US 3774821 A
In each fuel injection valve forming part of a fuel injection apparatus and associated with an internal combustion engine, there is disposed an electric heater which transmits heat to the fuel by contact-type heat exchange. The heat output of each heater is controlled by a device which processes input signals representing different engine variables.
Description (OCR text may contain errors)
United States Patent Liversa Nov. 27, 1973  POWDER FEED DEVICE FOR NON-FREE 2,102,619 12/1937 Francis 222/411 2,500,043 3/1950 Radtke 222/405 FLOWING POWDERS Inventor: Phillip A. Liversa, Bloomfield, NJ.
Westinghouse Electric Corporation, Pittsburgh, Pa.
Nov. 24, 1971 Assignee:
References Cited UNITED STATES PATENTS Primary Examiner-Samuel F. Coleman Assistant Examiner-H. Grant Skaggs Att0rneyA. T. Stratton et a1.
1 includes a centrally disposed linearly driven powder feed tube associated with a pair of rotatably and linearly driven wiper blades. The top of the powder feed tube is located just below the upper level of the powder and the wiper blades sweep the powder from the top of the container supply toward the centrally disposed tube which in turn delivers the powder out of the bottom of the container.
1 Claim, 3 Drawing Figures Pmmmnum 1975 O s 3 E: ITF a F m. a m
POWDER FEED DEVICE FOR NON-FREE FLOWING POWDERS BACKGROUND OF THE INVENTION or vibrators to deliver the powder and there are many disadvantages to these kinds of powder feeds when used in connection with sticky or non-free flowing powders such as tungsten or molybdenum. One of the principal problems with most powder feed mechanisms is that they feed from the bottom of the powder pile and the weight of the powder stack above that at the bottom of the container which is about to be fed causes packing of the powder. This packing is accentuated by the motion of any auger or vibrator and renders segregation of the powder for delivery through the bottom of the mechanism extremely difficult due to adhesion between the powder particles and because of the high friction, induced by the packing which must be overcome to move one powder particle with respect to another. If the height of the powder pile is significant delivery of tungsten or molybdenum from the bottom of a powder feeder is almost impossible because of the compaction which occurs through the weight of the powder pile.
SUMMARY OF THE INVENTION This invention relates to powder feeding devices and more particularly to a powder feed device for feeding non-free flowing powders such as molybdenum and tungsten.
The powder feed mechanism of this invention delivers powder from the top of the powder pile through the operation of simple wiping blades which are rotated at the top of the powder pile causing the powder to move unimpeded to a centrally disposed feed tube which moves linearly as the powder supply height decreases.
The smooth and unimpeded feeding of non-free flowing powders is accomplished in accordance with the present invention by providing a cylindrical powder container having a funnel shaped bottom terminating in a tubular extension. A powder feed tube is slidably mounted within the tubular extension and extends axially of the container. A pair of rotatable wiper blades are mounted adjacent the upper end of the powder feed tube to drive means which is associated with the powder feed tube and which imparts linear motion to the powder feed tube and both linear and rotary motion to the wiper blades. The wiper blades and the top of the powder feed tube are located adjacent the top of the powder pile within the cylindrical container and upon Operation of the drive means the rotating wiper blades wipe the top layer of powder toward the opening at the top of the powder feed tube to thereby deliver the powder from the top of the powder pile out of the bottom of the powder container tubular extension.
BRIEF DESCRIPTION OF THE DRAWING The attendant advantages of the powder feed mechanism of this invention will become more readily apparent and better understood as the following detailed description is considered in connection with the accompanying drawings, in which:
FIG. 1 is a side elevation view, partly in section, of the powder feed mechanism of this invention;
FIG. 2 is a sectional view taken along the line II-ll of FIG. 1; and
FIG. 3 is a top plan view of the powder feed mechanism of this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now in detail to the drawings wherein like reference characters represent like parts throughout the several views there is illustrated in FIG. 1 a feeder for non-free flowing powders constructed in accordance with this invention. The feeder, generally designated includes a powder container having a cylindrical upper portion 12 terminating in a funnel shaped bottom portion 14 and a tubular extension 16 with flared bottom opening 18.
The outer container is mounted to a support base 20 through the tubular extension 16 which is clamped to tension 16 between the clamp 22 and the support base 20. An upright support member 26 is mounted to the support base 20 and extends vertically. At the top of the support member 26 is mounted a motor 28 which drives a pair of drive pulleys 30. A pair of belts 32 connect the drive pulleys 30 to a mechanism driving head generally designated 34.
The mechanism driving head 34 is mounted on the container cap or lid 36 which rides on a raised rib or ring 38 welded to the exterior surface of the powder container 12. The container cap 36 has a threaded aperture 40 centrally disposed therein and a bushing 42 having a pair of shoulders 44 and 46 thereon is threaded into the threaded aperture 40 in the housing cap 36. The shoulder 44 of the bushing 42 serves to retain the bearing washer 48 against the top of the container cap and the driven pulley 50 is retained against the bearing washer 48 by the upper shoulder 46 of the bushing 42. The bushing 42 has a central aperture therethrough which is threaded at 52 and a threaded driving shaft 54 is threaded therethrough. The threaded driving shaft 54 includes therein an elongated keyslot 56. A key member 58 is mounted through the upper portion of the driven pulley 50 and extends into the elongated key slot 56 to thereby impart rotary motion to the shaft 54.
When the drive pulleys 30 are rotated by the motor 28 the belts 32 cause the driven pulley 50 to rotate and the rotation of the driven pulley 50 is imparted to the driving shaft 54 through the key 58 and the key slot 56. Upon rotation of the driving shaft 54 by the-key 58 the shaft will move axially as indicated by the arrow 60 through the interaction of the internal threads 52 on the bushing 42 and the threads 62 onthe drive shaft 54.
A plurality of wiper blades 64, are rigidly attached at '66 to-the bottom of'the shaft5'4. Two-wiper blades 64 have been illustrated but any number may be employed. Below the'wiper blade connection'66, loosely secured to the shaft extension is the inner powder delivery tube 70. The inner powder delivery tube is connected to the washer 72, which loosely surrounds the shaft extension 68, by a pair of arms 74-and the washer 72 rides on a bearingplate 76 which is'secured to the bottom of the shaft extension 68 byanut 78. The loose connection between the washer 72 and the shaft extension 68 permits the inner powder delivery tube 70 to be driven longitudinally by the driving shaft 54 but the powder delivery tube does not rotate with the shaft. Friction between the powder particles and the delivery tube as well as wear from such friction on the powder delivery tube is thus eliminated. The wiper blades 64 which extend radially from the shaft 54 are also given a slight upwardly directed bend so that when they sweep the top of the powder pile the disturbed particles will tumble downwardly toward the powder delivery tube 70.
In operation, the threaded shaft is rotated clockwise, as seen in FIGS. 2 and 3, causing the shaft 54 to be withdrawn out of the top of the driving head mechanism 34 until the top of the connection 66 abuts the underside of bushing 42. With the container cap 36 removed the powder container is filled with a non-free flowing powder such as tungsten or molybdenum and the cap 36 replaced. Motor 28 is actuated causing drive pulley 30 through belt 32 to drive the driven pulley 50 in a counterclockwise direction. Rotation of the pulleys 50 causes the shaft 54, through operation of the key 58, to also rotate in a counterclockwise, as viewed from above, direction. Rotation of the shaft 54 in a counterclockwise direction causes the shaft to move slowly downwardly in an axial direction because of the internal threads on the bushing 52. As the blades 64 rotate on the top of the powder, the powder is moved toward the open top of the inner powder delivery tube 70. Even when the rod 54 is raised so that the upper nut on fixed connection 66 abuts the bottom of the bushing 52, the inner powder delivery tube will not be withdrawn completely from the tubular extension 16 of the powder container. As the blades 64 are rotated powder is caused to slide on the top of the powder pile toward the top open end of the inner powder delivery tube 70 thus delivering powder from the top of the powder pile out the bottom opening 18 of the container.
As will be apparent the progressive downward movement of the inner powder delivery tube through that similar motion of the shaft 54 will cause the wiper blades 64 to continuously ride on the top of the powder pile. The angular position of the blades 64 with respect to the horizontal causes the powder disturbed at the top of the pile by the blades to roll or slide toward the open end of the powder delivery tube and by controlling the speed of rotation and linear descent of the powder delivery mechanism a timed fixed quantity amount of powder can be delivered out the bottom open end 18 of the tubular extension 16.
Although the powder feeding device of this invention has been disclosed as being particularly adapted for use with sticky powders such as tungsten or molybdenum it will be apparent that the powder delivery mechanism of this invention can be employed with the free flowing powders as well as non-free flowing powders.
1. A powder feed device for delivering a powder from a powder container, said powder being delivered from the top of a pile of powder within said container out of the bottom of said container, said powder feed device including;
a cylindrical container having a tubular extension extending from the central bottom portion thereof;
a cover member for covering the open top of said container, said cover member including a central aperture therethrough and a hollow bushing mounted in said aperture having internal threads therein;
a pulley mounted for rotation about said bushing;
drive shaft means extending through said bushing and having external threads thereon adapted to coact with the internal threads on said bushing to impart linear motion to said shaft when said shaft is rotated;
a powder feed tube telescopically received in the tubular extension of said container and extending upwardly into said powder container, said powder feed tube being loosely connected at its upper end to the lower end of said drive shaft means to thereby permit said drive shaft means to impart only linear vertical motion to said powder feed tube;
wiper blade means rigidly connected to said drive shaft means adjacent its connection to said powder feed tube, said wiper blade means extending up wardly at an angle away from said powder feed tube;
means for imparting rotary motion to said pulley; and
means including a key slot in said drive shaft means and a key on said pulley extending into said key slot for transmitting rotary motion from said pulley to said drive shaft means whereby said rotary motion of said drive shaft means is imparted to said wiper blade means and linear motion of said drive shaft means is imparted to both said wiper blade means and said powder feed tube.
UNITED STATES PATENT. OFFICE 1 CERTIFICATE 0F CORRECTION PatentNoe 3,774,821 Dated flgygmber 27, 1973 InventerQX Phmi A. Livera It is certified that error appears in the above-identified patent and .that said Letters Patent are hereby corrected as shown below:
-On the cover sheet of the patent, the inyentor's name should be changed from "Liversa" to L1vera Signed and sealed this 16th day of April 197% (SEAL) Attc: (at; H
EDX JAHD I-I.FLE TCHER,JR. G. RSHALL DANN Attesting Officer I Commissioner of Patents UICOMM'DC 037.4 l 0.. IOIIIIIIII'I "INN" emu 1 I. O-IIIPSM ream 'Po-mso (10 69