Apparatus for diverting a flow of exhaust from an engine of a truck

An apparatus is disclosed for diverting a flow of exhaust from an engine of a truck having a truck bed and a muffler system, with the truck bed having a duct system. The apparatus includes an inlet for receiving the flow of exhaust from the engine. The apparatus further includes a first outlet connected to the muffler system and a second outlet connected to the duct system. The apparatus additionally includes a diverter member positionable between a first position and a second position, wherein (1) fluid communication between the inlet and the first outlet is prevented when the diverter member is positioned in the first position, and (2) fluid communication between the inlet and the second outlet is prevented when the diverter member is positioned in the second position. Moreover, the apparatus includes an air cylinder for moving the diverter member between the first position and the second position. The apparatus also includes a sensor which detects decoupling of the second outlet from the duct system and generates an electrical signal in response thereto, wherein the air cylinder moves the diverter member between the first position and the second position in response to generation of the electrical signal. A method of directing exhaust from an engine of a truck is also disclosed.

BACKGROUND OF THE INVENTION 
The present invention relates generally to an apparatus and method for 
diverting exhaust from an engine of a truck, and more particularly to a 
method and apparatus for selectively diverting a flow of exhaust to either 
a bed duct system of the truck or a muffler system of the truck. 
A dump truck includes a bed for receiving material therein. Typically, the 
bed can be raised by a hydraulic system so as eject the material from the 
bed at an appropriate time. Thereafter, the bed can be lowered so that 
additional material may be loaded therein. 
During certain weather conditions, the material in the bed has a tendency 
to adhere to the walls of the bed (e.g. during cold weather conditions) 
thereby resisting ejection of the material from the bed. To overcome this 
problem, it is known to provide a duct system within the walls of the bed 
for receiving a flow of exhaust generated by the truck engine so that the 
flow of exhaust may be advanced therethrough thereby heating the walls of 
the bed. By providing heat to the walls of the bed in the above manner, 
the tendency of the material to adhere to the walls of the bed is reduced. 
Some dump truck designs which include a duct system within the walls of the 
bed have a bed duct input port that is interfaced with and exhaust system 
output port when the bed is located in a lowered position so that the flow 
of exhaust can be advanced from the exhaust system into the bed duct 
system. material from the bed, the bed duct input port is decoupled from 
the exhaust system output port. This decoupling causes the flow of exhaust 
to exit out of the exhaust system output port directly into the atmosphere 
thereby resulting in a high level of undesirable noise being created. Note 
that if the flow of exhaust is routed through a muffler system or a bed 
duct system, such high level of undesirable noise is avoided. 
In an attempt to overcome this problem, it is known to provide a diverter 
mechanism which prevents the flow of exhaust from exiting out of the 
exhaust system output port when the bed is being raised, or more 
particularly, when the bed duct input port is being decoupled from the 
exhaust system output port. Instead, at this time, the flow of exhaust is 
diverted to a muffler system so as to avoid the production of a high level 
of undesirable noise. 
One design of a diverter mechanism which diverts the flow of exhaust from 
the bed duct system to the muffler system utilizes the bed itself to 
contact a lever member during lowering of the bed. In particular, a 
portion of the bed is lowered onto the lever member so as to move the 
lever member. In turn, the lever member moves a flap, via a mechanical 
linkage, from a first position to a second position. In the first 
position, the flap prevents the flow of exhaust from advancing into the 
muffler system while enabling the flow of exhaust to enter the bed duct 
system. In the second position, the flap prevents the flow of exhaust from 
advancing into the bed duct system and enables the flow of exhaust to 
enter the muffler system. 
However, certain disadvantages exist with the above design. Firstly, the 
force applied by the bed onto the lever member is substantial and 
consequently causes the mechanical parts of the diverting mechanism to 
wear out relatively quickly. Secondly, the bed must be raised slightly in 
order for the diverter mechanism to move the flap from the first position 
to the second position. In the meantime, the bed duct input port separates 
from the exhaust system output port a slight distance before the flap is 
repositioned thereby causing a momentary occurrence of a high level of 
undesirable noise. 
SUMMARY OF THE INVENTION 
In accordance with one embodiment of the present invention, there is 
provided an apparatus for diverting a flow of exhaust from an engine of a 
truck having a truck bed and a muffler system, with the truck bed having a 
duct system. The apparatus includes a diverter member positionable between 
a first position and a second position, wherein (1) the flow of exhaust is 
prevented from being advanced into the muffler system and allowed to be 
advanced into the duct system when the diverter member is positioned in 
the first position, and (2) the flow of exhaust is prevented from being 
advanced into the duct system and allowed to be advanced into the muffler 
system when the diverter member is positioned in the second position. The 
apparatus further includes a sensor which detects raising of the truck 
bed, and generates a sensor signal in response thereto. In addition, the 
apparatus includes an actuator for moving the diverter member between the 
first position and the second position in response to generation of the 
sensor signal. 
Pursuant to another embodiment of the present invention, there is provided 
an apparatus for diverting a flow of exhaust from an engine of a truck 
having a truck bed and a muffler system, with the truck bed having a duct 
system. The apparatus includes an inlet for receiving the flow of exhaust 
from the engine. The apparatus further includes a first outlet connected 
to the muffler system and a second outlet connected to the duct system. In 
addition, the apparatus includes a diverter member positionable between a 
first position and a second position, wherein (1) fluid communication 
between the inlet and the first outlet is prevented when the diverter 
member is positioned in the first position, and (2) fluid communication 
between the inlet and the second outlet is prevented when the diverter 
member is positioned in the second position. Moreover, the apparatus 
includes an air cylinder for moving the diverter member between the first 
position and the second position. 
According to yet another embodiment of the present invention, there is 
provided a method of directing a flow of exhaust from an engine of a truck 
having a truck bed and a muffler system, with the truck bed having a duct 
system. The method includes the steps of (1) preventing the flow of 
exhaust from being directed to the muffler system and directing the flow 
of exhaust to the duct system when the truck bed is positioned in a 
lowered position, (2) detecting when an operator is raising the truck bed 
and generating an electrical signal in response thereto, and (3) 
preventing the flow of exhaust from being directed to the duct system and 
directing the flow of exhaust to the muffler system in response to 
generation of the electrical signal. 
It is therefore an object of the present invention to provide a new and 
useful apparatus and method for diverting exhaust from an engine of a 
truck. 
It is another object of the present invention to provide an improved 
apparatus and method for diverting exhaust from an engine of a truck. 
It is yet another object of the present invention to provide an apparatus 
and method for diverting exhaust from an engine of a truck in which its 
working parts do not wear out relatively quickly. 
It is a further object of the present invention to provide an apparatus and 
method for diverting exhaust from an engine of a truck in which a 
momentary occurrence of a high level of undesirable noise is not created 
when the truck bed is being raised from a lowered position to a raised 
position. 
It is a further object of the present invention to provide an apparatus and 
method for diverting exhaust from an engine of a truck which is relatively 
quiet during raising of the truck bed. 
The above and other objects, features, and advantages of the present 
invention will become apparent from the following description and the 
attached drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
While the invention is susceptible to various modifications and alternative 
forms, a specific embodiment thereof has been shown by way of example in 
the drawings and will herein be described in detail. It should be 
understood, however, that there is no intent to limit the invention to the 
particular form disclosed, but on the contrary, the intention is to cover 
all modifications, equivalents, and alternatives falling within the spirit 
and scope of the invention as defined by the appended claims. 
Referring now to FIGS. 1 and 2, there is shown a dump truck 10 (only a part 
of the dump truck is shown for clarity of description). The truck 10 
includes a truck bed 12, a muffler system 14, an engine (not shown) and an 
apparatus 16 for diverting exhaust from the engine. 
The bed 12 is configured to receive material (e.g. sand, asphalt, 
miscellaneous debris, etc.) and contain such material during travel of the 
truck 10 from one location to another location. At certain times, it will 
become desirable to eject or unload the material from the bed 12. In order 
to achieve the above, the bed 12 can be raised by a hydraulic system (not 
shown) from a lowered position as shown in FIG. 1 to a raised position as 
shown in FIG. 2. After the material has been ejected from the bed 12, the 
bed is returned to its lowered position. It should be noted that the bed 
12 may be raised to one of a number of raised positions depending on the 
desire of the operator and the specific task to be performed in order to 
eject the material from the bed. However, only one raised position is 
shown herein. 
During certain weather conditions, the material in the bed has a tendency 
to adhere to the walls of the bed (e.g. during cold weather conditions) 
thereby resisting ejection of the material from the bed 12. To reduce this 
adhering tendency, the bed 12 is provided with a bed duct system 18. When 
the bed 12 is positioned in its lowered position, the duct system 18 
receives a flow of exhaust 20 from the engine. As the flow of exhaust 20 
is advanced through the duct system 18, the walls of the bed 12 are heated 
thereby reducing the tendency of the material to adhere thereto. 
The duct system 18 includes an input port 22 (see FIG. 2) while the exhaust 
transferring apparatus 16 includes a housing 21 having an inlet 23, a 
first outlet 24 and a second outlet 26. When the bed 12 is positioned in 
its lowered position as shown in FIG. 1, the input port 22 of the duct 
system 18 is coupled to the second outlet 26 of the exhaust transferring 
apparatus 16. When the bed 12 is positioned in its raised position as 
shown in FIG. 2, the input port 22 of the duct system 18 is decoupled from 
the outlet 26 of the exhaust transferring apparatus 16. 
Referring now to FIGS. 3 and 4, the exhaust transferring apparatus 16 
further includes an air cylinder 28 having a movable shaft 30. The movable 
shaft 30 is coupled to a diverter member 32 by a mechanical linkage (not 
shown). The diverter member 32 is positionable in a first position as 
shown in FIG. 3 and a second position as shown in FIG. 4. In the first 
position, the diverter member 32 is positioned so that the flow of exhaust 
20 is prevented from being advanced to the muffler system 14. In the 
second position, the diverter member 32 is positioned so that the flow of 
exhaust 20 is prevented from being advanced to the duct system 18. 
When the diverter member 32 is located in the first position as shown in 
FIG. 3, the flow of exhaust 20 is directed through the second outlet 26 
and into the duct system 18 so as to heat the walls of the bed 12. When 
the diverter member 32 is located in the second position as shown in FIG. 
4, the flow of exhaust 20 is directed through the first outlet 24 and into 
the muffler system 14 so as avoid creation of a high level of undesirable 
noise. Creation of a high level of undesirable noise is also prevented 
when the flow of exhaust 20 is directed through the bed duct system 18. 
The second outlet 26 of the exhaust diverting apparatus 16 includes a lower 
outlet segment 36 and an upper outlet segment 38. A spring (not shown) is 
interposed between the lower outlet segment 36 and the upper outlet 
segment 38 so as to allow relative movement therebetween. This feature 
functions to dampen the impact of the bed 12 as it is lowered onto the 
upper outlet segment 38 after ejecting material from the bed. 
Referring again to FIGS. 1 and 2, the exhaust diverting apparatus 16 
further includes an air solenoid 40, a sensor 42, an inversion valve 44, a 
T-shaped connector 46 and an air source 48. The air source 48 provides 120 
psi of air pressure via air hoses 50 to the air solenoid 40 and to the 
inversion valve 44. The air solenoid 40 is connected to the T-shaped 
connector 46 via an air hose 52. The T-shaped connector 46 is connected to 
the inversion valve 44 via an air hose 54. The T-shaped connector 46 is 
further connected to a first input port 56 of the air cylinder 28 (see 
FIG. 3) via an air hose 58, while the inversion valve 44 is connected a 
second input port 60 of the air cylinder (see FIG. 3) via an air hose 62. 
The sensor 42 is connected to the air solenoid 40 via a signal line 64. As 
shown in FIG. 5, the sensor 42 includes a first sensor mechanism 66 and a 
second sensor mechanism 68. The first sensor mechanism 66 detects when a 
hoist control switch (not shown) is being actuated by an operator of the 
truck 10 in order to raise the bed 12, and generates an electrical signal 
on the line 64 in response thereto. The second sensor mechanism 68 is a 
hall effect sensor positioned in relation to the bed 12 so as to detect 
when the bed 12 is being raised upwardly from its lowered position, and 
generates an electrical signal on line 64 in response thereto. 
FIG. 6 is a chart which indicates various status relationships between the 
first sensor mechanism 66, the second sensor mechanism 68, the signal line 
64 and the air solenoid 40. When either the first sensor mechanism 66 and 
the second sensor mechanism 68 is generating an electrical signal, sensor 
42 generates a signal on the line 64. 
When no signal is being generated on line 64, the solenoid 40 is unpowered 
and does not pass a flow of air from the air supply 48 to the T-connector 
46. When the flow of air is not being passed to the T-connector 46, no air 
signal is being provided to the inversion valve 44 via air hose 54. 
Without this air signal, the inversion valve is free to pass the flow of 
air from the air supply 48 to the second input port 60 of the air cylinder 
28. In turn, the shaft 30 of the air cylinder 28 is caused to assume its 
extended position as shown in FIG. 3. Accordingly, the diverter member 32 
is caused to be placed in the first position thereby preventing the flow 
of exhaust 40 from being advanced to the muffler system 14. 
When a signal is being generated on line 64 by the sensor 42, the solenoid 
40 is powered and does pass the flow of air from the air supply 48 to the 
T-connector 46. When the flow of air is being passed to the T-connector 
46, an air signal is provided to the inversion valve 44 via air hose 54. 
This air signal causes the inversion valve to prevent the flow of air from 
being passed from the air supply 48 to the second input port 60 of the air 
cylinder 28. Also when the flow of air is being passed to the T-connector 
46, the flow of air is passed to the first input port 56 of the air 
cylinder 28. In turn, the shaft 30 of the air cylinder 28 is caused to 
assume its withdrawn position as shown in FIG. 4. As a result, the 
diverter member 32 is caused to be placed in the second position thereby 
preventing the flow of exhaust 40 from being advanced to the duct system 
18. 
Since the diverter member 32 is caused to assume the second position 
thereby diverting the flow of exhaust 20 to the muffler system 14 when the 
first sensor mechanism detects actuation of the hoist control switch by 
the operator of the truck, the flow of exhaust 20 is diverted to the 
muffler system 14 prior to any decoupling or separation between the input 
port 22 of the duct system 18 and the second outlet 26 of the exhaust 
diverting apparatus 16. Thus, no momentary occurrence of a high level of 
undesirable noise occurs when the bed 12 is moved from its lowered 
position to its raised position. 
Also, since the diverter member 32 is moved between its first position and 
its second position by the air cylinder 28, the working parts of the 
exhaust diverting apparatus 16 will not wear out relatively quickly. 
While the invention has been illustrated and described in detail in the 
drawings and foregoing description, such illustration and description is 
to be considered as exemplary and not restrictive in character, it being 
understood that only the preferred embodiment has been shown and described 
and that all changes and modifications that come within the spirit of the 
invention are desired to be protected.