US2170832A

US2170832A - Abrasive throwing machine

Info

Publication number: US2170832A
Application number: US49328A
Authority: US
Inventors: Verne E Minich
Original assignee: American Foundry Equipment Co
Current assignee: American Foundry Equipment Co
Priority date: 1934-05-25
Filing date: 1935-11-11
Publication date: 1939-08-29
Anticipated expiration: 1956-08-29

Description

Aug. 29, 1939. v. E. MINICH Y ABRASIVE THROWING MACHINE INV ENTQR Vern! Eflmu/i {Iiiya/lirlll!llirrll Driginal Filed May 25, 1934 K L ATTORNEYS Patented Aug. 29, 1939 UNITED STATES PATENT OFFICE 2,170,832 snaasrva 'rnnowmc 'mcnmn Original application May 25, 1934, Serial No.

Divided and this application November 11, 1935, Serial No. 49,328. Renewed April 10 Claims.

This invention relates to abrasive throwing machines and more particularly to apparatus for directing and controlling the abrasive thrown by themachine.

This application is a division oi my copending application, Serial No. 727,398, filed May 25, 1934.

This invention comprehends the provision of devices adapted to be associated with an abrasive throwing machine whereby the abrasive thrown may be controlled particularly as respects to the direction of flight; area covered by. the thrown abrasive, and intensity of impingement. The machine generally comprises spaced rotatably mounted discs having removable and replaceable throwing blades radially arranged therebetween. The blades are preferably shaped to contain the abrasive entirely within the area of the blade and out of wearing contact with the permanent parts of the machine. The blades preferably extend short of the center of the machine so as to provide a center inlet through which the abrasive feeding means may be inserted. The abrasive may be conveyed to the machine through a suitable feed pipe in which the abrasive is moved either by gravity, air blast, screw conveyor or other means. A discharge nozzle is adjustably connected to the end of the feed pipe, extends into the center inlet and directs the abrasive substantially radially across the inner ends of the throwing blades.

The direction in which the abrasive is thrown from the machine depends upon the point at which the abrasive is fed into the path of the rotating throwing blades. By adjusting the position bf the discharge opening of the feed nozzle the abrasive may be thrown in any desired direction. The length of the path swept by the thrown abrasive is determined by the peripheral length of the discharge opening in the reed nozzle. Means are provided for adjusting the peripheral length of the discharge opening in the feed noz zle, and thereby controlling and regulating the length of the path swept by the thrown abrasive.

The intensity of abrasive impingement against the work is determined by the peripheral length ing blades. The control devices may be adjusted to adapt the machine to a variety of difierent operating conditions.

An object of this invention is to provide means by which thrown abrasive may be directionally controlled so that the desired workarea will be impinged thereby.

Another object of this invention is to provide means whereby the area covered by the thrown abrasive may be regulated and controlled.

Still. another object of this invention is to provide means for regulating and controlling the intensity of impingement of the thrown abrasive.

Another object of this invention is to provide an abrasive throwing machine adapted to be adjusted to effectively clean and abrade under varying operating conditions articles and objects which vary in shape, hardness and surface characteristics.

Another object of this invention is to provide an abrasive throwing machine which is simple in construction, which .has a low power consumption for the work done, which imparts to. the abrasive a highly efiective abrasive velocity, which causes a minimum disintegration of the abrasive particles, which is durable and lasting in construction, which is not subjected to excessive wear from the abrasive when thrown from the machine, and which is highly effective for the cleaning of metal sheets, billets, castings, forgings and other metallic objects.

Other objects of this invention will become apparent as the disclosure proceeds. In order that a clearer understanding of my invention may be had, attention is hereby directed to the drawing forming a part of this application, and illustrating certain possible embodiments of my invention.

Referring to the drawing:

Fig. 1 is a longitudinal cross sectional view through an abrasive throwing machine having associated therewith a feed control device, this view being taken on line l-l of Fig. 2;

Fig. 2 is a transverse cross sectional view through the machine shown in Fig. 1, this view being taken on line 2-2 of Fig. 1;

Fig. 3 is a fragmentary top view of the abrasive sive control device shown in Fig. 5. certain parts being broken away tomore clearly illustrate the construction; and

Fig. '7 is a transverse cross sectional viewthe abrasive throwing machine comprises the spaced plates or discs I and 2 joined together by radially extending vanes 3. The rotor is suitably mounted upon a shaft (not shown) which is fixed to the hub extending from the disc I, see Fig. 2. Removable and replaceable wear plates or shoes 17 of generally channel form rest upon the vanes 3 and may be held in position by means of set screws 6 which extend through the plate 2 and engage with the sides of the removable blades. Any well known means, however, for securing the throwing blades in position may be used within the contemplation of this invention. The radial supporting vanes 3 and the throwing blades b extend short of the center of the rotor providing an open chamber or center inlet 0 centrally of the machine. It is understood that the side wall plates and 2 shown in Figs. 1 and 2 are generally circular in shape and the supporting vanes 3 and blades b are substantially similar in shape and size, so that the lower portion of the machine, as shown in Figs; 1 and 2, is substantially a duplicate of the upper portion of the machine as shown in Figs. 1 and 2.

A feeding device is provided which extends through an opening 40 cut through the center of the disc 2 and extends into the center inlet '0. The feeding device comprises a feed pipe I which conducts the abrasive to a feed nozzle l| adJustably mounted on the end of the pipe I. A screw conveyor, see Fig. 7, comprising the helical vane 8 supported by the core 9 may be used to move the abrasive through the pipe I. A.

spider it may be fixed within theendof pipe 'I to rotatably support the core 9 of the screw conveyor. Other means for feeding theabrasive into the feed nozzle H such as air blast, gravity, or. both may also be'used within the contemplation of this invention.

The feed nozzle II is provided with a discharge opening in the end thereof which is positioned adjacent to the inner ends of throwing blades b. The axial width of the discharge open-* ing is not greater and preferably less than the axial width of the throwing blades b\and is so shaped as to direct the abrasive into the chanwith a flanged portion it which extends around the collar portion ii of the feed pipe I and retains the feed nozzle II in position. A set screw extending through the flange portion It and engaging the collar portion It, may be used to retain the feed nozzle H in any desired adjusted position. Other. means for adiustably securing the feed nozzle ii to the end of the feed pipe 'Imaybeused.

A throwing machine having a diameter of approximately 20 inches and rotated at approximately' 2,200 revolutions per minute will effectively abrade and clean metallic castings, forge ings, billets, metal sheets and other metallic objects. When the discharge opening of the feed nozzle II is positioned at approximately the 12 o'clock position, a rotor 20 inches in diameter operating at 2,200 revolutions per minute will discharge the abrasive from approximately the 4 o'clock to the 8 o'clock position. With a given machine rotated at a specified R. P. M. the direction of discharge will be determined by the position of the discharge opening of the feed nozzle. The abrasive can, therefore, be thrown in any desired direction by swinging the nozzle around to the proper position and securing the same in this position by means of the set screw The discharge end of the feed nozzle H is fixed so as to direct the abrasive substantially radially across the inner ends it of the throwing blades b thus injecting the abrasive into the path of the moving blades when rotating at a high velocity.

The length of the path swept by the thrown abrasive is determined by the peripheral length of the discharge opening of the feed nozzle. With a discharge opening of fixed peripheral length, the path swept by the thrown abrasive will be substantially uniform in machines of the same diameter rotating at approximately the same speeds. With a given discharge opening the intensity of impingement depends upon the amount of abrasive fed through the machine per minute. The length of the path swept by the thrown abrasive can be varied in a given machine by changing the peripheral length of the discharge opening in the feed nozzle. The machine shown in Figs. 1, 2 and 3 is equipped with a feed nozzle the discharge opening of which may be varied in peripheral length. The feed nozzle H as shown comprises a neck portion 4| having spaced V-shaped

side wall plates

20 and 2| extending at right angles thereto. One end of the V-

shaped plates

20 and 2| are joined by an end wall 22 and abottom. :wall 23, The other end of the nozzle is closed by a movable end wall 24 suitably hinged by a rivet 28 to one of the side walls .2| of the nozzle. As illustrated more particularly in Fig. 4, the peripheral length of the discharge opening of the feed nozzle may be varied by swinging the end wall 24 in an arc. ,The peripheral length of the discharge opening in the nozzle may thus be varied from a maximum equal substantially to the peripheral width of the

side plates

20 and 2| to a minimum in which the end wall 22 and movable end wall 24 are substantially in abutment. The size of the intake end of the nozzle remains substantially unchanged at all times. If desired, both the

end walls

22 and 24 may be made movable in an arc.

Means are provided for retaining the movable end wall 24 in any desired adjusted position. The end wall 24 may be provided with a top flange portion 25 which extends away'from the dis-' charge opening so as to not interfere with the abrasive discharge. The flange portion 25 is provided with a downturned lip portion 21 which overhangs the side wall 20 of the nozzle. A

threaded set screw 26 or other device extends through the lip portion 21 and frictionally engages the side wall 2|! of the nozzle so as to releasably retain the end wall 24 of the nozzle in any desired adjusted position.

The discharge opening in the nozzle may be moved into, any position within the center inlet 0 'so as to direct the abrasive against the work surface. The nozzle is retained in the desired adjusted position by manipulating the set screw I! which secures the nozzle II to the feed pipe 1. Either a screw conveyor, gravity, low pressure air blast, or a combination of one or more of these may be used to force the abrasive through the discharge opening in the nozzle. With the V-shaped type of nozzle it is sometimes desirable to use a combination of gravity or conveyor and air blast feed, such as illustrated more particularly in Fig. '7. This will be described more fully hereinafter. g

There is shown in Figs. 5, 6 and 7 a modified form of V-shaped discharge nozzle in which the size and peripheral length of the discharge opening is varied as desired by means of one or more sliding shutters 3| which may be moved teenlarge or reduce the size of the discharge opening. The shutters 3| may be slidably retaineddn position by the provision of rolled edge portions 34 which slidably grip rim portions 33 extending outwardly from the top edge of the

side walls

20 and 2|. A suitable handle 32 may be provided for,v manipulating the sliding shutters 3|. The nozzle may be provided with fixed end walls 22 and or the end walls may be made movable in an are in' the manner illustrated in Fig. 4. The length of path swept by the thrown abrasive may be regulated by adjusting the sliding shutters 3| into the proper position. Directional control of the thrown abrasive may also be effected by swinging the discharge end of the nozzle into the proper position and securing the same inthis position by means of the adjusting screw ll. When this type of nozzle is used, the direction of flight of the thrown abrasive, as well as the length of path swept by the abrasive, may be varied as desired without requiring a change of nozzles.

Where a V-shaped nozzle is used, it may be advisable under certain operating conditions to augment the conveyor or gravity feed by a low pressure stream of -air. As illustrated in Fig. 7, the discharge end 36 of the air pipe 35 extends through the bottom portion 23 of the nozzle. A screw conveyor or gravity is used to carry the abrasive to the nozzle, at which point the air blast emitted from the discharge end 36 of the air pipe 35 blows the abrasive through the nozzle and distributes the abrasive so as to obtain a substantially uniform intensity of discharge throughout the cross-sectional area of the nozzle discharge opening. The discharge end 36 of the air pipe is so shaped to effectuate this result.

with a machine as above constructed the abrasive can be thrown in any desired direction so as to impinge the desired work area and perform effective work. The direction of discharge is conchange the length ofpath swept by the abrasive 76 at intervals, a feed nozzle having an adjustable abrasive.

discharge opening, such as shown in the figures. may be preferable. The abrasive may be propelled through the feed nozzle by means of gravity, conveyor, low air blast, or a combination of one or more of these. The discharge opening in the air nozzle is preferably so arranged as to direct the abrasive substantially radially across the inner ends of the blades. All of the abrasive fed into the machine is thus directed into the path of the moving blades and swirling of the abrasive within and around the machine is prevented. The axial width of the discharge opening is no greater and preferably less than the width of the throwing blade and is so shaped as to direct all of the abrasive within the conflne's of the removable throwing blade and out of contact with the permanent side plates 1 and 2 of the machine.

' annexed claims, it will be understood that various omissions, substitutions and changes may be made by those skilled in the art without departing fromv the spirit of the invention.

What is claimed is:

1. In a centrifugal blasting machine designed for throwing abrasive at blasting velocities comprising, spaced rotatably mounted throwing blades extending inwardly'short of the axis of rotation of said blades to provide a center inlet. abrasive feeding means including an elbow-shaped nozzle having a discharge opening extending into said center inlet operative to direct abrasive into the path of rotation of said blades for a limited arc, and means for controlling the length of path swept by the thrown abrasive including, a movable element associated with said elbow-shaped nozzle for adjusting the peripheral length of said discharge opening.

2. In a centrifugal blasting machine designed for throwing abrasive at blasting velocities comprising, spaced rotatably mounted throwing blades extending inwardly short of the axis of rotation of said blades to provide a center inlet, abrasive feeding means including an elbow-shaped nozzle having a discharge opening extending into said center inlet operative to direct the abrasive substantially radially into the path of rotation of said blades over a limited arc, and movable means associated with said nozzle opening for adjusting the circumferential length of said opening thereby regulating the length of path swept by the thrown 3. In a centrifugal blasting machine designed for throwing abrasive at blasting velocities comprising, spaced rotatably mounted throwing blades extending inwardly short of the axis of rotation of said blades to provide a center inlet, abrasive feeding means including a feed pipe conducting the abrasive to said center inlet, and means for controlling the length of path swept by the thrown abrasive, said means comprisinga feed nozzle arranged to receive the abrasive delivered thereto by said feed pipe, said feed nozzle extending into said center inlet having the discharge end thereof positioned to direct the abrasive substantially radially across the inner ends of the moving blades, and adjustably movable pivotally mounted means forming a side wall for said nozzle and operative upon adjustment to define the peripheral length of said discharge opening.

4. In a centrifugal blasting machine designed for throwing abrasive at blasting velocities comprising, spaced rotatably mounted throwing blades extending inwardly short of the axis of 7 rotation of said. blades to provide a center inlet. abrasive feeding means including a feed pipe conducting the-abrasive tosaid center inlet, and means for receiving the abrasive from said feed pipe and controlling the length of path swept by the abrasive, said means comprising a V-shaped feed nozzle within said center inlet having the discharge end thereof positioned to direct the abrasive substantially radially across the inner ends of the moving blades, and a movable end wall associated with said nozzle for increasing and decreasing the peripheral length of the discharge opening therein. a

5. In a centrifugal blasting machine designed for throwing abrasive at blasting velocities comprising, spaced rotatably mounted throwing blades extending inwardly short of the an; of rotation of said blades to provide a center inlet, abrasive feeding means including a feed pipe conducting the abrasive to said center inlet, and means for controlling the length oi path swept by the thrown abrasive, said means comprising a feed nozzle adiustably connected to said feed-pipe and extending into said center inlet having the discharge end thereof positioned to direct the abrasive substantially radially across the inner ends of the moving blades, and adjustable shutters fixed to said nozzle but adJustably movable for increasing and decreasing the peripheral length of the discharge opening. v

6. In a centrifugal blasting machine designed for throwing abrasive at blasting velocities comprising, spaced rotatably mounted throwing blades extending inwardly short of the axis of rotation of said blades to provide a center inlet, abrasive feeding means including a feed pipe, a nozzle positioned within said center inlet and adjustably mounted on said feed pipe for directing the abrasive discharge, means for forcing the abrasive through said nozzle and into the path of movement of said throwing blades, and adjustably movable shutters for increasing and decreasing the peripheral length of the discharge opening.

7. In a centrifugal blasting machine designed for throwing abrasive at blasting velocities comprising, spaced rotatably mounted throg blades extending inwardly short of the of rotation of said blades to provide a center inlet,

'abrasive. feeding means including a f nozzle at right angles to said conduit portion, said bend portion having a discharge I t extending into said cenizzr inlet and operative to direct the abrasive substantially radially across the inner ends of saidblades as they successively pass a predetermined point, and adjustably movable means for increasing and decreasing the peripheral length of said discharge opening.

8. A centrifugal blasting machine for throwing abrasive at blasting velocities comprising, a rotor mounted for high speed rotation including spaced throwing blades extending inwardly toward the axis of rotation of said rotor, an abrasive supply pipe, and a feed nozzle connected to said abrasive supply pipe having guide walls for conducting the abrasive substantially radially of said blades and onto the inner ends of said blades as they successively pass a predetermined point during rotation, said nozzle being provided with a pivotally mounted movable wall for adjusting the circumferenti'al length of said opening thereby regulating the length of path swept by the thrown abrasive.

9. A centrifugal blasting machine for throwing abrasive at blasting velocities comprising, a rotor mounted for high speed rotation including spaced throwing blades extending inwardly toward the axis of rotation of said rotor, an abrasive supply pipe, and a feed nozzle connected to said abrasive supply pipe having guide walls for conducting the abrasive substantially radially of said blades and onto the inner ends of said blades as they successively pass a predetermined point during rotation, said nozzle including side wall members constituting the terminal portion thereof and defining a discharge opening, and means hingedly conmeeting said side wall members whereby the distance between the ends thereof can be adjusted to vary the size of the discharge opening.

10. A centrifugal blasting machine for throwing abrasive at blasting velocities comprising, a rotor mounted for high speed rotation including spaced throwing blades extending inwardly toward the axis of rotation of said rotor, an abrasive supply pipe, and a feed nozzle connected to said abrasive supply pipe having guide walls for conducting the abrasive substantially radially of said blades and onto the inner ends of said blades as they successively pass a predetermined point during rotation, said nozzle including side walls defining a discharge opening, a shutter adapted to vary the size oi said discharge opening, and means mounting said shutter for sliding movement on the end of said nozzle.

VERNE E. lmNICH.