MXPA95005214A - Entering with display slot - Google Patents

Abstract

The present invention relates to a composite gear shift transmission of the type including a transmission main section of multiple speed ratios and an auxiliary transmission section connected in series, said main transmission section comprising a shift control assembly for it, including at least a first shift rod axially movable therein from a neutral position, not displaced to link and disengage, respectively, selected engagement ratios of the main transmission section, said auxiliary transmission section including at least a second shank of axially movable shifts therein for linking and decoupling selected engagement ratios of the auxiliary transmission section, and a shift shank interlock assembly of the type including an interlock member operable between a first position linking said first shank of camb ios and preventing its axial movement from said asialmente displaced displacement while allowing the axial movement of said second shift rod, and a second pisicion that links said shift rod and preventing its axial movement while allowing axial movement of said first rod changes characterized in that: (a) said first shift shank has at least one position and an interlock deactivation position corresponding to a predetermined, non-neutral gear ratio of said transmission section, and (b) said first shank of changes defines a recess of interlock disposed to receive therefrom said interlock pin member, when said first shift shank is in said interlock deactivation position and in said displaced position, thereby allowing axial movement of said second shank of change.

Description

ENTERING WITH DEACTIVATION SLOT INVENTORS: THOMAS NEAL RILEY and PHILIP ARTHUR MORRIS, citizens of the United States and the United Kingdom, respectively, residing at 4805 Romence Road, Portage, Michigan 49002, United States; and 5 Whittle Street, Worsley, Manchester M28 3T, England.

APPLICANT: EATON CORPORATION, a partnership of the United States, with address at Eaton Center, Cleveland, Ohio 44114-2584, United States.

BACKGROUND OF THE DISCLOSURE The present invention relates to composite transmissions having a main transmission section of multiple speed ratios, connected in series with an auxiliary section of transmission of multiple velocity ratios, and more particularly to such transmissions which have transmission mechanisms. interlock of change rail. Compound mechanical gear change transmissions comprising main transmission sections of multiple speed ratios, manually changed, connected in series with one or more auxiliary sections, usually of the combined range, divider, or range / divider type, are well known in the prior art. The auxiliary sections are usually auxiliary input and / or output transmission sections, but within the scope of the present invention, they may also comprise other devices, such as transfer cases or multi-speed traction axes. Examples of such composite transmission systems can be seen by reference to U.S. Patent Nos. 4,754,665 and 4,944,197, both assigned to the assignee of the present invention and incorporated herein by reference. As is well known to those skilled in the art, it is necessary to provide some type of interlock mechanism between the main and auxiliary transmission sections, to retain the main transmission section in neutral during a transient of changes of the auxiliary range section and / or to prevent / inhibit the changes of the auxiliary section when the main section is not in neutral. An example of a range interleaving mechanism is illustrated and described in the previously incorporated U.S. Patent No. 4,944,197, and also in U.S. Patent No. 4,445,393, assigned to the assignee of the present invention and incorporated in US Pat. the present by reference. Although the interlocking mechanisms of the prior art have operated in a generally satisfactory manner in relation to the basic interlock function, there have been certain operating conditions in which known interlocking mechanisms have not been fully satisfactory. As an example, in a composite transmission in which the auxiliary section is of the combined range / divider type, a problem arises when the operator shuts down the vehicle with the transmission at a relatively high speed (for example, the sixteenth speed in a forward 16-speed transmission). This necessarily requires that the auxiliary range / divider section be in its "high / high" condition. After (for example the next morning), when the operator resumes the operation of the vehicle and tries to change the transmission at a lower speed, it may be possible to change the transmission "down" just as far as the ninth speed (ie , the lowest speed in the "high" range), because the interlock mechanism prevents a range change (ie, from the high range to the low range). Typically, no change of range can be made without rotation of the main arrow, which will cause unlocking of the synchronizer in the auxiliary section, to allow the change of the auxiliary section from the high range to the low range. This is especially true after a period of stoppage in which the transmission oil is cold and thick, and there is a tendency for the synchronizer to "hang" on the low blocker. Summary of the Invention AccordinglyIt is an object of the present invention to provide an improved composite gear shift transmission that facilitates the changes of an auxiliary section in a situation where the interlocking mechanism would otherwise prevent such a change. It is a more specific objective of the present invention to provide such an improved composite gear shift transmission that allows a certain amount of rotation of the main shaft, to facilitate a change within the auxiliary section, in a situation in which the interlock mechanism It is in linkage. The foregoing and other objects of the invention are achieved by the provision of an improved composite gear shift transmission of the type including a multiple transmission velocity transmission main section and an auxiliary transmission section connected in series. The main transmission section comprises a shift control assembly, which includes at least a first shift rod axially movable therein from a neutral, non-shifted position, to link and disengage, respectively, gear ratios selected from the main section of transmission. The auxiliary transmission section includes at least one second shift rod axially movable therein for linking and de-linking selected gear ratios of the auxiliary transmission section. A change rod interlock assembly is included, of the type having an interlock member operable between a first position that links the first shift rod and preventing its axial movement from the axially non-displaced position while allowing axial movement of the second rod of changes, and a second position that links the second rod of changes and preventing its axial movement while allowing the axial movement of the first rod of changes. The improved transmission is characterized by the fact that the first shift rod has at least one normal position and one interlock deactivation position, corresponding to a predetermined, non-neutral gear ratio of the main transmission section. The first shift rod defines a recess of interlock arranged to receive the interlock pin member when the first shift rod is in the interlock deactivation position and the displaced position, thereby also allowing axial movement of the second rod of changes. . BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic illustration of a composite shift transmission of the type with which the present invention can be used. Figure 2 is a non-schematic illustration of the shift pattern for the transmission of Figure 1. Figure 3 is a somewhat schematic top view of the shift bar housing assembly of the transmission of the present invention. Figure 4 is a fragmentary perspective view of a change rail illustrating an aspect of the present invention. Description of the Preferred Embodiment Form Certain terminology will be used in the following description for convenience only, and will not be limiting. Certain words such as "up", "down", "right" and "left" will designate directions in the drawings to which reference is made. Words such as "front" and "rear" will refer respectively to the front and rear ends of the transmission, as conventionally mounted on the vehicle, being respectively left and right of the transmission as illustrated in figure 1. Words such as "inward" and "outward" will refer to directions towards and away, respectively, from the geometric center of the device and its designated parts. Such terminology includes the words mentioned above in a specific way, as well as their derivations and words of similar connotation. The term "composite transmission" is used to designate a gear shift transmission or gear change transmission having a main transmission section and an auxiliary transmission section connected in series, whereby the gear reduction selected in the main transmission section can be combined with the additional gear reduction selected in the auxiliary section of the transmission. The term "top speed change", as used herein, will mean the change from a lower speed ratio to a higher speed ratio, while the term "lower speed change", as used herein, it will mean the change from a higher speed ratio to a lower speed ratio. Referring now mainly to Figure 1, there is a schematic illustration of a composite transmission 11 of sixteen speeds. The transmission 11 is a sixteen-speed transmission type "(2) x (4) x (2)" having a two-speed divider section 13, a four-speed forward main section 15 and a two-speed range section 17, all connected in series. The gear of the transmission 11 may be of the planetary type or of the helical type. The input shaft 19 is supported within the front wall of the transmission housing (not shown) by means of a bearing 21, and is surrounded by two input gears 23 and 25, a selected gear of which is engaged to the input shaft by a synchronized clutch 27 to provide a two-speed divider input section. Frontal counterfighting assemblies 29 each include a countershaft 31 which carries counter-clockwise gears 33, 35, 37, 39, 41 and 43. The gears 33 and 35 mesh constantly with the input gears 23 and 25, respectively. In the main section 15, the gears 37, 39, 41 and 43 mesh constantly with the main arrow gears 45, 47, 49 and a reverse reverse gear (not shown) meshes with a reversing main arrow gear 51. Clutches synchronized double action 53 and 55 are provided in a main arrow 57 to engage the main arrow 57 to a selected element of an input arrow 19 or main arrow gears 45, 47 or 49. An unsynchronized clutch 59 is used to engage the reverse main arrow gear 51 to the main arrow 57. The rear end of the main arrow 57 extends to the two speed range section 17 and carries a fixed gear 61 for rotation therewith. A pair of auxiliary section countershaft assemblies 63 each include an auxiliary section counter shaft 65 carrying two auxiliary section countershaft gears 67 and 69. The gear 67 meshes constantly with the auxiliary input gear 61, while the gear 69 meshes constantly with an output gear 71 surrounding an output shaft 73. The output shaft 73 is supported on the rear end housing wall (not shown) by a bearing 75. A clutch of synchronized two positions 77 is carried by the output shaft 73 and is used to engage either the output gear 71 or the main shaft 57 to the output shaft 73. The pattern of changes to change the transmission 11 is illustrated schematically in the figure 2, in which the divisions in the vertical direction (arrow identified as "R") illustrate changes in the section of rank 17, while divisions in the horizontal direction (arrow ident "S") illustrate changes of the divisor section 13. However, those skilled in the art will understand that the present invention is not limited to any particular pattern of changes, except to the extent specifically outlined in the appended claims. In the present embodiment of the present invention, the divider section 13 is located forward of the main section 15, but it should be understood by those skilled in the art that the invention is not limited in this way. Alternatively, the divider section may be combined with the rank section 17 in a single auxiliary section disposed rearwardly of the main section 15. As another alternative, the present invention can be used in a transmission that does not have a divisor section at all, but only the main section 15 and the range section 17. Referring now mainly to figure 3, a change control unit is illustrated for changing the main section 15 and the range section 17. The shift control unit includes a shift bar housing assembly 81 which is capable of mounting in the upper opening of the transmission 11. The shift bar housing 81 it holds a first shift bar (also called a "shift rail") 83 and a second shift bar or rail 85 for independent axial movement therein. Each of the shift rails 83 and 85 carries a shift fork (not shown herein) for axial movement therewith. The construction and operation of the shift rail 83 in the present embodiment are preferably as set forth in U.S. Patent No. 4,920,815, assigned to the assignee of the present invention and incorporated herein by reference. In this way, the shift rail 83 is movable both axially (from right to left and from left to right in Figure 3) and rotationally about an axis 87 of the shift rail 83. The function of the shift rail 83 is to link the main arrow gears 45, 47, 49 and the reverse main arrow gear 51 to the main shaft 57. The second shift rail 85 moves only axially, and is operatively associated with a rail track extension. changes 89 extending axially out of the shift bar housing 81 and into the range section 17, for operative engagement with the range 77 clutch, to select between a low range and a high range, as previously described in relation to Figure 2. An interlocking mechanism, indicated generally at 91, is to include to prevent simultaneous movement of the shift rails 83 and 85 from centered, neutral positions, illustrated in Figure 3, although according to FIG. With the present invention, there will be an exception to the "general rule" insofar as both rails of changes can not be displaced from their neutral position at the same time. The shift bar housing 81 is provided with an opening 93 for receiving a shift finger (not shown) carried by a standard, direct control shift lever, or a transverse arrow of a remote control mechanism, as is well known by the technicians in the field. The shift rail 83 carries a fixed sleeve member 95 for rotational and axial movement therewith and defining a generally upwardly facing pin 97 adapted to receive the lower end of the shift finger, to define a ball-and-pin connection with this . Referring now principally to Figures 3 and 4, the interlock mechanism 91 will be described in greater detail. The shift rail 83 includes, towards its forward end (left end in Figure 3), an annular groove 99. Similarly, the shift rail 85 includes, towards its forward end, an annular groove 101 (shown only in FIG. figure 3). Arranged between the shift rails 83 and 85 is an interlock pin 103, the opposite axial ends of which are preferably beveled or frusto-conical. The shift rail 83 also defines an axial groove 105 which, in the present embodiment, opens toward the annular groove 99 for reasons that will be described later. The general operation of the interlock mechanism 91 will be understood by reference to U.S. Patent Nos. 4,445,393 and 4,944,197, previously incorporated. Briefly, with the shift rail 83 in its neutral position shown in Fig. 3, the sectional shifting rail of range 85 can be moved axially, in any direction from its neutral position shown in Fig. 3. When the rail changes 85 is moved axially, the upper end of the interlock pin 103 is no longer aligned with the annular groove 101, but instead instead links one of the full diameters of the shift rail 85. In this way, with the shift rail 85 moved axially from In its neutral position, the interlock pin 103 is forced downwardly into engagement with the annular groove 99 of the shift rail 83, thereby preventing the shift rail 83 from being moved axially to engage one of the synchronized clutches 53 or 55. As described in the "Background of Disclosure" section, there are certain situations in which a change of rank is desired, but such a change in rank, as a matter of practical cut, can not be achieved unless there is some rotation of the main arrow to cause unlocking of the synchronizer in the range section 17. To accommodate such situations, the axial slot 105 has been provided. As previously described, the Actuation of the shift rail 83 for selecting the various gear ratios in the main section 15 is achieved by moving the shift rail 83 axially and / or rotationally. In the present embodiment, the position of the axial groove 105 is in that portion of the shift rail 83 which is disposed adjacent the lower end of the interlock pin 103 provided that the shift rail 83 is moved to engage the clutch 59, and select the reverse gear. Therefore, when for example it is necessary to change from the sixteenth speed (high range) to the first speed (low range), the operator can move the gear rail 83 to the axial and rotational position corresponding to the reverse gear, as shown in FIG. described earlier. In that position of the shift rail 83, the interlock pin 103 will be disposed within the axial slot 105. Thus, even when the main section 15 is in a "linked engagement" condition, the fact that the interlock pin 103 is disposed in the axial slot 105 will still allow the shift rail 85 to be moved from its high range position to its low range position. Furthermore, with the shift rail 83 in the reverse gear position, there is hardly enough rotation of the main arrow 57 to facilitate the unlocking of the synchronizer in the range section 17. Once the section of range 17 is moved to In the low range position, the gear rail 83 can then be moved by the operator from the reverse gear position to the position of the first gear, in preparation to pass through the normal pattern of changes. Although the present invention has been described in relation to a main section 15 having a single shift rail 83, it should be understood by those skilled in the art that the invention is not limited in this way. As an alternative embodiment, and by way of example only, it will be possible to have a main section with a plurality of parallel rails of changes and an interlocking arrangement between those shifting rails and the shifting rail associated with the auxiliary section. In such an environment, the change rail for the main section that is used to select the reverse gear would be provided with a notch or a recess or slot or some other suitable structure disposed adjacent the interlock pin, such that the interlock pin Link the recess or axial groove, etc., as long as the particular rail selects the reverse gear. Then, to a large extent in the same way as previously described in relation to the present embodiment, it would be possible to make the desired rail in the auxiliary section, and having the particular gear rail in the reverse gear position would result in the necessary rotation of the main arrow 57 to unlock the synchronizer in the auxiliary section and allow the desired change of the auxiliary section. Also, although the invention has been described in relation to the changes of the main section 15 to the reverse gear during the change of the range section 17, the present invention is not limited in this way. However, reverse gear would typically be preferred because it results in some rotation of the main shaft 57, but at an extremely low gear ratio. Of course, as will be understood by those skilled in the art, the direction of rotation of the main arrow 57 is irrelevant, for the purposes of the present invention. The invention has been described in great detail in the foregoing description, and it is believed that various alterations and modifications of the invention will be apparent to those skilled in the art from reading and understanding the description. It is intended that such alterations and modifications be included in the invention, as long as they fall within the scope of the appended claims.

Claims (4)

1. CLAIMS 1. A composite gear shift transmission of the type including a transmission main section of multiple speed ratios and an auxiliary transmission section connected in series, said main transmission section comprising a change control assembly for it, including at least a first shift rod axially movable therein from a neutral, non-shifted position to link and de-link, respectively, selected gear ratios of the main transmission section; said auxiliary transmission section including at least one second shift rod axially movable therein for linking and de-linking selected gear ratios of the auxiliary transmission section; and a change rod interlock assembly of the type including an interlock member operable between a first position linking said first shift rod and preventing its axial movement from said axially non-displaced position while allowing the axial movement of said second shank of changes, and a second position that connects said second shank of changes and preventing its axial movement while allowing the axial movement of said first shank of changes; characterized in that: (a) said first shift rod has at least one normal position and one interlock deactivation position corresponding to a predetermined, non-neutral gear ratio of said main transmission section; and (b) said first shift rod defines a recess of interlock arranged to receive therein said interlock pin member, when said first shift rod is in said interlock deactivation position and in said displaced position, thereby allowing the axial movement of said second rod of changes.
2. 2. A composite shift gear transmission, as defined in claim 1, characterized in that said first shift rod defines an annular groove arranged to receive said interlock pin member when said first shift rod is in said neutral position, not displaced.
3. 3. A composite gear shift transmission, as defined in claim 2, characterized in that said recess of interlock is disposed immediately adjacent to and in open communication with said annular slit, whereby the movement of said first shank of changes from said The normal position to said interlock deactivation position results in the movement of said interlock pin member, relative to said first shift rod, from said annular slit to said interlock recess.
4. 4. A composite gear shift transmission, as defined in claim 3, characterized in that the location of said interlock recess, relative to said interlock pin member, corresponds to the movement of said first shift rod to select the reverse gear in said main transmission section.