Patent Description:
The field of this disclosure relates generally to materials-handling vehicles. More specifically, this disclosure relates to a structurally integrated sensor for a lift truck.

Multipurpose materials-handling lift trucks, including forklift trucks, are commonly used in manufacturing, shipping and warehousing facilities to lift and to transport materials. Lift trucks are ideally small and agile, have a small turning radius and compact footprint, and are able to repeatedly lift and/or haul thousands of pounds of materials. One type of such a vehicle is a counterbalanced forklift truck, having a counterweight that balances the weight of a load on the forks.

A counterbalanced lift truck generally includes a number of standard components, such as a lift assembly with an attachment, such as forks, that is used to lift a load, and a counterweight. Lift trucks have an energy source that provides power, and wheels to move the truck. A lift truck can include a roof over the operator compartment, such as an overhead guard. The operator compartment can include a seat for the driver, or it can include an operator's platform designed for truck operation while the driver stands. The operator compartment generally includes steering controls such as a steering wheel or tiller, speed controls such as a foot pedal or tiller-mounted throttle, and braking controls. Sensors may be placed on lift trucks to help drivers navigate and/or detect objects near the truck, including in the path of the truck. For example, sensors can be used to alert an operator that a pedestrian is near the truck.

In the absence of sensors, or with a poorly designed sensor arrangement on a lift truck, sensors may be damaged and/or fail, causing operator productivity to suffer. The driver's ability to focus on the operation and navigation of the truck are relevant to efficient materials transport.

The prior art document <CIT> discloses a counterbalanced forklift truck with a rear area monitoring device. The rear area monitoring device can be easily mounted to a trailer coupling at the rear end of the forklift truck. Thereby, the rear area monitoring device extends over the back end of the forklift truck. This document discloses the preamble of claim <NUM>.

The prior art document <CIT> discloses a hydraulic excavator comprising a reverse / turn detection means for detecting the backward movement of an upper rotatable vehicle body. The reverse / turn detection means preferably comprises a television camera and a flash means arranged within a bumper. The bumper is detachably attached to a concave portion of a counterweight of the excavator.

This background description is for the purpose of generally presenting the context of the following disclosure. Unless otherwise indicated herein, the subject matter described in this section is not prior art to the claims in this document and are not admitted to be prior art by inclusion in this section.

One aspect of this disclosure relates to a counterweight used for a lift truck according to claim <NUM>.

The claimed embodiment is a counterweight for a lift truck, in which the counterweight includes a frame that is formed by a substantially horizontal upper peripheral edge, a first substantially vertical side peripheral edge, a second substantially vertical side peripheral edge opposite the first substantially vertical side peripheral edge, and a lower peripheral edge. The counterweight includes a cavity surrounded by the frame, as well as a sensor-mounting recess. The sensor-mounting recess is positioned in the lower peripheral edge of the frame. The sensor-mounting recess is configured to provide an unobstructed horizontal line of sight of at least about <NUM> degrees for a sensor when the sensor is mounted within the sensor-mounting recess.

Another embodiment is a lift truck according to claim <NUM> having a counterweight, in which the lift truck includes a lift assembly having a mast and at least two forks, an operator compartment comprising truck steering and speed controls, a plurality of wheels, an energy source, a counterweight including a frame and a sensor-mounting recess, and a sensor. The lift assembly and the counterweight are positioned at opposite ends of the lift truck, such as at the front and rear ends, respectively. The sensor is positioned within the sensor-mounting recess and have an unobstructed horizontal line of sight of at least about <NUM> degrees. The frame of the counterweight includes an upper peripheral edge, two substantially vertical side peripheral edges, and a lower peripheral edge opposite the upper peripheral edge. The frame is configured to retain the sensor within the sensor-mounting recess such that a housing of the sensor is contained within the outermost contour of the counterweight.

Another embodiment is a method according to claim <NUM> including the steps of attaching a counterweight to one end of a materials-handling truck body, wherein the counterweight includes a sensor-mounting recess and a harness-routing pathway; attaching a sensor in the sensor-mounting recess, wherein the sensor is connectable to a wiring harness; and routing the wiring harness through the harness-routing pathway of the counterweight. The sensor is attached in the sensor-mounting recess such that the sensor has an unobstructed horizontal line of sight of at least about180 degrees.

In some additional, alternative, or selectively cumulative embodiments, the sensor mounted in a sensor-mounting recess includes an object-detection sensor.

In the claimed embodiment the lower peripheral edge of the frame of a counterweight includes a tow-pin hole and/or wherein the lower peripheral edge of the frame further comprises a tow pin and/or the lower peripheral edge of the frame further comprises a harness-routing pathway.

In some embodiments, the lower peripheral edge of the frame of a counterweight has a length between about <NUM> (<NUM> inches) and about <NUM> (<NUM> inches).

In some embodiments, the sensor-mounting recess of a counterweight has a height between about <NUM> (<NUM> inches) and about <NUM> (<NUM> inches).

In some embodiments, the sensor-mounting recess of a counterweight has a depth between about <NUM> (<NUM> inches) and about <NUM> (<NUM> inches).

In some embodiments, the ratio of the height of the upper peripheral edge of the frame of a counterweight to the height of the lower peripheral edge of the frame is between about <NUM>:<NUM> and about <NUM>:<NUM>.

In some embodiments, the ratio of the height of the upper peripheral edge of the frame of a counterweight to the height of the lower peripheral edge of the frame is less than <NUM>.

In some embodiments, a counterweight has a mass between about <NUM> and about <NUM>,<NUM>.

In some embodiments, the energy source of the lift truck having a counterweight includes an exhaust tube having an end that releases exhaust, the exhaust tube end being positioned external of the sensor-mounting recess.

In some embodiments, the lift truck having a counterweight has a lift capacity between about <NUM> ton and about <NUM> tons.

In some embodiments, the lift truck having a counterweight includes a sensor that is an object-detection sensor.

In some embodiments, the lift truck having a counterweight includes an object-detection sensor that is a lidar sensor.

In some embodiments, the lift truck having a counterweight provides an unobstructed horizontal line of sight for a sensor, when the sensor is positioned between about <NUM> (<NUM> inches) and about <NUM> (<NUM> inches) above floor level and when the lift truck is positioned on a substantially flat floor.

In some embodiments, a method of assembling a lift truck includes attaching a bracket to the sensor and securing the bracket in the sensor-mounting recess.

In some embodiments, a method of assembling a lift truck having a counterweight includes the counterweight including a cavity having a tow-pin hole therein, wherein the method further includes inserting a tow pin in the tow-pin hole.

Embodiments are illustrated by way of example, and not by way of limitation, in the accompanying drawings.

Example embodiments are described below with reference to the accompanying drawings. Unless otherwise expressly stated, the sizes, positions, etc., of components, features, elements, etc., as well as any distances therebetween, are not necessarily to scale, and may be disproportionate and/or exaggerated for clarity. The accompanying drawings form a part of the disclosure hereof wherein like numerals designate like parts throughout, and in which is shown by way of illustration embodiments that may be practiced. Thus, the same or similar numbers may be described with reference to other drawings even if they are neither mentioned nor described in the corresponding drawing. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present disclosure. Therefore, the following detailed description is not to be taken in a limiting sense, and the scope of embodiments is defined by the appended claims and their equivalents.

It should be recognized that the terms "comprise," "comprises," "comprising," "include," "includes," "including," "has," "have," and "having," when used in this document, are open-ended and specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. Unless otherwise specified, a range of values, when recited, includes both the upper and lower limits of the range, as well as any sub-ranges therebetween. Unless indicated otherwise, terms such as "first," "second," etc., are only used to distinguish one element from another and not to imply any relative order, placement, or ranking. For example, one element could be termed a "first element" and similarly, another element could be termed a "second element," or vice versa. The section headings used herein are for organizational purposes only and are not to be construed as limiting the subject matter described.

Unless indicated otherwise, the terms "about," "thereabout," "substantially," "approximately," etc. mean that amounts, sizes, formulations, parameters, and other quantities and characteristics are not and need not be exact, but may be approximate and/or larger or smaller, as desired, reflecting tolerances, conversion factors, rounding off, measurement error and the like, and other factors known to those of skill in the art. In certain embodiments, the terms "about," "substantially," and "approximately," refer to values that are, for example, within <NUM>% of the stated value, within <NUM>% of the stated value, within <NUM>% of the stated value, within <NUM>% of the stated value, within <NUM>% of the stated value, within <NUM>% of the stated value, within <NUM>% of the stated value, within <NUM>% of the stated value, within <NUM>% of the stated value, or within <NUM>% of the stated value.

Spatially relative terms, such as "right," left," "front," "rear," "below," "beneath," "above," and "upper," and the like, may be used herein for ease of description to describe one element's or feature's relationship to another element or feature, as illustrated in the drawings. It should be recognized that spatially relative terms are intended to encompass different orientations in addition to the orientation depicted in the drawings. For example, if an object in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the term "below" can, for example, encompass both an orientation of above and below. An object maybe otherwise oriented (e.g., rotated <NUM> degrees or at other orientations) and the spatially relative descriptors used herein may be interpreted accordingly.

For the purposes of the present disclosure, the phrase "combination of (A) and (B)" means (A), (B), or (A and B).

The embodiments described herein are merely examples, set forth by way of illustration only and not limitation. The description may use the phrases "in an embodiment" or "in embodiments," which may each refer to one or more of the same or different embodiments. Unless indicated otherwise, elements or operations of one embodiment may be used with other embodiments. Unless clearly indicated otherwise, all connections and all operative connections may be direct or indirect.

A counterweight ideally provides a counterbalanced lift truck with a low, stable mass opposite a load to improve truck stability. Having any material removed from the counterweight mass, particularly in a location that is low to the ground such as a sensor-mounting recess, is generally unfavorable and counterintuitive. Additionally, it may be technically difficult to design a cast counterbalance with pathways for cables and/or wires, including those that transmit power and/or data.

It is desirable to design a component, for example a counterweight, for a lift truck such that the component additionally provides a protected area for placing a sensor. If the component is a counterweight, this can be achieved by incorporating an indentation into the counterweight, such as a recess that is sized and positioned to maximize the sensor's capabilities when mounted, while also able to protect the sensor from physical damage when the truck is being operated. An aspect of a counterweight having a useful sensor-mounting recess can be achieved by ensuring that the recess is suitably configured to optimize use of the sensor during truck operation, such as providing the sensor with a large and unobstructed field of view. In addition, it is beneficial for the sensor-mounting recess to have ready access to an energy source to power the sensor, as well as to provide a suitable environment for optimum sensor performance, such as to limit exposure to unfavorable temperatures or gases.

As one skilled in the art will appreciate in light of this disclosure, certain embodiments of the counterweights and lift trucks, and designs therefor that are disclosed herein, may be capable of achieving certain advantages, including, in some cases, one or more of the following: (<NUM>) a sensor-mounting recess having multiple design features to facilitate optimum performance of a sensor, such as an unobstructed wide field of view; (<NUM>) a sensor-mounting recess having multiple design features to facilitate protection of a sensor from physical damage; (<NUM>) preserved and/or enhanced structural integrity of a counterweight including a cavity, a sensor-mounting recess, or a combination of a cavity and a sensor-mounting recess; (<NUM>) a counterweight designed to permit ready access of a sensor to a power source internal the vehicle; (<NUM>) a counterweight designed to vent a vehicle's energy source to a location external the truck body to ensure sensor performance is not compromised; and (<NUM>) a vehicle having multiple design features to facilitate efficient performance of an operator driving the vehicle. The foregoing and other advantages of various embodiments will be apparent upon reading this document.

<FIG> and <FIG> are isometric illustrations of a lift truck <NUM> according to one embodiment, showing the front and rear of the vehicle, respectively. Referring to <FIG>, the lift truck <NUM> has a lift assembly <NUM> including two forks <NUM> and a mast <NUM>, an operator compartment <NUM> including a seat <NUM>, a truck body <NUM>, an overhead guard <NUM>, front wheels <NUM>, rear wheels <NUM>, and a counterweight <NUM>. <FIG> additionally shows the operator compartment <NUM> having a foot pedal <NUM> and a steering wheel <NUM>, a panel <NUM> behind the seat <NUM>, and the counterweight <NUM> having a frame <NUM>, a cavity <NUM>, a sensor-mounting recess <NUM>, a harness-routing pathway <NUM>, and a tow-pin hole <NUM>.

The lift assembly <NUM> is used to lift a load and is attached to the truck body <NUM>. For example, the mast <NUM> can support a fork carriage having at least one fork <NUM> attached thereto. The fork carriage can be raised to different heights by movement of the mast <NUM>. The lift assembly <NUM> is configured to vertically lift a load on the forks using, for example, a hydraulic system. A lift assembly may also include paper roll clamps, carton clamps, multiple-forks assemblies, side-shifters, a container handler or spreader attachment, and other suitable attachments. In an embodiment, the lift assembly <NUM> includes a reach assembly, such as a pantograph-type reach assembly. In an embodiment, the lift truck <NUM> includes a tilt mechanism, connected to the lift assembly <NUM>, to tilt the top of the mast <NUM> back slightly, and therefore the ends of the forks <NUM> up slightly, to more stably carry a load. A sensor may be incorporated within, or attached to, the lift assembly <NUM>.

The operator compartment <NUM> shown in <FIG> and <FIG> contains a foot pedal <NUM>, a steering wheel <NUM>, and a seat <NUM>, as well as an overhead guard <NUM> that extends at the top of and over the operator compartment <NUM>. Embodiments of materials-handling vehicles disclosed herein may include none, some, or all of these components. For example, the lift truck <NUM> may have a steering control that is a steering tiller or joystick rather than a wheel <NUM>, or the steering controls may be integrated into the seat <NUM>, such as part of an armrest. Manual levers attached to the cowl of the lift truck <NUM> may be used for controlling the mast, and may be present in the operator compartment <NUM>. Vehicle speed and/or braking controls may include one or more of a foot pedal <NUM>, such as an accelerator pedal, a brake pedal, and/or an inching pedal. Alternatively, the operator compartment <NUM> may be free of foot controls, and vehicle speed and braking controls may be integrated into the seat <NUM> and/or into a hand throttle on a steering tiller. The operator compartment <NUM> may include a seat <NUM>, or it may be configured such that the driver operates the truck while standing and contain a lean bar or lean pad instead of a seat <NUM>. In an embodiment, a sensor may be incorporated within, or attached to, the operator compartment <NUM>.

As shown in <FIG> and <FIG>, the truck body <NUM> does not include doors for the operator compartment <NUM>. In an embodiment, there are one or more doors attached to truck body <NUM> for egress into and out of the operator compartment <NUM>. In an embodiment, a sensor may be incorporated within, or attached to, the truck body <NUM>. The truck body <NUM> may include one or more steps for an operator to use to access the operator compartment <NUM>. The truck body <NUM> may be designed with or configured to include a low platform such that the operator stands while driving the lift truck <NUM> rather than sits.

The lift truck <NUM> can include an overhead guard <NUM> that is positioned partially or completely over the operator compartment <NUM> and that may form a roof or cover for the operator compartment <NUM>. In an embodiment, the overhead guard <NUM> is solid and opaque, for example, to act as a sun shade to protect the operator from sunlight when the truck is used outside. Alternatively, the overhead guard <NUM> is transparent or semitransparent in whole or in part and/or has one or more apertures to enable the operator to view the forks <NUM>, top of the mast <NUM>, and/or its load when the mast <NUM> is raised. In an embodiment, a tilt mechanism can be incorporated within, or attached to, the overhead guard. In another embodiment, the overhead guard <NUM> comprises a sheet of plexiglass over substantially the entire roof area of the overhead guard <NUM> so as to maximize overhead visibility for the operator. In certain embodiments, a sensor may be incorporated within, or attached to, the overhead guard <NUM>.

As indicated in <FIG> and <FIG>, lift truck <NUM> has two front wheels <NUM> and two rear wheels <NUM>. The truck steering control, such as steering wheel <NUM>, may be configured to turn one or more of the rear wheels <NUM> when the lift truck <NUM> moves forward or backward. The wheels <NUM> and <NUM> are directly or indirectly attached to the body <NUM> of the truck <NUM> and are configured to roll to steerably move the truck <NUM> forward and backward. In an embodiment, the materials-handling vehicle includes a plurality of wheels. For example, a lift truck may have three wheels, or it may have four wheels, or it may have more than four wheels. All or a subset of the plurality of wheels may be steerable. Two of the wheels <NUM> or <NUM> of the lift truck <NUM>, as depicted in <FIG> and <FIG>, can independently be replaced with a single wheel to form a lift truck having three wheels. For example, the two rear wheels <NUM> shown in <FIG> may be replaced with a single rear wheel. Additional front or rear wheels can independently be added to the lift truck <NUM> to form a truck having more than four wheels.

In an embodiment, the lift truck <NUM> has a plurality of wheels that comprises at least one left wheel and at least one right wheel. In an embodiment, the lift truck <NUM> has a plurality of wheels that comprises two front wheels and one rear wheel. All or a subset of the wheels may be solid, or all or a subset of the wheels may be pneumatic, or the plurality of wheels may include a mixture of solid and pneumatic wheels.

In reference to <FIG>, the truck <NUM> has a panel <NUM> that is located behind the operator's seat <NUM>. The panel <NUM> may be a cover to a compartment that lies partially or completely behind counterweight <NUM>, such as between counterweight <NUM> and seat <NUM>. The compartment may contain, for example, an energy source for the truck <NUM>, power electronics and/or other truck parts.

<FIG>, <FIG>, <FIG>, and <FIG> are illustrations of an exemplary counterweight <NUM>. <FIG> and <FIG> show an embodiment of the counterweight <NUM> from the front, <FIG> shows the counterweight <NUM> of <FIG> and <FIG> from a front right perspective, and <FIG> is a right side view of the counterweight <NUM> of <FIG> and <FIG>. The counterweight <NUM> includes a frame <NUM> having substantially horizontal upper peripheral edge <NUM> that extends longitudinally between two substantially vertical side peripheral edges <NUM> and <NUM>. The substantially vertical side peripheral edges <NUM> and <NUM> are opposite and approximately parallel to each other. A lower peripheral edge <NUM> also extends longitudinally between the side edges <NUM> and <NUM> to complete the frame <NUM>. The substantially horizontal upper edge <NUM> and lower peripheral edge <NUM> are opposite and approximately parallel to each other. The peripheral edges <NUM>, <NUM>, <NUM>, and <NUM> form a frame <NUM> that surrounds cavity <NUM>. The edges of the frame <NUM> may be curved such that, for example, the vertical edges <NUM> and <NUM> wrap around the end of the truck <NUM> to extend partially along the sides of the truck <NUM>, such as is depicted in <FIG>. In an embodiment, the lower peripheral edge <NUM> of frame <NUM> curves under the bottom of the truck <NUM> to extend partially along the underside of the truck <NUM>, such as is depicted in <FIG>.

In an embodiment, the frame <NUM> is approximately rectangular in shape, with the side edges <NUM> and <NUM> having approximately equal lengths, and upper and lower edges <NUM> and <NUM> having approximately equal lengths that are longer than, and substantially perpendicular to, the side edges <NUM> and <NUM>. In an embodiment, the frame <NUM> may be approximately square in shape, where each of the peripheral edges <NUM>, <NUM>, <NUM>, and <NUM> have approximately equal lengths. The counterweight <NUM> may include one or more generally lateral (that is, vertical with respect to the truck <NUM>, and spanning the width of the cavity <NUM>) and/or longitudinal (that is, horizontal and spanning the length of the cavity <NUM>) frame reinforcements <NUM> that extend across edges of the frame <NUM>. For example, the counterweight <NUM> shown in <FIG> includes two lateral frame reinforcements 165a and 165b, and a counterweight <NUM> shown in <FIG> has two lateral frame reinforcements 265a and 265b as well as two longitudinal frame reinforcements 265c and 265d. In an embodiment, there are no lateral or longitudinal frame reinforcements spanning the cavity <NUM> of the counterweight frame <NUM>.

The length of the upper and lower peripheral edges <NUM> and <NUM> may independently be between about <NUM> (<NUM> inches) and about <NUM> (<NUM> inches), such as between about <NUM> (<NUM> inches) and about <NUM> (<NUM> inches), between about <NUM> (<NUM> inches) and about <NUM> (<NUM> inches), or between about <NUM> (<NUM> inches) and about <NUM> (<NUM> inches). The length of the side peripheral edges <NUM> and <NUM> may independently be between about <NUM> (<NUM> inches) and about <NUM> (<NUM> inches), such as between about <NUM> (<NUM> inches) and about <NUM> (<NUM> inches), or between about <NUM> (<NUM> inches) and <NUM> (<NUM> inches).

The height of the upper and lower peripheral edges <NUM> and <NUM>, respectively, may be the same or they may be different. Referring to <FIG>, the height of the upper peripheral edge <NUM> is defined as height S and that of the lower peripheral edge is defined as height T, as measured at the approximate vertical midpoint M of the counterweight <NUM> when viewed from the front (that is, in the two-dimensional plane defined by the four edges of the frame <NUM>). Notably, the height T includes the height of the sensor-mounting recess <NUM>. In an embodiment, the height T of the lower peripheral edge <NUM> is between about <NUM> (<NUM> inches) and about <NUM> (<NUM> inches), such as between about <NUM> (<NUM> inches) and about <NUM> (<NUM> inches), between about <NUM> (<NUM> inches) and about <NUM> (<NUM> inches), or it is about <NUM> (<NUM> inches). The height S of the upper peripheral edge <NUM> may be between about <NUM> (<NUM> inches) and about <NUM> (<NUM> inches), such as between about <NUM> (<NUM> inches) and <NUM> (<NUM> inches), between about <NUM> (<NUM> inches) and <NUM> (<NUM> inches), or between about <NUM> (<NUM> inches) and <NUM> (<NUM> inches).

In certain embodiments, the height S of the upper peripheral edge <NUM> is shorter than the height T of the lower peripheral edge <NUM>. The ratio of the height S of the upper peripheral edge <NUM> to the height T of the lower peripheral edge <NUM> may be between about <NUM>:<NUM> and <NUM>:<NUM>, such as between about <NUM>:<NUM> and <NUM>:<NUM>. In an embodiment, the ratio of the height S of the upper peripheral edge <NUM> to the height T of the lower peripheral edge <NUM> may be less than <NUM>. In a further embodiment, the ratio of the height S of the upper peripheral edge <NUM> to the height T of the lower peripheral edge <NUM> may be approximately <NUM>.

The counterweight <NUM> may be made of one or more pieces, with each piece having one or more mechanical properties such as tensile strength. A counterweight that is formed from, or made with, multiple counterweight pieces may in some circumstances be considered to be one functional unit that may be referred to herein as simply a "counterweight. " Thus, the term "counterweight" may mean a single-piece counterweight or a functional unit comprising multiple counterweight pieces, depending on context. Optionally, a lift truck <NUM> may contain one or more counterweights <NUM>. For example, the counterweight <NUM> may be a two-piece counterweight comprising multiple Gray Iron casting grades. In an embodiment, the counterweight <NUM> is a single piece of cast iron. The counterweight <NUM> may be made of steel, and may optionally include lead as a filler. In an embodiment, the counterweight <NUM> comprises steel and lead. In an embodiment, the counterweight <NUM> comprises one or more of steel, iron, and lead. In an embodiment, the counterweight <NUM> consists of one or more of steel, iron, and lead. In an embodiment, the counterweight <NUM> comprises cast steel.

The counterweight <NUM> may be attached to the opposite end of the truck <NUM> as the lift assembly <NUM>; that is, it may be attached to the rear end of the truck <NUM> shown in <FIG> and <FIG>. In an embodiment of a lift truck having the forks in the rear of the truck, the counterweight <NUM> may be attached to the front end of the lift truck. The counterweight can be made with one or more cast pieces, and different form factors can accommodate different shapes and/or arrangements of the lift truck components. For example, a lift truck having a hydrogen-based energy source may, for example, incorporate a counterweight that is formed with a tall edge in order to help protect the hydrogen tanks. Similarly, a lift truck having a lithium ion battery bank or combustion engine may incorporate a counterweight that is designed to have a shelf or enclosure within it, such as a compartment covered by panel <NUM> as depicted in <FIG>.

In an embodiment, the counterweight <NUM> has a mass between about <NUM> and about <NUM>,<NUM>, such as, for example, between about <NUM> and about <NUM>,<NUM>, between about <NUM> and about <NUM>,<NUM>, or between about <NUM> and about <NUM>,<NUM>. In an embodiment, the counterweight <NUM> has a mass greater than about <NUM>, greater than about <NUM>, greater than about <NUM>, greater than about <NUM>, or greater than about <NUM>,<NUM>. In certain embodiments, the counterweight <NUM> has a mass at least about <NUM>, at least about <NUM>, at least about <NUM>, at least about <NUM>, at least about <NUM>,<NUM>, at least about <NUM>,<NUM>, or at least about <NUM>,<NUM>.

With reference to <FIG>, <FIG>, and <FIG>, the sensor-mounting recess <NUM> may include a tow-pin hole <NUM> near the bottom of the recess <NUM>. The tow-pin hole <NUM>, if present, may lie directly in front of, or coaxially with, a harness-routing pathway <NUM>, or it may be offset from the central axis of the harness-routing pathway <NUM>. A tow-pin hole and/or tow pin may be used, for example, to conveniently attach trailers behind the truck, or to which a tow rope or chain may be attached. In an embodiment, the sensor-mounting recess <NUM> does not include a tow-pin hole <NUM>. The tow-pin hole <NUM> may be configured to snugly retain a tow pin that is, for example, a cylindrical metal bar having a diameter of about <NUM>,<NUM> (<NUM> inch). In an embodiment, the sensor-mounting recess <NUM> includes one or more tow-pin holes <NUM>.

The lower peripheral edge <NUM> of the counterweight <NUM> includes a sensor-mounting recess <NUM> having a harness-routing pathway <NUM>. The recess <NUM> and the pathway <NUM> are located in the lower peripheral edge <NUM>, which, in an embodiment, extends laterally toward the bottom of the lift truck <NUM>. The recess <NUM> is indented toward the body of the truck <NUM> with respect to the exterior surface of the counterweight <NUM> and is designed to encompass a sensor, partially or entirely, within the area defined by the outermost contour of the lower peripheral edge <NUM>. That is, a sensor may be tucked into the volume defined by the recess <NUM> as if the outermost surface of the counterweight formed a continuous surface and the recess <NUM> was not present. Such a design can protect a sensor that is mounted within the recess <NUM> from being physically damaged if, for example, the lift truck hits or brushes against a surface such as a wall or pillar, because the sensor is recessed into the counterweight <NUM>.

<FIG> and <FIG> show a sensor <NUM> mounted in two differently configured embodiments of the lower peripheral edge <NUM> of a counterweight <NUM>. As used herein, when referring to the physical footprint or volume of the sensor, unless otherwise indicated, the term "sensor" includes the physical housing of the sensor as well as any detection/imaging components thereof. In an embodiment, a sensor <NUM> does not substantially extend beyond the outermost contour of the counterweight <NUM> when the sensor is located in the sensor-mounting recess <NUM> and is contained within the outermost contour of the counterweight <NUM>. The design of the lower peripheral edge <NUM> that is adjacent to the sensor-mounting recess <NUM> may be configured to provide optimum sensor performance when a sensor is mounted in the recess <NUM>. In an embodiment, the portion of the lower peripheral edge <NUM> that is to the right and left sides of, and adjacent to, the harness-routing pathway <NUM>, shown in <FIG>, <FIG>, and <FIG> as 181a and 181b, may be indented with respect to the exterior surface of the counterweight <NUM>. The indentation of portions 181a and 181b may be identical, or they may be different. In an embodiment of the counterweight <NUM>, the portion of the lower peripheral edge <NUM> that is above and adjacent to the harness-routing pathway <NUM>, shown in <FIG> and <FIG> as 181c, may be indented with respect to the exterior surface of the counterweight <NUM>.

<FIG> illustrates an embodiment of a counterweight <NUM> having a lower peripheral edge <NUM> that includes a wide longitudinal indentation of 181a and 181b to provide a larger unobstructed window for the sensor's horizontal line of sight, as compared to the indentation design of the lower peripheral edge <NUM> illustrated in <FIG>.

With reference to <FIG>, an embodiment of the counterweight <NUM> may include a tow pin <NUM> that is external the sensor-mounting recess <NUM>. For example, the lower peripheral edge <NUM> of the counterweight <NUM> may include a tow pin <NUM> extending into the cavity <NUM> of the frame <NUM>. In an embodiment, the counterweight <NUM> includes a tow pin <NUM>.

<FIG> is a top cross-sectional view of an embodiment of a counterweight <NUM>, with the counterweight <NUM> cut at approximately the midpoint of the height of the sensor recess <NUM>. The configuration of the lower peripheral edge <NUM> may be such that a sensor <NUM> mounted in sensor-mounting recess <NUM> has an unobstructed horizontal line of sight having an angle theta (θ). The angle theta (θ) maybe at least about <NUM> degrees. A sensor <NUM> mounted in the sensor-mounting recess <NUM> may have an unobstructed horizontal line of sight having an angle theta (θ) of, for example, about <NUM> degrees, about <NUM> degrees, about <NUM> degrees, about <NUM> degrees, about <NUM> degrees, about <NUM> degrees, about <NUM> degrees, about <NUM> degrees, about <NUM> degrees, about <NUM> degrees, about <NUM> degrees, about <NUM> degrees, about <NUM> degrees, about <NUM> degrees, about <NUM> degrees, about <NUM> degrees, about <NUM> degrees, about <NUM> degrees, about <NUM> degrees, about <NUM> degrees, about <NUM> degrees, about <NUM> degrees, about <NUM> degrees, about <NUM> degrees, about <NUM> degrees, about <NUM> degrees, about <NUM> degrees, about <NUM> degrees, about <NUM> degrees, about <NUM> degrees, about <NUM> degrees, about <NUM> degrees, about <NUM> degrees, about <NUM> degrees, about <NUM> degrees, about <NUM> degrees, about <NUM> degrees, about <NUM> degrees, about <NUM> degrees, about <NUM> degrees, about <NUM> degrees, or about <NUM> degrees. The sensor <NUM> mounted in the sensor-mounting recess <NUM> may have an unobstructed horizontal line of sight having an angle theta (θ) of, for example, between about <NUM> and about <NUM> degrees, between about <NUM> and about <NUM> degrees, between about <NUM> and about <NUM> degrees, between about <NUM> and about <NUM> degrees, between about <NUM> and about <NUM> degrees, between about <NUM> and about <NUM> degrees, or between about <NUM> and about <NUM> degrees. In an embodiment, the sensor <NUM> mounted in sensor-mounting recess <NUM> has an unobstructed horizontal line of sight having an angle theta (θ) of, for example, at least about <NUM> degrees, at least about <NUM> degrees, at least about <NUM> degrees, at least about <NUM> degrees, at least about <NUM> degrees, or at least about <NUM> degrees.

The sensor <NUM> may be any type of sensor useful for a materials-handling vehicle. For example, the sensor <NUM> can be a sensor for detecting objects, including cameras or other imagers. For example, the sensor <NUM> may use light for detection, including any type of visible, infrared, or ultraviolet light, such as a laser. The sensor <NUM> may use sound for detection (such as ultrasonic or sonar), electromagnetic radiation other than light, including x-rays, microwaves, or radio waves for detection (such as RFID detectors), or the sensor <NUM> may be a standard camera, microscopic, fluorescent, telescopic, or photoelectric imager. The sensor <NUM> may be a scanning sensor or a flash sensor, and it may be a <NUM>-D or <NUM>-D sensor. The sensor <NUM> may include phased array technology. The sensor <NUM> may use multiple detection methods, such as to combine an infrared camera image with scanning lidar to identify multiple objects. In an embodiment, the sensor <NUM> is a lidar sensor. In an embodiment, the sensor <NUM> comprises a lidar sensor. In an embodiment, the sensor <NUM> includes lidar.

With reference to <FIG>, the harness-routing pathway <NUM> may have a cylindrical shape that extends through a portion of the depth of the counterweight <NUM>. In an embodiment, the harness-routing pathway <NUM> has a cylindrical shape that extends entirely through the depth of the counterweight <NUM>. As shown in <FIG>, the counterweight <NUM> may include one or more branching pathways <NUM>' that extend from a central harness-routing pathway <NUM>. The sensor <NUM> may have a harness including wires <NUM> that may be routed through the harness-routing pathway <NUM> and/or any branches <NUM>' thereof. The wires <NUM> may be, for example, routed to an energy source and/or a processor located in an engine compartment under the panel <NUM> of <FIG> or elsewhere.

<FIG> is a partially transparent illustration of an embodiment of a counterweight from a front right perspective, showing a harness-routing pathway <NUM> with wires <NUM> of a sensor <NUM> routed through it. The sensor-mounting recess <NUM> illustrated in <FIG> includes a sensor <NUM> mounted into the recess <NUM> using a bracket <NUM> placed into a tow-pin hole <NUM>.

<FIG> is side view of an embodiment of a sensor-mounting recess <NUM> showing a sensor bracket <NUM> that is configured to fit into a tow-pin hole <NUM>. An exemplary bracket <NUM> is illustrated in <FIG>. The bracket <NUM> shown has multiple screws at the corners that may be used to level the sensor <NUM> mounted therein, and is designed to secure the sensor <NUM> in the tow-pin hole <NUM> upon adjustment of the nut at the base of the bracket. In the embodiment of the bracket <NUM> illustrated in <FIG> and <FIG>, tightening the nut will expand the diameter of the portion of the bracket <NUM> that fits into tow-pin hole <NUM>, to provide a secure fit with no gap. The sensor <NUM> that is mounted in the sensor recess <NUM> in <FIG> has an unobstructed horizontal line of sight of at least <NUM> degrees, as the object-detection mechanism is in the upper half of the illustrated conical sensor <NUM>. Alternatively, the sensor <NUM> may be mounted into sensor-mounting recess <NUM> using a different type of bracket, such as an L-shaped bracket that is, for example, attached to the lower peripheral edge <NUM> adjacent to the harness-routing pathway <NUM>, or to an upper or lower surface of the sensor-mounting recess <NUM>.

As shown in <FIG>, the sensor-mounting recess <NUM> has a height H and a depth D, and the volume of the sensor <NUM> lies entirely within the outermost contour of the counterweight <NUM>. The height H of the sensor-mounting recess <NUM> may be between about <NUM>,<NUM> (<NUM> inch) and about <NUM> (<NUM> inches), such as, for example, between about <NUM>,<NUM> (<NUM> inches) and about <NUM> (<NUM> inches), between about <NUM>,<NUM> (<NUM> inches) and about <NUM> (<NUM> inches), or it may be between about <NUM>,<NUM> (<NUM> inches) and about <NUM>,<NUM> (<NUM> inches). The depth D may be of the sensor-mounting recess <NUM> may be about <NUM>,<NUM> (<NUM> inch) and about <NUM> (<NUM> inches), such as, for example, between about <NUM>,<NUM> (<NUM> inches) and about <NUM> (<NUM> inches), between about <NUM>,<NUM> (<NUM> inches) and about <NUM>,<NUM> (<NUM> inches), or it may be between about <NUM>,<NUM> (<NUM> inches) and about <NUM>,<NUM> (<NUM> inches).

In an embodiment, the height H and depth D of sensor-mounting recess <NUM> are independently adapted to accommodate an object-detecting sensor. For example, the height H may be the minimum height needed to mount a sensor <NUM>, or the height H may be the minimum height needed for a sensor to have an unobstructed field of view of at least about <NUM> degrees. The depth D may be the minimum depth needed to mount the sensor <NUM>, or the depth D may be the depth needed for a sensor to have an optimal focal length or optimal field of view. The size of the sensor-mounting recess <NUM> may depend upon the size of the sensor <NUM> that is being mounted, the optimal operating parameters of the sensor <NUM> (such as focal length or field of view), or both the size and optimal operating parameters of the sensor <NUM>.

<FIG> shows an embodiment of a counterweight <NUM> that includes a tow pin <NUM> that is external to the sensor-mounting recess <NUM>. For example, the lower peripheral edge <NUM> of the counterweight <NUM> may include a tow pin <NUM> extending into the cavity <NUM> of the frame <NUM>. In an embodiment, the counterweight <NUM> includes a tow pin <NUM>.

With reference to <FIG> and <FIG>, the lift truck <NUM> incorporates an energy source that provides power to the truck. The energy source turns one or more of a plurality of wheels to propel the truck forward and backward, and may also actuate the lift assembly. The energy source may include a battery or battery bank, an electric motor, an internal combustion engine, a hydrogen fuel cell, or any combination of the foregoing. The energy source used for turning the wheels and propelling the truck may be the same as, or may be different from, the energy source used for the lift assembly. For example, the energy source of the lift truck <NUM> may include a lithium ion battery or a bank of multiple such batteries for steering and driving, and the lift assembly may be actuated by a hydraulic system powered by an electric motor. In an embodiment, the energy source includes a lead-acid battery. A battery bank of multiple batteries may in some circumstances be considered to be one functional unit that may be referred to herein as simply a "battery. " Thus, the term "battery" may mean a single battery or a functional unit comprising multiple batteries, depending on context. In an embodiment, the energy source includes a lithium ion battery. In an embodiment, the energy source includes an internal combustion engine. In an embodiment, the energy source includes one or more of an internal combustion engine, a lithium ion battery, and a lead-acid battery.

With reference to <FIG> and <FIG>, the lift truck <NUM> may include an energy source that is located behind the seat <NUM>. The energy source may have an exhaust tube having an end <NUM> that releases exhaust to vent combustion gases and/or heat from an engine or engine compartment, and away from the operator's compartment <NUM>. The exhaust tube end <NUM> may be placed within the frame <NUM> of the counterweight <NUM>, such as shown in <FIG>, and vent exhaust gases and/or heat in a location that is distant and separated from the sensor-mounting recess <NUM>. Such a placement is advantageous in that the vented exhaust gases and/or heat would not adversely affect a sensor <NUM> that may be located in sensor-mounting recess <NUM>. In an embodiment, the exhaust tube end <NUM> is positioned external of the sensor-mounting recess <NUM>. For example, the exhaust tube end <NUM> may be positioned in the cavity <NUM> of the counterweight <NUM>, or it may be positioned near the overhead guard <NUM> and vent above the driver. In certain embodiments, the exhaust tube end <NUM> may be positioned below the lower peripheral edge <NUM> of the counterweight <NUM> and vent near the floor, or there may be a small cutout in lower peripheral edge <NUM> to allow the exhaust tube end <NUM> to vent therethrough (see, for example, <FIG>, <FIG>, and <FIG>). In an embodiment, the exhaust tube end <NUM> is positioned external of the counterweight <NUM>. In an embodiment, the exhaust tube end <NUM> is positioned in, or collinear with, the harness-routing pathway <NUM> in the sensor-mounting recess <NUM>.

<FIG> is a side view of the lift truck <NUM> depicted in <FIG>, showing the height of the opening of an exhaust tube having an end <NUM>, where gases and/or heat is released, relative to the position of the sensor-mounting recess <NUM> and the ground <NUM>. As indicated in <FIG>, the approximate vertical midpoint of the sensor-mounting recess <NUM> is located above the ground <NUM> at a height X and the approximate vertical midpoint of the exhaust tube end <NUM> is located above the ground <NUM> at a height Y. The ground <NUM> is considered to be an approximately planar surface upon which the lift truck lies, and may be a ramp or other raised supporting surface as well as a substantially flat floor, a warehouse aisle, a road, or the like. In certain embodiments of lift trucks <NUM> depicted by <FIG>, the height Y is greater than height X. For example, in an embodiment, the height Y is between about <NUM> (<NUM> inches) and about <NUM> (<NUM> inches), such as between about <NUM> (<NUM> inches) and about <NUM> (<NUM> inches). The exhaust tube end <NUM> may be located within the frame <NUM>, such as in the cavity <NUM> (see, for example, <FIG>). In an embodiment, the height X is between about <NUM> (<NUM> inches) and about <NUM> (<NUM> inches), between about <NUM> (<NUM> inches) and about <NUM> (<NUM> inches), or between about <NUM> (<NUM> inches) and about <NUM> (<NUM> inches).

In some embodiments, the exhaust tube end <NUM> may be located above the operator and near the top of the operator's compartment <NUM>, to vent near the overhead guard <NUM>. For example, the exhaust tube end <NUM> may extend from an exhaust stack pipe that mounts on top of the counterweight (see, for example, <FIG>, having a hole and mounting for such a pipe in the upper left corner of the drawing). In such embodiments, the height Y may be between about <NUM> (<NUM> inches) and about <NUM> (<NUM> inches), such as between about <NUM> (<NUM> inches) and about <NUM> (<NUM> inches).

In an alternate embodiment, the exhaust tube end <NUM> may be located below the sensor-mounting recess <NUM>, toward the ground <NUM>. For example, the exhaust tube end <NUM> may be located below the lower peripheral edge <NUM> of the counterweight <NUM> and vent near the floor, or lower peripheral edge <NUM> may be designed to allow the exhaust tube end <NUM> to vent therethrough (see, for example, <FIG>, <FIG>, and <FIG>). In such embodiments, the height Y is less than height X. For example, the height Y may be between about <NUM>,<NUM> (<NUM> inch) and about <NUM> (<NUM> inches), such as between about <NUM>,<NUM> (<NUM> inches) and about <NUM> (<NUM> inches).

For purposes of this description, a sensor <NUM> that is mounted in the sensor-mounting recess <NUM> of the truck <NUM>, such as an object-detection sensor, includes one or more arrays that are located approximately at, or have an average height approximately of, the horizontal midpoint of the sensor-mounting recess <NUM>. The sensor array may include a transmitter, a receiver, a detection array, an imager, or any combination of the foregoing. Thus, the height X of <FIG> may represent the height of the horizontal line of sight of a scanning laser sensor above the ground <NUM>. In an embodiment, the height of the horizontal line of sight of a sensor <NUM> mounted in sensor-mounting recess <NUM> is between about <NUM>,<NUM> (<NUM> inches) and about <NUM> (<NUM> inches), between about <NUM> (<NUM> inches) and about <NUM> (<NUM> inches), between about <NUM> (<NUM> inches) and about <NUM> (<NUM> inches), or between about <NUM> (<NUM> inches) and about <NUM> (<NUM> inches).

The lift truck <NUM> may be any type of materials-handling vehicle that includes a counterweight <NUM>. In an embodiment, the lift truck has a lift capacity between about <NUM> ton and about <NUM> tons, including between about <NUM> ton and about <NUM> tons, between about <NUM> ton and about <NUM> tons, about <NUM> ton, about <NUM> tons, about <NUM> tons, about <NUM> tons, about <NUM> tons, about <NUM> tons, about <NUM> tons, about <NUM> tons, and about <NUM> tons.

As described herein, the sensor-mounting recess <NUM> may provide benefits to materials-handling vehicles that may not include a counterweight <NUM>, or that may include a conventional counterweight without an integrated sensor-mounting recess <NUM>. For example, a materials-handling vehicle may incorporate a component such as a bumper or fender that includes a sensor-mounting recess <NUM> for mounting a sensor <NUM>. In certain embodiments, the frame <NUM> component of a materials-handling vehicle may include a sensor-mounting recess <NUM>. The sensor-mounting recess <NUM> may be located on an end, a side, or the overhead guard or roof (or other overhead component) of a materials-handling vehicle, thereby providing an environment that protects a sensor <NUM> mounted therein from physical damage while also allowing for optimum or desirable sensor performance. In an embodiment, a materials-handling vehicle includes a component having a sensor-mounting recess.

<FIG> is a flow chart illustrating a method of assembling a lift truck, according to one example embodiment. For the sake of clarity, this method will be described with reference the lift truck <NUM> described above as a specific example, but this method is not limited to that specific lift truck and may be practiced with any applicable materials-handling truck. In this embodiment, as illustrated in <FIG>, the lift truck <NUM> is assembled, in part, by attaching a counterweight <NUM> to one end of a truck body <NUM>, per step <NUM>. The counterweight <NUM> includes a cavity <NUM>, a sensor-mounting recess <NUM>, and a harness-routing pathway <NUM>. The cavity <NUM> has an opening on the exterior side of the outer surface of the counterweight <NUM> defined by a frame <NUM>, which is the exterior side of the outer surface of the counterweight <NUM> other than the opening of the cavity <NUM>.

Per step <NUM>, a lift assembly <NUM>, which may include a pair of forks <NUM> and a mast <NUM>, is attached to the opposite end of the truck body <NUM> as the counterweight <NUM>. In an alternative embodiment, the lift truck <NUM> is assembled by first attaching the lift assembly <NUM> to the truck body <NUM>, then attaching the counterweight <NUM> to the opposite end of the truck body <NUM> as the lift assembly <NUM>. That is, the order of steps <NUM> and <NUM> may be reversed. Other steps involved in completely assembling the lift truck <NUM> are not illustrated in <FIG>. Such other steps may occur before, after, or between the steps illustrated in <FIG>.

Next, per step <NUM>, the sensor <NUM>, having or connectable to a wiring harness <NUM>, is attached in the sensor-mounting recess <NUM>. The wires of the wiring harness <NUM> may transmit power and/or data to and from the sensor <NUM>. Per step <NUM>, the wires of the wiring harness <NUM> are routed through the harness-routing pathway <NUM> from the sensor-mounting recess <NUM> to the opposite side of the counterweight <NUM>. The wires of the wiring harness <NUM> may be attached to, for example, an energy source and/or a processor located in an engine compartment under the panel <NUM> of <FIG> or elsewhere on or in the lift truck <NUM>.

Optionally, the counterweight <NUM> comprises a tow-pin hole <NUM> within the cavity <NUM>, and, per step <NUM>, the method of <FIG> includes the step of inserting a tow-pin in the tow-pin hole <NUM>.

In an additional embodiment, the method of assembling a lift truck may include a method of mounting a sensor in the sensor-mounting recess. For the sake of clarity, this method will be described with reference the lift truck <NUM> described above as a specific example, but this method is not limited to that specific lift truck and may be practiced with any applicable materials-handling truck. A method of mounting a sensor in the sensor-mounting recess may include one or more of the following steps: the step of attaching a bracket <NUM> to the sensor <NUM>; the step of leveling the sensor <NUM> by adjustment of screws at the corners of bracket <NUM>; the step of adjusting the bracket <NUM> to fit snugly in the tow-pin hole <NUM> by tightening or loosening the bracket bolt to fill the gap between the tow-pin hole <NUM> and the bracket <NUM>; and the step of inserting bracket <NUM> into a tow-pin hole <NUM> within the sensor-mounting recess <NUM>. The bracket <NUM> may be adapted to fit into a tow-pin hole <NUM> on the counterweight <NUM>. Various designs of bracket <NUM> may be desired for attachment to various types of sensors <NUM> and/or for securing into the sensor-mounting recess <NUM>.

In an embodiment, a counterweight includes a means for mounting a sensor. For example, the counterweight <NUM> includes a means for mounting the sensor <NUM>. The means for mounting a sensor may include a hole within a recess, wherein the hole accepts a bracket, such as the bracket <NUM>, connected or connectable to the sensor, and wherein the recess is sized and shaped so as to fit the sensor in such a manner that provide an unobstructed horizontal line of sight of at least about <NUM> degrees for a sensor when the sensor is mounted. The hole may be, for example, a tow-pin hole, and a separate tow-pin may be additionally provided on the counterweight.

The counterweights <NUM> and <NUM>, including those depicted in <FIG> and <FIG>, are exemplary embodiments of the counterweights disclosed herein. It is understood that various features of the counterweights <NUM> and <NUM> are optional and may be omitted from a counterweight while maintaining one or more of the advantageous features of the disclosed counterweights. For example, the tow pin <NUM> is optional, as depicted in the embodiment of the counterweight <NUM> shown in <FIG>. In addition, the sensor <NUM> may not need the bracket <NUM> that is inserted in the tow-pin hole <NUM> of the sensor-mounting recess <NUM>, as shown in <FIG>. In an aspect, only the counterweight in <FIG> and <FIG> is claimed, but the other components are shown for context and setting and only for illustrative purposes. In a further aspect, the entire lift truck <NUM> in <FIG> and <FIG> is claimed.

Claim 1:
A counterweight (<NUM>, <NUM>) for a lift truck (<NUM>), the counterweight (<NUM>, <NUM>) comprising:
a frame (<NUM>, <NUM>) formed by a substantially horizontal upper peripheral edge (<NUM>), a first substantially vertical side peripheral edge (<NUM>), a second substantially vertical side peripheral edge (<NUM>) opposite the first substantially vertical side peripheral edge (<NUM>), and a lower peripheral edge (<NUM>, <NUM>);
a cavity (<NUM>, <NUM>) surrounded by the frame (<NUM>, <NUM>); characterized by
a sensor-mounting recess (<NUM>, <NUM>) in the lower peripheral edge (<NUM>, <NUM>) of the frame (<NUM>, <NUM>),
wherein the sensor-mounting recess (<NUM>, <NUM>) is configured to provide an unobstructed horizontal line of sight of at least about <NUM> degrees for a sensor (<NUM>, <NUM>) mounted within the sensor-mounting recess (<NUM>, <NUM>), and
wherein the lower peripheral edge (<NUM>, <NUM>) of the frame (<NUM>, <NUM>) further comprises a tow-pin hole (<NUM>) and/or wherein the lower peripheral edge (<NUM>, <NUM>) of the frame (<NUM>, <NUM>) further comprises a tow pin (<NUM>, <NUM>) and/or the lower peripheral edge (<NUM>, <NUM>) of the frame (<NUM>, <NUM>) further comprises a harness-routing pathway (<NUM>, <NUM>').