Information
-
Patent Grant
-
6267494
-
Patent Number
6,267,494
-
Date Filed
Friday, March 10, 200024 years ago
-
Date Issued
Tuesday, July 31, 200123 years ago
-
Inventors
-
-
Examiners
- Drodge; Joseph W.
- Cecil; Terry K.
Agents
-
CPC
-
US Classifications
Field of Search
US
- 116 28 R
- 116 200
- 116 303
- 366 41
- 366 68
- 193 DIG 2
- 193 117
- 414 698
- 414 683
- 414 148
- 141 94
- 340 438
- 340 457
- 340 6861
- 340 6862
- 340 689
-
International Classifications
-
Abstract
A warning system is disclosed for use on a concrete mixer to indicate that a charge hopper 28 is in a raised position. Such concrete mixers include an air supply, a mixing drum having an access port, a frame supporting the mixing drum, and a charge hopper 28 that is pivotally supported adjacent the access port. The charge hopper 28 is moveable between a raised position and a lowered position. The warning system includes an indicator device 70 operatively associated with the concrete mixer and configured for activation to indicate when the charge hopper is in the raised position. A valve 44 is operatively associated with the frame and in fluid communication with the air supply 14 and the indicator device 70. The valve 44 includes an actuator moveable between a first position to deactivate the indicator device and a second position to activate the indicator device. A contact structure 50 is operatively associated with the charge hopper to actuate the valve.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The subject invention relates generally to a warning system for a charge hopper, and, more particularly, to a warning system for use on mobile-type concrete mixers to signal the operators thereof when the concrete mixers' charge hoppers are in a raised position.
2. Background of the Related Art
Mobile-type concrete mixers are the workhorse in the building industry. There are tens-of-thousands of such concrete mixers in operation today throughout the world. Their basic function is to mix and deliver tons of concrete to a variety of settings including residential and industrial construction sites. Mobile-type concrete mixers can be classified into two groups—tractor-carried concrete mixers and tractor-drawn concrete mixers.
The tractor-carried concrete mixers have two basic configurations. They include a conventional configuration which is loaded and delivers concrete from the rear of the vehicle and a front-loader configuration which, as the name implies, is loaded and delivers concrete from the front of the vehicle. Although configured differently, they share similar characteristics. That is, they each include a cab for the operator to drive the vehicle, an air supply system, a mixing drum, frames to support the mixing drum, a charge hopper, and controls for operating the mixing drum and charge hopper.
Tractor-drawn concrete mixers basically comprise a trailer-mounted concrete mixer that is pulled by a tractor. They tend to have a larger capacity then tractor-carried concrete mixers and are often used for large pours such as found in highway and dam construction. Although configured somewhat differently then the tractor-carried concrete mixers, tractor-drawn concrete mixers share similar characteristics. That is, they include a cab in the tractor for the operator to drive the vehicle, an air supply system, a mixing drum, frames to support the mixing drum, a charge hopper, and controls for operating the mixing drum and charge hopper.
Both tractor-carried concrete mixers and tractor-drawn concrete mixers may alternatively be referred to simply as concrete mixers. To simplify the description of the present invention, reference will be made only to tractor-carried cement mixers. Those skilled in the art will appreciate that the present invention will benefit any and all types of mobile-type concrete mixers.
Referring to
FIGS. 1 and 2
, a perspective view of a conventional tractor-carried concrete mixer designated by reference numeral
10
and an elevational view of a rear portion of the concrete mixer
10
are illustrated, respectively. In the descriptions provided herein below, like reference numerals identify similar structural elements.
As noted above, a tractor-carried concrete mixer
10
includes a cab
12
that provides a protective enclosure in which the operator drives the truck and controls various functions of the concrete mixer. Concrete mixer
10
also includes an air supply system that provides compressed air for actuating a breaking system, for actuating pneumatic cylinders, and for general-purpose usage. The air supply system includes a compressor that is driven by the tractor's engine and charges a volume tank
14
to store compressed air for the above-described purposes.
Concrete mixer
10
further includes a mixing drum
16
for mixing and storing cement, aggregate, and water, i.e., concrete. The mixing drum
16
has a closed end and an open end. The open end is an access port
18
through which cement, aggregate, and water are poured into the interior of the mixing drum
16
and out of which concrete is poured.
The controls
19
are typically located within eyeshot of the access port
18
to enable an operator to manipulate the controls
19
while observing delivery of concrete from the mixing drum
16
. The type and number of controls
19
vary from concrete mixer to concrete mixer. However, all concrete mixers include a control to operate the mixing drum
16
, and to raise and lower the charge hopper as described in more detail herein below.
The mixing drum
16
is rotationally supported by a set of frames including a cab-side frame
20
and a hopper-side frame
22
. The cab-side frame
20
supports the closed end of the mixing drum
16
through a tapered roller bearing (not shown). The hopper-side frame
22
supports the open end of the mixing drum
16
through a pair of rollers (not shown) that ride against a support ring
24
attached to the mixing drum
16
. Extending from the upper portion of the hopper-side frame
22
is a near-side vertical support
26
and a complementary far-side vertical support (not shown).
The charge hopper
28
is funnel-shaped and is utilized in a lowered position to guide cement, aggregate, and water from storage containers at a concrete plant, through the access port
18
, and into the mixing drum
16
. The charge hopper
28
, when moved to a raised position, allows concrete to pour unobstructed from the mixing drum
16
, out through the access port
18
, down a chute attachment
30
(shown in its stored position), and into, for example a pour frame.
The near-side vertical support
26
and far-side vertical support provide mounting points for the charge hopper
28
. More specifically, the charge hopper
28
is pivotally mounted by a near-side pivot pin
32
to a near-side attachment arm
34
which is attached to the near-side vertical support
26
, and a complementary far-side pivot pin to a far-side attachment arm (not shown) which is attached to the far-side vertical support.
A first end
38
of a pneumatic lift cylinder
36
is mounted to the near-side vertical support
26
and a second end
40
is mounted to the charge hopper
28
for pivoting the charge hopper
28
between the lowered position and the raised position. That is, the charge hopper
28
is pivoted from the lowered position to the raised position by extending the pneumatic lift cylinder
36
, thereby pivoting the charge hopper
28
in the counter-clockwise direction about the pivot pins as indicated by the “Y” arrow (FIGS.
1
and
3
). The charge hopper
28
is pivoted from the raised position to the lowered position by retracting the pneumatic lift cylinder
36
, thereby pivoting the charge hopper
28
in the clockwise direction about the pivot pins as indicated by the “X” arrow (FIGS.
1
and
2
). The charge hopper
28
, illustrated in
FIGS. 1 and 3
. is shown in the raised position while the charge hopper
28
illustrated in
FIG. 2
is shown in the lowered position. Although the lift cylinder
36
is described herein as a “pneumatic” lift cylinder, such lift cylinders might also be hydraulically operated.
Those skilled in the art will appreciate that when the charge hopper
28
is in the raised position it increases the overall height of the tractor-carried concrete mixer
10
by approximately one to two feet. Therefore, proper operation of the concrete mixer
10
dictates that the charge hopper
28
should be located in the lowered position any time the vehicle is traveling over roadways; thereby preventing it from accidentally hitting low overpasses, power cables, light poles, etc., and causing severe property damage and personal injury. However, due to a wide variety of distractions found at construction sites, it is relatively easy for an operator to forget that the charge hopper is in the raised position.
It would be beneficial to provide a system to warn an operator of a tractor-carried concrete mixer or tractor-drawn concrete mixer that the charge hopper is in the raised position. Such a system should be relatively inexpensive, easy to install, operate and maintain.
SUMMARY OF THE INVENTION
The subject invention is directed to a warning system for use on a concrete mixer that includes an air supply, a mixing drum having an access port, and a charge hopper pivotally supported adjacent the access port, wherein the charge hopper is mounted for movement between a raised position and a lowered position.
An embodiment of the warning system includes an indicator device operatively associated with the concrete mixer and configured to be activated to indicate when the charge hopper is in the raised position. A valve is operatively associated with the concrete mixer and in communication with the air supply and the indicator device. The valve includes an actuator moveable between a first position to deactivate the indicator device and a second position to activate the indicator device. A contact structure is operatively associated with the charge hopper to actuate the valve. In use, pressurized air is transmitted from the air supply to the indicator device when the actuator of the valve is in the first position. The indicator device may be a diaphragm-type indicator having a warning arm that pivots into the field of vision of an operator when it is activated.
Another embodiment of the present invention includes a kit for mounting on a concrete mixer to indicate when a charge hopper is in a raised position. The kit includes at least one conduit, an indicator device configured to be activated to indicate when the charge hopper is in the raised position, a valve configured to communicate with an air supply and the indicator device through the at least one conduit, wherein the valve includes an actuator moveable between a first position to deactivate the indicator device and a second position to activate the indicator device, and a contact structure configured to actuate the valve. The kit may be packaged in any type of packaging available on the market. For example, the packaging may be a box with formed inserts to support its contents.
Another embodiment of the present invention includes a method for indicating when a charge hopper is in a raised position on a concrete mixer. Preferably, the method includes the step of providing an indicator device operatively associated with the concrete mixer and a valve operatively associated with the concrete mixer and in communication with an air supply and the indicator device, the valve including an actuator moveable between a first position to deactivate the indicator device and a second position to activate the indicator device. The method further includes the steps of pivoting the charge hopper to the raised position, actuating the valve to move the actuator from the first position to the second position, and activating the indicator device to indicate the charge hopper is in the raised position.
These and other unique features of the present invention generally described as a warning system for a charge hopper will become more readily apparent from the following drawings and description thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
So that those of ordinary skill in the art to which the subject invention appertains will more readily understand how to make and use the invention described herein, preferred embodiments of the invention will be described in detail herein below with reference to the drawings wherein:
FIG. 1
is a perspective view of a tractor-carried concrete mixer having a charge hopper in a raised position;
FIG. 2
is a side elevational view of a rear portion of a tractor-carried concrete mixer that includes an embodiment of the present invention;
FIG. 3
is a side elevational view of a rear portion of a tractor-carried concrete mixer that includes an embodiment of the present invention;
FIG. 4
is a schematic view of a two-position, three-port valve used in an embodiment of the present invention;
FIG. 5
is a side elevational view in cross section of a low-pressure indicator,
FIG. 6
is a side elevational view in cross section of an alternate type of indicator;
FIG. 7
is a schematic view of a two-position, three-port valve used in an embodiment of the present invention; and
FIG. 8
is a perspective view of a kit for marketing an embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As described above in reference to
FIGS. 1-3
, a typical tractor-carried concrete mixer
10
includes a cab
12
for an operator to drive the vehicle, an air supply system, a mixing drum
16
, a set of frames
20
and
22
to support the mixing drum
16
, and a charge hopper
28
. The charge hopper
28
is moved to a lowered position so cement, aggregate, and water may be poured into the upper portion of the charge hopper
28
as shown by arrow “Z” (FIG.
2
), funneled through the access port
18
, and dumped into the mixing drum
16
. The charge hopper
28
is moved to a raised position to allow concrete to pour unobstructed from the mixing drum
16
, down a chute attachment
30
(shown in its stored position), and poured into, for example, a pour frame.
Referring in particular to
FIGS. 2 and 3
. an embodiment of the present invention is illustrated. The embodiment is assembled to the tractor-carried concrete mixer
10
. A detailed description of the embodiment follows herein below. As noted above, although the description provided herein and the figures referred to concern a tractor-carried concrete mixer, the present invention may be utilized on any mobile-type concrete mixer.
A mounting bracket
42
is mounted to the near-side attachment arm
34
. A valve
44
is mounted to the mounting bracket
42
with its actuator
46
facing upward. The valve
44
can alternatively be described as a switching device. The mounting bracket
42
may be made adjustable with respect to the near-side attachment arm
34
, for example, by including slots in the mounting bracket
42
and using screws to secure it in place. In addition, the valve
44
may be made adjustable with respect to the mounting bracket
42
, for example, by including slots in the mounting bracket
42
and using screws to secure the valve
44
in place. It is notable that the mounting bracket
42
and valve
44
may in the alternative be mounted to the charge hopper
28
. Circumstances relating to a particular installation will dictate the most preferable mounting location.
Referring to
FIG. 4
, as illustrated schematically, the valve
44
is a plunger actuated, two-position, three-port type pneumatic valve. The three ports are identified as port “A”, port “B”, and port “C”. In position 1, wherein the plunger is depressed, an air passage is formed between port “A” and port “B”. In position 2, wherein the plunger is released to allow a spring to act within the valve, an air passage is formed between port “B” and port “C”. Those skilled in the art will appreciate that other types of valves may be used in the present embodiment without departing from the breath and scope of the invention.
Referring again to
FIGS. 2 and 3
, a supply conduit
48
provides fluid communication between the volume tank
14
and port “A” of the valve
44
. The supply conduit
48
may be made of rigid tubing, flexible tubing, or a combination of both. Circumstances relating to a particular installation will dictate the most preferable types of materials to use.
A contact structure
50
is mounted to the charge hopper
28
. The contact structure
50
may be made adjustable with respect to the charge hopper
28
, for example, by including slots in the contact structure
50
and using screws to secure it in place. The contact structure
50
is positioned on the charge hopper
28
so that it depresses the plunger actuator
46
when the charge hopper
28
is in the lowered position (
FIG. 2
) and releases the plunger actuator
46
when the charge hopper
28
is in the raised position (FIG.
3
). The term “raised position” shall be interpreted broadly to include any position other than the lowered position.
It is notable that if the mounting bracket
42
and valve
44
are mounted to the charge hopper
28
as described above, then the contact structure
50
would be mounted to, for example, the near side attachment arm
34
so that it will function to actuate the plunger actuator
46
as described above. It is also notable that the contact structure
50
may be configured to actuate any type of actuator
46
available such as a lever actuator, magnetic actuator, etc. If, for example the actuator is a magnetic actuator, then the contact structure
50
may simply be a portion of the charge hopper
28
which has magnetic properties sufficient to activate the valve
44
.
A low-pressure indicator
52
(“L.P. indicator”) is mounted to the tractor-carried concrete mixer
10
in a location that is conspicuous to the operator when he is preparing to move the vehicle. The L.P. indicator is a diaphragm-type indicator. Generally, regardless of the particular configuration, indicators are considered to be “activated” when they signal an operator that the charge hopper is in the raised position, and “deactivated” when the signal is removed or disabled. The L.P. indicator
52
includes an inlet connector
54
for attaching a conduit. Although in most cases it may be preferable to locate the L.P. indicator
52
in the cab
12
, under certain circumstances it may be preferable to locate it, for example, near the driver's-side door handle of the cab
12
or near the concrete mixer controls
19
(FIG.
1
).
A signal conduit
56
provides fluid communication between port “B” of the valve
44
and the inlet connector
54
. The signal conduit
56
may be made of rigid tubing, flexible tubing, or a combination of both. Circumstances relating to a particular installation will dictate the most preferable types of materials to be used.
Referring to
FIG. 5
, the L.P. indicator
52
is shown to include an upper housing
58
and a lower housing
60
. A cavity
62
is formed there between. An air channel
64
extends between the inlet connector
54
and the cavity
62
. A diaphragm
66
is sandwiched between the upper housing
58
and lower housing
60
, thereby dividing the cavity
62
into an upper chamber
61
and a lower chamber
63
. A pin
68
extends from the diaphragm and through the lower housing
60
. A warning arm
70
is pivotally mounted by a dowel
72
to the lower housing
60
at a point proximate the pin
68
. The warning arm
70
includes a detent
74
that aligns with the pin
68
when the warning arm
70
is in the raised position as shown.
The pin
68
engages the detent
74
when air pressure is applied via the signal conduit
56
and air channel
64
to the upper chamber
61
of the cavity
62
. The pin
68
disengages the detent
74
when air pressure is removed from the upper chamber
61
of the cavity
62
. At such time, the warning arm
70
swings down in counter-clockwise direction as illustrated by arrow “S” to the lowered position (shown in dotted lines). An L.P. indicator that may be used in the present embodiment is the Wig-Wag® low air pressure indicator (part no. 900-0202) manufactured by Stemco Manufacturing Company (Longview, Tex.).
Referring to
FIG. 6
, an alternate type of indicator
76
is illustrated. The indicator
76
is similar to the L.P. indicator
52
, however, it includes a spring
78
in upper chamber
61
for biasing the diaphragm
66
and the pin
68
downwardly to engage the detent
74
. In addition, the indicator
76
does not include the air channel
64
, but instead includes an air channel
80
for emitting air pressure from the signal conduit
56
to the lower chamber
63
. When air pressure is emitted to lower chamber
63
. the diaphragm
66
and the pin
68
are urged upwardly to disengage the pin
68
from the detent
74
and allow the warning arm
70
to drop down to the lower position. Those skilled in the art will appreciate that other types of pressure sensitive indicators may be used in the present embodiment without departing from the breath and scope of the invention.
Referring to
FIG. 7
, a schematic for a valve
82
that may be used with the alternate type of indicator
76
is illustrated. The valve
82
is a plunger actuated, two-position, three-port type pneumatic valve. The three ports are identified as port “A”, port “B”, and port “C”. In position 1, wherein the plunger is depressed, an air passage is formed between port “B” and port “C”. In position 2, wherein the plunger is released to allow a spring to act within the valve, an air passage is formed between port “A” and port “B”.
Referring to
FIGS. 1-5
, in operation, an operator of the tractor-carried concrete mixer
10
prepares to deliver concrete to a construction site. The tractor-carried concrete mixer
10
includes an embodiment of the present invention. The embodiment utilizes indicator
52
and valve
44
.
In preparation, the volume tank
14
is charged with air pressure and the charge hopper
28
is moved to the lowered position. While the charge hopper
28
pivots clockwise to the lowered position as indicated by arrow “X” in
FIGS. 1 and 2
, the contact structure
50
contacts and depresses the plunger actuator
46
of valve
44
. At such time, the valve
44
is switched from position 2 to position 1 (
FIG. 4
) and pressurized air is provided from volume tank
14
through supply conduit
48
, valve
44
, signal conduit
56
, and to L.P. indicator
52
. With pressurized air applied to L.P. indicator
52
, the diaphragm
66
extends the pin
68
downward. The operator then swings the warning arm
70
up into the raised position so that the pin
68
engages the detent
74
and maintains the warning arm
70
in the raised position as illustrated in
FIGS. 2 and 5
. The operator is then certain that the charge hopper
28
is in the lowered position and that he can safely travel to the construction site.
After arriving at the construction site, but before pouring the concrete, the operator raises the charge hopper
28
utilizing the controls at the control panel
19
. While the charge hopper
28
pivots counter-clockwise to the raised position as indicated by arrow “Y” in
FIGS. 1 and 3
, the contact structure
50
releases the plunger actuator
46
of valve
44
. At such time, the valve
44
is switched from position 1 to position 2, the pressurized air from supply conduit
48
is closed off at port “A”, and the pressurized air in the L.P. indicator
52
and the signal conduit
56
is bled off through port “C” of valve
44
. With pressurized air removed from the L.P. indicator
52
, the diaphragm
66
moves upwardly to disengage the pin
68
from the detent
74
. The warning arm
70
then swings downward in the counter-clockwise direction (as illustrated by arrow “S”) to the lowered position as illustrated in
FIGS. 3 and 5
.
When the operator has finished pouring concrete and he is ready to leave the construction site, he may in haste jump into the cab
12
of the tractor-carried concrete mixer
10
without lowering the charge hopper
28
. As noted above, traveling over roadways with the charge hopper
28
in the raised position can cause severe property damage and personal injury. Assuming, for example, that the L.P. indicator
52
is installed in a position in the cab
12
so that the warning arm
70
is in the operator's forward field of vision when it is in the lowered position, the operator will immediately recognize that the charge hopper
28
is still in the raised position. At such time, the operator returns to the control panel
19
and lowers the charge hopper
28
. After the charge hopper
28
is lowered, the operator returns to the cab
12
, raises the warning arm
70
, and safely leaves the construction site.
To utilize the present invention on tractor-drawn concrete mixers, some modifications to the above-described system may be required. For example, in the case where an L.P. indicator
52
is located in the tractor's cab or near the driver's-side door, a quick-disconnect connector may be included in the signal conduit
56
so that the conduit
56
may be separated when the trailer is unhitched from the tractor.
Referring to
FIG. 8
, an embodiment of the present invention is illustrated as part of a kit
84
. The kit
84
is a convenient way in which embodiments of the present invention may be marketed. Included in the kit
84
is the L.P. indicator
52
, mounting bracket
42
, valve
44
, supply and signal conduit
48
and
56
, contactor structure
50
, and associated hardware
86
. The kit
84
may be packaged as follows. The contents of the kit
84
are positioned on a base board
88
and sealed in position with a clear plastic overlay
90
utilizing vacuum-packing methods that are well known in the art. Of course, those skilled in the art will recognize the numerous other packaging systems that may be used to package the contents, for example, boxes with inserts, plastic or paper bags, etc.
In view of the above, it is clear that the above-described system may be used to warn an operator that a charge hopper of a concrete mixer is in the raised position. It is also clear that the system is relatively inexpensive and easy to install on new or used tractor-carried concrete mixers. Furthermore, it is clear that the system is easy to operate and maintain.
While the invention has been described with respect to preferred embodiments, those skilled in the art will readily appreciate that various changes and/or modifications can be made to the invention without departing from the spirit or scope of the invention as defined by the appended claims. It is noted that 35 U.S.C. § 112, paragraph 6, is not intended to be invoked unless a claim appended hereto, or otherwise added, specifically includes “means for” terminology.
Claims
- 1. In a concrete mixer including an air supply, a mixing drum having an access port, a frame supporting the mixing drum, and a charge hopper pivotally supported adjacent the access port and moveable between a raised position and a lowered position, the improvement comprising:(a) an indicator device operatively associated with the concrete mixer and configured for activation to indicate when the charge hopper is in the raised position; (b) a switching device operatively associated with the frame and the charge hopper and in fluid communication with the air supply and the indicator device, the switching device including an actuator moveable between a first position to deactivate the indicator device and a second position to activate the indicator device; and (c) a contact structure operatively associated with the frame and the charge hopper to actuate the switching device.
- 2. A concrete mixer as recited in claim 1, wherein the switching device is mounted on the frame and the contact structure is mounted on the charge hopper.
- 3. A concrete mixer as recited in claim 1, wherein the switching device is mounted on the charge hopper and the contact structure is mounted on the frame.
- 4. A concrete mixer as recited in claim 1, wherein the switching device is a two-position, three-port pneumatic valve.
- 5. A concrete mixer as recited in claim 1, wherein pressurized air is transmitted from the air supply to the indicator device when the actuator is in the first position.
- 6. A concrete mixer as recited in claim 1, wherein pressurized air is transmitted from the air supply to the indicator device when the actuator is in the second position.
- 7. A concrete mixer as recited in claim 1, wherein the indicator device is a diaphragm-type indicator device.
- 8. A concrete mixer as recited in claim 1, wherein the indicator device is located in a cab of the concrete mixer and includes a warning arm configured to move into an operator's forward field of vision when the charge hopper is in the raised position.
US Referenced Citations (17)