Patent Description:
Material handling vehicles have been developed to transport goods loaded onto generally standardized transport platforms (e.g., pallets). Pallets generally can include vertical supports (e.g., stringers) connected to a support platform. The pallet and loaded goods may be lifted and transported with forks on the material handling vehicle. <CIT> discloses a pallet detection assembly for a material handling vehicle, the pallet detection assembly comprising:a body defining a cavity and including a proximity sensor housed at least partially within the cavity;an actuation plate including a tab coupled thereto and extending in a direction toward the body;an actuator including a cylinder coupled to the body and a plunger slidably received within the cylinder and coupled to the actuation plate, wherein the actuation plate is configured to non-pivotally displace relative to the body. <CIT> discloses a material handling vehicle with two pallet detection assemblies arranged at the inner edge of the forks.

The present disclosure relates generally to load detection systems and, more specifically, to a pallet detection assembly for a material handling vehicle.

The present disclosure provides material handling vehicle including a fork carriage having a first fork and a second fork laterally separated from the first fork, a first pallet detection assembly arranged adjacent to a laterally-outer edge of the first fork, and a second pallet detection assembly arranged adjacent to a laterally-outer of the second fork. The first pallet detection assembly includes a first body defining a first cavity and having a first proximity sensor housed at least partially within the first cavity, a first actuation plate having a first tab coupled thereto and extending in a direction toward the first body, a first actuator including a first cylinder coupled to the first body and a first plunger slidably received within the first cylinder and coupled to the first actuation plate. The first actuator is configured to movably couple the first actuation plate to the first body so that the first actuation plate is configured to non-pivotally displace relative to the first body. The second pallet detection assembly includes a second body defining a second cavity and having a second proximity sensor housed at least partially within the second cavity, a second actuation plate including a second tab coupled thereto and extending in a direction toward the second body, and a second actuator including a second cylinder coupled to the second body and a second plunger slidably received within the second cylinder and coupled to the second actuation plate. The second actuator is configured to movably couple the second actuation plate to the second body so that the second actuation plate is configured to non-pivotally displace relative to the second body.

Before any aspect of the present disclosure are explained in detail, it is to be understood that the present disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The present disclosure is capable of other configurations and of being practiced or of being carried out in various ways.

The following discussion is presented to enable a person skilled in the art to make and use aspects of the present disclosure. The following detailed description is to be read with reference to the figures, in which like elements in different figures have like reference numerals. The figures, which are not necessarily to scale, depict selected configurations and are not intended to limit the scope of the present disclosure.

It is also to be appreciated that material handling vehicles are designed in a variety of configurations to perform a variety of tasks. It will be apparent to those of skill in the art that the present disclosure is not limited to any specific material handling vehicle, and can also be provided with various other types of vehicle configurations, including for example, order pickers, SWING-REACH®, and any other lift vehicles. The various systems and methods disclosed herein are suitable for any of driver controlled, pedestrian controlled, remotely controlled, and autonomously controlled material handling vehicles.

In general, the pallet detection assemblies include an actuation plate that is selectively movable relative to a body within which a proximity senor is housed. The actuation plate is configured to move or displace non-pivotally relative to the body. That is, the each point along the load detection plate moves in unison and travel the same amount of distance relative to the body.

With reference to <FIG>, a pallet detection assembly <NUM> includes a body <NUM>, an actuation plate <NUM>, an actuator <NUM>. The pallet detection assembly <NUM> may include a first spring assembly <NUM>, and a second spring assembly <NUM>. In general, the actuator <NUM> movably couples the actuation plate <NUM> to the body <NUM>, so that the actuation plate <NUM> displaces non-pivotally relative to the body <NUM>, this displacement may be against a biasing force of the first spring assembly <NUM> and the second spring assembly <NUM>.

With specific reference to <FIG>, the body <NUM> defines a cavity <NUM> within which a proximity sensor <NUM> is at least partially housed. The body <NUM> may include a sensor mounting bracket <NUM>, a top wall <NUM>, a first side wall <NUM>, a second side wall <NUM>, a rear wall <NUM>, and a bottom wall <NUM>. In general, the top wall <NUM>, the first side wall <NUM>, the second side wall <NUM>, the rear wall <NUM>, and the bottom wall <NUM> may be coupled to one another or formed as a unitary component to define the cavity <NUM>. The rear wall <NUM> may define a first opening <NUM>, a second opening <NUM>, a third opening <NUM>, with the second opening <NUM> being arranged longitudinally between the first opening <NUM> and the third opening <NUM>. In the illustrated example, a barrel <NUM> may be arranged generally concentrically with the third opening <NUM> and may extend from the rear wall <NUM> in a direction toward the actuation plate <NUM>.

The sensor mounting bracket <NUM> may be engaged with the second side wall <NUM> longitudinally between the first opening <NUM> and the second opening <NUM>. The sensor mounting bracket <NUM> may support the proximity sensor <NUM> within the cavity <NUM> formed by the body <NUM>.

In the illustrated example, the proximity sensor <NUM> may include a sensor surface <NUM> arranged at one end thereof. The proximity sensor <NUM> may output a signal from the sensor surface <NUM> (e.g., a magnetic signal, an inductive signal, an electromagnetic sensor, etc.) and the proximity sensor <NUM> may be configured to detect if the output signal emitted from the sensor surface <NUM> is blocked or unblocked. It is to be appreciated that a variety of styles of sensors could be used in place of or in addition to a proximity sensor, including one or more mechanical or electrical switches, such as snap-action, or pressure switches or strain gauges, as non-limiting examples.

In the illustrated example, the actuation plate <NUM> may include a tab <NUM> coupled to the actuation plate <NUM> and that extends in a direction toward the body <NUM>. In general, the tab <NUM> may be arranged on the actuation plate <NUM> so that the tab <NUM> eventually aligns with and covers the sensor surface <NUM> of the proximity sensor <NUM> during non-pivotal displacement of the actuation plate <NUM> toward the body <NUM>. In the illustrated example, the actuation plate <NUM> may include an angled portion <NUM> arranged an end thereof. The angled portion <NUM> may extend in a direction toward the body <NUM>. In some examples, the angled portion <NUM> may facilitate non-pivotal displacement of the actuation plate <NUM> relative to the body <NUM> if a load is dropped onto the forks of an MHV from above (i.e., not slide along the forks).

The actuator <NUM> may include a cylinder <NUM> and a plunger <NUM> slidably received within the cylinder <NUM>. The cylinder <NUM> may be received within and coupled to the second opening <NUM> of the body <NUM>. The plunger <NUM> may be coupled to the actuation plate <NUM>. The slidable movement governed by the plunger <NUM> received within the cylinder <NUM> may provide a non-pivotal coupling between the actuation plate <NUM> and the body <NUM>. That is, the actuator <NUM> may be configured to movably couple the actuation plate <NUM> to the body <NUM> so that that actuation plate <NUM> is configured to non-pivotally displace relative to the body <NUM>. The first spring assembly <NUM> and the second spring assembly <NUM> may be configured to provide stability and a biasing force against which an input force may non-pivotally displace the actuation plate <NUM> in a direction toward the body <NUM>.

The first spring assembly <NUM> and the second spring assembly <NUM> may be arranged on opposing sides of the actuator <NUM>. That is, the first spring assembly <NUM> may be coupled between the body <NUM> and the actuation plate <NUM> on one side of the actuator <NUM> and the second spring assembly <NUM> may be coupled between the body <NUM> and the actuation plate <NUM> on a longitudinally-opposing side of the actuator <NUM>. Each of the first spring assembly <NUM> and the second spring assembly <NUM> may include a spring <NUM> and a shaft <NUM>. Each of the springs <NUM> may be biased between the body <NUM> and the actuation plate <NUM> and may be configured to bias the actuation plate <NUM> in a direction away from the body <NUM>.

In general, each of the shafts <NUM> may be slidably received within and arranged concentrically within the springs <NUM>. The shaft <NUM> of the first spring assembly <NUM> may be coupled to the first opening <NUM> of the body <NUM>. The shaft <NUM> of the first spring assembly <NUM> may be slidably received by one of the actuation plate <NUM> and the first opening <NUM> to enable the spring <NUM> of the first spring assembly <NUM> to compress during non-pivotal displacement of the actuation plate <NUM> in a direction toward the body <NUM>. The shaft <NUM> of the second spring assembly <NUM> may be configured to be slidably received within the barrel <NUM> of the body <NUM> to compress the spring <NUM> of the second spring assembly <NUM> during non-pivotal displacement of the actuation plate <NUM> in a direction toward the body <NUM>. In the illustrated example, the shaft <NUM> of the second spring assembly <NUM> may extend partially toward but not into the barrel <NUM>, when the actuation plate <NUM> is in an extended position (see <FIG>). In some examples, the shaft <NUM> of the second spring assembly <NUM> may at least partially extend into and through the barrel <NUM>, when the actuation plate <NUM> is in the extended position (see <FIG>).

With specific reference to <FIG>, during operation, the pallet detection assembly <NUM> may be mounted to an MHV in a location to ensure that a pallet supported on forks of the MHV engages the actuation plate <NUM> when the pallet is properly seated and received fully onto the forks. Prior to the MHV engaging a load, or when a load is not fully received on the forks, the actuation plate <NUM> may be in an extended position (see <FIG>). As the MHV receives a palletized load, the pallet may engage the actuation plate <NUM> and provide an input force thereto that overcomes the biasing force of the first spring assembly <NUM> and the second spring assembly <NUM>, which results in the actuation plate <NUM> non-pivotally displacing toward the body <NUM>. As the actuation plate <NUM> non-pivotally displaces toward the body <NUM>, the tab <NUM> coupled to the actuation plate <NUM> may displace toward the sensor surface <NUM> of the proximity sensor <NUM>. Once the tab <NUM> displaces an amount sufficient to at least partially cover the sensor surface <NUM>, the proximity sensor <NUM> may transition from an unblocked state where the sensor surface <NUM> is unblocked by the tab <NUM> and a blocked position where the sensor surface <NUM> is at least partially blocked by the tab <NUM>. In some examples, when the proximity sensor <NUM> transitions to the blocked state, the MHV may have fully received the palletized load on the forks.

With reference to <FIG>, the pallet detection assembly <NUM> includes one or more proximity sensors <NUM>. For example, as illustrated in <FIG>, the proximity sensor <NUM> may be a first proximity sensor <NUM> and the pallet detection assembly <NUM> may include a second proximity sensor <NUM> having a sensor surface <NUM>. The body <NUM> may include a second sensor mounting bracket <NUM> engaged with the second side wall <NUM> longitudinally between the second opening <NUM> and the third opening <NUM>. The second sensor mounting bracket <NUM> may support the second proximity sensor <NUM> within the cavity <NUM> formed by the body <NUM>. In general, the first proximity sensor <NUM> and the second proximity sensor <NUM> may be axially aligned with and axially separated from one another.

With specific reference to <FIG>, the body <NUM> may include a second tab <NUM> that is coupled to the actuation plate <NUM> and extends toward the body <NUM>. The second tab <NUM> may extend from the actuation plate <NUM> toward the body <NUM> a different distance than the tab <NUM>. In the illustrated example, the second tab <NUM> may extend a further distance toward the body <NUM> than the tab <NUM>. In this way, for example, the pallet detection assembly <NUM> of <FIG> may define two pallet detection states. That is, when the second proximity sensor <NUM> transitions to the blocked state after the actuation plate <NUM> is displaced by an input force by a first distance d1, the MHV may be supporting a load on the forks but the load may not yet be fully received on the forks. If the actuation plate <NUM> is displaced further to a distance d2 where the first proximity sensor <NUM> transitions to the blocked state, the MHV may have fully received the load on the forks.

As described herein, the pallet detection assembly <NUM> may be installed on an MHV. Turning to <FIG>, an MHV <NUM> may include one or more pallet detection assemblies <NUM> coupled to a fork carriage <NUM>. The fork carriage <NUM> may include a fork backrest <NUM>, a first fork <NUM>, and a second fork <NUM> each coupled to the fork carriage <NUM>, and a pair the pallet detection assemblies <NUM>. In the illustrated embodiment, the MHV <NUM> may include a one of the pallet detection assemblies <NUM> coupled to the fork carriage <NUM> adjacent to a laterally-outer edge <NUM> of the first fork <NUM> and another of the pallet detection assemblies <NUM> coupled to the fork carriage <NUM> arranged adjacent to a laterally-outer edge <NUM> of the second fork <NUM>.

In some embodiments, the MHV <NUM> may include a controller <NUM> having memory <NUM> and a processor <NUM>. The controller <NUM> may be in communication with the first proximity sensor <NUM> and, in some embodiments, the second proximity sensor <NUM>. In some embodiments, the controller <NUM> may be in communication with a display <NUM>.

In general, the arrangement of two or more of the pallet detection assemblies <NUM> on the fork carriage <NUM> may enable the detection of whether a load <NUM> is received on the first fork <NUM> and the second fork <NUM> and whether or not the load is askew. For example, <FIG> illustrates potential outputs of the proximity sensors <NUM> on both of the pallet detection assemblies <NUM> of the MHV <NUM> in the configuration of the pallet detection assemblies <NUM> that include one proximity sensor <NUM>. When both of the proximity sensors <NUM> are unblocked, the controller <NUM> may provide an indication, for example, to the display <NUM>, a warehouse management system (WMS) in communication with the controller <NUM>, or another external controller that a load is not received on the forks. If the only one of the pallet detection assemblies <NUM> is in the blocked state and the other is in the unblocked state, the controller may provide an indication that a load is arranged askew on the forks. If both of the pallet detection assemblies <NUM> are in the blocked state, then the controller <NUM> may provide an indication that the load is fully received on the forks and properly aligned.

The pallet detection assembly <NUM> includes a first proximity sensor <NUM> and a second proximity sensor <NUM>. <FIG> illustrates potential outputs of the first proximity sensor <NUM> and the second proximity sensor <NUM> on both of the pallet detection assemblies <NUM> of the MHV <NUM>. That is, the MHV <NUM> includes a first pallet detection assembly and a second pallet detection assembly that both include a first proximity sensor <NUM> and a second proximity sensor <NUM>. When all of the proximity sensors are unblocked, the controller <NUM> may provide an indication that a load is not received on the forks. When one of the second proximity sensors <NUM> is in the blocked state and one of the second proximity sensor <NUM> is in the unblocked state (both of the first proximity sensors <NUM> are unblocked), the controller <NUM> may provide an indication that a load is arranged askew on the forks. When both of the second proximity sensors <NUM> are in the blocked state and both of the first proximity sensors <NUM> are in the unblocked state, the controller <NUM> may provide an indication that a load is centered but not fully received on the forks. When both of the second proximity sensors <NUM> are in the blocked state, one of the first proximity sensors <NUM> is in the blocked state, and one of the first proximity sensors <NUM> is in the unblocked state, the controller may provide an indication that a load is received on the forks but askew. When both of the second proximity sensors <NUM> and both of the first proximity sensors <NUM> are in the blocked state, the controller <NUM> may provide an indication that a load is fully received on the forks and properly aligned.

In some examples, the pallet detection assembly <NUM> may be designed to include alternative shapes and configurations of the actuation plate <NUM>. For example, <FIG> illustrates an example of the pallet detection assembly <NUM> that includes a spacer plate <NUM> coupled to an outer surface of the actuation plate <NUM>. The spacer plate <NUM> may provide a smooth surface against which a pallet or load may provide an input force to non-pivotally displace the actuation plate <NUM> relative to the body <NUM>.

<FIG> illustrated an example of the pallet detection assembly <NUM> where the angled portion <NUM> extends vertically beyond a first end <NUM> of the body <NUM> (e.g., a top end from the perspective of <FIG> and <FIG>. In this way, for example, the angled portion <NUM> may further aid in non-pivotally displacing the actuation plate <NUM> relative to the body <NUM> when a load is vertically placed on the forks of the MHV <NUM>.

<FIG> illustrate the pallet detection assembly <NUM> where the tab <NUM> is integrated into the actuation plate <NUM> (e.g., integrally formed as a unitary component). In the illustrated example, the actuation plate <NUM> may not include an angled portion. In the illustrated example, the tab <NUM> is formed by a top surface <NUM> of the actuation plate <NUM>. In the illustrated example, the proximity sensor <NUM> is moved (compared to the embodiment of <FIG>) within the cavity <NUM> to a top portion <NUM> of the cavity <NUM>. In this way, for example, as the actuation plate <NUM> is non-pivotally displaced toward the body <NUM>, the top surface <NUM> may eventually be displaced into a position where it blocks the sensor surface <NUM> of the proximity sensor <NUM>.

While various spatial and directional terms, such as top, bottom, lower, mid, lateral, horizontal, vertical, front, and the like may be used to describe examples of the present disclosure, it is understood that such terms are merely used with respect to the orientations shown in the drawings. The orientations may be inverted, rotated, or otherwise changed, such that an upper portion is a lower portion, and vice versa, horizontal becomes vertical, and the like.

Claim 1:
A material handling vehicle (<NUM>), comprising:
a fork carriage (<NUM>) including a first fork (<NUM>) and a second fork (<NUM>) laterally separated from the first fork;
a first pallet detection assembly (<NUM>) arranged adjacent to a laterally-outer edge of the first fork (<NUM>), wherein the first pallet detection assembly comprises:
a first body (<NUM>) defining a first cavity (<NUM>) and including a first proximity sensor (<NUM>) housed at least partially within the first cavity;
a first actuation plate (<NUM>) including a first tab (<NUM>) coupled thereto and extending in a direction toward the first body (<NUM>); and
a first actuator (<NUM>) including a first cylinder (<NUM>) coupled to the first body (<NUM>) and a first plunger (<NUM>) slidably received within the first cylinder (<NUM>) and coupled to the first actuation plate (<NUM>), wherein the first actuator is configured to movably couple the first actuation plate to the first body so that the first actuation plate is configured to non-pivotally displace relative to the first body; and
a second pallet detection assembly (<NUM>) arranged adjacent to a laterally-outer of the second fork (<NUM>), wherein the second pallet detection assembly comprises:
a second body (<NUM>) defining a second cavity (<NUM>) and including a second proximity sensor (<NUM>) housed at least partially within the second cavity;
a second actuation plate (<NUM>) including a second tab (<NUM>) coupled thereto and extending in a direction toward the second body; and
a second actuator (<NUM>) including a second cylinder (<NUM>) coupled to the second body (<NUM>) and a second plunger (<NUM>) slidably received within the second cylinder and coupled to the second actuation plate (<NUM>), wherein the second actuator is configured to movably couple the second actuation plate to the second body so that the second actuation plate is configured to non-pivotally displace relative to the second body.