1. Field of the Invention
The subject invention generally pertains to truck loading docks and more specifically to fan for ventilating a truck or trailer parked at the dock.
2. Description of Related Art
Trucks often back their trailers into a loading dock for loading or unloading the trailer of its cargo. Depending on the type of cargo, dockworkers may sometimes spend hours working inside the trailer as they move items in or out via a conveyor. While working inside the trailer, the temperature inside can get quite uncomfortable, particularly on hot days.
In an attempt to solve this problem, the first choice, of course, might be to install a fan to ventilate the trailer. D. L. Manufacturing of North Syracuse, N.Y., for example, provides an AEROTEC fan for just that purpose. Although the AEROTEC fan may provide some advantages over other more conventional fans, the AEROTEC fan and others still fall short of addressing all of the issues that may arise while trying to ventilate a trailer at a loading dock.
First, many trailers are 53 feet long and in some cases even longer. In order for a fan to force air from the doorway of the dock all the way over to the trailer's opposite end or nose of the trailer (front end of the trailer closest to the truck/tractor), the fan outlet is preferably aimed directly at the nose of the trailer. This, unfortunately, places the fan in front of the doorway, which can interfere with loading and unloading operations. The AEROTEC fan attempts to address this problem by using a diffuser that can break away when struck.
Second, having an AEROTEC or similar fan mounted at a fixed position means that the fan must be positioned sufficiently away from the doorway so as not to interfere with operation of the dock door. This, unfortunately, is not a good location for a fan. The discharge of the fan should preferably protrude well into the doorway and even into the trailer itself to avoid creating a static pressure or deadhead at the nose of the trailer that could impede fan discharge air from penetrating the full depth of the trailer.
Third, installing a fan at a fixed location makes it difficult to address ventilation needs that may change while the trailer is being loaded or unloaded. The discharge of the fan, for instance, may need to be redirected as the positions of the dockworkers and cargo within the trailer change.
Fourth, the effectiveness a fan mounted at a fixed location may vary depending on the location or alignment of the trailer opening relative to the doorway. If the back end of the trailer is higher or lower than expected or shifted laterally off to one side or the other, airflow through the trailer may be inadequate.
Fifth, loading docks often have a series of side-by-side doorways for servicing multiple trucks. If a fixed-location fan is dedicated to serving just one doorway, then each doorway may need its own fan. But, it may be costly to fully ventilate a multi-station loading dock with an equal number of fixed-location fans.
Even a movable floor mounted fan is not the best solution, as floor space in the area of a loading dock is often limited, traffic in the area can be heavy, and the airflow from a fan with a relatively low discharge may be obstructed by loads that are on the bed of the trailer. Thus, a need exists for an apparatus and method for more effectively ventilating a trailer at a loading dock.
In some embodiments, a ventilation system for a trailer at a loading dock includes a fan supported by a positioning mechanism that renders the fan selectively movable to vary the extent to which the fan protrudes into the doorway.
In some embodiments, the positioning mechanism can move the fan to a stored position completely clear of the projected doorway passageway.
In some embodiments, the positioning mechanism includes a track and track follower that allows the fan to move linearly.
In some embodiments, the positioning mechanism includes an articulated arm with a plurality of pivot points that enable the mechanism to reach around a door track or other obstructions near the doorway.
In some embodiments, the articulated arm includes a telescoping segment for adjusting the arm's reach.
In some embodiments, the positioning mechanism permits the fan to rotate 360-degrees.
In some embodiments, the positioning mechanism allows a single fan to selectively operate at two or more doorways.
In some embodiments, a lamp is supported by the fan and/or the positioning mechanism.
In some embodiments, the positioning mechanism helps support a power cord that leads to the fan.
In some embodiments, the fan the positioning mechanism is mounted off the floor.
To help ventilate the interior of trailer 10 once it is docked, as shown in
To ventilate trailer 10, mechanism 28 can allow movement of fan 24 to direct air 30 towards a front end 32 of trailer 10, as shown in
Referring further to
Referring to
With this design, fan 24 can be moved selectively in and out across an imaginary door plane 66 defined by an exterior face of a door 70 (
To help hold fan 24 in place once it is properly positioned, pins 48, 50, 52 and 54 can each be a screw with a locknut that is sufficiently tightened to create a frictional holding force at each pivotal axis 58, 60, 62 and 64.
To ensure that positioning mechanism 28 has sufficient length for reaching various desired locations, second arm 46 may comprise a telescoping segment 78 that fits within an outer tube 80. The resulting telescoping assembly can be locked in place once arm 46 is set at a desired length, or arm 46 can be left with its telescoping feature. In some cases, the telescoping assembly is locked in place by a screw 82 that connects one end of a brace 84 that extends between pin 50 and screw 82. Brace 84 reinforces arm 46 by countering the bending moment created by the weight of fan 24.
First arm 28 can be provided with some braces 86 that not only reinforce arm 44 but also provides a way for a power cord 88 of fan 24 to be threaded through and supported by first arm 28.
To illuminate the interior of trailer 10, a lamp 90 can be coupled to base 40 by attaching lamp 90 to fan 24 (
In this example, fan 94 includes a flexible diffuser 104 that can resiliently recover from an impact should it occur. Diffuser 104 can be made of a tough fabric or some other impactable material. Diffuser 104 can also be installed on fan 24 of ventilation system 22. Alternatively, a diffuser could be mounted elsewhere—such as to the interior of the trailer—and then coupled to the fan 94. In this context, the “diffuser” could actually be an extended duct (of fabric or other material) extending along or across the interior of the trailer. Such an arrangement would allow the duct diffuser to carry air in a contained, directed manner, further into the trailer. It should also be noted that other advantageous structure besides diffuser 104 could be attached to the fan, such as a filter for the conveyed air, a heater for the air and/or a dehumidifier. These three illustrative, representative structures as well as the diffuser 104 are referred to herein as “air treatment components.”
Although the invention is described with reference to a preferred embodiment, it should be appreciated by those of ordinary skill in the art that various modifications are well within the scope of the invention. For example, although fans 24 and 94 are illustrated as centrifugal fans, other types of fans could also be used. Also, lamp 90 shown mounted to fan 24 of