US3532233A - Automatic valve for sealed silo - Google Patents

Description

@cfi. 6, 1970 R. F. SKELTON 3,5 32,233

AUTOMATIC VALVE FOR SEALED SILO Filed April 1, 1969 drum/02 $5M a e k/(021 a5 32 4 1 United States Patent 01 Ftice 3,532,233 Patented Oct. 6, 1970 3,532,233 AUTOMATIC VALVE FOR SEALED SILO Robert F. Skelton, Blutfton, Ind., assignor to Mix-Mill, Inc., Blulfton, Ind., a corporation of Delaware Filed Apr. 1, 1969, Ser. No. 812,007 Int. Cl. B25g 33/14, 65/46 U.S. Cl. 214-17 Claims ABSTRACT OF THE DISCLOSURE BACKGROUND OF THE INVENTION Sealed silos conventionally have a gas-keted plate se cured to a discharge opening in the silo which must be removed each time silage is removed from the silo and replaced to reseal the silo. Even where an automatic auger has been used to discharge silage, a gasketed plate has been used to seal the silo. The advantages of an automatic auger system are therefore lost through the time required to remove and replace the gasketed plate.

SUMMARY OF THE INVENTION The valve assembly of this invention provides for the automatic opening of the discharge valve for an automatically controlled auger each time the auger motor is actuated. The torque reaction force set up in the electric motor in overcoming the resistance of the loaded auger is used to roll the motor through 90 degrees prior to rotating the auger. The motor is supported on a frame by a cradle which is connected to open the discharge valve each time the motor rotates to start the auger. Opening of the discharge opening is therefore assured since the cradle has less resistance than the loaded auger and will pivot prior to the operation of the auger. Damage to the motor from shock on impact with the frame on return movement of the cradle is prevented by connecting an air bleed check valve between the cradle and the frame. A seal assembly is provided between the auger and anger housing to maintain the sealed condition of the silo when the discharge valve is closed.

Other objects and advantages of the invention will be come apparent from the following detailed description when read in connection with the accompanying drawings, in which:

FIG. 1 is an elevation view of the invention showing the discharge valve assembly connected to an automatic auger for a sealed silo.

FIG. 2 is an end view of the invention showing the valve assembly in the closed position.

FIG. 3 is an end view similar to FIG. 2 showing. the valve assembly in the open position.

FIG. 4 is a view taken on line 4-4 of FIG. 2 showing the seal assembly for the auger.

DESCRIPTION OF THE INVENTION Although the disclosure hereof is detailed and exact to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention which may be embodied in other specific structure. The scope of the invention isdefined in the claims appended hereto.

.The sealed silo valve assembly 10 of this invention is used to open a discharge valve 12 provided in a housing 14 for an auger 16 which extends outwardly through a discharge opening 17 in a wall 18 for a sealed silo. Only a portion of the wall 18 of the silo is shown since such silos are well known. The auger 16 is driven by means of a motor 20 connected to the auger 16 by a V-belt 22 mounted on a drive sheave 24 secured to the motor drive shaft 26 and a driven sheave 28 secured to the end of the shaft 15 for the auger 16. The motor 20 is controlled by an automatic control 30 of any conventional design to discharge silage from the silo as needed. A conventional rotating type armature motor is shown in the drawing, however, any type of motor having one part movable with respect to the other part is within the contemplation of this invention.

The silo is opened to allow for the discharge of silage by means of the valve 12 which includes a valve plate 32 pivotally mounted on a pin 34 provided at the end of a discharge chute 36 connected to the auger housing 14. The valve plate .32 is biased to a closed position with respect to an opening 38 at the end of the discharge chute 36 by means of a counterweight 410 secured to a bracket 42 which extends outwardly from the plate 32. The weight of the counterweight 40 is sufficient to hold the valve plate 32 tightly against the opening 38 at the end of the discharge chute 36.

The valve 12 is sealed by means of a seal material 44 provided on the surface of the valve plate 32 for sealing engagement with the opening 38 at the end of the discharge chute 36. The seal material contemplated herein includes any resilient material such as a layer of sponge rubber or any seal surface that will form a seal at the end of the discharge chute. The seal material 44 will engage the periphery of the opening 38 when the valve plate is rotated to the closed position. A resilient material should be used in order to compensate for variations in the contour of the periphery of the opening 38.

In order to open the valve 12 each time the auger 16 is started, means are provided for pivoting the valve plate 32 away fromv the opening 38; in the discharge chute 36. Such means is in the form of a cradle type support 46 connected to the valve plate 32 by an adjustable chain 48. The support '46 is mounted for pivotal movement on a bracket 50 by means of a pivot pin 52 journalled in a bearing 54 in the bracket 50. The motor 20' is secured to the cradle 46 and is mounted for pivotal movement on a bracket 56 by means of the drive shaft 26 which is journalled in a bearing '58 provided in the bracket 56. The drive shaft 26 is axially aligned with the pivot pin 52 to form a common axis for the motor 20 and the cradle 46. It should be understood that the cradle support 46 can be mounted to pivot about an axis offset from the axis of the drive shaft 26 of the motor 20. The weight of the motor 20 is generally unbalanced about the axis of the drive shaft 26.

When the motor 20 is started, the reaction force created by the resistance of the auger 16 to rotate will cause the motor 20 and cradle 46 to rotate about the axis of the drive shaft 26 and pivot pin 52. The motor torque is sufiicient to overcome the unbalanced weight of the motor as Well as the counterweight 38. The rotary motion of the cradle 46 is limited by a stop 60 provided on the cradle 46 which is positioned to engage the bracket '50. The position of the stop 60 will allow the cradle 46 to move through approximately degrees before auger 16 turns at normal speed.

As long as power is applied to motor 20, the reaction force keeps the cradle 46 against stop 60 against the bias of counterweight 38 and the unbalanced weight of r 3 the motor 20. When the control 30 turns the motor 20 off, the unbalanced weight of the motor 20 and cradle 46 will rotate the motor and cradle to the starting position. The counterweight 38 will close the valve plate 32.

The return motion of the motor 20 and cradle 46 is cushioned by means of an air bleed valve assembly 62 secured to the cradle 46 and to the auger housing 14. This assembly includes a piston 64 connected to the auger housing 14 and a cylinder 66 connected to an arm :68 on the cradle 46. The connections to the housing 14 and the arm 68 should be sufficiently free to allow the check valve assembly to follow the motion of the motor support 46. Air bleed 01f from the cylinder 66 is controlled by means of an adjustable screw 70 provided in the cylinder 66 which can be set to limit the discharge rate of air from the cylinder. The return motion of the support 46 is limited by means of the arm 68 which is positioned to engage the bracket 50.

The motion of the cradle support 46 is transferred to the valve plate 32 by means of the chain 48. When the motor 20 rotates on start up, the plate 32 will be pivoted to an open position prior to initiation of rotation of the auger 16. When the motor stops, the counterweight 40 will bias the valve plate 32 to the closed position. The silo will therefore be opened automatically whenever silage is to be discharged from the silo and will automatically reclose whenever the auger motor is stopped.

In order to maintain the silo sealed, means are provided for sealing the end of the auger housing 14 in the form of a seal assembly 71. This assembly includes an end wall 72 provided in the housing 14 and having an aperture 74 to receive the auger shaft 15 which is journalled in bearings 76 and 78 provided on each side of the seal assembly 70. A seal housing 80 is secured to the end wall 72 and has a central cavity 82 threaded to receive a threaded plug 84. A packing gland 86 is positioned within the cavity 82 and is squeezed by the threaded plug 84 to sealingly engage the shaft 15.

The biasing means, sealing means, cushioning means and linkage are not restricted to the specific forms shown. Other equivalent means may be used. However, the form shown and described works well in actual practice and is simple and economical to make and repair.

What is claimed is:

1. The combination of a sealed silo having a discharge opening, a valve to open or seal said discharge opening, an auger mounted in the silo and extending into the opening, a motor having a pair of relatively rotatable parts, means connecting one of said parts to said auger and adapted to drive said auger when said motor is energized, means mounting the other part of said motor for pivotal movement about an axis, means limiting the pivotal motion of said other part of said motor at a predetermined location respecting said axis, and means to transmit said pivotal movement to said valve.

2. The combination according to claim 1 wherein said valve includes a valve plate pivotally connected to said discharge opening and a counterweight to bias said valve plate to a closed position with respect to said discharge opening.

3. The combination according to claim 2 including a layer of sealing material on said valve plate to seal said discharge opening.

4. The combination according to claim 1 including means restraining the return motion of said other part of said motor.

5. The combination according to claim 4 wherein said restraining means comprises an air bleed check valve.

6. The combination according to claim 1 including a discharge housing for said auger and means sealing said auger in said discharge housing.

7. The combination according to claim 6 wherein said sealing means includes a wall having an aperture to receive said auger, a cylindrical housing mounted on said wall and having a threaded central cavity to receive said auger, a packing gland in said cavity and a threaded plug threadedly received in said cavity to squeeze said packing gland against said auger.

8. The combination according to claim .1 wherein said one of said parts is mounted to pivot about an axis coaxial -with the axis of said other part.

9. A valve assembly for a sealed silo having an auger extending into a discharge housing having a discharge opening mounted on the silo and an electric motor connected to drive the auger, said assembly comprising a valve movable to open or seal the discharge opening, a support for supporting the auger motor for pivotal movement about an axis in response to a reaction force set up in the auger on starting of the motor, a link connecting said support to said valve to open said valve in response to pivotal movement of said support, and means restraining return motion of said motor.

10. A valve assembly according to claim 9 wherein said valve includes a valve plate having a resilient sealing layer on one surface and a counterweigrt to bias said valve plate to a closed position with respect to said discharge opening.

References Cited UNITED STATES PATENTS IROBERT G. SHERIDAN, Primary Examiner US. Cl. X.R. 19865, 213

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