INTERNAL MIXER RAM WEIGHT AND HOPPER APPARATUS AND METHOD FOR FEEDING MIXER

Abstract: A ram weight (52) for controlling movement of materials in a closed internal mixer hopper is moveable between a chute (36) leading to the mixer inlet (32) and a ram weight compartment (54) above the chute (36). The ram weight compartment (54) has spaced apart guide members (70, 72) providing an opening through which material and gasses may flow out of the compartment (54) during upward movement of the ram weight (52) which reduces the force required to lift the ram weight and minimizes leakage from the hopper (38) at the upper wall (56).

Description: INTERNAL MIXER RAM WEIGHT AND HOPPER APPARATUS AND METHOD FOR FEEDING MIXER Technical Field This invention relates to high intensity mixing machines for elastomeric materials. A batch of ingredients including carbon black is fed into a hopper which has a ram weight connected to a piston rod for controlling movement of the materials into the mixer. The hopper is closed except when the ingredients are being loaded. Background Art An internal mixer hopper may be open as shown in U.S. Patent No. 5,492,403 but is preferably closed with a carbon black chute and valve and a charging section having a charging door for feeding materials into the hopper. With a closed hopper the ram weight has been contained in a compartment at the upper end of the hopper to guide the ram weight. The upward movement of the ram weight in the compartment at the upper end of the hopper has produced high pressures which has increased the power required to raise the ram weight. Also an exhaust dust collector has been required at the top of the chamber to reduce the dust ejected from the hopper by the upward movement of the ram weight in the chamber. Disclosure of Invention The present invention is directed to a high intensity mixer and hopper construction and method of reciprocating a ram weight to feed and control the flow of ingredients into the mixer. The hopper is closed except during the feeding of carbon black and oils into a carbon black chute by opening a valve in the chute and feeding the elastomeric ingredients into the hopper by opening a charging door in a wall of the hopper. The hopper of this invention has a ram weight compartment for guiding movement of the ram weight and an opening in the compartment through which material and gasses may flow into and out of the hopper chamber during movement of the ram weight. A piston rod extending through the upper wall of the hopper is connected to the ram weight and to a piston cylinder apparatus mounted on top of the hopper. During upward movement of the ram weight in the ram weight compartment, the carbon black and elastomeric ingredients collect in the compartment at the upper wall of the hopper and above the ram weight. With the construction of this invention, these materials are transferred from the compartment to a storage space in the hopper through an opening in the compartment and the pressure is reduced so that dust is not ejected from the hopper and a dust collector at the upper wall is not required. Also the force necessary to lift the ram jet to the top of the compartment is minimized due to the reduction in pressure in the compartment. In accordance with one aspect of the invention there is provided an internal mixer of the type having a mixing chamber and a feed hopper with a ram weight to control movement of materials from a storage space in the feed hopper into the mixing chamber. The feed hopper has a ram weight compartment for guiding movement of the ram weight characterized by an opening in the compartment in communication with the storage space whereby materials and gasses in the ram weight compartment may flow into the storage space and reduce the pressure in the compartment resisting upward movement of the ram weight and at the same time reduce the pressure in the compartment which causes the materials and gasses from the compartment into the space outside the hopper. In accordance with another aspect of the invention there is provided a method of mixing an elastomeric material in an internal mixer of the type having rotors for rotation in a mixing chamber, a feed hopper located above the internal mixer and in communication with said mixing chamber through an inlet of the mixer and a ram weight vertically movable in said hopper from an upper position in a ram weight compartment of the feed hopper to a lower position adjacent the inlet comprising (a) raising the ram weight to the upper position; (b) opening a charging door to the charge the hopper with an elastomeric material; (c) closing the charging door; (d) opening a valve in the hopper to add carbon black to the elastomeric material in the hopper; (e) closing the valve; (f) lowering the ram weight to the lower position to feed the carbon black and elastomeric material into the mixing chamber; (g) raising the ram weight; (h) opening the valve, adding oil to the hopper and then closing the valve; (i) lowering the ram weight to a float position; (j) opening a drop door to drop a mixed batch of carbon black, elastomeric materials and oils from the mixing chamber; (k) closing the drop door and raising the ram weight with the valve and the charging door closed, characterized by: (1) ejecting the carbon black and elastomeric materials plus mixing gases from the ram weight compartment into a storage space in the hopper during raising of the ram weight to reduce the pressure in the compartment resisting upward of the ram weight and to reduce the pressure causing leakage of said gasses and materials from the ram weight compartment. Brief Description of the Drawings Fig. 1 is an elevation partly in section of an internal mixer and hopper embodying the invention. Fig. 2 is a side view partly in section taken along line 2-2 in Fig. 1. Fig. 3 is a sectional view of the hopper and ram weight compartment taken along line 3-3 in Fig. 2 with part being broken away. Figs 4-8 are views like Fig. 1 showing steps in the operation of the mixer and hopper assembly. Detailed Description of the Invention Referring to Figs. 1 and 2 an internal mixer 10 is shown having a mixing chamber 12 and a pair of rotors 14-16 rotatable about parallel axes on shafts 18-20. The mixing chamber 12 has an inlet opening hereinafter referred to as the inlet 32, and an outlet 34. The inlet 32 is in communication with a chute 36 attached to a hopper 38 for receiving ingredients to be mixed in the mixing chamber 12. The hopper 38 has a storage space 40 above the chute 36 for receiving the ingredients to be mixed in the mixing chamber 12. These ingredients include elastomeric materials fed into the storage space 40 through a charging opening 42 from a charged hopper compartment 44. The charging opening 42 may be opened and closed by a charging door 46. Carbon black and oils may be fed into the storage space 40 by a carbon black chute 48 having a butterfly valve 50 for opening and closing the chute. A ram weight 52 is vertically movable through the chute 36 and through a ram weight compartment 54 in the hopper 38 located above the chute 36 and under an upper wall 56 of the hopper. The ram weight 52 is generally rectangular in cross-section and is slidably movable in the ram weight compartment 54 which has a generally rectangular opening 58 for containing the ram weight as shown in Fig. 3. Three sides of the ram weight compartment 54 are provided by the sides 60, 62, and 64 of the hopper 38. A fourth side 66 of the ram weight compartment 54 has an opening 68 between spaced guide members such as flanges 70 and 72. The opening 68 is in communication with the storage space 40. of the hopper 38 whereby materials and gasses in the ram weight compartment 54 above the ram weight 52 may flow into the storage space 40. The flanges 70 and 72 extend from the upper wall 56 of the hopper to the chute 36. Mounted above the upper wall of the hopper 56 is a piston cylinder 74 having a piston rod 76 extending through an opening in the upper wall and connected to the ram weight 52 for moving the ram weight vertically in the hopper. In this manner, the ram weight 52 controls the movement of materials form the storage space 40 in the hopper 38 into the mixing chamber 12 of the internal mixer 10. The charging door 46 may be hinged and move from an open position shown in Fig. 1 to a closed position shown in Fig. 4 by suitable means such as a pneumatic cylinder 78. Also a dust collector 80 may be mounted above and in communication with the charge hopper compartment 44 to control the escape of dust during the charging operation. A drop door 82 is provided for opening and closing the internal mixer outlet 34 and may be rotated into and out of position in the outlet 34 on a shaft 84 turned by suitable power means. In operation, when the ram weight 52 is raised in the ram weight compartment 54 in the position shown in Figs. 1 , 2 and 3, the materials and gasses above the ram weight are moved by the movement of the ram weight form the space above the ram weight through the opening 68 into the storage space 40 in the hopper 38. In this way there is not a build up of pressure in the ram weight compartment 54 which would increase the force required by the piston cylinder 74 to raise the ram weight 52 and also cause leakage of the materials and gasses above the ram weight through the upper wall 56 of the hopper 38. To illustrate the operation of the hopper 38 and internal mixer 10, reference is made to Figures 1 and 4-8. By referring to Fig. 1 the ram weight 52 is in the raised position, the charging door 46 is open and the carbon black valve 50 is closed. Also the drop door 82 of the internal mixer 10 is closed. In this condition the elastomeric material, such as rubber, is conveyed to the charge hopper compartment 44 and through the charging door 46 into the storage space 40 of the hopper 38. The charging door 46 is then closed. The carbon black valve 50 then opens to add carbon black after which it closes. As shown in Fig. 4, ram weight 52 moves down under pressure and is held down. Then the carbon black valve 50 is opened to add carbon black and closes depositing the carbon black over the ram weight 52. the ram weight 52. Referring to Fig. 5 the ram weight 52 is raised. The carbon black valve 50 is opened and oil is injected through the inlet 32 into the mixing chamber 12. Referring to Fig. 6 the ram weight 52 is moved downward under pressure from the piston cylinder with the carbon black valve 50 closed and the charging door 46 closed providing a float condition. Referring to Fig. 7, the batch of mixed ingredients in the mixing chamber 12 is dropped by opening the drop door 82. In this condition the ram weight is held in position without exerting pressure and both the charging door 46 and carbon black valve 50 are closed. During these operations the rotors 14 and 16 may be rotated to mix the ingredients and eject the mixed batch from the mixing chamber. Referring to Fig. 8, the ram weight 52 is lifted to the upper position with the charging door 46 and carbon black valve 50 closed at the same time the drop door 82 is closed. During this upward movement, the carbon black and elastomeric materials above the ram weight 52 in the ram weight compartment 54 flow through the opening 68 into the storage space 40 of the hopper relieving the pressure above the ram weight. It has been found that this apparatus and method is very effective in preventing leakage of dust from the ram weight compartment 54 into the space surrounding the internal mixer tin and hopper 38. While a certain representative embodiment and details have been shown for the purpose of illustrating the invention, it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the scope of the invention. Having thus described the invention, it is now claimed:

Claims: CLAIMS 1. An internal mixer of the type having a mixing chamber and a feed hopper with a ram weight to control movement of materials from a storage space in said feed hopper into said mixing chamber, said feed hopper having a ram weight compartment for guiding movement of said ram weight characterized by an opening in said compartment in communication with said storage space whereby materials and gasses in said ram weight compartment may flow into said storage space and reduce the pressure in said compartment resisting upward movement of the ram weight and at the same time reduce the pressure in said compartment which could cause said materials and gasses from said compartment to be injected into the space outside said hopper. 2. The internal mixer of claim 1 further characterized by said ram weight compartment having spaced apart guide members and said opening is in the space between said guide members. 3. The internal mixer of claim 1 further characterized by said feed hopper having a charging opening in communication with a charge hopper compartment and a charging door for opening and closing said charging opening. 4. The internal mixer of claim 1 further characterized by said feed hopper having a carbon black chute with a carbon black valve for opening said chute to feed carbon black and oils into said hopper and close said chute to seal the space in said hopper. 5. The internal mixer of claim 1 further characterized by said opening in said ram weight compartment extending to an upper wall of said hopper for ejection of the materials and gasses adjacent said upper wall. 6. The internal mixer of claim 1 further characterized by a piston-cylinder apparatus mounted over said hopper with a piston rod extending through an opening in said upper wall of said feed hopper and connected to said ram weight whereby movement of said ram weight is provided by movement of said piston rod in response to change in pressure in said piston cylinder apparatus. 7. A method of mixing an elastomeric material in an internal mixer of the type having rotors for rotation in a mixing chamber, a feed hopper located above said internal mixer and in communication with said mixing chamber through an inlet of said mixer and a ram weight vertically movable in said hopper from an upper position in a ram weight compartment of said feed hopper to a lower position adjacent said inlet comprising (a) raising said ram weight to said upper position; 1 (b) opening a charging door to said charge said hopper with an elastomeric material; (c) closing said charging door; (d) opening a valve in said hopper to add carbon black to said elastomeric material in said hopper; (e) closing said valve; (f) lowering said ram weight to said lower position to feed said carbon black and elastomeric material into said mixing chamber; (g) raising said ram weight; (h) opening said valve, adding oil to said hopper and then closing said valve; (i) lowering said ram weight to a float position; (j) opening a drop door to drop a mixed batch of carbon black, elastomeric materials and oils from said mixing chamber; (k) closing said drop door and raising said ram weight with said valve and said charging door closed, characterized by: (I) ejecting said carbon black and elastomeric materials plus mixing gases from said ram weight compartment into a storage space in said hopper during raising of said ram weight to reduce the pressure in said compartment resisting upward movement of said ram weight and to reduce the pressure causing leakage of said gases and materials from said ram weight compartment. 8. The method of claim 7 wherein said ram weight compartment has an opening in communication with said storage space in said hopper further characterized by ejecting said materials and said gasses from said compartment through said opening upon raising of said ram weight. 9. The method of claim 8 wherein said ram weight compartment has spaced apart guide members with said opening being disposed between said guide members further characterized by raising said ram weight with said guide members in sliding contact with said ram weight to eject said materials and said gasses from said compartment into said storage space through said opening. 10. An internal mixer apparatus and method characterized by providing for ejection of elastomeric materials and gasses from a ram weight compartment upon upward movement of said ram weight substantially as described herein or as shown in the accompanying drawings. c:\9607ajft95206A.pal AMENDED CLAIMS [received by the International Bureau on 11 November 1997 ( 11 .11 .97) ; original claims 1 , 7 and 10 amended ; remaining claims unchanged (2 pages ) ] 1. An internal mixer of the type having a mixing chamber and a feed hopper with a ram weight to control movement of materials from a storage space in said feed hopper into said mixing chamber, said feed hopper having a closed ram weight compartment for guiding movement of said ram weight characterized by an opening in said compartment in communication with said storage space whereby materials and gasses in said ram weight compartment may flow into said storage space and reduce the pressure in said compartment resisting upward movement of the ram weight and at (he same time reduce the pressure in said compartment which could cause said materials and gasses from said compartment to be injected into the space outside said hopper. 2. The internal mixer of claim 1 further characterized by said ram weight compartment having spaced apart guide members and .said opening is in the space between said guide members. 3. The internal mixer of claim 1 further characterized by said feed hopper having a charging opening in communication with a charge hopper compartment and a charging door for opening and closing said charging opening. 4. The internal mixer of claim 1 further characterized by said feed hopper having a carbon black chute with a carbon black valve for opening said chute to feed carbon black and oils into said hopper and close said chute to seal the space in said hopper. 5. The internal mixer of claim 1 further characterized by said opening in said ram weight compartment extending to an upper wall of said hopper for ejection of the materials and gasses adjacent said upper wall. 6. The internal mixer of claim 1 further characterized by a piston-cylinder apparatus mounted over said hopper with a piston rod extending through an opening in said upper wall of said feed hopper and connected to said ram weight whereby movement of said ram weight is provided by movement of said piston rod in response to change in pressure in said piston cylinder apparatus. 7. A method of mixing an elastomeric material in an internal mixer of the type having rotors for rotation in a mixing chamber, a feed hopper located above said internal mixer and in communication with said mixing chamber through an inlet of said mixer and a ram weight vertically movable in said hopper from an upper position in a closed ram weight compartment of said feed hopper to a lower position adjacent said inlet comprising (a) raising said ram weight to said upper position; (b) opening a charging door to said charge said hopper with an elastomeric material; (c) closing said charging door; (d) opening a valve in said hopper to add carbon black to said elastomeric material in said hopper; (e) closing said valve; (0 lowering said ram weight to said lower position to feed said carbon black and elastomeric material into said mixing chamber; (g) raising said ram weight; (h) opening said valve, adding oil to said hopper and then closing said valve; (i) lowering said ram weight to a float position; (j) opening a drop door to drop a mixed batch of carbon black, elastomeric materials and oils from said mixing chamber; (k) closing said drop door and raising said ram weight with said valve and said charging door closed, characterized by: (1) ejecting said carbon black and elastomeric materials plus mixing gases from said ra weight compartment into a storage space in said hopper during raising of said ra weight to reduce the pressure in said compartment resisting upward movement of said ram weight and to reduce the pressure causing leakage of said gases and materials from said ram weight compartment. 8. The method of claim 7 wherein said ram weight compartment has an opening in com unication with said storage space in said hopper further characterized by ejecting said materials and said gasses from said compartment through said opening upon raising of said ram weight. 9. The method of claim 8 wherein said ram weight compartment has spaced apart guide members with said opening being disposed between said guide members further characterized by raising said ram weight with said guide members in sliding contact with said ra weight to eject said materials and said gasses from said compartment into said storage space through said opening. 10. An internal mixer apparatus and method characterized by providing for ejection of elastomeric materials and gasses from a closed ram weight compartment upon upward movement of said ram weight substantially as described herein or as shown in the accompanying drawings. c:\971 1 ajt\9520fiA.clm

Inventors: CAIN WILLIAM JACKSON, SASSON PETER GERALD JUNIOR, CAIN, WILLIAM, JACKSON, SASSON, PETER, GERALD, JUNIOR
Applicants: CAIN WILLIAM JACKSON, GOODYEAR TIRE & RUBBER, SASSON PETER GERALD JUNIOR, CAIN, WILLIAM, JACKSON, SASSON, PETER, GERALD, JUNIOR, THE GOODYEAR TIRE & RUBBER COMPANY
Application year: 1996
Main classification: B29B7
IPC codes: B29B7