Information
-
Patent Grant
-
6460600
-
Patent Number
6,460,600
-
Date Filed
Tuesday, April 17, 200123 years ago
-
Date Issued
Tuesday, October 8, 200221 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
- MacMillan, Sobanski & Todd, LLC
-
CPC
-
US Classifications
Field of Search
-
International Classifications
-
Abstract
An apparatus for producing a plurality of cast products includes a plurality of molds, and a casting apparatus which casts products in the molds. A multi-level pallet carries the molds containing the cast products on at least two vertical levels. A loading apparatus loads the molds onto the multi-level pallet. A conveyor moves the multi-level pallet through a cooling area which is sufficient to cool the cast products for removal from the molds. An unloading apparatus unloads the molds from the multi-level pallet. In a method of producing a plurality of cast products, the products are cast in a plurality of molds. The molds are loaded onto a multi-level pallet which carries the molds on at least two vertical levels. The multi-level pallet is conveyed through a cooling area which is sufficient to cool the cast products for removal from the molds. After cooling, the molds are unloaded from the multi-level pallet.
Description
BACKGROUND OF THE INVENTION
This invention relates in general to the manufacture of cast products, and in particular to an apparatus and a method for producing cast products including an improved method of cooling the products after casting.
Cast products are typically manufactured by pouring or injecting molten material into molds, and then allowing the molten material to cool so that it solidifies. The solidified products are then removed from the molds. In a continuous manufacturing process, the molds containing the molten material are often transported on a conveyor until they are sufficiently cooled so that the products can be removed from the molds. In some processes, the molds are transported on a conveyor which is configured in a serpentine pattern.
The conventional use of a conveyor for cooling cast products typically requires a large amount of floor space in the manufacturing plant, even when the conveyor is configured in a serpentine pattern. The cooling on the conveyor also limits the speed at which cast products can be manufactured in the process. Thus, it would be desirable to provide an improved apparatus and method for producing cast products, including an improved method of cooling the products after casting.
SUMMARY OF THE INVENTION
The present invention provides an apparatus for producing a plurality of cast products. The apparatus includes a plurality of molds, and a casting apparatus which casts products in the molds. A multi-level pallet carries the molds containing the cast products on at least two vertical levels. A loading apparatus loads the molds onto the multi-level pallet. A conveyor moves the multi-level pallet through a cooling area which is sufficient to cool the cast products for removal from the molds. An unloading apparatus unloads the molds from the multi-level pallet.
The invention also provides a method of producing a plurality of cast products. In a first step, the products are cast in a plurality of molds. The molds are then loaded onto a multi-level pallet which carries the molds on at least two vertical levels. The multi-level pallet is conveyed through a cooling area which is sufficient to cool the cast products for removal from the molds. After cooling, the molds are unloaded from the multi-level pallet.
The use of multi-level pallets to carry the molds on a conveyor greatly increases the number of molds which can be cooled in a given floor space. This allows the manufacturer to speed up the casting process. Alternatively, the casting process can be conducted at the same speed, and the amount of floor space used for cooling can be reduced, thereby reducing manufacturing costs.
Various other advantages of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiment, when read in light of the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
is a top view, partially broken away, of an apparatus for producing cast products in accordance with the present invention.
FIG. 2
is a side view of a pallet holding three molds on a conveyor of the apparatus shown in FIG.
1
.
FIG. 3
is a side view of a loading station of the apparatus shown in FIG.
1
.
FIG. 4
is a front view of the loading station of
FIG. 3
, showing a multi-level pallet loaded with twelve molds.
FIG. 5
is a side view of an unloading station of the apparatus shown in FIG.
1
.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings,
FIG. 1
illustrates an apparatus, indicated generally at
100
, for producing cast products in accordance with the present invention. Although the invention will be shown and described in conjunction with the particular apparatus
100
disclosed herein, it will be appreciated that the apparatus
100
can be other than as shown and described if desired.
The apparatus
100
includes a casting apparatus, indicated generally at
106
, for casting products in molds
102
. (One mold
102
is shown in phantom near the bottom of
FIG. 1
, and additional molds
102
are shown at the top right of the drawing). The casting apparatus
106
is conventional and therefore need not be described in any detail. The casting apparatus
106
can be any type of apparatus suitable for casting the products in the molds
102
. A typical casting apparatus includes a source of molten material and an apparatus for transporting the molten material from the source to the molds
102
. For example, the molten material can be poured into the molds
102
from heated containers, or it can be pumped through a conduit and injected into the molds.
In the illustrated embodiment, the casting apparatus
106
includes a source
108
of molten material (shown schematically), such as a furnace having a molten material reservoir. The molten material is transferred from the source
108
to a plurality of heated tiltable ladles
110
which are conveyed on a monorail
112
around a loop. When each of the ladles
110
reaches a pouring zone
114
, the molten material is poured from the ladle
110
into a respective mold
102
. The ladle
110
returns on the monorail
112
to the source
108
of molten material, where it is filled again with the molten material. Preferably, the casting apparatus
106
is computer controlled.
As shown in
FIG. 2
, the molds
102
are conventional and therefore need not be described in any detail. The molds
102
can be any type of molds suitable for casting the products, such as open molds or injection molds. Each of the molds
102
has one or more cavities (not shown) in which molten material is received for casting the products. In a specific embodiment, each mold
102
has two cavities for casting products. The illustrated apparatus also includes a plurality of trays
104
. The trays
104
hold the molds
102
to keep them oriented in a stable position during the casting process. However, it will be appreciated that the molds
102
can be used without the trays
104
.
The cast products can be any type of products which can be formed by a casting process. For example, the cast products can be vehicle parts, such as wheel end components or exhaust manifolds. The material used for casting the products can be any suitable casting material, including metals such as iron, aluminum or steel, metal alloys such as iron alloys or aluminum alloys, ceramics or plastics.
As shown in
FIG. 1
, the apparatus
100
also includes a first conveyor
10
to move the molds through the pouring zone
114
. Any type of conveyor
10
suitable for moving the molds
102
can be used as the first conveyor
10
. The illustrated first conveyor
10
is a pallet type of conveyor which uses a plurality of single level pallets
116
to move the molds
102
. As shown in
FIG. 2
, the pallets
116
ride on rollers
118
which enable the pallets
116
to be moved along the first conveyor
10
, one pallet
116
after another. The trays
104
holding the molds
102
are mounted on top of the pallets
116
. In the embodiment shown, each pallet
116
holds three molds
102
, although the number of molds
102
per pallet
116
can be other than illustrated if desired.
The illustrated first conveyor
10
is a conveyor line
10
having conveyor sections
10
A through
10
J in successive order (sections
10
E through
10
H not shown). The trays
104
and molds
102
are loaded on a pallet
116
at conveyor section
10
A. The apparatus
100
includes a push device
132
having an extendable hydraulic cylinder (not shown). The cylinder extends to push an empty pallet (not shown) into conveyor section
10
A for loading, thereby forcing the loaded pallet
116
to move into conveyor section
10
B. This action is continuously repeated, and the pallet
116
carrying the trays
104
and molds
102
moves through conveyor sections
10
C,
10
D, etc., in sequence (from right to left in FIG.
1
). When the pallet
116
reaches conveyor section
101
, the molds
102
carried by the pallet
116
are located in the pouring zone
114
. The molten material is poured from the ladles
110
into the molds
102
in the pouring zone
114
.
After the pallet
116
moves through conveyor section
10
J, the pallet
116
reaches a pallet transfer assembly, indicated generally at
120
. The pallet transfer assembly
120
moves the pallet
116
from the end of the first conveyor
10
to the start of a second conveyor
20
. The pallet transfer assembly
120
includes a pair of spaced apart rails
122
which extend transversely between the first and second conveyors
10
,
20
. A movable conveyor section
124
is mounted on the rails
122
, and rides on the rails
122
on a plurality of rollers
126
. The movable conveyor section
124
also has rollers (not shown) mounted on its upper surface. The rollers on the upper surface of the movable conveyor section
124
are aligned with the rollers
118
of the first conveyor
10
so that the pallet
116
can move from the first conveyor
10
onto the movable conveyor section
124
. The pallet transfer assembly
120
includes a catch device
128
which stops the pallet
116
. The pallet transfer assembly
120
also includes a transverse hydraulic cylinder
130
which is attached to the movable conveyor section
124
to move it along the rails
122
. When the pallet
116
is located on the movable conveyor section
124
, the transverse cylinder
130
moves the movable conveyor section
124
from the first conveyor
10
to the second conveyor
20
. The pallet transfer assembly
120
further includes a push device
132
having an extendable hydraulic cylinder (not shown). The cylinder extends to push the pallet
116
from the movable conveyor section
124
into a starting conveyor section
20
A of the second conveyor
20
.
The illustrated second conveyor
20
is a conveyor line
20
having conveyor sections
20
A through
20
J in successive order (sections
20
C through
20
F not shown). As the push device
132
continuously pushes pallets
116
into the conveyor section
20
A, the preceding pallets
116
are forced to move through conveyor sections
20
B,
20
C, etc., in sequence (from left to right in FIG.
1
). When a pallet
116
reaches conveyor section
201
, the pallet
116
is located in a loading station
134
of the apparatus
100
. As described in detail below, the trays
104
and molds
102
are removed from the pallet
116
in the loading station
134
. The empty pallet
116
then continues along the second conveyor
20
until it reaches another pallet transfer assembly
120
like the one described above. The pallet transfer assembly
120
moves the empty pallet
116
from the end of the second conveyor
20
to the start of the first conveyor
10
(conveyor section
10
A) for another cycle.
The apparatus
100
of the invention includes an improved cooling apparatus, indicated generally at
136
, for cooling the cast products. As best shown in
FIGS. 3 and 4
, the cooling apparatus
136
starts with the loading station
134
, where a plurality of trays
104
and molds
102
are transferred from the single level pallet
116
to a multi-level pallet indicated generally at
138
. As described in detail below, a plurality of the multi-level pallets
138
are moved along a cooling conveyor system
140
(shown in
FIG. 1
) for cooling the cast products. The multi-level pallet
138
has at least two vertical levels for carrying the trays
104
and molds
102
, and preferably at least three vertical levels. In the illustrated embodiment, the multi-level pallet
138
is constructed as a rack having four vertical levels
142
,
144
,
146
and
148
or shelves for carrying the trays
104
and molds
102
. The vertical levels
142
,
144
,
146
and
148
of the multi-level pallet
138
are separated by a distance sufficient to allow cooling of the cast products for removal from the molds
102
. If the vertical levels
142
,
144
,
146
and
148
are too close to one another, heat from a mold
102
on a lower level
142
may travel upward and prevent sufficient cooling of a mold
102
on an adjacent upper level
144
. Preferably, the multi-level pallet
138
is constructed to carry a plurality of trays
104
and molds
102
on each of the vertical levels
142
,
144
,
146
and
148
. In the illustrated embodiment, the multi-level pallet
138
carries three trays
104
and molds
102
on each of the four vertical levels
142
,
144
,
146
and
148
.
The loading station
134
includes a loading apparatus
150
which transfers the trays
104
and molds
102
from the single level pallet
116
to the multi-level pallet
138
. Any type of apparatus suitable for transferring the trays
102
and molds
104
to the multi-level pallet
138
can be used. In the illustrated embodiment, the loading apparatus
150
includes an elevator-like frame
152
having a first frame portion
154
and a second frame portion
156
. A loading elevator
158
is mounted inside the first frame portion
154
for upward and downward movement, as indicated by arrow M. The loading elevator
158
can travel a vertical distance D (from ground zero
160
to an upper elevation
162
of its travel) which is equal to the distance between the first level
142
and the fourth level
148
of the multi-level pallet
138
. An arm
164
is carried by the loading elevator
158
, and extends out of the frame
152
over the second conveyor
20
. A cable
166
and pulley
168
apparatus is attached to the arm
164
inside the frame
152
for moving the loading elevator
158
and the arm
164
upward and downward. A hoist
170
mounted on the top of the second frame portion
156
retracts or extends the cable
166
to raise or lower the loading elevator
158
and the arm
164
. The second frame portion
156
extends over conveyor section
30
E of conveyor line
30
of the cooling conveyor system
140
. The multi-level pallet
138
on the conveyor section
30
E is positioned inside the second frame portion
156
for loading of the trays
104
and molds
102
.
The loading apparatus
150
includes a motive power device
172
for moving the trays
104
and molds
102
from the single level pallet
116
to the multi-level pallet
138
. In the illustrated embodiment, the motive power device
172
is a pushing device
172
which is mounted on the bottom of the arm
164
. The illustrated pushing device
172
includes an extendable hydraulic cylinder
174
having a linkage
176
attached at the end, and a transversely extending push board
178
attached to the linkage
176
. When the arm
164
is in the lowered position shown in
FIG. 3
, the push board
178
of the pushing device
172
is adjacent to the three trays
104
in the single level pallet
116
. In operation, a clamp
180
mounted on the second conveyor
20
clamps onto the pallet
116
to hold it in place. Any suitable clamping device
180
can be used, such as a pneumatic clamp cylinder
182
attached to a hook
184
which clamps the pallet
116
. Then the hydraulic cylinder
174
is extended to push the trays
104
and the molds
102
from the single level pallet
116
into the loading elevator
158
.
A clamp
186
mounted on the second frame portion
156
clamps onto the top of the multi-level pallet
138
to hold it in place. Any suitable clamping device
186
can be used, such as a pneumatic clamp cylinder
186
. If the trays
104
and molds
102
are to be loaded onto the first level
142
of the multi-level pallet
138
, the hydraulic cylinder
174
is extended to push the trays
104
and molds
102
onto the first level
142
. If the trays
104
and molds
102
are to be loaded onto the second
144
or higher level of the multi-level pallet
138
, the hoist
170
is operated to move the loading elevator
158
and the arm
164
to the appropriate vertical position. Then the hydraulic cylinder
174
is extended to push the trays
104
and the molds
102
onto the selected level of the multi-level pallet
138
. Instead of having a single pushing device
172
mounted for movement with the loading elevator
158
, the loading apparatus
150
could include multiple stationary pushing devices, one for each level of the multi-level pallet
138
. The multi-level pallet
138
having four levels
142
,
144
,
146
and
148
can hold the trays
104
and molds
102
carried on four of the single level pallets
116
.
After the trays
104
and molds
102
are loaded on the multi-level pallet
138
, the molten material in the molds
102
is allowed to cool so that it solidifies and forms solid cast products which can be removed from the molds
102
. As shown in
FIG. 1
, the improved cooling apparatus
136
of the invention includes a cooling conveyor system, indicated generally at
140
, for allowing the cooling of the material in the molds
102
. The cooling conveyor system
140
can be any type of conveyor system suitable for transporting the multi-level pallets
138
to cool the material in the molds
102
. In the illustrated embodiment, the cooling conveyor system
140
includes individual conveyor lines
30
,
40
,
50
and
60
which are operatively connected to one another in successive order. The illustrated conveyor lines
30
,
40
,
50
and
60
are arranged in a serpentine configuration, although other configurations can be used. The multi-level pallets
138
are moved on rollers
118
(shown in
FIG. 3
) along the conveyor lines
30
,
40
,
50
and
60
, one pallet
138
after another.
Conveyor line
30
includes conveyor sections
30
A through
30
L in successive order (sections
30
H through
30
K not shown), extending from right to left in FIG.
1
. The multi-level pallets
138
are placed on the conveyor line
30
at conveyor section
30
A. A push device
132
has a hydraulic cylinder (not shown) which pushes the multi-level pallet
138
from conveyor section
30
A to conveyor section
30
B. As additional multi-level pallets
138
are placed on the conveyor line
30
and pushed by the push device
132
, the multi-level pallet
138
moves through conveyor sections
30
C and
30
D. When it reaches conveyor section
30
E, the multi-level pallet
138
is positioned in the loading station
134
, where it is loaded with trays
104
and molds
102
as described above. After loading, the multi-level pallet
138
moves through conveyor sections
30
F,
30
G, etc., until it reaches the end of conveyor line
30
. A pallet transfer assembly
120
is located at the end of conveyor line
30
to move the multi-level pallet
138
from the end of conveyor line
30
to the start of conveyor line
40
.
Conveyor line
40
includes conveyor sections
40
A through
40
H in successive order (sections
40
B through
40
E not shown), extending from left to right in FIG.
1
. The multi-level pallet
138
moves to the end of conveyor line
40
, where it reaches another pallet transfer assembly
120
. The pallet transfer assembly
120
moves the multi-level pallet
138
from the end of conveyor line
40
to the start of conveyor line
50
.
Similarly, conveyor line
50
includes conveyor sections
50
A through
50
H in successive order (sections
50
D through
50
G not shown), extending from right to left in FIG.
1
. The multi-level pallet
138
moves to the end of conveyor line
50
, where it reaches another pallet transfer assembly
120
. The pallet transfer assembly
120
moves the multi-level pallet
138
from the end of conveyor line
50
to the start of conveyor line
60
.
Conveyor line
60
includes conveyor sections
60
A through
60
K in successive order (sections
60
B through
60
E not shown), extending from left to right in FIG.
1
. The multi-level pallet
138
moves to the end of conveyor line
60
, where it reaches an unloading station
188
. As described in more detail below, the trays
104
and molds
102
are unloaded from the multi-level pallet
138
in the unloading station
188
. After the multi-level pallet
138
is unloaded, a catch device
128
extends a hydraulic cylinder (not shown) to pull the multi-level pallet
138
from the unloading station
188
. The empty multi-level pallet
138
is then returned to conveyor section
30
A for another cycle through the cooling conveyor system
140
.
FIG. 5
illustrates the unloading station
188
where the trays
104
and molds
102
are removed from the multi-level pallets
138
after cooling. The unloading station
188
includes an unloading apparatus
190
which transfers the trays
104
and molds
102
from the multi-level pallet
138
to an unloading conveyor
192
. Any type of apparatus suitable for transferring the trays
104
and molds
102
from the multi-level pallet
138
can be used. In the illustrated embodiment, the unloading apparatus
190
includes an elevator-like frame
194
having a first frame portion
196
and a second frame portion
198
. An unloading elevator
200
is mounted inside the first frame portion
196
for upward and downward movement in the direction of arrow M
1
. A cable
202
and pulley
204
assembly is carried by the unloading elevator
200
for moving it upward and downward. A hoist
206
mounted on the top of the second frame portion
198
retracts or extends the cable
202
to raise or lower the unloading elevator
200
. The multi-level pallet
138
on conveyor section
60
K of the conveyor line
60
is positioned inside the second frame portion
198
for unloading.
The unloading apparatus
190
includes multiple motive power devices
208
for moving the trays
104
and molds
102
from the multi-level pallet
138
onto the unloading elevator
200
. In the illustrated embodiment, the motive power devices
208
are pushing devices
208
which are mounted adjacent the multi-level pallet
138
. Each of the illustrated pushing devices
208
includes an extendable hydraulic cylinder
210
having a transversely extending push bar
212
attached at an end thereof. In the illustrated embodiment, the unloading apparatus
190
includes one pushing device
208
for each level of the multi-level pallet
138
. The pushing devices
208
are aligned with the trays
104
in the respective levels
142
,
144
,
146
and
148
of the multi-level pallet
138
. It will be appreciated that the unloading apparatus
190
could include a single movable pushing device, like that shown in
FIG. 3
, instead of the multiple pushing devices
208
.
In operation, a clamp
214
mounted on the second frame portion
198
clamps onto the top of the multi-level pallet
138
to hold it in place. Any suitable clamping device
214
can be used, such as a pneumatic clamp cylinder
214
. The unloading elevator
200
is moved into alignment with one of the levels
142
,
144
,
146
or
148
of the multi-level pallet
138
. Then the hydraulic cylinder
210
of the pushing device
208
aligned with the selected level is extended to push the trays
104
and the molds
102
onto the unloading elevator
200
. If the trays
104
and molds
102
are to be unloaded from the first level
142
of the multi-level pallet
138
, the hydraulic cylinder
210
is extended to push the trays
104
and molds
102
off the unloading elevator
200
and onto the unloading conveyor
192
. If the trays
104
and molds
102
are to be unloaded from the second level
144
or a higher level of the multi-level pallet
138
, the pushing device
208
aligned with that level first pushes the trays
104
and molds
102
onto the unloading elevator
200
. Then the hoist
206
is operated to move the unloading elevator
200
down to the first level
142
. Then the pushing device
208
aligned with the first level
142
is extended to push the trays
104
and the molds
102
onto unloading conveyor
192
.
The unloading conveyor
192
has rollers
126
which enable the trays
104
and molds
102
to move away from the unloading apparatus
190
. (The unloaded trays
104
and molds
102
are also shown in
FIG. 1.
) The trays
104
and molds
102
are then removed from the unloading conveyor
192
, and the finished cast products (not shown) are removed from the molds
102
. The empty trays
104
and molds
102
can be returned to conveyor section
10
A for another cycle through the process.
In accordance with the provisions of the patents statutes, the principle and mode of operation of this invention have been described and illustrated in its preferred embodiment. However, it must be understood that the invention may be practiced otherwise than as specifically explained and illustrated without departing from the scope or spirit of the attached claims.
Claims
- 1. An apparatus for producing a plurality of cast products comprising:a plurality of molds; a casting apparatus which casts products in the molds; a multi-level pallet which carries the molds containing the cast products on at least two vertical levels; a loading apparatus which loads the molds onto the multi-level pallet; a conveyor which moves the multi-level pallet through a cooling area which is sufficient to cool the cast products for removal from the molds; and an unloading apparatus which unloads the molds from the multi-level pallet.
- 2. The apparatus defined in claim 1 wherein the conveyor moves the multi-level pallet on a serpentine path through the cooling area.
- 3. The apparatus defined in claim 1 wherein the loading apparatus comprises a loading elevator.
- 4. The apparatus defined in claim 3 wherein the loading elevator travels a vertical distance which is equal to a distance between a bottom level and a top level of the multi-level pallet.
- 5. The apparatus defined in claim 1 wherein the unloading apparatus comprises an unloading elevator.
- 6. The apparatus defined in claim 5 wherein the unloading elevator includes a clamping device which holds the multi-level pallet and a motive power device which moves the molds from the multi-level pallet.
- 7. The apparatus defined in claim 6 wherein the unloading elevator includes a plurality of the motive power devices, with one of the motive power devices being aligned with each level of the multi-level pallet.
- 8. The apparatus defined in claim 1 wherein the apparatus comprises a plurality of the multi-level pallets, and wherein the conveyor moves the plurality of multi-level pallets simultaneously through the cooling area.
- 9. The apparatus defined in claim 1 further comprising a plurality of trays which hold the molds to keep them oriented in a stable position.
- 10. The apparatus defined in claim 1 wherein the multi-level pallet carries a plurality of the molds on each of the vertical levels.
- 11. The apparatus defined in claim 1 wherein the multi-level pallet carries the molds on at least three vertical levels.
- 12. The apparatus defined in claim 1 wherein the vertical levels of the multi-level pallet are separated sufficiently to allow cooling of the cast products for removal from the molds.
- 13. The apparatus defined in claim 1 further comprising a single level pallet which carries the molds on a single vertical level, and a conveyor which moves the single level pallet from the casting apparatus to the loading apparatus.
- 14. The apparatus defined in claim 13 wherein the loading elevator includes a clamping device which holds the single level pallet and a motive power device which moves the mold from the single level pallet to the multi-level pallet.
- 15. A method of producing a plurality of cast products comprising:casting products in a plurality of molds; loading the molds onto a multi-level pallet which carries the molds on at least two vertical levels; conveying the multi-level pallet through a cooling area which is sufficient to cool the cast products for removal from the molds; and unloading the molds from the multi-level pallet.
- 16. The method defined in claim 15 wherein the loading step comprises loading the molds with a loading elevator.
- 17. The method defined in claim 15 wherein the unloading step comprises unloading the molds with an unloading elevator.
- 18. The method defined in claim 17 wherein the unloading step includes holding the multi-level pallet in place when moving the molds from the multi-level pallet.
- 19. The method defined in claim 15 wherein the conveying step comprises conveying a plurality of the multi-level pallets through the cooling area simultaneously.
- 20. The method defined in claim 15 wherein the molds are loaded onto a multi-level pallet which carries the molds on at least three vertical levels.
US Referenced Citations (9)
Foreign Referenced Citations (1)
Number |
Date |
Country |
2056341 |
Mar 1981 |
GB |