Patent Description:
Known materials handling vehicles include a power unit, a mast assembly, and a platform assembly that includes a fork carriage assembly coupled to the mast assembly for vertical movement relative to the power unit. The mast assembly and platform assembly may each include components that are controlled by a hydraulic working fluid, such as pressurized oil. Valves provided within hydraulic fluid circuits associated with the mast and platform assemblies may control the flow of the working fluid to the components for effecting various functions performed by the components, such as raising/lowering, traversing (also known as side shifting), and tilting of the fork carriage assembly.

An example of such a materials handling vehicle is known from <CIT>.

In accordance with the claimed invention a materials handling vehicle is provided. The materials handling vehicle comprises a load handling assembly including a mast assembly, and a fork carriage assembly comprising a fork support and at least one fork assembly, the at least one fork assembly including a first fork member, which is fixed to the fork support, and a second fork member. The materials handling vehicle further comprises a tilt assembly that tilts the fork support relative to the mast assembly such that a central axis of the at least one fork assembly is positionable in a plurality of different positions relative to a horizontal direction. The horizontal direction is defined with respect to a floor surface on which the vehicle is located. The materials handling vehicle further comprises a fork extension/retraction assembly that moves the second fork member relative to the first fork member in a first direction that is parallel to the central axis of the at least one fork assembly such that the fork extension/retraction assembly selectively moves the second fork member toward or away from the fork support in the first direction.

The tilt assembly comprises at least one tilt cylinder assembly including a cylinder and a piston.

The extension of the piston may cause the tilt assembly to tilt the fork support relative to the mast assembly such that the fork support and the at least one fork assembly move into a tilt position, and a subsequent retraction of the piston may cause the tilt assembly to tilt the fork support relative to the mast assembly such that the fork support and the at least one fork assembly move into a home position.

The at least one tilt cylinder assembly may have direction of elongation generally in the vertical direction.

The materials handling vehicle further comprises at least one cam assembly coupled to a corresponding tilt cylinder assembly, the cam assembly driven by the piston of the tilt cylinder assembly to tilt the fork support relative to the mast assembly.

The cam assembly comprises a cam weldment including a roller stud that is not concentric with a bearing surface of the cam weldment.

Rotation of the cam weldment may cause the roller stud to move with an arc-like movement corresponding to the rotation of the cam weldment, wherein the arc-like movement tilts the fork support relative to the mast assembly.

The fork support may be tiltable by the tilt assembly such that the central axis of the at least one fork assembly is positionable up to about plus (+) or minus (-) <NUM> degrees relative to the horizontal direction.

The materials handling vehicle may further comprise a spacer structure that sets the central axis of the at least one fork assembly at a predetermined angle relative to the horizontal direction.

The vehicle may comprise two fork assemblies.

The second fork member may be positioned over the first fork member.

The materials handling vehicle may further comprise a power unit, a platform assembly including an operator compartment, and a main mast assembly, wherein the mast assembly comprises an auxiliary mast assembly. The main mast assembly may vertically move the platform assembly and the auxiliary mast assembly relative to the power unit.

A headlength of the load handling assembly, which headlength is defined as a length from an outer surface of the fork support opposite to the mast assembly, to an inner surface of the tilt assembly, may be less than about ten (<NUM>) inches (<NUM>).

The mast assembly may comprise a generally vertical first mast structure and a generally vertical second mast structure, wherein the second mast structure is rotatable relative to the first mast structure.

The headlength may encompass the fork support, the second mast structure, and the tilt assembly.

The tilt assembly may comprise at least one tilt cylinder assembly including a cylinder and a piston, the cylinder mounted to a flange that extends outwardly from the fork support toward the mast assembly.

The headlength may encompass the fork support, the second mast structure, the at least one tilt cylinder assembly, and the flange.

In accordance with a preferred aspect, a materials handling vehicle is provided. The materials handling vehicle comprises a power unit, a platform including an operator compartment, a load handling assembly including an auxiliary mast assembly, and a main mast assembly that moves the platform and load handling assembly relative to the power unit. The materials handling vehicle further comprises a fork carriage assembly comprising a fork support and first and second fork assemblies. Each of the first and second fork assemblies includes a first fork member, which is fixed to the fork support, and a second fork member. The materials handling vehicle further comprises a tilt assembly that tilts the fork support relative to the mast assembly such that a central axis of first and second fork assemblies is positionable in a plurality of different positions relative to a horizontal direction. The horizontal direction is defined with respect to a floor surface on which the vehicle is located. The materials handling vehicle further comprises a fork extension/retraction assembly that moves the second fork member of each fork assembly relative to the first fork member in a first direction that is parallel to the central axis of the first and second fork assemblies such that the fork extension/retraction assembly selectively moves the second fork members toward or away from the fork support in the first direction.

The tilt assembly comprises first and second tilt cylinder assemblies, each including a cylinder and a piston.

The extension of the piston may cause the tilt assembly to tilt the fork support relative to the auxiliary mast assembly such that the fork support and the fork assemblies move into a tilt position, and a subsequent retraction of the piston may cause the tilt assembly to tilt the fork support relative to the mast assembly such that the fork support and the fork assemblies move into a home position.

The tilt cylinder assemblies may each have direction of elongation generally in the vertical direction.

The materials handling vehicle further comprises first and second cam assemblies coupled to a corresponding tilt cylinder assembly, the cam assemblies driven by the piston of the corresponding tilt cylinder assembly to tilt the fork support relative to the auxiliary mast assembly.

Each cam assembly comprises a cam weldment including a roller stud that is not concentric with a bearing surface of the respective cam weldment.

Rotation of each cam weldment may cause the corresponding roller stud to move with an arc-like movement corresponding to the rotation of the cam weldment, wherein the arc-like movement tilts the fork support relative to the auxiliary mast assembly.

The fork support may be tiltable by the tilt assembly such that the central axis of the fork assemblies is positionable up to about plus (+) or minus (-) <NUM> degrees relative to the horizontal direction.

The materials handling vehicle may further comprise a spacer structure that sets the central axis of the fork assemblies at a predetermined angle relative to the horizontal direction.

The second fork member of each fork assembly may be positioned over the corresponding first fork member.

A headlength of the load handling assembly, which headlength is defined as a length from an outer surface of the fork support opposite to the auxiliary mast assembly, to an inner surface of the tilt assembly, may be less than about ten (<NUM>) inches (<NUM>).

The auxiliary mast assembly may comprise a generally vertical first mast structure and a generally vertical second mast structure, wherein the second mast structure is rotatable relative to the first mast structure.

The tilt assembly may comprise first and second tilt cylinder assemblies, each including a cylinder and a piston, the cylinder of each tilt cylinder assembly mounted to a corresponding flange that extends outwardly from the fork support toward the auxiliary mast assembly.

The headlength may encompass the fork support, the second mast structure, the tilt cylinder assemblies, and the flanges.

While the specification concludes with claims particularly pointing out and distinctly claiming the present embodiments, it is believed that the present embodiments will be better understood from the following description in conjunction with the accompanying Drawing Figures, in which like reference numerals identify like elements, and wherein:.

The following text sets forth a broad description of numerous different embodiments of the present disclosure. The description is to be construed as exemplary only and does not describe every possible embodiment since describing every possible embodiment would be impractical, if not impossible, and it will be understood that any feature, characteristic, component, composition, ingredient, product, step or methodology described herein can be deleted, combined with or substituted for, in whole or part, any other feature, characteristic, component, composition, ingredient, product, step or methodology described herein. It should be understood that multiple combinations of the embodiments described and shown are contemplated and that a particular focus on one embodiment does not preclude its inclusion in a combination of other described embodiments. Numerous alternative embodiments could also be implemented, using either current technology or technology developed after the filing date of this patent, which would still fall within the scope of the claims.

Referring now to the drawings, and particularly to <FIG>, which illustrate a materials handling vehicle <NUM> constructed in accordance with embodiments. In the illustrated embodiment, the vehicle <NUM> comprises a turret stockpicker, such as the turret stockpicker disclosed in <CIT> entitled "ELECTRONICALLY CONTROLLED VALVE FOR A MATERIALS HANDLING VEHICLE," assigned to the applicant, Crown Equipment Corporation.

The vehicle <NUM> includes a power unit <NUM>, a platform assembly <NUM> including an operator compartment OC, and a load handling assembly <NUM>. The power unit <NUM> includes a power source, such as a battery unit <NUM>, a pair of load wheels <NUM>, see <FIG>, positioned under the platform assembly <NUM>, and a steered wheel <NUM>, see <FIG>, positioned under the rear <NUM> of the power unit <NUM>. The vehicle <NUM> further comprises a main mast assembly <NUM> coupled to the power unit <NUM> on which the platform assembly <NUM> moves vertically. The main mast assembly <NUM> comprises a first mast 28a fixedly coupled to the power unit <NUM>, and a second mast 28b movably coupled to the first mast 28a, see <FIG> and <FIG>. While the illustrated main mast assembly <NUM> includes two masts 28a, 28b, the main mast assembly <NUM> may include additional or fewer masts.

A main mast piston/cylinder unit <NUM> is provided in the first mast 28a for effecting vertical movement of the second mast 28b and the platform assembly <NUM> relative to the first mast 28a and the power unit <NUM>, see <FIG>. It is noted that a load handling assembly <NUM> (to be discussed in greater detail below) is mounted to the platform assembly <NUM>; hence, the load handling assembly <NUM> moves with the platform assembly <NUM> when the main mast assembly <NUM> is raised or lowered. A cylinder 50a forming part of the piston/cylinder unit <NUM> is fixedly coupled to the power unit <NUM>. A piston or ram 50b forming part of the piston/cylinder unit <NUM> is fixedly coupled to the second mast 28b such that movement of the piston 50b effects movement of the second mast 28b relative to the first mast 28a. The piston 50b comprises a pulley 50c on its distal end, which engages a pair of chains <NUM> and <NUM>. One unit of vertical movement of the piston 50b results in two units of vertical movement of the platform assembly <NUM> and load handling assembly <NUM>. Each chain <NUM>, <NUM> is fixedly coupled at a first end 52a, 54a to the first mast 28a and coupled at a second end 52b, 54b to the platform assembly <NUM>. Hence, upward movement of the piston 50b relative to the cylinder 50a effects upward movement of the platform assembly <NUM> and load handling assembly <NUM> via the pulley 50c pushing upwardly against the chains <NUM>, <NUM>. Downward movement of the piston 50b effects downward movement of the platform assembly <NUM> and load handling assembly <NUM>. Movement of the piston 50b also effects movement of the second mast 28b.

The load handling assembly <NUM> comprises an auxiliary mast assembly <NUM> including a first mast structure <NUM>, which comprises a generally vertical mast structure that is movable back and forth transversely in a first direction relative to the platform assembly <NUM>, as designated by an arrow D200 in <FIG>, via a traverse hydraulic motor <NUM>, see also <FIG>, <FIG> and <FIG>. The auxiliary mast assembly <NUM> further comprises a second mast structure <NUM>, which comprises a generally vertical mast structure that moves transversely with the first mast structure <NUM> and is also capable of rotating relative to the first mast structure <NUM> via first and second pivot piston/cylinder units 102a and 102b, see <FIG>. In the illustrated embodiment, the second mast structure <NUM> is capable of rotating back and forth through an angle of about <NUM>°.

Coupled to the second mast structure <NUM> of the auxiliary mast assembly <NUM> is a fork carriage assembly <NUM> comprising a pair of forks <NUM> and a fork support <NUM>. The fork carriage assembly <NUM> is capable of moving vertically relative to the second mast structure <NUM>, as designated by an arrow <NUM> in <FIG>. Rotation of the second mast structure <NUM> relative to the first mast structure <NUM> permits an operator to position the forks <NUM> in one of at least a first position, illustrated in <FIG>, <FIG> and <FIG>, and a second position, illustrated in <FIG>, where the second mast structure <NUM> has been rotated through an angle of about <NUM>° from its position shown in <FIG>, <FIG> and <FIG>. The fork carriage assembly <NUM> will be described in more detail below.

According to embodiments, the forks <NUM> comprise a first fork assembly <NUM> and a second fork assembly <NUM>, although additional or fewer fork assemblies may be included. The first fork assembly <NUM> comprises a first fork member 160A, which is fixed to the fork support <NUM>, and a second fork member 160B positioned over the first fork member 160A. The second fork member 160B is movable in the direction of the arrow D200 shown in <FIG> relative to the first fork member 160A via a first extension piston/cylinder unit 106a of a fork extension/retraction assembly <NUM> (see <FIG>), the direction of the arrow D200 defining a direction of elongation of the first and second fork members 160A, 160B. With reference additionally to <FIG>, the second fork assembly <NUM> comprises a first fork member 162A, which is fixed to the fork support <NUM>, and a second fork member 162B. The second fork member 162B is movable in the direction of the arrow D200 shown in <FIG> relative to the first fork member 162A via a second extension piston/cylinder unit 106b of the fork extension/retraction assembly <NUM>, see <FIG>, the direction of the arrow D200 defining a direction of elongation of the first and second fork members 162A, 162B. The second extension piston/cylinder unit 106b may be substantially similar to the first extension piston/cylinder unit 106a. When the first and second extension piston/cylinder units 106a and 106b of the fork extension/retraction assembly <NUM> are actuated so as to extend their pistons, the second fork members 160B and 162B move away from, i.e., extend out from, the fork support <NUM> and the first fork members 160A and 162A so as to define telescopic or extended forks. Conversely, when the first and second extension piston/cylinder units 106a and 106b of the fork extension/retraction assembly <NUM> are actuated so as to retract their pistons, the second fork members 160B and 162B move toward the fork support <NUM> and the first fork members 160A and 162A.

A piston/cylinder unit <NUM> is provided in the second mast structure <NUM> for effecting vertical movement of the fork carriage assembly <NUM> relative to the second mast structure <NUM>, see <FIG>. A cylinder 70a forming part of the piston/cylinder unit <NUM> is fixedly coupled to the second mast structure <NUM>. A piston or ram 70b forming part of the unit <NUM> comprises a pulley 70c on its distal end, which engages a chain <NUM>. One unit of vertical movement of the piston 70b results in two units of vertical movement of the fork carriage assembly <NUM>. The chain <NUM> is fixedly coupled at a first end 72a to the cylinder 70a and fixedly coupled at a second end 72b to the fork support <NUM>. The chain <NUM> extends from the cylinder 70a, over the pulley 70c and down to the fork support <NUM>. Upward movement of the piston 70b effects upward movement of the fork carriage assembly <NUM> relative to the second mast structure <NUM>, while downward movement of the piston 70b effects downward movement of the fork carriage assembly <NUM> relative to the second mast structure <NUM>.

<FIG> illustrate more detailed views of the fork carriage assembly <NUM>, particularly the fork support <NUM>. The fork support <NUM> comprises a frame <NUM> having a generally rectangular shape. The frame <NUM> provides the structural support for the forks <NUM> via a conventional rod or pin (not shown) that is coupled to the frame <NUM> at respective fork pivot locations 82A, 82B and extends through fork hanger openings 84A, 84B at the top of each of the forks <NUM>. The forks <NUM> are pivotably supported to the fork support <NUM> at the fork pivot locations 82A, 82B, as will be discussed in greater detail herein.

A backside of the frame <NUM>, illustrated in <FIG>, includes a pair of generally vertically extending flanges 88A, 88B that extend outwardly from the frame <NUM> toward the auxiliary mast assembly <NUM>. A tilt assembly <NUM> is provided for tilting the fork support <NUM> and the forks <NUM> relative to the auxiliary mast assembly <NUM>. The tilt assembly <NUM> comprises first and second tilt cylinder assemblies 92A, 92B, each having a direction of elongation generally in the vertical direction, which vertical direction is perpendicular to a horizontal direction Hz (see <FIG> and <FIG>), wherein the horizontal direction Hz is defined with respect to the floor surface on which the vehicle <NUM> is located. First and second cylinders 94A, 94B of the tilt cylinder assemblies 92A, 92B are coupled to mount units 96A, 96B, which are fixed to the frame <NUM> of the fork support <NUM> and to the respective flanges 88A, 88B. With reference to <FIG>, the cylinders 94A, 94B are coupled to the mount units 96A, 96B via first mounting structure <NUM> (only the first mounting structure <NUM> for the cylinder 94A is shown in <FIG> and will be described herein, it being understood that the first mounting structure <NUM> for the other cylinder 94B is the same as the described mounting structure <NUM>) that permits the cylinder assemblies 92A, 92B to pivot within slots 99A, 99B formed in the mount units 96A, 96B. The exemplary first mounting structure <NUM> illustrated in <FIG> comprises a pin 97A, e.g., a clevis pin, that extends through opposing bores formed in the mount unit 96A adjacent to the slot 99A and is received in an opening 97B within the first cylinder 94A. The pin 97A may be fixed in place with a cotter pin 97C as shown in <FIG>. It is understood that other suitable types of mounting structures can be used for pivotably supporting the cylinder assemblies 92A, 92B to the mount units 96A, 96B.

First and second pistons or rams 102A, 102B of the tilt cylinder assemblies 92A, 92B are coupled to respective first and second cam assemblies 104A, 104B that are rotatable with respect to the flanges 88A, 88B. Referring still to <FIG>, the cam assemblies 104A, 104B each include a cam lever arm 105A, 105B, which are pivotably coupled to the respective rams 102A, 102B via second mounting structure <NUM> (only the second mounting structure <NUM> for the first cam assembly 104A is shown in <FIG> and will be described herein, it being understood that the second mounting structure <NUM> for the second cam assembly 104B is the same as the described mounting structure <NUM>). The exemplary second mounting structure <NUM> illustrated in <FIG> comprises a pin 108A, e.g., a clevis pin, that extends through opposing bores formed in the mount unit ram 102A and is received in an opening 108B within the cam lever arm 105A. The pin 108A may be fixed in place with a cotter pin 108C as shown in <FIG>. It is understood that other suitable types of mounting structures can be used for pivotably supporting the rams 102A, 102B to the cam lever arms 105A, 105B.

The first cam assembly 104A will now be described, it being understood that the second cam assembly 104B is the same as the described first cam assembly 104A. The cam assembly 104A comprises a keeper plate <NUM> that is bolted to the cam lever arm 105A via bolts 112A, 112B. The keeper plate <NUM> prevents dirt/debris from entering the cam assembly 104A and couples the cam lever arm 105A to a cam weldment <NUM>, i.e., the bolts 112A, 112B respectively extend through a spacer/washer structure 105A1, which is assembled onto the pin 108A, and a bore 105A2 formed in the cam lever arm 105A, 105B and are threaded into threaded openings 114A<NUM>, 114A<NUM> formed in the cam weldment 114A. The cam weldments <NUM> are coupled to respective cam rollers <NUM> (see <FIG> and <FIG>) that move in a generally vertical direction within channels <NUM> defined by the second mast structure <NUM> of the auxiliary mast assembly <NUM>. Movement of the cam assemblies 104A, 104B and the cam rollers <NUM> causes tilting of the fork support <NUM> and the forks <NUM> relative to the auxiliary mast assembly <NUM>. Specifically, a roller stud <NUM> of the cam weldment <NUM>, upon which roller stud <NUM> the cam roller <NUM> is supported, is not concentric with the bearing surface of the cam weldment <NUM>. Thus, when the tilt cylinder assembly 92A is actuated to cause the ram 102A to extend or retract to thereby drive rotation of the cam lever arm 105A and the cam weldment <NUM>, the roller stud <NUM> moves with an arc-like movement corresponding to the rotation of the cam weldment <NUM>. This arc-like movement causes the frame <NUM> of the fork support <NUM> and the forks <NUM> to tilt relative to the auxiliary mast assembly <NUM> such that a central axis CA (see <FIG>, <FIG>, and <FIG>) of each of the fork assemblies <NUM>, <NUM> is positionable in a plurality of different positions relative to the horizontal direction Hz, as will be described in greater detail below. More specifically, the arc-like movement of the roller stud <NUM><NUM> effectively pushes the top of the frame <NUM> of the fork support <NUM> toward/away from the auxiliary mast assembly <NUM> when the first and second cylinders 94A, 94B of the tilt cylinder assemblies 92A, 92B are extended/retracted, i.e., the frame <NUM> of the fork support <NUM> pivots toward/away from the auxiliary mast assembly <NUM> at a pivot point defined by lower carriage/mast roller studs <NUM> coupled to the flanges 88A, 88B.

A manifold <NUM>, illustrated in <FIG>, is provided to supply hydraulic fluid to the first and second extension piston/cylinder units 106a, 106b of the fork extension/retraction assembly <NUM> and to the first and second tilt cylinder assemblies 92A, 92B of the tilt assembly <NUM> via flow path defining conduits or hoses, hereinafter referred to as "hydraulic hoses". In the exemplary manifold shown in <FIG>: a first hydraulic hose 132A provides hydraulic fluid to the first extension piston/cylinder unit 106a during a fork extend operation; a second hydraulic hose 132B provides hydraulic fluid to the second extension piston/cylinder unit 106b during a fork extend operation; a third hydraulic hose 132C provides hydraulic fluid to the second tilt cylinder assembly 92B during a tilt retract operation; a fourth hydraulic hose 132D provides hydraulic fluid to the first tilt cylinder assembly 92A during a tilt retract operation; a fifth hydraulic hose 132E provides hydraulic fluid to the second tilt cylinder assembly 92B during a tilt extend operation; a sixth hydraulic hose 132F provides hydraulic fluid to the first extension piston/cylinder unit 106a during a fork retract operation; a seventh hydraulic hose <NUM> provides hydraulic fluid to the first tilt cylinder assembly 92A during a tilt extend operation; and an eighth hydraulic hose <NUM> provides hydraulic fluid to the second extension piston/cylinder unit 106b during a fork retract operation. Additional ports 134A, 134B are provided in the manifold for main hydraulic fluid supply and return to a hydraulic fluid source (not shown) located on the vehicle <NUM>. It is understood that other manifold configurations could be used, including using separate manifolds for one or more of the piston/cylinder units 106a, 106b and/or tilt cylinder assemblies 92A, 92B.

With reference to <FIG>, a headlength HL. of the load handling assembly <NUM>, which headlength HL is defined as a length from an outer surface 64A of the fork support <NUM>, i.e., a surface of the fork support <NUM> opposite to the second mast structure <NUM> of the auxiliary mast assembly <NUM>, to a surface of the tilt assembly <NUM>, i.e., an inner surface 92A1, 92B1 of the tilt cylinder assemblies 92A, 92B is less than about ten (<NUM>) inches (<NUM>) and may be about <NUM> to about <NUM> inches (<NUM> to <NUM>). The inner surface 92A1, 92B1 of the tilt cylinder assemblies 92A, 92B may generally coincide with an inner surface 44A of the second mast structure <NUM> of the auxiliary mast assembly <NUM>, i.e., a surface of the auxiliary mast assembly <NUM> opposite to the fork support <NUM>, and an inner surface of the flanges 88A, 88B. The headlength HL encompasses the fork support <NUM>, the second mast structure <NUM> of the auxiliary mast assembly <NUM>, the tilt cylinder assemblies 92A, 92B, the flanges 88A, 88B, and the manifold <NUM>, i.e., all of these structures are located within the headlength HL. The headlength HL of the load handling assembly <NUM> according to the present embodiment is believed to be significantly less than headlengths of prior art load handling assemblies that utilize different assemblies for effecting tilting of the fork support and forks.

Turning now to <FIG> and <FIG>, select positions of the fork support <NUM> and forks <NUM>, along with the corresponding positions of the tilt cylinder assemblies 92A, 92B, cam assemblies 104A, 104B, and cam rollers <NUM> are shown. It is understood that the positions shown in <FIG> and <FIG> are exemplary and are meant to show select ones of many possible positions.

Initially, it is noted that scenario A corresponds to a configuration wherein a first spacer structure SP<NUM> (see <FIG>) is provided to set a "home" position of the fork support <NUM> and forks <NUM> such that the central axis CA of each of the fork assemblies <NUM>, <NUM> is generally parallel to the horizontal direction Hz. Scenario B corresponds to a configuration wherein a second spacer structure SP<NUM> (see <FIG>) is provided to set a "home" position of the fork support <NUM> and forks <NUM> such that the central axis CA of each of the fork assemblies <NUM>, <NUM> is set at a predetermined positive first angle θ<NUM> relative to the horizontal direction Hz, wherein the first angle θ<NUM> may be, for example, about <NUM> degrees. Scenario C, shown only in <FIG>, corresponds to a configuration wherein a third spacer structure SP<NUM> is provided to set a "home" position of the fork support <NUM> and forks <NUM> such that the central axis CA of each of the fork assemblies <NUM>, <NUM> is set at a predetermined positive second angle θ<NUM> relative to the horizontal direction Hz, wherein the second angle θ<NUM> may be less than the first angle θ<NUM>, for example, about <NUM> degrees. The "home" position is defined by a position of the fork support <NUM> wherein the outer surface 64A thereof is generally perpendicular to the horizontal direction HZ.

Scenario A<NUM> illustrated in <FIG> represents the home position of the fork support <NUM> and forks <NUM> with the first spacer structure SP<NUM>, wherein the central axis CA of each of the fork assemblies <NUM>, <NUM> is generally parallel to the horizontal direction Hz. The forks <NUM> are provided in a retracted position in scenario A<NUM>, wherein the piston of the first and second extension piston/cylinder units 106a and 106b of the fork extension/retraction assembly <NUM> are in their retracted positions such that the second fork members 160B and 162B are located in close proximity to the fork support <NUM>. The scenario A<NUM> illustrated in <FIG> represents a "tilt" position of the fork support <NUM> and forks <NUM> with the first spacer structure SP<NUM>, wherein the central axis CA of each of the fork assemblies <NUM>, <NUM> is positioned at a third angle θ<NUM> relative to the horizontal direction Hz. The third angle θ<NUM> may be, for example, about -<NUM> degrees. The forks <NUM> are provided in the retracted position in scenario A<NUM>.

Scenario B<NUM> illustrated in <FIG> represents the home position of the fork support <NUM> and forks <NUM> with the second spacer structure SP<NUM>, wherein the central axis CA of each of the fork assemblies <NUM>, <NUM> is set at the first angle θ<NUM> relative to the horizontal direction Hz. The forks <NUM> are provided in the retracted position in scenario B<NUM>. The scenario B<NUM> illustrated in <FIG> represents the tilt position of the fork support <NUM> and forks <NUM> with the second spacer structure SP<NUM>, wherein the central axis CA of each of the fork assemblies <NUM>, <NUM> is generally parallel to the horizontal direction Hz. The forks <NUM> are provided in the retracted position in scenario B<NUM>.

Scenario A<NUM> illustrated in <FIG> represents the home position of the fork support <NUM> and forks <NUM> with the first spacer structure SP<NUM>, wherein the central axis CA of each of the fork assemblies <NUM>, <NUM> is generally parallel to the horizontal direction Hz. The forks <NUM> are provided in an extended position in scenario A<NUM>, wherein the piston of the first and second extension piston/cylinder units 106a and 106b of the fork extension/retraction assembly <NUM> are in their extended positions such that the second fork members 160B and 162B are spaced from the fork support <NUM>, e.g., by about <NUM> inches (<NUM>), about <NUM> inches (<NUM>), or up to about <NUM> inches (<NUM>) as desired. The scenario A<NUM> illustrated in <FIG> represents the tilt position of the fork support <NUM> and forks <NUM> with the first spacer structure SP<NUM>, wherein the central axis CA of each of the fork assemblies <NUM>, <NUM> is positioned at the third angle θ<NUM> relative to the horizontal direction Hz. The forks <NUM> are provided in the extended position in scenario A<NUM>.

Scenario B<NUM> illustrated in <FIG> represents the home position of the fork support <NUM> and forks <NUM> with the second spacer structure SP<NUM>, wherein the central axis CA of each of the fork assemblies <NUM>, <NUM> is set at the first angle θ<NUM> relative to the horizontal direction Hz. The forks <NUM> are provided in the extended position in scenario B<NUM>. The scenario B<NUM> illustrated in <FIG> represents the tilted position of the fork support <NUM> and forks <NUM> with the second spacer structure SP<NUM>, wherein the central axis CA of each of the fork assemblies <NUM>, <NUM> is generally parallel to the horizontal direction Hz. The forks <NUM> are provided in the extended position in scenario B<NUM>.

Scenario C shown in <FIG> is provided to illustrate another exemplary spacer structure SP<NUM> to define a home position of the fork support <NUM> and forks <NUM> at an additional angle relative to the horizontal direction Hz.

A schematic diagram of a hydraulic circuit <NUM> of the vehicle <NUM> is illustrated in <FIG> and <FIG>. The hydraulic circuit <NUM> in the embodiment shown comprises a manifold <NUM>, which may be located in an upper portion 42A of the first mast structure <NUM> of the load handling assembly <NUM>, see <FIG>.

Hydraulic hoses <NUM> enable working fluid communication between the valves and pumps, cylinders, and motors associated with the hydraulic circuit <NUM>. Provided in the manifold <NUM> are a plurality of mechanical and electronically controlled valves that receive the working fluid, e.g., a pressurized hydraulic oil, during normal operation of the vehicle <NUM>, e.g., when the components of the vehicle are fully operational. The electronically controlled valves of the manifold <NUM> may comprise electronically controlled solenoid-operated proportional valves, coupled to and actuated by a controller <NUM> in response to operator generated commands via first and second multi-function controllers 220A and 220B (see <FIG> and <FIG>), and are provided for implementing various vehicle functions associated with the respective valve.

Exemplary valves in the illustrated manifold <NUM> include an auxiliary lower valve <NUM> that controls the flow of the working fluid out of the auxiliary hoist piston/cylinder unit <NUM> when a lowering command is being implemented; an auxiliary raise valve <NUM> that controls the flow of the working fluid into the auxiliary hoist piston/cylinder unit <NUM> when a raise command is being implemented; a traverse valve <NUM> that controls the flow of the working fluid to and/or from the traverse hydraulic motor <NUM> when a traverse command is being implemented; a pivot valve <NUM> that controls the flow of the working fluid to and/or from the first and second pivot piston/cylinder units 102a, 102b when a pivot command is being implemented; an extend valve <NUM> (see <FIG>) that controls the flow of the working fluid to and/or from the first and second extension piston/cylinder units 106a and 106b when a second/fourth fork member extension/retraction command is being implemented; a tilt control valve <NUM> (see <FIG>) that controls the flow of the working fluid to and/or from the first and second tilt cylinder assemblies 92A, 92B when a tilt command is being implemented; and a fork function valve <NUM> that controls fork function (tilt or extend. ) speed and direction. A load handler valve <NUM> is also provided in the manifold <NUM>. The load handler valve <NUM> controls a pressure level within the hydraulic manifold <NUM> such that the hydraulic fluid pressure downstream from the load handler valve <NUM> is at a sufficient level for proper operation of a selected one or more of the electronically controlled solenoid valves <NUM>, <NUM>, <NUM>, <NUM>, <NUM>.

In the illustrated embodiment, the auxiliary lower valve <NUM> may comprise a solenoid-operated, two-way, normally closed, proportional directional valve; the auxiliary raise valve <NUM> may comprise a solenoid-operated, two-way, normally closed, proportional directional valve; the traverse valve <NUM> may comprise a solenoid-operated, <NUM>-way, <NUM>-position, proportional directional, load sensing valve; the pivot valve <NUM> may comprise a solenoid-operated, <NUM>-way, <NUM>-position, proportional directional, load sensing valve; the load handler valve <NUM> may comprise a solenoid-operated, proportional pressure control relief valve; the fork function valve <NUM> may comprise a <NUM>-way, <NUM>-position proportional valve.

The hydraulic circuit <NUM> comprises other electronically controlled solenoid-operated valves mounted in the power unit <NUM>. For example, an electronically controlled solenoid-operated non-proportional valve <NUM> is provided for blocking fluid flow out of the mast piston/cylinder unit <NUM> until the valve <NUM> is energized. An electronically controlled solenoid-operated non-proportional valve <NUM> is provided for blocking working fluid to the mast piston/cylinder unit <NUM> when not energized and allows fluid flow to the mast piston/cylinder unit <NUM> when the valve <NUM> is energized. An electronically controlled solenoid-operated non-proportional valve <NUM> is provided for blocking working fluid flow to the manifold <NUM> if working fluid is being provided to or exiting the mast piston/cylinder unit <NUM> and allows working fluid flow to the manifold <NUM> when the valve <NUM> is energized. An electronically controlled solenoid-operated proportional valve <NUM> is provided and functions as a load holding valve for the mast piston/cylinder unit <NUM> and must be energized when the mast piston/cylinder unit <NUM> is lowered such that the working fluid flows through the valve <NUM> back through a pump <NUM>.

An electronically controlled solenoid-operated, normally closed, non-proportional valve <NUM> is coupled to a base of the cylinder 70a of the auxiliary hoist piston/cylinder unit <NUM> and is energized by the controller <NUM> during a controlled descent of the piston 70b of the unit <NUM>.

In accordance with embodiments and with reference to <FIG>, the hydraulic circuit <NUM> further comprises fork extend and retract check valves <NUM>, <NUM> in communication with the extend control valve <NUM>. A flow divider valve <NUM> is in communication with the fork extend check valve <NUM> to limit the flow of hydraulic fluid to the first and second extension piston/cylinder units 106a, 106b of the fork extension/retraction assembly <NUM>. The flow divider valve <NUM> is intended to provide a <NUM>:<NUM> flow volume to the first and second extension piston/cylinder units 106a, 106b.

The hydraulic circuit <NUM> additionally comprises a counterbalance retract valve <NUM> in communication with the tilt control valve <NUM>. When a load is present on the forks <NUM> (or just the weight of the forks <NUM> themselves), the fork support <NUM> will want to tilt down, rolling the cam weldments <NUM> backwards, and thus causing the cam lever arms 105A, 105B to push the tilt cylinder assemblies 92A, 92B in to their retracted position, which causes a load-induced pressure within the tilt cylinder assemblies 92A, 92B. The counterbalance retract valve <NUM> is provided to help to prevent drift of the fork support <NUM> and also has a feedback port that requires back pressure within the hydraulic circuit <NUM> so that the forks <NUM> do not quickly drop when a fork lower command is given. Pressure has to be given to the back side of the counterbalance retract valve <NUM> before it will open and allow flow therethrough.

With reference to <FIG>, two exemplary configurations for a pair of cam rollers <NUM>, <NUM>' and roller studs <NUM>, <NUM>' are respectively shown from above. The cam rollers <NUM>, <NUM>' and roller studs <NUM>, <NUM>' are located in respective channels <NUM>, <NUM>' defined by the second mast structures <NUM>, <NUM>' of the corresponding auxiliary mast assemblies <NUM>, <NUM>'.

With reference to <FIG>, the cam rollers <NUM> are cylindrical in shape, having first and second side edges 120A, 120B that are respectively generally parallel to one another. The roller studs <NUM> and the cam rollers <NUM> supported thereon may be oriented at an angle θ relative to a centerline CL extending between the spaced apart cam rollers <NUM>, such that one of the side edges 120A of each cam roller <NUM> is generally flush with an inner surface 44A of the respective second mast structures <NUM> that define the corresponding channels <NUM>. The angle θ may be less than about <NUM> degrees.

Turning now to <FIG>, the roller studs <NUM>' and the cam rollers <NUM>' supported thereon according to this embodiment may be generally parallel to a centerline CL extending between the spaced apart cam rollers <NUM>. The cam rollers <NUM>' illustrated in <FIG> are conical in shape, having first and second side edges 120A', 120B' that taper inwardly as the cam rollers <NUM>' extend toward one another, such that the first and second side edges 120A', 120B' of the cam rollers <NUM>' generally correspond to the shape of tapered inner surfaces 44A', 44B' of the respective second mast structures <NUM>' that define the corresponding channels <NUM>'. The conical shape of the cam rollers <NUM>' shown in <FIG> may allow for more surface contact between the cam rollers <NUM>' and the mast structure <NUM>', resulting in smoother movement of the cam rollers <NUM>' within the channels <NUM>'.

The embodiments disclosed herein may be incorporated into other materials handling vehicles, and are not limited to the turret truck illustrated in the drawings. Further, the various features, aspects, and embodiments described herein can be used in any combination(s) with one another, or on their own.

Claim 1:
A materials handling vehicle (<NUM>) comprising:
a load handling assembly (<NUM>) including a mast assembly (<NUM>);
a fork carriage assembly (<NUM>) comprising a fork support (<NUM>) and at least one fork assembly (<NUM>), the at least one fork assembly (<NUM>) including a first fork member (160A), which is fixed to the fork support (<NUM>), and a second fork member (160B); and
a fork extension/retraction assembly (<NUM>) configured to move the second fork member (160B) relative to the first fork member (160A) in a first direction that is parallel to the central axis of the at least one fork assembly (<NUM>) such that the fork extension/retraction assembly (<NUM>) is configured to selectively move the second fork member (160B) toward or away from the fork support (<NUM>) in the first direction
characterized by
a tilt assembly (<NUM>) configured to tilt the fork support relative to the mast assembly (<NUM>) such that a central axis of the at least one fork assembly (<NUM>) is positionable in a plurality of different positions relative to a horizontal direction, the horizontal direction defined with respect to a floor surface on which the vehicle (<NUM>) is located; wherein
the tilt assembly (<NUM>) comprises at least one tilt cylinder assembly (92A, 92B) including a cylinder (50a) and a piston (50b); and
the materials handling vehicle (<NUM>) further comprises at least one cam assembly (104A, 104B) coupled to a corresponding tilt cylinder assembly (92A, 92B), the cam assembly (104A, 104B) configured to be driven by the piston (50b) of the tilt cylinder assembly (92A, 92B) to tilt the fork support (<NUM>) relative to the mast assembly (<NUM>), wherein the cam assembly (104A, 104B) comprises a cam weldment (<NUM>) including a roller stud (<NUM>) that is not concentric with a bearing surface of the cam weldment (<NUM>).