ent.
The two speed planetary gear, whether mechanically or hydraulically coupled, can be used as an under-drive or overdrive as required.
As indicated above the transmission (without the use of the two speed planetary gear shown in Figure 3) provides sixteen forward speed and sixteen reverse speeds.
These forward speeds are groupèd into four ranges A, B, C and D as shown in Figure 15. Range A is a creeper range, ranges 3 and C are the field working ranges and range D is the road speed range. Figure 15 indicates the ground speeds obtainable (in Kilometer/hour) in each ratio of a typical transmission embodying the invention at selec-ted engine speeds and clearly illustrates the flexible nature of the trans~ission and the gooa spread of ground speeds.
The legend at the top right hand corner of Figure 15 indi-cates the selected engine speed p, q, r and s on the block marking, these speeds being 2400, 2040, 1730 and 1400 engine revolutions per ~inute respectively (2400 revs/min being the rated engine speed of the engine).
Selection of these ranges is under the control of a lever (not shown) which moves in a gate 66 shown in Figure 12. Each range A, B, C and ~ has four sub-ratios 1 to 4 selected by a second lever (not shown) which moves in a straight gate 49 of Figure 4.
Also, the gate 66 controls the selection of the four basic reverse ranges Rl, R2,~ R3 and R4 which again each have four sub-ratios 1 to 4 controlled by gate 49~
~7~68 Thus using the two gates 49 and 66 sixteen forward and reverse ratios can be selected.
The transmission also provides a "park" facllity which is selected on gate 49 and designated "P" and which locks the transmission up to function as a parkin~ brake.
All the ratios of the main change speed set X, the two speed auxiliary output set Y, and the constant mesh input set Z are selected by rotatable cams having cam tracks which are engaged by followers which in turn move J
gear selector forks to make the required gear changes.
The main change speed set X is controlled by the lever which moves down the straight yate 49 shown in Figure 9.
As can be seen between each ratio position a neutral con-dition is provided and the park facility designated "P"
is available in which the set X is locked-up by simul-taneously engaging the two synchronising devices 21 and 22.
The left and right hand portions of Figure 5 show schematically the shifting sequence of the two synchro-nising units 21 and 22 res~ectivelj~. Figure 5 indicates the synchronising units are arranged so that normally when one synchronising unit is operated to engage a gear the other synchronising unit is in its neutral condition N. The facility is provicled to simultaneously engage the first and fourth gear ratios provided by gears 15 and 18 in order to place the transmission.in its park condition P.
The schematic shift pattern shown in Figure 5 is in practice translated into a single cam groove 51'formed in the periphery of a rotatable cam member 50. For ease of reference the development of this cam member is shown in Figure 6 from which it will be readily apparent that the length EF of the groove 51 corresponds to the left hand portion of Figure 5 and the lenght GH of the groove 51 corresponds to the right hand portion of Figure 5.
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~ 7168 The two cam followers which operate in groove 51 thus share a common neutral portion GI of the groove.This arrange-ment in which two followers operate in the same groove 51 greatly simplifies the cam arrangement and z,aves a con-siderable am~unt of space inside the transmission housing by avoiding the need for two separate cams and their associated rotating means.
The cam 50 is shown diagrammatically in Figure 7 and is arranged to be rotated by a toothed sector 52 which engages teeth 53 formea on the cam. Thus pivoting of the toothed sector 52 as indicated by the arrow W in Figure 7 results in rotation of the cam 50 as indicated by the arrow K.
Figure 8 shows the cam operating mechanism used in the selection of the ratios in the auxiliary output set Y and the input set Z. The cam 50 is positioned behind this cam arrangement as viewed in Figure 8, the sector 52 being sec~-ed to a sleeve 54 which is rotated by a lever 55 coupled with the gear selection lever which moves in gate 49.
As can he seen from Figure 8 the lever 55, sleeve 54, sector 52 and cam 50 are carried by a detachable cover 120 which is located on the right hand side of the transmission housing in the position indicated by dotted circle 120 in Figure 1. ~his cover has support webs 121 and 122 which project through a circular aperture 123 in the housing and which support the cam 50 and cams 59 and 68 referred to below.
Turning now to the control of the auxiliary output set Y and the movement of the collar 37, this is under the control of cam tracks 56 and 57 cut in the periphery of a rotatable cam 59. These cams, whose developments are shown in Fiyure 10, are representations of the shift pat-tern for the auxiliary output set Y and the collar 37 as shown schematically in Figure 16. Thus the cam groove 56 '7 corresponds to the let hand portion of Figure 16 and the groove 57 c~rresponds to the right hand portion of Figure 16.
A cam follower shown at 60 in Figure 11 engages the groove 57 while a corresponding follower (not shown~ en-gages the groove 56. As these followers follow along their respective grooves the necessary axial sliding move- i ment of the associated selector forks to effect the move-ment of the geax 23 and the collar 37 occurs. As will be appreciated, since the throw required to change the operating ratio of the auxiliary output set Y is large this must be reflected in the sideways throw T of the cam groove 56 which is appreciably greater than that of groove 57.
As can be seen from Figures 10 and 11 by appropriate operation of the cam 59 four different speed ratios can be obtained using the two positions of the gear 23 and the two alternative positions of the collar 37.
The cam 57 is rotated by a geared sector 61 which en-gages a gear 62 formed on the cam 59 in a similar manner to `' the way in which the selector 52 engages the gear 53. The sector 61 is splined onto a shaft 63 at 6~ and the shaft 63 is rotated via an arm 65 connected with the gear lever (not shown) which moves in the gate 66 shown in Figure 12.
Shaft 63 is again carried by cover 120. Thus movement of the lever which moves in the gate 66 rotates the shaft 63 and hence rotates the cam 59 via sector 61 and gear 62.
Control of the synchronising unit 36 is effected by a cam groove 67 cut in a cam 68. The develop~ent' of this groove is shown in Figure 13 and is again simply the shift pattern for the synchronising unit 36 as shown schematically in Figure 14.
The cam groove 67 is engaged by the follower 6g shown in Figure 11. Rotation of the cam 68 is effected by a 6~3 geared sector 70 which is splined onto the shaft 63 at 64 and drives a gear 71 formed on the cam 68. As previously described, for forward drive ratios the synchronising sleeve 36b and collar 37 are either both moved to the left or to the right from their neutral positions. This requires syn-chronisation of the rotation of cams 59 and 68. This syn-chronisation is achieved by virtue of the fact that both gear sectors 61 and 70 are rotated from the same splined connection 64 on the shaft 63.
When the input train Z is operated to give a reverse drive ratio the synchronising sleeve 36b and collar 37 are moved one to the left and one to the right of their neutral positions in order to transmit drive to the idler gears 33 and 34.
In order that the synchronising sleeve 36b and collar 37 can occupy positions on opposite sides of their neutral position it is necessary to break the synchronisation of the rotation of cams 59 and 68. This is achieved by axially displacing the shaft 63 so that the splines 6~ disengage the gear sector 61 whilst remaining engaged with the sector 70. This sliding of the shaft 63 is achieved by either pulling or pushing on the cable 72 which operates the toggle linkage 73 secured to the end of the shaft 63.
Thus, for example, when reverse range Rl is selected on the gate 66 this is achieved in two states. Firstly if the lever is not already in the range A position it is moved to this position and in so doing rotates the two cams 59 and 68 in synchronism under the control of shaft 63 to the appro-priate position for range A. Next the lever is moved from the range A position to the reverse range Rl position. This movement firstly disp]aces the cable 72 which in turn moves the shaft 63 thus disengaging sector 61 and hence leaving the output set Y and collar 37 in the range ~ position and secondly rotates the cam 68 in the reverse direction to mo~e 16~
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tne synchronising sleeve~36b from the range A position to the range Rl position. '' As will be appreciated the transmission provides four manual forward/reverse shuttle changes between the A, Rl : B, R3 and C, R4 positions. ~ach of these shuttle changes involves the movement of only the synchronising coupling sleeve 36b to the right or left as the case may be.
Figure 17 and 18 show in tabular form the-gear wheels used in the transmission shown in the drawings to provide each of the transmission's thirty,two ratios. It has been found possible to arrange for several of the gear wheels used in the transmission to have the same number of teeth enabling either actual common gear wheels or at least common '-gear wheel hobbing machinery to be used to provide these gear wheels thus giving a significant economy in the manu-facture of the transmission by still further reducing the number of different gear wheels provided. In one example of the transmission described, gear wheel 11 has the same number of teeth as gear wheel 32, gear wheel 13 has the same number of teeth as gear wheel 28, gear wheel 16 has the same number of teeth as gear wheel 29, and gear ,wheel 18 has the same number of teeth as gear wheel 31.
As stated above ranges B and C are the two field working ranges while range D is the road speed range. Thus, for example, when a tractor is being operated in a field with a particular implement it is normally operating in either range B or range C and there is normally little requirement to switch between these two ranges although the op~rator will require the facllity to switch from which ever ~7~
of these ranges is being used to the road speed D range on, for example, his journey to and from the field. For this reason the range selection gate 66 shown in Figure 12 is laid-out with the road speed range D positioned between the two field working ranges B and C so that range D can be reached directly from either range B or range C. It will also be seen from a consideration of Figure 17 that changing.to range D from rangeB or range C requires only one change in the transmission coupling For example, changing to range C from range D only involves the sliding of coupling sleeve 36b and changing to range B from range D only involves.the sliding of gear 23. This compares favourably with changes between ranges B and C which in-volve sliding of both coupling sleeve 36_ and gear 23.
Thus, with the range D position between the range B and C
positions, changes between each of the adjacent ranges on the gate 66 only involves one change in the transmission coupling. -.
The profiles of carn grooves 56 and 57 are basicallystraight or large radius curved tracks jointed together smoothly by the use of appropriate radii 56a, 56b and 57a, 57b (see Figure 10). This simple pxofi].e is possible .
since the ratio changes controlled by these grooves are not synchronised.
However, the grooves 51 and 67 which control the synchronised changes are "wavy" in nature. Thus for example, referring to Figure 13 the groove 67 makes the change from portion 67a to 67b by way of radiused por-tions 67c, 67 , 67e and 67f on the left side of,the groove and complementary radiused portion 67g, 67h, 67i, and 67i on the other side of the groove.
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- Comparison of Figures 10 and 13, which are laid out on the same scale, indicates that after a given cam move-ment R o:f cam 68 a sideshift S away from neutral of the follower engaged in the groove 67 has occurred whéreas for the same movement R of cam 59 a larger si~eshift Sl is ob-tained. This ensures that the sleeve 37 is engaged with teeth 31a or 32a before the synchronising unit 36 couples - the gear 28 or 29 to the shaft 30.
In practice the sideshift S is arranged to take up the clearances in the synchronising unit and bring the syn-chronising clutch parts 36a into engagement while the side-shi~t Sl is sufficient to partially engage the sleeve 37 with either teeth 31~ or 32a. After synchronisation has taken place the groove 67 effects ~urther axial sliding of the synchronising coupling sleeve 36b thus coupling gear 28 or 29 to the shaft 30. During this further movement along groove 67 the sleeve 37 is moved to its full en-gaged position by groove 57 completing a total sideshift movement of S2 as shown in Figure 10.
The shape of groove 67 and the manner in which it effects movement of the associated follower and sleeve will now be discussed in more detail. Figure 19 shows part of the groove 67 of Fiyure 13 on an enlarged scale. Dotted circle 100 indicates the neutral position of the cam fol-lower which engages the groove 67 at contact point L. If a force F is now applied to the cam 68 this will cause the cam follower to move the distance S to the right as viewed in Figure 19, as a result of contact with the ~one P
of the side of the groove 67, to take up the clearances in the synchronising clutch parts into friction~l engage-ment in order to carry out their synchronising action.
Dotted circle 101 shows the pOsitioll of the follower when the synchronising clutch parts are actually carrying out the synchronising action and the follower is contacting the groove 67 at the point M on zone ~ of the cam.
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, 71~i !3 la As can be seen from Fi~ure 19 tangents 102 and 103 to the side of the groove 67 at contact points L and M
respectively are inclined at angles C~<~ and CX
respectively to the line of action of the force F applied to the cam from the selector lever. Typically anyle C~
will be ~5 degrees and angle ~ will be less than 20 degrees and typically 8 to 13 degrees (say 10 degreés).
The use of a small angle CY< during synchronisation ensures that the axial force FF actually applied to the follower ana hence to the associated selector fork is as large as possible so that the effort which must be applied to the gear selector lever in order to engage any synchromesh gear is maintained as low as possible~
The fact that tile force FF is larger for smaller angles ofc~
can be readily seen from the simplified two dimensional representations of the geometry of cam follower and groove as shown in Figure 19 in which the cam groove wall is represented by the straight line ~ at an angle C~ to the direction of application of the force F appliea to the cam.
If the cam follower initially contacts the wall (iine ~
at point 0 and the F force moves the cam through a small peripheral distance 00' so that the wall occupies the dotted line position ~ it will be seen that the point of contact of the follower with the groove wall will have moved axially to the position 0''.
Equating the work input and output of the cam and xoller system we have:-F x cam movement = FF x axial displacement of, cam follower F x 00' = FF x 00'' F = FF x 00'' oo F = FF tan c~
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Thus as o~ decreases so the value o~ FF increases fora given value of F.
After synchronisation has taken place the synchronising coupler is free to move axially and engage the desired gear ratio, circle 104 in Figure 19 showing the fully engaged position. This movement of the synchronising coupler is brought about by the contact of the zone N of the side of the groove 67 (corresponding to say portion 67d or Figure 13) with the groove follower. Since it is not nece-ssary to apply the same level of force to the synchronising coupler after synchronisation has occurred the curved zone N of the side of the groove is generally inclinea at a lar-ger angle. This larger inclination also means that a larger axial movement of the selector fork and associated coupler can be obtained for a given amount of rotation of the cam when the follower is operating on the zone N of the side of the groove.
Thus the shape of the zones P and N of the,,side of the groove 67 are chosen to give a lar~e axial movement of the cam follower for a given amount of rotation of the cam while the shape of zone Q adjacent the contact point M is chosen to provide the greatest axial force during actual syn-chronisation.
It will be appreciated that at the contact point L FFL = F/tan 45 = F/l Similarly at the contact point M
FFM = F/tan 10 = F/.1736 Thus the force generated at the follower is approxi-mately 5.7 times greater at contact point M. Since the force required durin~ synchronisation is approximately five times more than required at the neutral L position this results , .
7~~8 in a suhstantially constant load beiny required at the selector lever fox all selector lever positions.
Typically the mean force multiplication ratio of the selector mechanism (that is the ratio Force at the selector fork Force at the driverS hand ~is about 5 to 1 while this ratio ratio is about 2.3 to 1 at the neutral position and about 13 to 1 when synchronisation is occurring. The average mul-tiplication ratio of the cam on its whole travel is total cam displacement total selector fork displacement C/ g Typically this ratio is of the order of 2 to 1.
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The above described "wavy" cam shape is also employed in the other parts of cam 68 and on cam 50 which controls syn-chronising units 21 and 22.
Also, although in the construction described above, the cam tracks engaged by the various followers are provided by grooves cut into cam members it will be understood that the tracks could be provided by raised circumferentially extend-ing projections formed on the peripheral surfaces ofthe cams.
Additionally instead of each follower moving between opposed walls provided by a groove or raised projections, the fol-lower could be biased into engagement with a single circum-ferentially extendin~ wall.
Figure 21sh~ws an alternative form of ratio selection arrangement for input set Z and main change speed gear set X.
The input set Z is controlled by a selector member 130 which is pivotally supported at 131 on a rotatable sleeve 132 carried by a removable cover 133 which closes a trans-mission casing aperture similar to the aperture 123 referred to above. The lower end of member 130 is connected at 134 with a twin pronged selector member 135 which is splined a~
136 for ~47~6~3 axial sliding movement within sleeve 132.
The prongs 137 and 138 of selector member 135 engage recesses 139 and 140 in members 141 and 142 carried by selector rails 143 and 144 respectively. Rails 143 and 144 are connected with synchronising unit 36 and collar 37 res-pectively.
Selector membe.r 130 is connected with a selector lever 145 as shown diagrammatically at 146 in Figure 24, this l.ever being movable along an S - shaped gate showll dia-grammatically at 147.
Figure 21 shows the lever in a neutral position in whicll neither synchronising unit 36 no~ collar 37 is coupling any of the gears 28, 29, 31, 32 of input set Z to their associated shafts. In order to couple gears 29 ana 32 with shafts 30 and 19 the selector member 130 is rotated with the sleeve 132 and member 135 about axis 148 from the position shown in Figure 21 in a counter clockwise sense when viewed in the direction of arrow C by the movement of lever 1~5 to the position A/C of gate 147. This moves both selector ', rails 143 and 144 rearwardly thus coupling gears 29 and 32 to shafts 30 and 19. As indicated by the gate marking A/C
either range A or range C is engaged by this ~novement of lever 145 aepending on the position of gear 23 of set Y.
In this alternative selection arrangement the movement of gear 23 can be achieved by a convenient means, for example, this can be achieved electro ~ydraulically at the press of a button which operates a solenoid-operate valve con-trolling the supply of hydraulic fluid to a hydraulic actuator.
In order to ensure that collar 37 engages before syn-chronising unit 36 the clearances in the connecting link-age (not shown~ between prong 137 and the synchronising unit 36 are arranged to be greater than the clearances in ~ , .
~2 the connecting linkage (not shown) between prong 13~ and the collar 37.
In a similar fashion movement of lever 145 to the B/D
position rotates the selector member 135 in a clockwise sense about axis 148 thus coupling gears 28 and 31 to shafts 30 and 19 and engaging range B or D depending on the position of gear 23.
A reverse RA is obtained by pivotting lever 145 to the left from the B/D position to pivot member 130 in an anti-clockwise sense about pivot 131 and thus disengaging prong 138 from recess 140. This disconnects the rail 144 from the selector mechanism and allows the selection of reverse range RA to be completed by the movement of the lever 145 to the RA position of gate 147 which rotates member 135 in . a counter clockwise sense about axis 148 and moves sleeve 36b rearwardly to couple gear 29 to shaft 30.
A further reverse range RB is obtained by pivotting lever 145 to the right from the A/C position to pivot member 130 in a clockwise sense about pivot 131 and thus dis-engage prong 138 from recess 140 into recess 139 with prong 137. This disconnects the rail 144 from the selector mechanism and allo~s the selection of reverse range ~B to be completed by the movement of the lever 145 to the RB
position of gate 147 which rotates member 135 and a clock-wise sense about axis 148 and moves sleeve 36b forwardly to couple gear 28 to shaft 30.
As will be appreciated two reverse ranges are select-able with the gear lever in the RA position dependent on the position of gear 23 and similarly two reverse ranges are selectable with the gear lever in the RB position de-pendent on the position of gear 23.
The four speed main change speed gear set X is con-~ .
7~
~ 23 rolled by a rotary selector member 150 which is supportedby the cover 133 and is connected (as shown diagramma-tically at 151) with a further selector lever 152 which moves in a straight gate 153. Member 150 is connected by shaft 154 with a plate-type cam member 155 (in a manner not shown) so that rotation of member 150 rotates shaft 154 and thus cam 155 about an axis 156.
Cam member 155 is shown schematically in Figure 22 when viewed in the dixection of arrow C and includes a slot 157 for the passage of selector member 135 and two cam tracks 158 and 159 for the operation of synchronising units 22 and 21 respectively. Each cam track is engaged by a separate follower 160, ].61, only the follower 161 of cam track 158 being visible in Figure 21, and the centres of both followers 160, 161 are located and maintained on line 170 in Figure 22.
With the lever 152 in the position shown in Figure 21 both followers line in the neutral positions indicated by dotted circles 160 and 161 in Figure 21. Each follower is connected with the associated synchronising uni.t by an arm ,~
and shif$ rod as shown by arm 162 and rod 163 of follower 161.
As will be appreciated if the lever 152 is rotated rearwardly to the second speed position the cam member 155 is rotated counter clockwise as viewed in Figure 22 and the followers occupy the position 160' and 161' res-pectively this movin~ the sleeve 21a rearwardly to engage the second speed of the main change speed gear set X.
In a similar fashion if lever 152 is rotated forwardly from the neutral position shown in Figure 21 to the third speed position cam member 155 is rotated in a clockwise sense as viewed in Figure 22 and the followers occupy ~he positions 16~" and 161" in the cam tracks thus moving the 73~
sleeve 22a forwardly to engage the third speed of the gear set X.
As will be appreciated the first and fourth speeds of gear set X can be selected by movement of the lever 152 to the appxopriate positions of gate.153 and results in fol-lower positions 160''', 161''' and 160'''' and 161'''' respectively in Figure 22.
As indicated above Figure 22 shows the cam member 155 schematically and the two cam tracXs 158 ana 159 are not depicted as having the 'wavy' cam shape described above in detail with reference to Figure 19 and 20. It will be understood, however, that in practice the wavy cam shape will be used on cam tracks 158 and 159 to re-duce the lever effort required at synchronisation.
In such fields as, for example, tractors and fork-lift trucks there is a requirement for transmissions which provide several ratios in the forward and reverse drive directions and a mutual forward/reverse shuttle facility.
Problems arise with ratio selecting mechanisms for use with transmissions of the type in which the selection of a given ratio involves the movement of more than one ratio coupling member (typically an axially movable sleeve or collar by a single ratio selector member (typically a gear selector lever).
An example of a transmission of the type referred to in the preceding paragraph is described and claimed in the Applicants recently allowed U.K. Patent No. 2055162 in which six gear wheels mounted on three shafts provide two forward and two reverse drive ratios. The constructional details of the six gear wheel transmission assembly of U.K. Patent No.
2055162 are described in the present application to provide a better understanding of the construction and operation o~
the selecting mechanism of the present invention.
It is an object of the present invention to provide an improved form of ratio selecting mechanism which is compact and which is suitable for use with transmission assemblies of, for example, tye type described and claimed in the Applicant's previously referred to U.K. Patent No. 2055162.
According to the present invention there is provided a transmission ratio selecting mechanism including a ratio selector means, first and second ratio coupling members . .
movable to couple associated gear wheels with first and second shafts respectively to select a number of ratios of an associated transmission, and linkage means for moving the ratio coupling members in response to movement of the ratio selector means, the linkage means including disconnecting means for disconnecting one of the ratio coupling members from the selector means during selection of at least one of the transmission ratios, the selecting mechanism being arranged so that for the selection of said at least one ratio both the gear coupling members are initially moved axially of their respective shafts in synchronism in the same direction by the selector means so that one coupling member couples one of the associated gear wheels with one of the shafts thus completing the first part of the selection of said at least one ratio, the disconnecting means is then operated, and selection of said at least one ratio is completed by further movement of only the other coupling member axially of its respective shaft in the opposite direction in response to further movement of the selector means to couple another of the associated gear wheels with the other shaft, the selector means being arranged to return the ratio coupling members to synchronism on movement of the selector means to select another ratio.
A selecting mechanism of the form described in the preceding paragraph is particularly suitable for use in selecting the ratios of the transmission assembly of the APplicants ~reviously referred to U.K. Patent.
The linkage means may include a member which is angularly movable in response to movements of the selector means with first and second cam members arranged to be moved by the angularly movable member to move said first and second ratio coupling members respectively, and the disconnecting means arranged to disconnect the angularly movable member from one L7~
of the cam members during selection of said at least one ratio.
Conveniently the disconnecting means includes a toggle linkage connected with the selector means for displacing the angularly movable member in a direction generally parallel to its axis of angular movement to disconnect drive from said one cam member.
The ~irst ratio engaging member may comprise a coupling sleeve forming part of a non-synchromesh clutch unit and the second ratio engaging member may comprise a coupling sleeve forming part of a synchromesh clutch unit of the type specified, the linkage means ensuring that the non-synchromesh coupling sleeve is brought into engagement first during the selection of each ratio of the associated transmission.
Reference throughout this specification to synchromesh units or clutch units of the type specified refer to units which include a coupling member (for example a sleeve) axially slidable relative to the shaft for coupling a gear.to said shaft, the coupling member being slidable from a non-engaged position in which said gear is not coupled to the shaft, through a synchronising position in which clutch members in the synchromesh unit are in frictional contact to synchronise the rotational speeds of said gear and shaft to a fully engaged position in which said gear is coupled to said shaft and axial movement of the coupling member is completed.
In a further form of the invention the linkage means includes a selecting mechanism having tw~ generally parallel shift rails one of each ratio coupling member, and a selector member connected with the ratio selector means, the ratio selector member having a formation engageable with _ .. _ .. _ _ _ . . . _ _ . ...
~7~
co-operating formations associated with the two rails, the formation on the selector member being movable in directions generally parallel to the direction of extension of the rails to move said rails and also being movable during the selection of said at least one ratio in directions generally perpendicularly to said directions of extension in order to disconnect the formation on the selector means from its co-operating rail formation, thus connecting the associated ratio coupling member from the ratio selector means.
Where the selecting mechanism is used in the control of synchromesh clutch unit of the type specified using cam members as described above the cam member associated with the synchromesh sleeve preEerably has three zones, a first zone contacted by the follower during movement of the coupling member towards the synchronising position, a second zone contacted by the follower during synchronisation and a third zone contacted by the follower after synchronisation has taken place and as the coupling member is moved towards the fully engaged position, the first, second and third zones being shaped so that a tangent to the cam surface at the point of contact with the follower during synchronisation makes a smaller angle with the direction of movement of the cam member than tangents drawn to points of contact with the first and third zones of the cam surface, so that for a given selection force applied to the cam member a larger ratio engagement force is applied to the follower during synchonisation than when the follower is in contact with the first and third zones.
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The invention will no~ be described~ by way of exan)ple only~
with re~erence to the accornpanying drawings in ~hich:-Figure 1 is a vertical section through an agricul-tural tractor transrnission embodying the invention;
Figure 2 is a diagrammatic reprcsentation of part of an input gear set Z of the transmission part of which is not visible in Figure l;
Figure 3 shows the provision of an additional plane-tary gear to-double the number of ratios provided by the transmission.
Figure ~ shows the speed selection gate of the trans-mission;
Figure 5 shows the sequence of movement of the syn-chronising devices of a main change speed gear set X of the transmission;
Figure 6 shows the cam groove used to control the synchronising devices of the main change speed gear set X;
Figure 7 shows diagrammatically the manner in which the cam having the groove o~ Figure 6 is rotated;
Figure 8 shows in plan the manner in which the input set cam and auxiliary output set cam are sequenced relati~e to each other;
Figure 9 is a sectional view on the line A-A of Fi~ure 8;
~ Figure 10 shows the cam grooves which control the auxiliary output set Y and the non-synchromesh coupler of the input gear set Z
Figure 11 shows a side view in the direction of arrow B of Figure 8 of the upper half of the cam arrange-ment shows in Figure 8;
Figure 12 shows the range selection gate of the transmission;
Figure 13 shows the cam groove which controls the synchromesh coupler of the input gear set Z;
Figure 14 shows the sequence of movem~nts of the synchromesh coupler of thc input gear set;
.
Figure 15 shows graphically the ground speeds obtainable (in Kilometres/hour) in each ratio o~ a typical transmission in accordance with the invention at selected engine speeds.
Figure 16 shows the sequence of movements oE the couplers of the auxiliary output gear set Y and the non-synchromesh coupler of the input gear set Z;
Figure 17 and 18 show in tabular form the ~ear wheels used to obtaion each transmission ratio;
Figure 19 shows part of the cam groove of Figure 13 on an enlarged scale;
Figure 20 is a simplified representation of the geometry of the cam follower and groove shown in Figure 19;
Figure 21 shows a vertical section through an alternative ratio selection arrangement for input gear set Z and main change speed gear set X, and Figure 22 shows schematically the plate-type cam member used in the arrangement of Figure 21.
The basic transmission construction is shown ;n Figure 1.
It comprises a main four speed chanye speed gear set ~, a two speed auxiliary output gear set Y, and a constant mesh input gear set Z capable of providing two forward speeds and two re~erse speeds. Input gear set Z is the subject of the Applicants previously referred to UK Patent No. 2055162.
The main change speed set X comprises four gears 10,11,12 and 13 which are splined onto a lay shaft 14 and four constant mesh gears 15,16,17 and 18 which are rotatably mounted on the two portions 19 and 20 of the transmission output shaft.
The gears 15 and 16 are associated with clutch means in the form of a first synchronising unit 21 while the gears 17 and 18 are associated with further clutch means in the form of a second synchronising unit 22.
i8 .
As will be appreciated, a first ratio is provided in the main change speed set X by sliding the sleeve 21a of the synchronising unit 21 to the left so that power is transmitted from the shaft 19 through gears 15 and 10 onto the lay shaft 14 and ~ack to portion 20 of the output shaft via the auxiliary output train Y. In a similar fashion a second ratio is obtained by sliding the sleeve 21a to the right thus transmitting power from the shaft portion 19 via gears 16 and 11 to the lay shaft 14 and hence to the output shaft poxtion 20 via the output set Y.
Similarly, two further ratios can be obtained by sliding the second sleeve 22aof the synchronising unit 22 to the left and right respectively.
The output gear set Y comprises a gear 23 slidable on splines 24 provided on the output shaft portion 20.
This gear 23 is engageable with a gear 25 which rotates with the lay shaft 14 to provide a low auxiliary output train ratio . By sliding the gear 23 on the splines 24 teeth 26 on the gear 23 can be meshed with co-operating teeth 27 on the gear 18 thus locking the gear 18 to the shaft portion 20 and providing a higher output train ratio via gears 13 and 18.
The input gear set Z comprises gears 28 and 29 which are rotatably mounted on an input shaft 30. These two gears are in constant mesh with gears 31 and 32 which are in turn rotatably mounted on the output shaft portion 19.
Mounted behind the gears 28, 29, 21 and 32 as viewed in Figure 1, are two idl.er gears 33 and 34 shown diagrammati-cally in Figure 2 which mesh with gears 32 and 28 respect-ively. The idler gears rotate with a common shaft 35.
/
B
~7~68 ~3 Associ.ated with the gears 28 and 29 is a further clutch means in the form of a third synchronising unit 36 whose sleeve 36b can be used to couple either the gear 28 or the gear 29 to the inpu~ shaft 3~. The clutch means for coupling either the gear 31 or 32 to the output shaft 19 comprises a simple sliding collar 37 which is coupled with shaft 19 and engageable with teeth 31a and 32a provided on gears 31 and 32 respectively.
The input gear set Z can be arranged to provide a high forward ratio by moving the sleeve 36b to the left to couple the gear 28 to the input shaft 30 and also sliding the collar 37 to the left to contact the gear 31 with the shaft portion 19. A low forward ratio can be provided by engaging the sleeve 36b with the gear 29 and sliding the collar 37 to the right to couple the gear 32 with the shaft portion 19.
A first reverse ratio is obtained from the input set Z when the sleeve 36_ couples the gear 28 to the input shaft 30 and the collar 37 couples the gear 32 to the shaft portion 19. With the synchronising sleeve and the collar in these positions drive passes from the input shaft 30 via gear 28, gear 34, shaft 35, gear 33 and gear 32 to the shaft portion 19. A further reverse ratio is obtained by engaging the synchronising sleeve 36_ with the gear 29 and moving the collar 37 to couple the gear 31 w.ith the shaft portion 19. In this condition drive is transmitted from the input shaft 30 via gear 29, g~ar 32, gear 33, shaft 35, gear 34, gear 28 and gear 31 to the shaft portion 19.
Thus the input set Z, is capable of providiny two forward speec~and two reverse speeds which enable the whole transmission to provide, if required, sixteen forward speeds and sixteen reverse speeds.
~7~613 Since, as described below, the collar 37 is always arranged to couple either the gear 31 or 32 to the output shaft portion 19 before the synchronising sleeve 36b couples either the gear 28 or~29 to the input shaft 30, tke collar 37, when coupling the gear 31 or 32 to the shaft portion 19, only has to overcome the re~tively low rotational inertia of the ~ears of input train Z since the higher inertia ~tems~such as the shaft 30 and the associated clutch parts (not shown) are not at that time coupled by the synchronising device 36. This makes it possible to use a simple sliding collar 37 rather than another synchronisin~
unit thus making input set Z significantly cheaper and also more compact than if another synchronising unit was ~used in place of collar 37. In this later regard it will be noted that the maximum radial dimension of collar 37 is signifi-cantly less than that of sleeve 36b thus allowing shafts 30 and 19 to be appreciably closer together than if collar 37 were to be replaced by another synchronising unit. This allows the whole transmission to be of a more compact design.
If desired, the speed range can be further increased by the addition of a two speed planetary gear on the input end of the transmission as shown in Figure 3. The planetary gear includes a sun wheel 38 formed integrally on an input shaft extension 39, planet gears 40 mounted on a planet carrier 41, and an annulus gear 42 which is held fixed.
A slidable sleeve 43 can occupy the position shown in Figure 3 in which it couples the planet carrier 41 with the previously described input shaft 30 to provide a first planetary ratio or can be slid axially to engage teeth 44 formed on the input shaft extension 39 to d;rectly couple the input shaft extension to the shaft 30 thus locking out ~L3 47~613 the planetary gear to provide a second ratio.
It will be appreciated that mechanical coupling of the two speed planetary gear using the sleeve 43 can be re-placea by a hyd~aulically operated clutch arrange~ent.
The two speed planetary gear, whether mechanically or hydraulically coupled, can be used as an under-drive or overdrive as required.
As indicated above the transmission (without the use of the two speed planetary gear shown in Figure 3) provides sixteen forward speed and sixteen reverse speeds.
These forward speeds are groupèd into four ranges A, B, C and D as shown in Figure 15. Range A is a creeper range, ranges 3 and C are the field working ranges and range D is the road speed range. Figure 15 indicates the ground speeds obtainable (in Kilometer/hour) in each ratio of a typical transmission embodying the invention at selec-ted engine speeds and clearly illustrates the flexible nature of the trans~ission and the gooa spread of ground speeds.
The legend at the top right hand corner of Figure 15 indi-cates the selected engine speed p, q, r and s on the block marking, these speeds being 2400, 2040, 1730 and 1400 engine revolutions per ~inute respectively (2400 revs/min being the rated engine speed of the engine).
Selection of these ranges is under the control of a lever (not shown) which moves in a gate 66 shown in Figure 12. Each range A, B, C and ~ has four sub-ratios 1 to 4 selected by a second lever (not shown) which moves in a straight gate 49 of Figure 4.
Also, the gate 66 controls the selection of the four basic reverse ranges Rl, R2,~ R3 and R4 which again each have four sub-ratios 1 to 4 controlled by gate 49~
~7~68 Thus using the two gates 49 and 66 sixteen forward and reverse ratios can be selected.
The transmission also provides a "park" facllity which is selected on gate 49 and designated "P" and which locks the transmission up to function as a parkin~ brake.
All the ratios of the main change speed set X, the two speed auxiliary output set Y, and the constant mesh input set Z are selected by rotatable cams having cam tracks which are engaged by followers which in turn move J
gear selector forks to make the required gear changes.
The main change speed set X is controlled by the lever which moves down the straight yate 49 shown in Figure 9.
As can be seen between each ratio position a neutral con-dition is provided and the park facility designated "P"
is available in which the set X is locked-up by simul-taneously engaging the two synchronising devices 21 and 22.
The left and right hand portions of Figure 5 show schematically the shifting sequence of the two synchro-nising units 21 and 22 res~ectivelj~. Figure 5 indicates the synchronising units are arranged so that normally when one synchronising unit is operated to engage a gear the other synchronising unit is in its neutral condition N. The facility is provicled to simultaneously engage the first and fourth gear ratios provided by gears 15 and 18 in order to place the transmission.in its park condition P.
The schematic shift pattern shown in Figure 5 is in practice translated into a single cam groove 51'formed in the periphery of a rotatable cam member 50. For ease of reference the development of this cam member is shown in Figure 6 from which it will be readily apparent that the length EF of the groove 51 corresponds to the left hand portion of Figure 5 and the lenght GH of the groove 51 corresponds to the right hand portion of Figure 5.
:, ,.
~ 7168 The two cam followers which operate in groove 51 thus share a common neutral portion GI of the groove.This arrange-ment in which two followers operate in the same groove 51 greatly simplifies the cam arrangement and z,aves a con-siderable am~unt of space inside the transmission housing by avoiding the need for two separate cams and their associated rotating means.
The cam 50 is shown diagrammatically in Figure 7 and is arranged to be rotated by a toothed sector 52 which engages teeth 53 formea on the cam. Thus pivoting of the toothed sector 52 as indicated by the arrow W in Figure 7 results in rotation of the cam 50 as indicated by the arrow K.
Figure 8 shows the cam operating mechanism used in the selection of the ratios in the auxiliary output set Y and the input set Z. The cam 50 is positioned behind this cam arrangement as viewed in Figure 8, the sector 52 being sec~-ed to a sleeve 54 which is rotated by a lever 55 coupled with the gear selection lever which moves in gate 49.
As can he seen from Figure 8 the lever 55, sleeve 54, sector 52 and cam 50 are carried by a detachable cover 120 which is located on the right hand side of the transmission housing in the position indicated by dotted circle 120 in Figure 1. ~his cover has support webs 121 and 122 which project through a circular aperture 123 in the housing and which support the cam 50 and cams 59 and 68 referred to below.
Turning now to the control of the auxiliary output set Y and the movement of the collar 37, this is under the control of cam tracks 56 and 57 cut in the periphery of a rotatable cam 59. These cams, whose developments are shown in Fiyure 10, are representations of the shift pat-tern for the auxiliary output set Y and the collar 37 as shown schematically in Figure 16. Thus the cam groove 56 '7 corresponds to the let hand portion of Figure 16 and the groove 57 c~rresponds to the right hand portion of Figure 16.
A cam follower shown at 60 in Figure 11 engages the groove 57 while a corresponding follower (not shown~ en-gages the groove 56. As these followers follow along their respective grooves the necessary axial sliding move- i ment of the associated selector forks to effect the move-ment of the geax 23 and the collar 37 occurs. As will be appreciated, since the throw required to change the operating ratio of the auxiliary output set Y is large this must be reflected in the sideways throw T of the cam groove 56 which is appreciably greater than that of groove 57.
As can be seen from Figures 10 and 11 by appropriate operation of the cam 59 four different speed ratios can be obtained using the two positions of the gear 23 and the two alternative positions of the collar 37.
The cam 57 is rotated by a geared sector 61 which en-gages a gear 62 formed on the cam 59 in a similar manner to `' the way in which the selector 52 engages the gear 53. The sector 61 is splined onto a shaft 63 at 6~ and the shaft 63 is rotated via an arm 65 connected with the gear lever (not shown) which moves in the gate 66 shown in Figure 12.
Shaft 63 is again carried by cover 120. Thus movement of the lever which moves in the gate 66 rotates the shaft 63 and hence rotates the cam 59 via sector 61 and gear 62.
Control of the synchronising unit 36 is effected by a cam groove 67 cut in a cam 68. The develop~ent' of this groove is shown in Figure 13 and is again simply the shift pattern for the synchronising unit 36 as shown schematically in Figure 14.
The cam groove 67 is engaged by the follower 6g shown in Figure 11. Rotation of the cam 68 is effected by a 6~3 geared sector 70 which is splined onto the shaft 63 at 64 and drives a gear 71 formed on the cam 68. As previously described, for forward drive ratios the synchronising sleeve 36b and collar 37 are either both moved to the left or to the right from their neutral positions. This requires syn-chronisation of the rotation of cams 59 and 68. This syn-chronisation is achieved by virtue of the fact that both gear sectors 61 and 70 are rotated from the same splined connection 64 on the shaft 63.
When the input train Z is operated to give a reverse drive ratio the synchronising sleeve 36b and collar 37 are moved one to the left and one to the right of their neutral positions in order to transmit drive to the idler gears 33 and 34.
In order that the synchronising sleeve 36b and collar 37 can occupy positions on opposite sides of their neutral position it is necessary to break the synchronisation of the rotation of cams 59 and 68. This is achieved by axially displacing the shaft 63 so that the splines 6~ disengage the gear sector 61 whilst remaining engaged with the sector 70. This sliding of the shaft 63 is achieved by either pulling or pushing on the cable 72 which operates the toggle linkage 73 secured to the end of the shaft 63.
Thus, for example, when reverse range Rl is selected on the gate 66 this is achieved in two states. Firstly if the lever is not already in the range A position it is moved to this position and in so doing rotates the two cams 59 and 68 in synchronism under the control of shaft 63 to the appro-priate position for range A. Next the lever is moved from the range A position to the reverse range Rl position. This movement firstly disp]aces the cable 72 which in turn moves the shaft 63 thus disengaging sector 61 and hence leaving the output set Y and collar 37 in the range ~ position and secondly rotates the cam 68 in the reverse direction to mo~e 16~
,, '"'~
tne synchronising sleeve~36b from the range A position to the range Rl position. '' As will be appreciated the transmission provides four manual forward/reverse shuttle changes between the A, Rl : B, R3 and C, R4 positions. ~ach of these shuttle changes involves the movement of only the synchronising coupling sleeve 36b to the right or left as the case may be.
Figure 17 and 18 show in tabular form the-gear wheels used in the transmission shown in the drawings to provide each of the transmission's thirty,two ratios. It has been found possible to arrange for several of the gear wheels used in the transmission to have the same number of teeth enabling either actual common gear wheels or at least common '-gear wheel hobbing machinery to be used to provide these gear wheels thus giving a significant economy in the manu-facture of the transmission by still further reducing the number of different gear wheels provided. In one example of the transmission described, gear wheel 11 has the same number of teeth as gear wheel 32, gear wheel 13 has the same number of teeth as gear wheel 28, gear wheel 16 has the same number of teeth as gear wheel 29, and gear ,wheel 18 has the same number of teeth as gear wheel 31.
As stated above ranges B and C are the two field working ranges while range D is the road speed range. Thus, for example, when a tractor is being operated in a field with a particular implement it is normally operating in either range B or range C and there is normally little requirement to switch between these two ranges although the op~rator will require the facllity to switch from which ever ~7~
of these ranges is being used to the road speed D range on, for example, his journey to and from the field. For this reason the range selection gate 66 shown in Figure 12 is laid-out with the road speed range D positioned between the two field working ranges B and C so that range D can be reached directly from either range B or range C. It will also be seen from a consideration of Figure 17 that changing.to range D from rangeB or range C requires only one change in the transmission coupling For example, changing to range C from range D only involves the sliding of coupling sleeve 36b and changing to range B from range D only involves.the sliding of gear 23. This compares favourably with changes between ranges B and C which in-volve sliding of both coupling sleeve 36_ and gear 23.
Thus, with the range D position between the range B and C
positions, changes between each of the adjacent ranges on the gate 66 only involves one change in the transmission coupling. -.
The profiles of carn grooves 56 and 57 are basicallystraight or large radius curved tracks jointed together smoothly by the use of appropriate radii 56a, 56b and 57a, 57b (see Figure 10). This simple pxofi].e is possible .
since the ratio changes controlled by these grooves are not synchronised.
However, the grooves 51 and 67 which control the synchronised changes are "wavy" in nature. Thus for example, referring to Figure 13 the groove 67 makes the change from portion 67a to 67b by way of radiused por-tions 67c, 67 , 67e and 67f on the left side of,the groove and complementary radiused portion 67g, 67h, 67i, and 67i on the other side of the groove.
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7~t;i3 j 1~ .
- Comparison of Figures 10 and 13, which are laid out on the same scale, indicates that after a given cam move-ment R o:f cam 68 a sideshift S away from neutral of the follower engaged in the groove 67 has occurred whéreas for the same movement R of cam 59 a larger si~eshift Sl is ob-tained. This ensures that the sleeve 37 is engaged with teeth 31a or 32a before the synchronising unit 36 couples - the gear 28 or 29 to the shaft 30.
In practice the sideshift S is arranged to take up the clearances in the synchronising unit and bring the syn-chronising clutch parts 36a into engagement while the side-shi~t Sl is sufficient to partially engage the sleeve 37 with either teeth 31~ or 32a. After synchronisation has taken place the groove 67 effects ~urther axial sliding of the synchronising coupling sleeve 36b thus coupling gear 28 or 29 to the shaft 30. During this further movement along groove 67 the sleeve 37 is moved to its full en-gaged position by groove 57 completing a total sideshift movement of S2 as shown in Figure 10.
The shape of groove 67 and the manner in which it effects movement of the associated follower and sleeve will now be discussed in more detail. Figure 19 shows part of the groove 67 of Fiyure 13 on an enlarged scale. Dotted circle 100 indicates the neutral position of the cam fol-lower which engages the groove 67 at contact point L. If a force F is now applied to the cam 68 this will cause the cam follower to move the distance S to the right as viewed in Figure 19, as a result of contact with the ~one P
of the side of the groove 67, to take up the clearances in the synchronising clutch parts into friction~l engage-ment in order to carry out their synchronising action.
Dotted circle 101 shows the pOsitioll of the follower when the synchronising clutch parts are actually carrying out the synchronising action and the follower is contacting the groove 67 at the point M on zone ~ of the cam.
7,~"~
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, 71~i !3 la As can be seen from Fi~ure 19 tangents 102 and 103 to the side of the groove 67 at contact points L and M
respectively are inclined at angles C~<~ and CX
respectively to the line of action of the force F applied to the cam from the selector lever. Typically anyle C~
will be ~5 degrees and angle ~ will be less than 20 degrees and typically 8 to 13 degrees (say 10 degreés).
The use of a small angle CY< during synchronisation ensures that the axial force FF actually applied to the follower ana hence to the associated selector fork is as large as possible so that the effort which must be applied to the gear selector lever in order to engage any synchromesh gear is maintained as low as possible~
The fact that tile force FF is larger for smaller angles ofc~
can be readily seen from the simplified two dimensional representations of the geometry of cam follower and groove as shown in Figure 19 in which the cam groove wall is represented by the straight line ~ at an angle C~ to the direction of application of the force F appliea to the cam.
If the cam follower initially contacts the wall (iine ~
at point 0 and the F force moves the cam through a small peripheral distance 00' so that the wall occupies the dotted line position ~ it will be seen that the point of contact of the follower with the groove wall will have moved axially to the position 0''.
Equating the work input and output of the cam and xoller system we have:-F x cam movement = FF x axial displacement of, cam follower F x 00' = FF x 00'' F = FF x 00'' oo F = FF tan c~
~'b ~ .
7~
Thus as o~ decreases so the value o~ FF increases fora given value of F.
After synchronisation has taken place the synchronising coupler is free to move axially and engage the desired gear ratio, circle 104 in Figure 19 showing the fully engaged position. This movement of the synchronising coupler is brought about by the contact of the zone N of the side of the groove 67 (corresponding to say portion 67d or Figure 13) with the groove follower. Since it is not nece-ssary to apply the same level of force to the synchronising coupler after synchronisation has occurred the curved zone N of the side of the groove is generally inclinea at a lar-ger angle. This larger inclination also means that a larger axial movement of the selector fork and associated coupler can be obtained for a given amount of rotation of the cam when the follower is operating on the zone N of the side of the groove.
Thus the shape of the zones P and N of the,,side of the groove 67 are chosen to give a lar~e axial movement of the cam follower for a given amount of rotation of the cam while the shape of zone Q adjacent the contact point M is chosen to provide the greatest axial force during actual syn-chronisation.
It will be appreciated that at the contact point L FFL = F/tan 45 = F/l Similarly at the contact point M
FFM = F/tan 10 = F/.1736 Thus the force generated at the follower is approxi-mately 5.7 times greater at contact point M. Since the force required durin~ synchronisation is approximately five times more than required at the neutral L position this results , .
7~~8 in a suhstantially constant load beiny required at the selector lever fox all selector lever positions.
Typically the mean force multiplication ratio of the selector mechanism (that is the ratio Force at the selector fork Force at the driverS hand ~is about 5 to 1 while this ratio ratio is about 2.3 to 1 at the neutral position and about 13 to 1 when synchronisation is occurring. The average mul-tiplication ratio of the cam on its whole travel is total cam displacement total selector fork displacement C/ g Typically this ratio is of the order of 2 to 1.
.
The above described "wavy" cam shape is also employed in the other parts of cam 68 and on cam 50 which controls syn-chronising units 21 and 22.
Also, although in the construction described above, the cam tracks engaged by the various followers are provided by grooves cut into cam members it will be understood that the tracks could be provided by raised circumferentially extend-ing projections formed on the peripheral surfaces ofthe cams.
Additionally instead of each follower moving between opposed walls provided by a groove or raised projections, the fol-lower could be biased into engagement with a single circum-ferentially extendin~ wall.
Figure 21sh~ws an alternative form of ratio selection arrangement for input set Z and main change speed gear set X.
The input set Z is controlled by a selector member 130 which is pivotally supported at 131 on a rotatable sleeve 132 carried by a removable cover 133 which closes a trans-mission casing aperture similar to the aperture 123 referred to above. The lower end of member 130 is connected at 134 with a twin pronged selector member 135 which is splined a~
136 for ~47~6~3 axial sliding movement within sleeve 132.
The prongs 137 and 138 of selector member 135 engage recesses 139 and 140 in members 141 and 142 carried by selector rails 143 and 144 respectively. Rails 143 and 144 are connected with synchronising unit 36 and collar 37 res-pectively.
Selector membe.r 130 is connected with a selector lever 145 as shown diagrammatically at 146 in Figure 24, this l.ever being movable along an S - shaped gate showll dia-grammatically at 147.
Figure 21 shows the lever in a neutral position in whicll neither synchronising unit 36 no~ collar 37 is coupling any of the gears 28, 29, 31, 32 of input set Z to their associated shafts. In order to couple gears 29 ana 32 with shafts 30 and 19 the selector member 130 is rotated with the sleeve 132 and member 135 about axis 148 from the position shown in Figure 21 in a counter clockwise sense when viewed in the direction of arrow C by the movement of lever 1~5 to the position A/C of gate 147. This moves both selector ', rails 143 and 144 rearwardly thus coupling gears 29 and 32 to shafts 30 and 19. As indicated by the gate marking A/C
either range A or range C is engaged by this ~novement of lever 145 aepending on the position of gear 23 of set Y.
In this alternative selection arrangement the movement of gear 23 can be achieved by a convenient means, for example, this can be achieved electro ~ydraulically at the press of a button which operates a solenoid-operate valve con-trolling the supply of hydraulic fluid to a hydraulic actuator.
In order to ensure that collar 37 engages before syn-chronising unit 36 the clearances in the connecting link-age (not shown~ between prong 137 and the synchronising unit 36 are arranged to be greater than the clearances in ~ , .
~2 the connecting linkage (not shown) between prong 13~ and the collar 37.
In a similar fashion movement of lever 145 to the B/D
position rotates the selector member 135 in a clockwise sense about axis 148 thus coupling gears 28 and 31 to shafts 30 and 19 and engaging range B or D depending on the position of gear 23.
A reverse RA is obtained by pivotting lever 145 to the left from the B/D position to pivot member 130 in an anti-clockwise sense about pivot 131 and thus disengaging prong 138 from recess 140. This disconnects the rail 144 from the selector mechanism and allows the selection of reverse range RA to be completed by the movement of the lever 145 to the RA position of gate 147 which rotates member 135 in . a counter clockwise sense about axis 148 and moves sleeve 36b rearwardly to couple gear 29 to shaft 30.
A further reverse range RB is obtained by pivotting lever 145 to the right from the A/C position to pivot member 130 in a clockwise sense about pivot 131 and thus dis-engage prong 138 from recess 140 into recess 139 with prong 137. This disconnects the rail 144 from the selector mechanism and allo~s the selection of reverse range ~B to be completed by the movement of the lever 145 to the RB
position of gate 147 which rotates member 135 and a clock-wise sense about axis 148 and moves sleeve 36b forwardly to couple gear 28 to shaft 30.
As will be appreciated two reverse ranges are select-able with the gear lever in the RA position dependent on the position of gear 23 and similarly two reverse ranges are selectable with the gear lever in the RB position de-pendent on the position of gear 23.
The four speed main change speed gear set X is con-~ .
7~
~ 23 rolled by a rotary selector member 150 which is supportedby the cover 133 and is connected (as shown diagramma-tically at 151) with a further selector lever 152 which moves in a straight gate 153. Member 150 is connected by shaft 154 with a plate-type cam member 155 (in a manner not shown) so that rotation of member 150 rotates shaft 154 and thus cam 155 about an axis 156.
Cam member 155 is shown schematically in Figure 22 when viewed in the dixection of arrow C and includes a slot 157 for the passage of selector member 135 and two cam tracks 158 and 159 for the operation of synchronising units 22 and 21 respectively. Each cam track is engaged by a separate follower 160, ].61, only the follower 161 of cam track 158 being visible in Figure 21, and the centres of both followers 160, 161 are located and maintained on line 170 in Figure 22.
With the lever 152 in the position shown in Figure 21 both followers line in the neutral positions indicated by dotted circles 160 and 161 in Figure 21. Each follower is connected with the associated synchronising uni.t by an arm ,~
and shif$ rod as shown by arm 162 and rod 163 of follower 161.
As will be appreciated if the lever 152 is rotated rearwardly to the second speed position the cam member 155 is rotated counter clockwise as viewed in Figure 22 and the followers occupy the position 160' and 161' res-pectively this movin~ the sleeve 21a rearwardly to engage the second speed of the main change speed gear set X.
In a similar fashion if lever 152 is rotated forwardly from the neutral position shown in Figure 21 to the third speed position cam member 155 is rotated in a clockwise sense as viewed in Figure 22 and the followers occupy ~he positions 16~" and 161" in the cam tracks thus moving the 73~
sleeve 22a forwardly to engage the third speed of the gear set X.
As will be appreciated the first and fourth speeds of gear set X can be selected by movement of the lever 152 to the appxopriate positions of gate.153 and results in fol-lower positions 160''', 161''' and 160'''' and 161'''' respectively in Figure 22.
As indicated above Figure 22 shows the cam member 155 schematically and the two cam tracXs 158 ana 159 are not depicted as having the 'wavy' cam shape described above in detail with reference to Figure 19 and 20. It will be understood, however, that in practice the wavy cam shape will be used on cam tracks 158 and 159 to re-duce the lever effort required at synchronisation.
Claims (11)
1. A transmission ratio selecting mechanism including a ratio selector means, first and second ratio coupling members movable to couple associated gear wheels with first and second shafts respectively to select a number of ratios of an associated transmission, and linkage means for moving the ratio coupling members in response to movement of the ratio selector means, the linkage means including disconnecting means for disconnecting one of the ratio coupling members from the selector means during selection of at least one of the transmission ratios, the selecting mechanism being arranged so that for the selection of said at least one ratio both the gear coupling members are initially moved axially of their respective shafts in synchronism in the same direction by the selector means so that one coupling member couples one of the associated gear wheels with one of the shafts thus completing the first part of the selection of said at least one ratio, the disconnecting means is then operated, and selection of said at least one ratio is completed by further movement of only the other coupling member axially of its respective shaft in the opposite direction in response to further movement of the selector means to couple another of the associated gear wheels with the other shaft, the selector means being arranged to return the ratio coupling member to synchronism on movement of the selector means to select another ratio.
2. A selecting mechanism according to claim 1 in which the linkage means includes a member which is angularly movable in response to movements of the selector means, first and second cam members are arranged to be moved by the angularly movable member to move said first and second ratio coupling members respectively, and the disconnecting means is arranged to disconnect drive from the angularly movable member to one of the cam members during selection of said at least one ratio.
3. A selecting mechanism according to claim 2 in which the disconnecting means is arranged to displace the angularly movable member in a direction generally parallel to its axis of angular movement to disconnect drive to said one cam member.
4. A selecting mechanism according to claim 3 in which the disconnecting means includes a toggle linkage connected with the selector means for displacing the angularly movable member.
5. A selecting mechanism according to claim 3 in which the angularly movable member comprises a shaft with a splined portion which engages first and second drive members for angularly displacing the first and second cam members respectively, the disconnecting means being arranged to axially displace the shaft to disengage one of the drive members from the splined portion.
6. A selecting mechanism according to claim 5 in which the drive members each comprise a toothed sector which engages the splined portion and gear teeth associated with each respective cam member.
7. A selecting mechanism according to claim 5 in which the cam members each comprise a cylindrical member with a cam formation formed around its periphery, each formation being engaged by a cam follower arranged to move the associated coupling member.
8. A selecting mechanism according to claim 1 in which the linkage means includes two generally parallel shift rails one for each ratio coupling member and a selector member connected with the ratio selector means, the ratio selector member having a formation engageable with co-operating formation associated with the two rails, the formation on the selector member being movable in directions generally parallel to directions of extension of the rails to move said rails and also being movable during the selection of said at least one ratio in directions generally perpendicularly to said directions of extension in order to disconnect the formation on the selector means from its co-operating rail formation thus connecting the associated ratio coupling member from the ratio selector means.
9. A selecting mechanism according to claim 1 in which the first ratio coupling member comprises a coupling sleeve forming part of a non-synchromesh clutch unit and the second ratio coupling member comprises a coupling sleeve forming part of a synchromesh clutch unit of the type specified, the linkage means ensuring that the non-synchromesh coupling sleeve is brought into engagement first during the selection of each ratio of the associated transmission.
10. A selecting mechanism according to claim 2 and claim 9 in which the first and second cam members are arranged to be rotated at the same speed when moving in synchronism and the phasing of said first and second cam members ensures engagement of th non-synchromesh coupling sleeve first.
11. A selecting mechanism according to claim 2 and claim 9 in which the cam member associated with the synchromesh sleeve has a cam formation for engagement by a follower connected with the synchromesh sleeve, the cam formation having three zones, a first zone contacted by the follower during movement of the coupling member towards the synchromeshing position, a second zone contacted by the follower during synchronisation and a third zone contacted by the follower after synchronisation has taken place and as the coupling member is moved towards the fully engaged position, the first, second and third zones being shaped so that a tangent to the cam surface at the point of contact with the follower during synchronisation makes a smaller angle with the direction of movement of the cam member than tangents drawn to points of contact with the first and third zones of the cam surface so that for a given selection force applied to the cam member a larger ratio engagement is applied to the follower during synchronisation than when the follower is in contact with the first and third zones.
Applications Claiming Priority (6)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB7925589 | 1979-07-23 | ||
| GB7925589 | 1979-07-23 | ||
| GB7925590 | 1979-07-23 | ||
| GB7925590 | 1979-07-23 | ||
| GB7925588 | 1979-07-23 | ||
| GB7925588 | 1979-07-23 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1147168A true CA1147168A (en) | 1983-05-31 |
Family
ID=27260747
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000356098A Expired CA1147168A (en) | 1979-07-23 | 1980-07-14 | Transmission ratio selecting mechanism |
Country Status (9)
| Country | Link |
|---|---|
| AR (1) | AR222883A1 (en) |
| CA (1) | CA1147168A (en) |
| ES (2) | ES493637A0 (en) |
| FI (1) | FI69916C (en) |
| IN (1) | IN152350B (en) |
| MX (1) | MX150752A (en) |
| PL (1) | PL131622B1 (en) |
| TR (1) | TR21497A (en) |
| YU (1) | YU186480A (en) |
-
1980
- 1980-07-14 CA CA000356098A patent/CA1147168A/en not_active Expired
- 1980-07-22 FI FI802310A patent/FI69916C/en not_active IP Right Cessation
- 1980-07-22 YU YU186480A patent/YU186480A/en unknown
- 1980-07-22 IN IN834/CAL/80A patent/IN152350B/en unknown
- 1980-07-23 PL PL22583780A patent/PL131622B1/en unknown
- 1980-07-23 AR AR28187780A patent/AR222883A1/en active
- 1980-07-23 TR TR2149780A patent/TR21497A/en unknown
- 1980-07-23 MX MX18325580A patent/MX150752A/en unknown
- 1980-07-23 ES ES493637A patent/ES493637A0/en active Granted
-
1981
- 1981-02-13 ES ES499430A patent/ES499430A0/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| ES8105204A1 (en) | 1981-06-01 |
| MX150752A (en) | 1984-07-11 |
| PL131622B1 (en) | 1984-12-31 |
| YU186480A (en) | 1983-09-30 |
| ES8205975A1 (en) | 1982-07-01 |
| FI802310A (en) | 1981-01-24 |
| FI69916C (en) | 1986-05-26 |
| PL225837A1 (en) | 1981-04-10 |
| AR222883A1 (en) | 1981-06-30 |
| TR21497A (en) | 1984-07-12 |
| IN152350B (en) | 1983-12-24 |
| ES499430A0 (en) | 1982-07-01 |
| ES493637A0 (en) | 1981-06-01 |
| FI69916B (en) | 1985-12-31 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |