MECHANISM

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The subject patent application claims priority to, and all the benefits of, United States Provisional Patent Application N2 63/145,584, filed on February 4, 2021, the entire contents of which are incorporated by reference herein.

BACKGROUND

[0002] Bidirectional pedal systems are often used in vehicular applications (for example trucks and utility vehicles) to control vehicle operations. Such pedal systems typically include a bidirectional pedal assembly (also known as an over-center rocker pedal) configured to move relative to a fixed base between first and second operational states on opposite sides of a neutral state. Upon release of an applied force by an operator, the bidirectional pedal assembly returns to the neutral state under the influence of one or more biasing elements associated with the assembly. Other than the biasing elements urging the bidirectional pedal assembly to the neutral state, the assembly is generally unconstrained from moving between the first and second operational states through the neutral state. The arrangement can undesirably result in oscillations about the neutral state, particularly upon increasing the size and/or weight of the bidirectional pedal assembly, and/or connecting structures to the bidirectional pedal assembly that increase torque about the fixed base.

[0003] Such concerns are pronounced in the context of bidirectional pedal systems utilizing electronic sensors. The angular position of the bidirectional pedal assembly relative to the fixed base is sensed by an electronic sensor, after which the position signal of the sensor is transmitted electronically to a controller configured to generate a corresponding control command. Should the bidirectional pedal assembly oscillate about the neutral state, unintended position signals are transmitted to the electronic control unit of the engine or other electronically controlled operation. Such signals can result in undesired movement of the vehicle. Therefore, there is need in the art for an improved bidirectional pedal system that returns to the neutral state while preventing oscillation about the neutral state. SUMMARY

[0004] A bidirectional pedal assembly for a machine is disclosed. The bidirectional pedal assembly comprises a first housing configured for mounting on the machine, a shaft supported by the first housing, and a pivot body supported on the shaft and movable between a neutral state, a first operational state, and a second operational state opposite the first operational state relative to the neutral state. The bidirectional pedal assembly further comprises a biasing assembly disposed between the first housing and the pivot body for biasing the pivot body toward the neutral state. The bidirectional pedal assembly may further comprise a centering assembly at least partially disposed between the pivot body and the first housing. The centering assembly may include a return ramp having a ramp surface defining a trough, and a centering follower movable along the ramp surface. The centering follower may be biased toward engagement with the trough. The centering follower moves within the trough to define a central position of the pivot body within the neutral state, and wherein engagement of the centering follower with the trough urges the pivot body toward the central position within the neutral state.

[0005] A bidirectional pedal assembly for a machine is further disclosed. The bidirectional pedal assembly comprises a first housing defining an interior and configured for mounting on the machine, a shaft supported by the first housing, and a pivot body supported on the shaft and movable between a neutral state, a first operational state, and a second operational state opposite the first operational state relative to the neutral state. The bidirectional pedal assembly further comprises a biasing assembly disposed between the first housing and the pivot body for biasing the pivot body toward the neutral state. The bidirectional pedal assembly may further comprise a damper assembly disposed in the interior of the first housing and operatively coupled between the pivot body and the first housing for damping movement of the pivot body.

[0006] A method of operating a bidirectional pedal assembly is further disclosed. The bidirectional pedal assembly has a housing, a pedal pivotable relative to the housing first and second biasing members selectively engageable with the pedal, a return ramp having a ramp surface defining a trough, a centering follower engaged with the return ramp and movable along the ramp surface. The method may comprise the step of moving the pedal between a first operational state when the pedal is engaged with the first biasing member and a second operational state when the pedal is engaged with the second biasing member to define a neutral state when the pedal is disengaged from both the first and second biasing members. The method may further include a step of urging the centering follower toward the return ramp to move the centering follower along the ramp surface within the trough, and a step of pivoting the pedal into a central position of the neutral state with the centering follower.

[0007] Any of the above aspects can be combined in full or in part. Any features of the above aspects can be combined in full or in part. Any of the above implementations for any aspect can be combined with any other aspect. Any of the above implementations can be combined with any other implementation whether for the same aspect or a different aspect.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Advantages of the present disclosure will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings.

[0009] FIG. 1 is an environmental view of an operator’s cab for a machine including two bidirectional pedal assemblies according to a first embodiment.

[0010] FIG. 2 is a front perspective view of the bidirectional pedal assemblies of FIG. 1 showing a pedal.

[0011] FIG. 3 is a rear perspective view of one bidirectional pedal assembly of FIG. 1.

[0012] FIG. 4A is a side elevation view of the bidirectional pedal assembly of FIG. 3 showing the pedal in a neutral state.

[0013] FIG. 4B is a side elevation view of the bidirectional pedal assembly of FIG. 3 showing the pedal in a first operational state and with the pedal in the neutral state shown in phantom.

[0014] FIG. 4C is a side elevation view of the bidirectional pedal assembly of FIG. 3 showing the pedal in a second operational state and with the pedal in the neutral state shown in phantom.

[0015] FIG. 5 is a partial exploded view of the bidirectional pedal assembly of FIG. 3 with the pedal shown spaced from a first housing and a second housing.

[0016] FIG. 6 is an exploded view of the first housing of FIG. 5 showing a pivot body, a trunnion shaft, a biasing assembly, and a centering assembly.

[0017] FIG. 7 is a cross-sectional view of the first housing of FIG. 5 shown with the pivot body in the neutral state.

[0018] FIG. 8 is a cross-sectional view of the first housing of FIG. 5 shown with the pivot body in the first operational state. [0019] FIG. 9 is a cross-sectional view of the first housing of FIG. 5 shown with the pivot body in the second operational state.

[0020] FIG. 10 is a perspective cross-sectional view of the first housing of FIG. 5 shown with the pivot body in the second operational state.

[0021] FIG. 11A is a partially-broken cross-sectional view of the first housing of FIG. 7 showing the pivot body disengaged from the biasing assembly.

[0022] FIG. 1 IB is a close-up cross-sectional view of a portion of FIG. 11 A showing the pivot body, the biasing assembly, and the first housing.

[0023] FIG. 12 is a simplified cross-sectional view of the pivot body and the centering assembly of FIG. 7.

[0024] FIG. 13 is a simplified cross-sectional view of the pivot body and the centering assembly of FIG. 8.

[0025] FIG. 14 is a close-up cross-sectional view of the centering assembly showing a first return ramp and a centering follower.

[0026] FIG. 15 is a simplified cross-sectional view of the pivot body and the centering assembly with an alternative second return ramp.

[0027] FIG. 16 is a top-side view of the bidirectional pedal assembly with the second housing and pedal removed to show an interior of the first housing.

[0028] FIG. 17 is a cross-sectional view of the bidirectional pedal assembly with the pedal and the pivot body shown in the neutral state.

[0029] FIG. 18 is a partial cross-sectional view of the first housing with the pivot body in the first operational state.

[0030] FIG. 19 is another partial cross-sectional view of the first housing with the pivot body in the second operational state.

[0031] FIG. 20 is a perspective view of a second implementation of a bidirectional pedal assembly showing a base plate.

[0032] FIG. 21 is an exploded view of the bidirectional pedal assembly of FIG. 20 showing a first housing, a pivot body, a trunnion shaft, a biasing assembly, and a centering assembly.

[0033] FIG. 22 is a perspective cross-sectional view of the bidirectional pedal assembly of FIG. 20 shown with the pivot body in the neutral state. [0034] FIG. 23 is a partially-broken cross-sectional view of the bidirectional pedal assembly of FIG. 20.

DETAILED DESCRIPTION

[0035] Referring to the partial environmental view in FIG. 1, a pair of bidirectional pedal assemblies 100, 101 are illustrated in one exemplary embodiment of an operator’s cab of a machine. FIG. 1 illustrates two bidirectional pedal assemblies 100, 101 positioned in a side-by- side arrangement, a first bidirectional pedal assembly 100 controls one operation and/or component of the machine, while a second bidirectional pedal assembly 101 controls another operation and/or component of the machine. Heavy construction equipment is one type of machinery that may utilize a bidirectional pedal. More specifically, in a continuous tracked tractor (e.g., excavator or other crawler), the left bidirectional pedal assembly 100 (from a perspective of an operator) can control the left track whereas the right bidirectional pedal assembly 101 can control the right track. Other heavy equipment machines such as a wheeled backhoe loader can be similarly controlled by the left and right bidirectional pedal assemblies 100, 101, as disclosed herein, to provide for control of a digging arm. Other applications are also contemplated, such as one bidirectional pedal assembly 100 controlling the blade of a bulldozer, while the other bidirectional pedal assembly 101 controls the ripper of the same or to control the drive wheels of a skid-steer type machine.

[0036] While embodiments disclosed herein illustrate two bidirectional pedal assemblies configured to operate in tandem, the present disclosure contemplates one, two, three, or four or more bidirectional pedal assemblies may be incorporated into a vehicle. In other words, each bidirectional pedal assembly 100, 101 can operate as an independently functioning unit. In figures illustrating two bidirectional pedal assemblies (e.g., FIGS. 1 and 2), the structure and function of one bidirectional pedal assembly will be disclosed in greater detail, but the structure and function of the other bidirectional pedal assembly should be considered essentially the same.

[0037] Returning to FIG. 1, the bidirectional pedal assembly 100 includes a first housing 102 configured to be mounted on the machine. A pedal 104 is pivotally coupled to the first housing 102 about a shaft, such as a trunnion shaft 106 (see FIG. 4) disposed within the first housing 102. As illustrated in FIGS. 4A-4C, the pedal 104 is configured to pivot about the trunnion shaft 106 between a first operational state (FIG. 4B) and a second operational state (FIG. 4C) opposite the first operational state relative to a neutral state (FIG. 4A). In a preferred embodiment, the pedal 104 is a treadle configured to receive input from an operator’s foot to move the treadle to one of the first operational state and the second operational state.

[0038] FIG. 4A illustrates the pedal 104 in the neutral state. In the neutral state, no input from the operator is being applied to the pedal 104. In general, in the neutral state, the foot of the operator is either not positioned on the pedal 104 or resting on the pedal 104 without sufficient force to overcome the components biasing the pedal 104 to the neutral state. In other words, the neutral state is a default configuration for the pedal 104 and the bidirectional pedal assembly 100 generally. Typically, in the neutral state, a sensor 138 (FIG. 2) associated with the bidirectional pedal assembly 100 is either not transmitting an active signal to a controller (not shown) associated with the machine, or transmitting a signal that the bidirectional pedal assembly 100 is in the neutral state. In short, when in the neutral state, the particular active operation of the machine under the control of the bidirectional pedal assembly 100 will not occur until the bidirectional pedal assembly 100 is actuated to one of the first operational state or the second operational state (i.e., the operational states).

[0039] To move the pedal 104 to one of the operational states, the operator applies a force, also referred to herein as a user input. It can be readily appreciated that in one aspect of the present disclosure, the user input can be by pivoting the pedal 104 with the foot of the operator. With continued reference to FIGS. 1-4, the pedal 104 includes a fore portion 108 and an aft portion 110. In a general sense, the fore portion 108 of the pedal 104 includes a portion of the pedal 104 on one side of the trunnion shaft 106 (i.e., a vertical plane extending through the trunnion shaft 106) such that application of the user input to the fore portion 108 creates a torque about the trunnion shaft 106 and thereby pivots the pedal 104 to the first operational state illustrated in FIG. 4B. Similarly, the aft portion 110 of the pedal 104 includes a portion of the pedal 104 on the other side of the trunnion shaft 106 (i.e., a vertical plane extending through the trunnion shaft 106) such that application of the user input to the aft portion 110 creates a torque about the trunnion shaft 106 and thereby pivots the pedal 104 to the second operational state illustrated in FIG. 4C. An intermediate portion 132 is disposed between the fore portion 108 and the aft portion 110. In other words, the trunnion shaft 106 is intermediate the fore portion 108 and the aft portion 110 of the pedal 104 and coupled to the intermediate portion 132. The first and second operational states about the trunnion shaft 106 intermediate the fore portion 108 and the aft portion 110 of the pedal 104 further characterize the bidirectional pivoting movement of the bidirectional pedal assembly 100. The opposing configuration of the first operational state and the second operational state generally classifies the pedal assembly as a bidirectional pedal assembly.

[0040] For purposes of the disclosure, the terms “first operational state” and “second operational state” include any degree of pivoting movement in the directions of the first operational state and second operational state, respectively, from the neutral state sufficient to engage a biasing assembly, discussed below. In other words, this may include fully depressing the pedal 104 to a terminus or maximum, or depressing the pedal 104 by a lesser amount to pivot the pedal 104 away from the neutral state.

[0041] As illustrated in the exemplary embodiment of FIG. 1, the pedal 104 includes a pedal surface oriented at an angle relative to horizontal. Doing so can advantageously provide for ease of operation and increased comfort for the operator. In particular, the fore portion 108 is elevated relative to the aft portion 110 such that application of a user input in a generally horizontal direction can provide the needed torque to pivot the pedal 104 from the neutral state to the first operational state. The configuration does not require the operator to hyperextend the ankle joint. Because the aft portion 110 is positioned closer to the operator relative the fore portion 108, application of a user input in a generally vertical direction can be made without undue difficulty.

[0042] In some applications of the bidirectional pedal assembly 100, it may be preferable to operate the machine other than via the pedal 104. To effect pivoting of the pedal 104 the user input may be through actuating a handle 112 with the hand and arm of the operator. With reference to FIGS. 1-3, the bidirectional pedal assembly 100 may include the handle 112 operably coupled to the pedal 104. In one exemplary embodiment, the handle 112 is configured to pivot concurrently with the pedal 104. In other words, each of the pedal 104 and the handle 112 are configured to receive a user input. Upon the user input to either the pedal 104 and/or the handle 112, both the pedal 104 and the handle 112 pivot. Among other advantages, the configuration provides alternatives for the operator to prevent fatigue, accommodate individuals with a physical disability, and the like.

[0043] Shown best in FIG. 3, a first damper assembly 114 having a pedal end 116 and a housing end 118 may be coupled between the pedal 104 and the first housing 102. Specifically, the pedal end 116 is pivotably coupled to the pedal 104 and the housing end 118 is pivotably coupled to the first housing 102. The first damper assembly 114 damps pivoting movement of the pedal 104 to reduce oscillations of the pedal 104 during operation. [0044] With reference to FIGS. 1-4, an exemplary operation of the bidirectional pedal assembly 100 is described. As mentioned, without the influence of external forces, the pedal 104 is in the neutral state illustrated in FIG. 4A. Upon a user input to, for example, the fore portion 108 of the pedal 104 (or to the handle 112, if applicable), the pedal 104 will pivot in a first radial direction of arrow 158 to the first operating position illustrated in FIG. 4B. Upon a user input to, for example, the aft portion 110 of the pedal 104 (or to the handle 112, if applicable), the pedal 104 will pivot in a second radial direction of arrow 160 to the first operating position illustrated in FIG. 4C. As the pedal 104 pivots from the neutral state, a biasing assembly 134 (shown in FIG. 6 and discussed in further detail below) arranged on a corresponding side of the trunnion shaft 106 will be biased. Concurrently, the pedal end 116 of the first damper assembly 114 is displaced relative to the housing end 118. As the pedal pivots toward the first operational state, the sensor 138 generates a signal indicative of the position, and the associated operation(s) of the machine are controlled accordingly.

[0045] Those skilled in the art appreciate that a biasing assembly stretched or compressed by a force will oscillate after the force is released. The biasing assembly will continue to oscillate unless a counteracting force acts on the oscillating motion. Thus, upon release of the user input, the biased biasing assembly 134 urges the pedal 104 in the second radial direction 160 towards the neutral state. The pedal 104 and the handle 112 having some amount of mass moving at a given speed will be associated with an inertia that urges it to pass through the neutral state into a second operational state. Yet as the pedal 104 moves into the second operational state, the biasing assembly 134 on the opposite side of the trunnion shaft 106 urges the pedal 104 in the first radial direction 158 towards the neutral state. In such a configuration, the biasing assembly 134 is continuously biasing the pedal 104 to the neutral state. In exemplary embodiments using coiled springs, overshoot can again occur based on the spring constants of the biasing assembly 134 relative to the inertia of the pedal 104 and handle 112. In short, the system acts as an underdamped harmonic oscillator with component friction as the only damping mechanism.

[0046] The angular displacement of the pedal 104 past the neutral state (upon returning to the same) defines “overshoot” and is undesirable in an electronically controlled machine, as previously disclosed herein. In particular, as the pedal 104 moves into the second operational state against the intention of the operator, the sensor 138 generates a signal indicative of the same, which could cause rapidly changing signals to the system (e.g., brakes, engine, etc.). To this end, the first damper assembly 114 exerts a retarding force on the pedal 104 that is proportional to the speed at which the pedal 104 and handle 112 assembly are pivoting. In other words, as the angular velocity of the pedal 104 and handle 112 increases so too does the retarding force exerted by the first damper assembly 114 opposing the movement. In this way, user inputs that are relatively slow will not be significantly inhibited by the first damper assembly 114, while rapid movements that may cause undesirable overshoot are slowed.

[0047] Some implementations of the bidirectional pedal assembly 100 may omit the handle 112 and the first damper assembly 114. In general, the mass of an object will contribute to the inertia, and therefore affect the magnitude of the damping force required to prevent oscillation. In the implementation having the handle 112 omitted the first damper assembly 114 may also be omitted due to the resulting reduction in mass. The first damper assembly 114 may alternatively be modified to produce a smaller damping force corresponding to the mass of the pedal 104.

[0048] Turning now to FIG. 5 a first partially exploded view of a bidirectional pedal assembly 100 in accordance with an exemplary embodiment of the present disclosure is illustrated. Here, the pedal 104, handle 112, and first damper assembly 114, are shown spaced from the first housing 102. A second housing 120 is arranged between the pedal 104 and the first housing 102 to reduce ingress of contaminants into the bidirectional pedal assembly 100. With the second housing 120 spaced from the first housing 102, an interior 122 defined in the first housing 102 is visible. The bidirectional pedal assembly 100 further comprises a pivot body 124 at least partially disposed in the interior 122 and supported on the trunnion shaft 106. As with the pedal 104, the pivot body 124 is movable between a neutral state, a first operational state, and a second operational state opposite the first operational state.

[0049] The first housing 102 further defines a pivot carrier 126 extending therethrough for receiving the trunnion shaft 106. The trunnion shaft 106 is disposed in the pivot carrier 126 and supported by the first housing 102. The pivot carrier 126 defines an axis Al about which the trunnion shaft 106 may pivot. The pivot body 124, being supported on the trunnion shaft 106, is thereby pivotable about the axis Al between the first operational state and the second operational state. The pedal 104 is supported on the pivot body 124 to and therefore also pivots with the pivot body 124 about the axis Al.

[0050] As mentioned above, the second housing 120 is disposed between the first housing 102 and the pedal 104, and additionally, the second housing 120 is supported on the pivot body 124 and moveable therewith relative to the first housing 102. The second housing 120 defines a cavity 128, that opens in a generally downward direction toward the first housing 102 and is sized so as to receive at least a portion of the first housing 102. Said differently, the second housing 120 is arranged generally above the first housing 102, with the first housing 102 at least partially disposed in the cavity 128.

[0051] The sensor 138 is coupled to the first housing 102 and arranged adjacent to the trunnion shaft 106 to measure angular position of the trunnion shaft 106 relative to the first housing 102. The sensor 138 is configured to provide a signal indicative of the angular displacement of the trunnion shaft 106 with respect to the first housing 102. An exemplary sensor includes those sensitive to magnetic flux. A magnet 136 may be coupled to the trunnion shaft 106 so as to move relative to the first housing 102 when the pedal is actuated, and magnetically sensitive elements within the sensor 138 provide a signal indicative of the rotational position of the trunnion shaft 106 and thus of the pedal 104 with respect to the first housing 102. The sensor 138 is positioned with an electrical connector facing down, or away from the pedal 104 in the configuration shown in FIG. 3, to interface with machine wiring from below. The sensor 138 may be positioned with the electrical connector facing a different direction to interface with machine wiring in a different location. Other exemplary sensors are also contemplated, including but not limited to electromechanical sensors, optical sensors, and the like.

[0052] Referring now to the exploded views of FIGS. 5 and 6, the pedal 104 and second housing 120 of FIG. 5 have been removed showing elements arranged in the interior 122 of the first housing 102. The first housing 102 may further include a pair of mounting feet 140 for supporting and stabilizing the bidirectional pedal assembly 100 on the machine. Each of the mounting feet 140 may include a hole for securing the first housing 102 to the machine as well as a flange 142 for mounting the first damper assembly 114. Shown best in FIG. 5, the mounting feet 140 further define a mounting plane 236, which may generally be a bottom surface of the first housing 102. The mounting plane 236 may be shaped to match a cab floor of the machine for aligning or positioning the bidirectional pedal assembly 100 on the machine. In addition to the mounting feet 140, the first housing 102 may further include a cover plate 144 removably coupled to a bottom side of the first housing 102. The cover plate 144 may be coupled to the first housing 102 using fasteners, monolithically formed, or otherwise attached to permit access to the interior 122. [0053] The trunnion shaft 106 is exploded along the axis Al and the sensor 138 has been removed. As mentioned above, the magnet 136 is coupled to the trunnion shaft 106 and rotates about the axis Al as the pivot body 124 is moved by the pedal 104. The magnet 136 is arranged on an end of the trunnion shaft 106 adjacent to the sensor 138 to increase the magnetic flux near the sensor 138. In the embodiment shown here, two magnets 136 are arranged on the trunnion shaft 106 and oriented with their poles perpendicular to the axis Al. Other arrangements are possible, such as more than two magnets, or magnets that are oriented such that the poles are oriented parallel to the axis.

[0054] The first housing 102 may further include first and second spring arms 146, 148 that are configured to protrude into the interior 122 from opposing sides. The spring arms 146, 148 are selectively engageable with the biasing assembly 134 to retain the biasing assembly 134 within the interior 122 and to limit engagement between the biasing assembly 134 and the pivot body 124. Each spring arm 146, 148 has a distal end 150 that is cantilevered in the interior 122 and may include a curved segment 152, which promotes smooth engagement with the biasing assembly 134. In the embodiment shown in FIG. 6, the spring arms 146, 148 are integrally formed with the first housing 102. In alternative embodiments the spring arms 146, 148 may be coupled or otherwise fastened to the first housing 102.

[0055] With continued reference to FIG. 6, the pivot body 124 is shown spaced above the first housing 102. In FIG. 7 a cross-sectional view taken along line 7-7 (FIG. 5) of the pivot body 124 in the neutral state is shown. The pivot body 124 may include a trunk portion 166, a shaft portion 168 arranged below the trunk portion 166, and a first and second lever portion 170, 172 arranged on the trunk portion 166 opposite of the shaft portion 168. The shaft portion 168 has a generally circular cross section that extends parallel to the axis Al and defines a pivot bore 174. The first and second lever portions 170, 172 extend away from the trunk portion 166 in a direction perpendicular to the axis Al. The pivot bore 174 is sized to receive the trunnion shaft 106 such that the trunnion shaft 106 may be disposed in the pivot bore 174 to facilitate the pivoting movement of the pivot body 124.

[0056] In addition to the pivot bore 174, the pivot body 124 further defines a second bore 176 perpendicular to the pivot bore 174 and extending into the trunk portion 166 toward the first and second lever portions 170, 172. The second bore 176 has an opening 178 that is defined in the trunk portion 166 across the pivot bore 174 from the lever portions 170, 172. The opening 178 has a tapered profile, such as a chamfer, that decreases in diameter into the second bore 176.

[0057] Each of the first and second lever portions 170, 172 includes a pair of pads 180 that are configured to engage the biasing assembly 134. Each pad 180 is arranged adjacent to the spring arm 146, 148 of the first housing 102, such that as the pivot body 124 moves between the first operational state and the second operational state, one pair of the pads 180 passes on either side of one of the spring arms 146, 148. Similar to the spring arms 146, 148, each of the pads 180 may include a curved segment 182, which promotes smooth engagement with the biasing assembly 134. Some implementations of the bidirectional pedal assembly 100 may include a second damper assembly 154 disposed in the interior 122 of the first housing 102 for damping movement of the pivot body 124. The second damper assembly 154 may be implemented in addition, or in the alternative to, the first damper assembly 114. For example, the first damper assembly 114 may be included when the handle 112 is used with the bidirectional pedal assembly 100, and the second damper assembly 154 may be used when the bidirectional pedal assembly 100 is installed in a machine without the handle 112. The second damper assembly 154, which is shown in FIG. 6 spaced above the pivot body 124, may have a pivot end 162 and a housing end 164. The second damper assembly 154 may be coupled to the pivot body 124 at the pivot end 162 and to the first housing 102 at the housing end 164 such that movement of the pivot body 124 between the first operational state and the second operational state displaces the pivot end 162 relative to the housing end 164. As with the first damper assembly 114, described above, the second damper assembly 154 damps movement of the pivot body 124 relative to the first housing 102 to reduce undesired oscillation of the pedal 104 during operation.

[0058] Best shown in FIGS. 16, 18, and 19, the second damper assembly 154 may include a cylinder 222, a rod 224, and a piston 226. The piston 226 is slidably disposed in the cylinder 222 and coupled to the rod 224, which protrudes from the cylinder 222. The cylinder 222 contains a viscous fluid that may flow through an orifice (not shown) in the piston 226, which slows the movement of the piston 226, and therefore the rod 224. The second damper assembly 154 may be configured with a linear damping rate or a non-linear damping rate. A cylinder eye 228 may be coupled to the cylinder 222 and configured to pivotably couple to one of the pivot body 124 and the first housing 102. A rod eye 230 may be coupled to the rod 224 and configured to pivotably couple to the other of the pivot body 124 and the first housing 102. As shown here, the cylinder eye 228 is arranged at the housing end 164 of the second damper assembly 154 and the rod eye 230 is arranged at the pivot end 162 of the second damper assembly 154.

[0059] The second damper assembly 154 is arranged generally perpendicular to the axis Al and in some instances may be disposed entirely in the interior 122 of the first housing 102, such as shown in FIGS. 16 and 17. The second damper assembly 154 may further be arranged with the pivot end 162 adjacent to a first biasing member 192 (discussed in further detail below) and with the housing end 164 adjacent to a second biasing member 194 (discussed in further detail below). The terms first and second are used only for convenience and should not be interpreted as limiting. Specifically, the pivot end 162 could be adjacent to either the first or second biasing members 192, 194 and the housing end 164 could be adjacent to either the first or second biasing member 192, 194. As mentioned above, the pivot end 162 of the second damper assembly 154 may be pivotably coupled to the pivot body 124. More specifically, the rod eye 230 may be coupled to the first lever portion 170 using, for example, a threaded fastener. The housing end 164 of the second damper assembly 154 may be pivotably coupled to the first housing 102. The first housing 102 may include a damper post 232, which may be coupled to the cylinder eye 228 of the second damper assembly 154. The damper post 232 may be arranged between the pivot body 124 and the second damper assembly 154 such that the housing end 164 is spaced from the pivot body 124 in a direction of the axis Al.

[0060] In FIGS. 18 and 19, the bidirectional pedal assembly 100 is shown with the pivot body 124 in the first and second operational states, respectively. As mentioned above, as the pivot body 124 moves between the first and second operational states, the rod eye 230 and the damper rod 224 are moved in a corresponding manner relative to the damper cylinder 222. A distance 234 is defined between the rod eye 230 and the damper cylinder 222, which is proportional to displacement of the piston 226 within the damper cylinder 222. When the pivot body 124 is in the first operational state (FIG. 18), the rod eye 230 the distance 234 is greater than when the pivot body 124 is in the second operational state (FIG. 19). When the pivot body 124 is in the neutral state the distance 234 is less than the distance 234 when the pivot body 124 is in the first operational state and greater than the distance when the pivot body 124 is in the second operational state.

[0061] With renewed reference to FIG. 6, the trunnion shaft 106 defines two cross bores, a first cross bore 184 and a second cross bore 186. The first cross bore 184 is configured for receiving a fastener 188 to secure the trunnion shaft 106 to the pivot body 124. During assembly, the trunnion shaft 106 is received by the pivot bore 174 and the fastener 188 is inserted through a corresponding bore in the pivot body 124, which is aligned with the first cross bore 184. The fastener 188 prevents relative movement between the trunnion shaft 106 and the pivot body 124. The second cross bore 186 is coaxially aligned with the second bore 176 of the pivot body 124 for receiving a portion of a centering assembly 190, as discussed in further detail below.

[0062] In order to oppose movement away from the neutral state of the pivot body 124, the biasing assembly 134 is disposed between the first housing 102 and the pivot body 124. To this end, the biasing assembly 134 may include a first biasing member 192 and a second biasing member 194. The first biasing member 192 may be arranged on a first side of the axis Al and the second biasing member 194 may be arranged on a second side of the axis Al. More specifically, the first biasing member 192 is selectively engaged with the first housing 102 and the first lever portion 170 and the second biasing member 194 is selectively engaged with the first housing 102 and the second lever portion 172.

[0063] In the embodiment shown here, the first biasing member 192 and the second biasing member 194 may be coil springs, such as the springs illustrated in FIGS. 6-9. Each of the first biasing member 192 and the second biasing member 194 may include an inner coil spring and an outer coil spring in a nested arrangement. Each of the first biasing member 192 and the second biasing member 194 may further include a cap 195 arranged for engagement with the curved segment 182 of the first lever portion 170 and the second lever portion 172, respectively, as well as the curved segment 152 of the first spring arm 146 and the second spring arm 148, respectively. The caps 195 prevent misalignment of the inner and outer coil springs of the respective biasing members relative to each other. The caps 195 promote smooth operation of the bidirectional pedal assembly 100 by allowing slight pivoting movements between the biasing members 192, 194 and the pivot body 124 during operation, which may prevent binding and wear. Alternative arrangements are contemplated.

[0064] Best shown in FIGS. 7-9, because the biasing assembly 134 is selectively disposed between the first housing 102 and the pivot body 124, each biasing member 192, 194 only opposes movement of the pivot body 124 that is away from the neutral state. In other words, the first biasing member 192 is prevented from urging the pivot body past the neutral state and toward the second operational state and the seconding biasing member 194 is similarly prevented from urging the pivot body past the neutral state and toward the first operational state. More specifically, movement of the pivot body 124 from the neutral state toward the first operational state engages the first biasing member 192 with the first lever portion 170 and movement of the pivot body 124 from the neutral state toward the second operational state engages the second biasing member 194 with the second lever portion 172.

[0065] With renewed reference to FIG. 6, the bidirectional pedal assembly 100 further comprises the centering assembly 190. The centering assembly 190 may be at least partially disposed between the pivot body 124 and the first housing 102. Said differently, the centering assembly 190 is operably arranged between the pivot body 124 and the first housing 102 such that a portion of the centering assembly 190 is movable in coordination with the pivot body 124 relative to the first housing 102, and another portion of the centering assembly 190 is fixed relative to the first housing 102. The centering assembly 190 includes a return ramp 196 having a ramp surface 198 that defines a trough 200, and a centering follower 202 that is movable along the ramp surface 198. As shown here, the centering follower 202 is operably coupled to the pivot body 124 and movable therewith between the first and second operational states. Specifically, the centering follower 202 may be disposed in the second bore 176 of the pivot body 124 and the second cross bore 186 of the trunnion shaft 106. More specifically, movement of the pivot body 124 between the first operational state and the second operational state causes movement of the centering follower 202 between corresponding first and second operational states. Furthermore, the neutral state of the pivot body 124 corresponds to a neutral state of the centering follower 202. In other implementations of the bidirectional pedal assembly 100, the centering assembly 190 could be configured with different portions arranged differently. For example, the return ramp 196 may be operably coupled to the pivot body 124 and movable therewith and the centering follower 202 may be fixed relative to the first housing 102.

[0066] The return ramp 196 is arranged in the interior 122 of the first housing 102 between the cover plate 144 and the pivot body 124. The ramp surface 198 is oriented away from the cover plate 144 and toward the interior 122 for engagement with the centering follower 202. The return ramp 196 includes a seat 204 arranged opposite the cover plate 144 for supporting the first and second biasing members 192, 194 in the interior 122. Similar to the caps 195 discussed above, the seats 204 may also prevent binding and wear between components. The ramp surface 198 may include sloped sides 206 that meet to form a depression in the ramp surface 198. Here, the sloped sides 206 generally meet near a midpoint of the ramp surface 198 and further define the trough 200. The sloped sides 206 may be symmetrical, such as shown here, or may have an asymmetrical arrangement where one side is more steeply sloped than the other.

[0067] In addition to the centering follower 202, the centering assembly 190 further includes a collet 208 disposed in the second bore 176 of the pivot body 124 and defining an inner bore 210, and a biasing device 212 disposed in the inner bore 210. The collet 208 is disposed between the centering follower 202 and the pivot body 124, with the centering follower 202 partially disposed in the inner bore 210 of the collet 208 and a tip portion 214 protruding toward the return ramp 196. One implementation of the biasing device 212 is realized as a spring, which is arranged between the centering follower 202 and the collet 208 for urging the centering follower 202 toward the ramp surface 198.

[0068] Referring now to FIGS. 11 A- 12, the pivot body 124 and the centering follower 202 are shown in the neutral state, with the tip portion 214 of the centering follower 202 protruding toward the ramp surface 198 and engaged with the trough 200. The centering follower 202 is slidable within the inner bore 210 of the collet 208 and engaged with the biasing device 212 such that the biasing device 212 opposes movement of the centering follower 202 further into the inner bore 210. In other words, as the centering follower 202 is further inserted into the inner bore 210, the biasing device 212 exerts increased force opposing the insertion. The biasing device 212 biases the centering follower 202 toward engagement with the ramp surface 198 such that the tip portion 214 is biased toward engagement with the trough 200.

[0069] As the pivot body 124 is moved between the first operational state and the second operational state, the centering follower 202 is continuously engaged with the ramp surface 198 and the tip portion 214 follows the profile of the ramp surface 198, i.e. moves the centering follower 202 in the inner bore 210 of the collet 208 relative to the pivot body 124. When the pivot body 124 is in the neutral state the centering follower 202 protrudes the furthest from the inner bore 210 and engages the trough 200. That is, engagement of the centering follower 202 with the trough 200 corresponds to the mid-point of the ramp surface 198, and to a central position of the pivot body 124 in the neutral position. The tip portion 214 is engaged with the trough 200 when there is two points of contact between the tip portion 214 and the ramp surface 198. At the central position of the pivot body 124, the pivot body 124 is firmly held in place by the engagement of the centering follower 202 and the trough 200. Engagement of the centering follower 202 with the sloped sides 206 of the ramp surface 198 urges the pivot body 124 toward the central position of the neutral state.

[0070] Best shown in FIGS. 12-14, the collet 208 has a gripping portion 216, which receives the centering follower 202 and is arranged in the tapered profile of the opening 178 in the pivot body 124. The gripping portion 216 includes a flared lip 218, which has an outer diameter that is larger than the inner diameter of the second bore 176 of the pivot body 124. Because the flared lip 218 is larger than the second bore 176 the flared lip 218 contacts the tapered profile of the opening 178 when the collet 208 is inserted into the second bore 176. As the collet 208 is further inserted into the second bore 176, the tapered profile exerts a compressive force on the gripping portion 216, which reduces an inner diameter of the inner bore 210 of the collet 208.

[0071] Movement of the pivot body 124 away from the neutral state causes the centering follower 202 to move along the ramp surface 198 such that only one of the sloped sides 206 of the ramp surface 198 are engaged with the centering follower 202. Because the ramp surface 198 is sloped toward the trough 200 and the centering follower 202 is biased toward engagement with the trough 200, the centering follower 202 exerts a restoring force on the collet 208 and the pivot body 124 that urges the pivot body 124 toward the neutral state. When the centering follower 202 is engaged with the trough 200 the force required to move the centering follower 202 toward either of the first and second operational states is equal, which prevents excess movement of the pivot body 124, and by extension the pedal 104. When the centering follower 202 is inserted into the inner bore 210 the biasing device 212 is compressed against the collet 208, which in turn urges the collet 208 into the second bore 176, further engaging the flared lip 218 with the opening 178 and causing the gripping portion 216 to constrict around the centering follower 202. Constriction of the gripping portion 216 on the centering follower 202 stabilizes the centering follower 202 and reduces excess movement of the pivot body 124 when moved away from the neutral state.

[0072] Referring to FIGS. 11A and 11B, during the manufacture of the bidirectional pedal assembly 100, each of the components is subject to certain dimensional tolerances, which in some cases may stack together and introduce backlash in the moving components. One example of undesirable backlash is when the pedal 104 and pivot body 124 are in the neutral state, where each of the first and second biasing members 192, 194 is disengaged from the pivot body 124. Here, a gap 220 (FIG. 1 IB) is defined between the pivot body 124 and each of the first biasing member 192 and the second biasing member 194. Due to the gap 220, the pivot body 124 may pivot in the neutral state to define a range of movement in the neutral state. Said differently, the range of movement is the amount that the pivot body 124 may pivot within the neutral state. In FIG. 11 A, the range of movement may be defined by an angular displacement a of the pivot body 124 away from vertical, such that the range of movement is equal to the sum of the angular displacement a in the first radial direction 158 (FIG. 4B) and the angular displacement a in the second radial direction 160 (FIG. 4C).

[0073] When the pivot body 124 is in the first operational state the first lever portion 170 engages the first biasing member 192, and as the pivot body 124 moves toward the second operational state the first lever portion 170 disengages from the first biasing member 192, and thus enters the neutral state. As the pivot body 124 continues to move toward the second operational state, the second lever portion 172 engages the second biasing member 194, and thus enters the second operational state. Specifically, in the neutral state the pivot body 124 engages neither the first biasing member 194 nor the second biasing member 194. The range of movement is defined by the angular movement of the pivot body 124 in the neutral state, i.e. engaging neither the first biasing member 192 nor the second biasing member 194.

[0074] As discussed above, the centering assembly 190 may prevent excess movement of the pivot body 124. Continuous engagement between the centering follower 202 and the ramp surface 198 causes the pivot body 124 to move toward a center of the neutral state with reduced backlash. The central position of the pivot body 124 is defined by engagement of the centering follower 202 with both of the sloped sides 206 of the ramp surface 198 within the trough 200. Said differently, as the pivot body 124 moves between the first operational state and the second operational state, the tip portion 214 of the centering follower 202 slides along the sloped sides 206 of the ramp surface 198, when the tip portion 214 contacts only one of the sloped sides 206, the tip portion 214 will slide along one of the sloped sides 206 toward the other of the sloped sides 206 until the centering follower 202 is stabilized between the two sloped sides 206.

[0075] Turning now to FIG. 15, a simplified cross-sectional view of the pivot body 124 engaged with an alternative centering assembly 190' is shown. As will be appreciated from the subsequent description below, the alternative design of the centering assembly 190' is similar to the centering assembly 190 described above in connection with FIGS. 6-14. As such, the components and structural features of the centering assembly that are the same as the first design of the centering assembly 190 are provided with the same reference numerals and the components. Reference numbers corresponding to structural features specific to the second design of the centering assembly 190' are identified with a prime symbol (e.g. centering assembly 190'). While the specific differences will be described in detail, for the purposes of clarity and consistency, only certain structural features and components common between these embodiments will be discussed.

[0076] Accordingly, the alternative centering assembly 190' includes a return ramp 196' having a ramp surface 198' that defines a trough 200' and a centering follower 202 that is movable along the ramp surface 198'. The centering follower 202 is operably coupled to the pivot body 124 and movable therewith between the first and second operational states. The return ramp 196' includes a seat 204' arranged opposite the cover plate 144 for supporting the first and second biasing members 192, 194 (see FIG. 7). The ramp surface 198' may include sloped sides 206' that form a depression in the ramp surface 198'. The sloped sides 206' may be curved so as to form a non-linear profile of the ramp surface 198'. The profile of the ramp surface 198' affects the relative displacement of the centering follower 202 as the pivot body 124 is moved. Here, the sloped sides 206' are curved about a point near the axis Al, and as such may have a nearly constant distance to the axis Al. When the pivot body 124 is pivoted outside the neutral state (i.e. the centering follower 202 is disengaged from the trough 200') the relative displacement of the centering follower 202 is constant, and therefore does not result in increased effort for the operator to pivot the pedal 104. The profile of the ramp surface 198' may be adapted to match desired operational characteristics.

[0077] Turning now to FIGS. 20-23, a second implementation of a bidirectional pedal assembly is shown. As will be appreciated from the subsequent description below, this implementation of the bidirectional pedal assembly is similar to the bidirectional pedal assembly 100 described above in connection with FIGS. 1-19. As such, the components and structural features of the second implementation of the bidirectional pedal assembly 100" that are the same as, or otherwise correspond to, the first implementation of the bidirectional pedal assembly 100 are provided with the same reference numerals with the addition of a double prime symbol (e.g. 100 and 100"). While the specific differences between these versions will be described in detail, for the purposes of clarity, consistency, and brevity, only certain structural features and components common between these versions will be discussed and depicted in the drawings of the second implementation of the bidirectional pedal assembly 100". Here, unless otherwise indicated, the above description of the first implementation of the bidirectional pedal assembly 100 may be incorporated by reference with respect to the second implementation of the bidirectional pedal assembly 100" without limitation.

[0078] In FIG. 20 the second implementation of the bidirectional pedal assembly 100" is shown without a pedal or handle coupled to the first housing 102". Similar to above, two bidirectional pedal assemblies 100" are usable as a pair in a side-by-side arrangement. Spacing between adjacent bidirectional pedal assemblies 100" may be effected by way of a base plate 250", which may couple to each of the bidirectional pedal assemblies 100" and to the floor of the operator’s cab. The base plate 250" may comprise several mounting tabs 252" configured to be coupled to the bidirectional pedal assemblies 100" as well as base flanges 254" for fastening both bidirectional pedal assemblies 100" to the floor. The base plate 250" may further comprise a sensor wall 256" spaced from the base flanges 254" to form a hood for the sensor 138". The sensor wall 256" protects the sensor 138" from damage, which may be caused by foreign objects becoming lodged between the bidirectional pedal assemblies 100". Additionally, the bidirectional pedal assembly 100" as shown here may comprise a spacer 258" coupled to the pivot body 124". The spacer 258" may be used to adjust the height of the pedal (shown in FIG. 5) depending on the application or to the preferences of a specific operator.

[0079] In FIG. 21, an exploded view of the bidirectional pedal assembly 100" is shown. As with above, the bidirectional pedal assembly 100" may comprise the first housing 102" defining the interior 122" and the second housing 120". The second housing 120" is disposed between the first housing 102" and the pedal, and additionally, the second housing 120" is supported on the pivot body 124" and moveable therewith relative to the first housing 102". The second housing 120" defines a cavity 128", that opens in a generally downward direction toward the first housing 102’ and is sized so as to receive at least a portion of the first housing 102". The sensor 138" is coupled to the first housing 102" and arranged adjacent to the trunnion shaft 106" to measure angular position of the trunnion shaft 106" relative to the first housing 102". The sensor 138" is configured to provide a signal indicative of the angular displacement of the trunnion shaft 106" with respect to the first housing 102". The trunnion shaft 106" is exploded along the axis Al and the sensor 138" is shown removed.

[0080] The first housing 102" may further include first and second spring arms 146", 148" that protrude into the interior 122" from opposing sides of the first housing 102". The spring arms 146", 148" are selectively engageable with the biasing assembly 134" to retain the biasing assembly 134" within the interior 122" and to limit engagement between the biasing assembly 134" and the pivot body 124". In this implementation of the bidirectional pedal assembly 100", each spring arm 146", 148" comprises two arm portions spaced apart by a gap 260". Each arm portion of the first and second spring arms 146", 148" has a distal end 150" that protrudes into the interior 122" and may include a curved segment 152", which promotes smooth engagement with the biasing assembly 134". In the embodiment shown in FIG. 21, the spring arms 146", 148" are integrally formed with the first housing 102". Here too, the bidirectional pedal assembly 100" may include the second damper assembly 154" disposed in the interior 122" of the first housing 102" for damping movement of the pivot body 124". The second damper assembly 154", which is shown in FIG. 21 spaced above the pivot body 124", may have a pivot end 162" and a housing end 164". The second damper assembly 154" may be coupled to the pivot body 124" at the pivot end 162" and to the first housing 102" at the housing end 164" such that movement of the pivot body 124" between the first operational state and the second operational state displaces the pivot end 162" relative to the housing end 164". The second damper assembly 154" damps movement of the pivot body 124" relative to the first housing 102" to reduce undesired oscillation of the pedal 104" during operation. Although not illustrated, it should be appreciated that the second implementation of the bidirectional pedal assembly 100" may be utilized with the first damper 114, as described above and shown in FIGS. 1-5.

[0081] With continued reference to FIG. 21, the pivot body 124" is shown spaced above the first housing 102". In FIG. 22 a perspective cross-sectional view taken along line 22-22 (FIG. 21) of the pivot body 124" in the neutral state is shown. The pivot body 124" may include a trunk portion 166", a shaft portion 168" arranged below the trunk portion 166", and a first and second lever portion 170", 172" arranged on the trunk portion 166" opposite of the shaft portion 168". The shaft portion 168" has a generally circular cross section that extends parallel to the axis Al and defines a pivot bore 174". The first and second lever portions 170", 172" extend away from the trunk portion 166" in a direction perpendicular to the axis Al. The pivot bore 174" is sized to receive the trunnion shaft 106" such that the trunnion shaft 106" may be disposed in the pivot bore 174" to facilitate the pivoting movement of the pivot body 124". The pivot body 124" further defines a second bore 176" perpendicular to the pivot bore 174" and extending into the trunk portion 166" toward the first and second lever portions 170", 172". The second bore 176" has an opening 178" that is defined in the trunk portion 166" across the pivot bore 174" from the lever portions 170", 172". The opening 178" has a tapered profile, such as a chamfer, that decreases in diameter into the second bore 176".

[0082] Each of the first and second lever portions 170", 172" includes a pad portion 180" that is configured to engage the biasing assembly 134". Each pad portion 180" is arranged adjacent to the respective spring arm 146", 148" and configured to fit in the gap 260" between corresponding arm portions of the respective spring arm 146", 148", such that as the pivot body 124" moves between the first operational state and the second operational state, the pad portion 180" passes between the corresponding arm portions of the respective spring arms 146", 148". Similar to the spring arms 146", 148", the pad portion 180" may include a curved segment 182", which promotes smooth engagement with the biasing assembly 134".

[0083] The bidirectional pedal assembly 100" comprises a centering assembly 190" similar to the centering assembly 190' shown above in FIG. 15. The centering assembly 190" may be at least partially disposed between the pivot body 124" and the first housing 102". Said differently, the centering assembly 190" is operably arranged between the pivot body 124" and the first housing 102" such that a portion of the centering assembly 190" is movable in coordination with the pivot body 124" relative to the first housing 102", and another portion of the centering assembly 190" is fixed relative to the first housing 102". The centering assembly 190" includes a return ramp 196" having a ramp surface 198" that defines a trough 200" and a centering follower 202" that is movable along the ramp surface 198". The centering follower 202" is operably coupled to the pivot body 124" and movable therewith between the first and second operational states. In other implementations of the bidirectional pedal assembly 100", the centering assembly 190" could be configured with different portions arranged differently. For example, the return ramp 196" may be operably coupled to the pivot body 124" and movable therewith and the centering follower 202" may be fixed relative to the first housing 102".

[0084] The return ramp 196" includes a seat 204" arranged opposite the cover plate 144" for supporting the first and second biasing members 192", 194" (see FIG. 21). The ramp surface 198" may include sloped sides 206" that form a depression in the ramp surface 198". The sloped sides 206" may be curved so as to form a non-linear profile of the ramp surface 198". The profile of the ramp surface 198" affects the relative displacement of the centering follower 202" as the pivot body 124" is moved. Here, the sloped sides 206" are curved about a point near the axis Al, and as such may have a nearly constant distance to the axis Al. When the pivot body 124" is pivoted outside the neutral state (i.e. the centering follower 202" is disengaged from the trough 200") the relative displacement of the centering follower 202" is constant, and therefore does not result in increased effort for the operator to pivot the pedal. The profile of the ramp surface 198" may be adapted to match desired operational characteristics.

[0085] Referring now to FIG. 23, the pivot body 124" and the centering follower 202" are shown in the neutral state, with the tip portion 214" of the centering follower 202" protruding toward the ramp surface 198" and engaged with the trough 200". The centering follower 202" is slidable within the inner bore 210" of the collet 208" and engaged with the biasing device 212" such that the biasing device 212" opposes movement of the centering follower 202" further into the inner bore 210". In other words, as the centering follower 202" is further inserted into the inner bore 210", the biasing device 212" exerts increased force opposing the insertion. The biasing device 212" biases the centering follower 202" toward engagement with the ramp surface 198" such that the tip portion 214" is biased toward engagement with the trough 200".

[0086] Several examples have been discussed in the foregoing description. However, the examples discussed herein are not intended to be exhaustive or limit the invention to any particular form. The terminology that has been used is intended to be in the nature of words of description rather than of limitation. Many modifications and variations are possible in light of the above teachings and the invention may be practiced otherwise than as specifically described.