US1735600A - Abrasive-feeding system for glass-grinding machines - Google Patents

Description

Nov. 12, 1929. J. P. CROWLEY ABRASIVE FEEDING SYSTEM FOR GLASS GRINDING MACHINES :s sheets-sheet A1 4Filed. DSO. 24, 1923 .Nov. 1 2, 1929. 1 P1, CROWLEY 1,735,600

ABRASIVE FEEDING SYSTEM FOR GLASS GRINDING MACHINES Filed Dec. 24, 1923 3 Sheets-Sheet 2 ArraqA/fri Nov. l2, 1929. J. P. CROWLEY 735y600 ABRASIVE FEEDING SYSTEM FOR GLASS GRINDING MACHINES Filed D60. 24, 19,23 3 SheeLs-Sl'leei'I v5 ATTU/VE'Y I Patented Nov. 12, 1929 uNrrlazD-s'ra'rlazs PATENT oFFlc-E f JOSEPH P. CROWLEY,

OF TOLEDO, OHIO, ASSIGNOR T0 LIBBEY-OWEN S GLASS OOM-PANT, 0F TOLEDO, OHIO, A CORPORATION 'OF OHIO ABRASIVE-FEEDING VSYSTEM FOR GLASS-GRINDIN'G MACHINES Application. mea December 24, 192s.v serial No. 682,495.

This invention relates to an improved'proc` l the grinding machine disclosed in my cepending application, Serial No. 659,435, filed August 27, 1923. y

According to the present invention, the new sand, or used sand which has been collected from the several grinding units, is mixed with water and then flowed through a series of grading tanks in which the abrasive is separated into a plurality of distinct grades. Preferably, two similar series of these tanks are'provided, and while the abrasive mixture is flowing through one series and being graded, the previously graded abrasive in the other series of tanks may be drained off into a series of storage reservoirs, each reservoir being adapted to hold one grade of abrasive and being provided with a suitable agitator maintaining the abrasive in suspension. Thiscomprises the grading system.

The feeding system consists of a series, here shown as three, of endless pipe circuits extending past the several grinding machines. A certain grade of abrasive is maintained 1n practically continuous circulation in each pipe circuit, and may be drawn upon when desired to su ply the need of any one or more of the grin ing units. The abrasive mlxture in circulation in each circuit is 'replenished when necessary from the storage reservoirs, and the abrasive mixture may be selected from any one or a group of these reservoirs to obtain just the desired grade of abasive for that particular circuit.

When the grinding operation of a machine is started a portion of the heaviest grade of abrasive is delivered from its pipe line to the machine. After a suitable interval this grade may be shut ofl:` and the next finer grade fed to the machine, and so on until the grinding operation is completed. A continuous pressure is maintained on the abrasive supply in each pipe line, which serves not only to force plurality of plate glass the abrasive material from the pipe line to thel selected machines, but also serves to maintain the abrasive in circulation in the circuit vand keep the solid material in suspension. The used abrasive and water from the several machines How to a sump from which the better part of the mixture is pumped back to the grading tanks and regraded.

The invention will be better understood from the following detailed description of one approved form of the apparatus. f

In the accompanying drawings:

Fig. 1 is a plan view of the entire abrasive supplying system.

Fig. 2 is an end elevation on an enlarged scale, looking from the right of Fig. l1.

Fig. 3 is an elevation, looking from the left at Fig. 2, showing one of the series of grading tanks and the storage reservoirs.

Fig. 4 is a longitudinal vertical section through a portion of one'of the series of grading tanks.

Fig. 5 is an enlarged section through the means for draining the abrasive which hasr settled out in any single grading tank, into its respective storage reservoir.

Fig. 6 is a section through the series of feed pipes showing the valves for delivering. the abrasives to one of the grinding machines.'

Fig. 7 is an elevation, on an enlarged scale, of one of the gate valves for intermittently interrupting the iiow of abrasive through the pipe line, and the operating cam for this valve.

Fig. 8 is an elevation taken at right angles to Fig. 7 and on a smaller scale, showing a single driving means for the three gate valves.

The grinding machines 1, which are merely shown conventionally in the present drawings, may be of substantially the construction disclosed in my prior application, Serial No.

and the used abrasive and water thrown olf from the grinding machine flow into a drain pipe 3 through wliich they pass to an underground sump 4 at one end of the factory. In the installation shown in the,drawings, two opposite rows of grinding machines 1 are provided, and there is a drain pipe 3 for each row of machines, the two drain pipes leading to the saine sump 4.

The several grades of abrasive to be used, here shown as three, although any desired number might be used, are maintained in circulation inthe three parallel pipe lines 5, 6 and 7, which extend past all of the grinding units. As here illustrated, the three pipe lines extend overhead at a point midway between the two parallel rows of grinding machines 1. The pipe line 5 contains a supply of the heaviest sand, or other abrasive, suitably suspended in water. Pipe line 6 carries an intermediate grade of abrasive and pipe line-7 carries thevtnest grade. Asshowni'ig. 6, a. series of similar valves" 8, 9 and 10, are provided in the respective pipes 5, 6 and 7, opposite each one of the grinding machines. These three valves are adapted to discharge into a common 4basin or hopper 11, which guides the abrasive mixture into the feed pipe 2 for that particular grinding machine 1. By suitably manipulating the valves 8, 9 or 10, any grade'of abrasive may be fed tothe machine when desired. The simple form of valve here shown is adapted to be manually operated, but automatically operated valves may be used, provided with suitable timing mechanism for feedingthe different grades of abrasive successively to the machine for any'selected-period of time. One 'approved type of mechanism for automatically feeding the abrasives is disclosed and claimed in my `copending application, Serial No. 659,436, iiled August 27, 1923. The present application discloses an improvement on, and a con-n tinuatio'n in part of, the system disclosed in this previously liled applicat-ion.

The new sand'or other abrasive to be used i is first delivered into a mixing tank 12'Wl1ere water is added and the mixture is maintained in suspension by a suitable agitator indicated at 13. This mixture is forced by pump 14 through delivery pipe 15 which has branches 16 and 17 leading respectively to two similar series of grading tanks 18 and 19. The used sand from sump 4 is delivered by pump 80 through pipe 81 to the'pipe 15, already described, from which, like the new sand, it is similar compartments, here numbered 20 to 29, respectively. As shown more particularly in Fig. 4, the abrasive mixture is delivered into one end of the first compartment 20, through strainer 30, and after lowin through tank 20 flows over the partition 31 into the next tank or compartment 21. While the abrasive mixture is flowing through tank 20, the heaviest portion of the abrasive will settle to the bottom of the tank, as indicated at 32. The abrasive mixture which has overtlowedwall 31 into tank 21 will pass through that tank and overflow the next partition 33 which is somewhat lower than partition 31, into the next tank 22, and so on throughout the series. While the mixture is flowlng through each successive tank, the heaviest portion of the abrasive then remaining will settle to the bottom of that particular tank. It will be 'obvious that the "deposit collected in each tank will be successively lighter as the flow continues throughout the series from tank 20 to tank 29. It will also be noted that the tanks increase in length throughout the group from tank 20 to tank 29, since as the abrasive re-` mainingin suspension becomes lighter, a longer time is required for it to settle out. A series of nine storage reservoirs, or makeup tanks, 34 to 42,respectively, are provided, and these tanks are preferably arranged below and midway between the two .series of grading tanks. Delivery pipes 43 lead downwardly from tanks 20, whereby the abrasive collected in either or both of the grading tanks 20 may be delivered to the storage reservoir 34. In a similar manner delivery pipes 44 lead from the two grading l tanks 21 to the second storage reservoirs 35,'and so on throughout the series, the next to the last grading tanks 28 delivering the abrasive deposited therein to the last storage reservoir 42. As shown more particularly in Fig. 5, a valve 45 is provided at the upper end of delivery pipe 43, and when it is desired to deliver into reservoir 34 the kabrasive 32 which has settled out in tank 20, this valve 45 is opened. A connection 46 is provided for injecting water under pressure into the upper end of pipe 43 and lower end of tank 20 directly above the valve 45. This is to break upthe caked abrasive which will be depositedat this point and permit a free flow of the abrasive through the valve 45 and pipe 43 to the reservoir. Water pipe 46 is provided with a valve 47 for turning on or oit this supply as found necessary. It will be understood that each of the delivery pipes from the respective grading tanks to their respective reservoirs 1s supplied with a valve system similar to that disclosed in Fig. 5.

The abrasive which settles out in thel last grading tank 29 of the series will ordinarily be too ,line for further use, and this abrasive is drained off through ipe 48 to the sewer. The water which overows from the ends of tanks 29 flows back through pipes 49 and 50 to the mixing tank 12, where it may be reused with new abrasive.'

Each of the reservoirs 34 to 42, is provided with a suitably driven agitator, such as indicated'at 51 'in tank 34, for maintaining the mixture therein in suspension. A

lo water-line will also beprovided, (omitted from the drawings for the sake of clearness), leading to each reservoir for supplying the necessary amount of liquid to the mixture therein.

The apparatus as so far disclosed, com" prises the grading system, and it will be noted that this system provides a continuously maintained supply of nine different grades of abrasive w ich may be drawn on k as desired to supply the feeding system now to be described.

Adjacent the reservoir 34 is located a smaller supply-tank or service-tank 52, which, together with the pipe circuit 5, contains the heaviest grade of abrasive mixture then in use. The abrasive is drawn out from this, service tank through pipe 53 and forced by eithery one of the alternative pumps 5.4 or 55, into the pipe line 5. The two parallel pumps 54 and 55 are provided so that either one may be repaired or re laced without necessitating shutting down 't e operation ofv the circuit. This heavy grade of abrasive flows through the pipe circuit 5 past all of the grinding units, and such of the abrasive as is not drawnout through the Valves 8 and fed to certain of the machines, is returned through the discharge end of pipe 5 back into the service-tank 52, from which it o is again pumpedthrough the pipe circuit as before. A similar service-tank 56 for the intermediate grade of abrasive is located between the reservoirs A36 and 37, and this grade of abrasive is drawn from tank 56 by pumps 57, forced through pipe circuit 6 and discharged back into the tank 56 as in the circuit first described. A third service-tank 58 for the finest abrasive is located in the pipe circuit 7, this abrasive being forced through the pipe by the pumps 59.

g A continuous pipe 60 extends past all of the "reservoirs and service-tanks, as shown pam ticularly in F ig. l, and branches from this pipe 60 connect with each of the reservoirs f 34 to 42, each of the service-tanks 52, 56 and 58, and each of the pumps 54, 55, 57 and 59. By means of a separate valve in each of these branches communication with that respective tank or pump and the pipe 60 may be opened 60 or shut off' as desired. Furthermore, there is a valve 61 in the pipe 60 between reservoir 36 and pumps 57, and a second valve .62 in pipe 60 between reservoir 39 and pumps 59. Normally, the valves 61 and 62 will be closed. The heavier grade of abrasive is drawn into pipecircuit 5 by means of pumps 54 or 5 5 through pipe 60` from any one or all of the cuit 5. If it lshould be desired to use even` finer abrasive in this system, the valve 61 may be opened and finer grades of abrasive obtained through pipe 60 from any of the reservoirs 37 to 39. However, the reservoirs 34 to 36 will ordinarily supply the pipe 5,

and valve 61 will remain closed. As pre-vvv viously stated, the abrasive in pipe line 5,

which is not delivered to any of thegrinding' machines 1, 'returnsjfrom the outlet end of pipe 5 into the service-tank 52 from which it is again drawn through valve outlet 53 into the supply end of pipe line 5. Of course the supply of abrasive in the pipe line 5 and service-tank 52 will gradually be used up as this supply is drawn upon by the various grinding machines, and the supplymay be replenished as often as found necessary by drawing upon any .one or all of the reservoirs 34 to 36, as previously described.

In an exactly similar manner the intermediate grade of abrasive which iows through pipe line 6 and supply reservoir 56 is replenished from the abrasive stored in reservoirs 37, 38 and 39. If desired, finer abrasive may be drawn into this system from reservoirs 40, 41 or 42, by opening the normally closed valve 62 in pipe 60. In an exactly similar manner the finestI grade of abrasive in pipe line 7 and service-tank 58 is supplied from the abrasive stored in reservoirs 40, 4l and 42.

l An overflow pipe 63 (see Fig. 2) extends past all of the resevoirs and service-tanks with branches opening into the upper ends of each of these tanks. This pipe 63 discharges into the sump 4. In this way any excess of abrasive mixture in any of t-he service-tanks or reservoirs will liow back to the sump. To avoid confusing the drawings this pipe is not shown in Figs. l and 3.

At a convenient point in each of the pipe lines 5, 6 and 7, near its discharge end is located a cut-off valve 64, preferably of the gate type as shown in Figs. 7 and 8. The operating stem 65 of each valve has a pin 66 traveling in the cam slot 67 of a large rotary cam 68, keyed on a horizontal drive shaft 69. As shown in Fig. 8, the three cams may all be conveniently mounted on the Asame drive shaft 69, which is driven through suitable reduction gearing 70 from a motor7l. When v pin 66 is in the outerportion of the camslot 67 the valve is closed, but when the pin is in the inner portion of the cam the valve is open.

These gate valves 64 will be intermittently opened or closed by the mechanism just described. We will"describe the operation of the heavier abrasive in pipe line 5, although an exactly similar cycle of events 1s s1multaneously but independently taking place in each ot the pipe lines 6 and 7. `Since the pump 54 or 55 is constantly operating, a pressure is being putupon the abrasive mixture in the pipe line, tending to keep a continuous How through the pipe. When valve 64 is open this flow may proceed through the circuit and back to service-tank 52, although some of it may flow through such of the valves 8 as are open at this time. When valve 64 is closed, the flow through the pipe or conduit back to the service-tank 52 is cut off and the only outlet for the abrasive, now under considerable pressure from the pump, is through the open valves 8. In this way a positive ilow of abrasives through all of the Valves 8 then open is insured, and there will be sulicient force behind this flow to blow out any valve'that may tend to become plugged by an accumulation of abrasive. The intermittent low through the pipe line, during the intervals when the valve 64 is open, will serve to kee the abrasive in suspension in the pipe. uch abrasive as passes by the lvalve 64 during these intervals Hows back to service-tank 52 and is ready for a new 'ourney through the pipe line. As stated a ove, the same cycle of operations is independently taking place in each of the other pipe lines 6 and 7 It will be noticed that while a complete installation is disclosed for grading abrasive, feeding the selectedgrades of abrasiveto the grinding machine, and regarding the used abrasive, this system comprises two simultaneously operating, but independent, systems, i. e., a grading system for providing and maintaining a constant supply of various grades of abrasive, from which the abrasives to be used may be blended; and a separate feeding system for maintaining certain selected grades of abrasive in circulation past the several grinding machines.

In the grading system new abrasive or used abrasive may be independently or simultaneously delivered to either or both of two in- 'dependent series of grading tanks. Preferably, the grading process will be carried on alternately in these two series of tanks, theabrasive previously graded in one series of tanks being drained off into the storage reservoirs while the grading operation is being carried on simultaneously in bot-l1 series of tanks, or, if there is suiiicient abrasive on hand or it is desired to clean or repair the grading tanks, the grading operation may be entirely discontinued for a period without interfering with the continuous flow! of abrasive in the feeding system which is replenished from the storage reservoirs. The several grades of abrasive are stored and maintained in suspension ready for use in the series of storage reservoirs 34 to 42, and the three selected grades of abrasive for use in the machines may be varied and replenished as desired from these reservoirs.

A system quite similar to the above may be used in the polishing room to furnish one or more grades of rouge to each of the polishing machines. It is contemplated that such a system, with rouge used instead of abrasive, shall be within the scope of the following claims.

Claims:

1. In a system for supplying abrasive to a plurality of grinding machines, means for maintaining a circulation of the abrasive past the several machines, means at each machine permitting withdrawal of a portion of the abrasive when desired, a series of storage reservoirs for different grades of abrasive, means permitting selective replenishment of the circulating system from these reservoirs, and a series of grading tanks for supplying the reservoirs. f

2. In a system for supplying abrasive to a plurality of grinding machines, means for maintaining a circulation of the abrasive past the several machines, means at each machine permitting withdrawal of a. portion of the abrasive when desired, a series of ystorage reservoirs for different grades of abrasive, means permitting selective replenishment of the circulating system from these reservoirs, a series of grading tanks for supplying the reservoirs, and means for returning the used abrasive to the grading tanks.

3. In a system for supplying abrasive to a plurality of grinding machines, .means -for maintaining a circulation of the abrasive past the several machines, means at each machine permitting withdrawal of a portion of the abrasive when desired, a series of storage reservoirs for dii'erent grades of abrasive, means permitting selective replenishment of the circulating system from these reservoirs, a series of grading tanks for supplying the reservoirs, and means for feeding new abrasive to the grading tanks.

4. In a system for supplying abrasive to a plurality of grinding machines, a supply tank for the abrasive mixture, a conduit eX- tending in proximity to the several-machines, means for circulating abrasive from the supply tank through the conduit and returning the unused abrasive to the supply tank, means -at each machine permitting withdrawal of abrasive from the conduit as desired, a series of storage reservoirs for different grades of abrasive, means permitting selective replenishment of the circulating system from these reservoirs, and a. series of grading tanks for supplying the reservoirs.

5. In a system for supplying abrasive to a plurality of rinding machines, a supply tank for the a rasive mixture, a conduit extending in proximity to the several machines, means for circulating abrasive from the supply tank through the conduit and returning the unused abrasive to the supply tank, means -at each machine permitting withdrawal of abrasive from the conduit as desired, a series of storage reservoirs for different grades of abrasive, means permitting selective replenishment of the circulating system from these reservoirs, a series of grading tanks for supplying the reservoirs, and means for returning the used abrasive to the grading tanks.

6. In a system for supplying abrasive to a plurality. of grinding machines, a plurality of supply tanks for different abrasive mixtures, conduits extending from each tank past the several machines, and means for circulating the abrasive mixtures through the conduits and returning the unused abrasives to the respective supply tanks, means at each machine permitting withdrawal of abrasive as desired from any conduit, a series of storage reservoirs for different grades of abrasive, means permitting selective replenishment of the different grades of ciculating abrasive from certain of these reservoirs, and a series of grading tanks for supplying the reservoirs.

. 7. In a system for supplying abrasive to a the respective supply tanks, means at each machine permitting withdrawal of abrasive as desired from any conduit, a series ofstorage reservoirs for different grades of abrasive, means permitting selective replenishment of the different grades of circulating abrasive from certain of these reservoirs, a series of grading tanks for supplying the reservoirs, and means for returning the used abrasive to the grading tanks.

,8. In a system for supplying abrasives to grinding machines, means for grading the abrasives, means forseparately storing the graded abrasives in suspension in a liquid, means permitting selective combining of the various grades to obtain the desired grade for use, means for continuously, circulating this selected abrasive to and past the several machines, and means permitting selective delivery of portions of this circulating abrasive to any machine.

9. In a system for supplying abrasives to grinding machines, means for grading the abrasives, means for separately storing the graded abrasives in suspension in a liquid, means permitting selective combining of the various grades to obtain the desired gradeffor use, means for continuously circulating this selected abrasive to and past the several machines, means permitting selective delivery of portions of this circulating abrasive to any machine, and means for gradin the used abrasivev and returning it tov t e storage means.

10.v In an apparatus to supply abrasives to inding mechanism, a series of grading tan s through which abrasive in suspension flows, a series of storage reservoirs into which the graded abrasives deposited in the grading tanks'are withdrawn, means for feeding abrasive to the grinding machines, and means permitting selective drawing from certain of the storage tanks to supply the desired grade of abrasive to the feeding means.

11. In an apparatus to supply abrasives to grinding mechanism, a series of grading tanks through which abrasive in suspension flows, a series of storage reservoirs into which the graded abrasives deposited in the grading tanks are withdrawn, the reservoirs being divided into a plurality of groups, means for feeding abrasive from each group to the grinding machines, and means permitting selective drawing from any reservoirs in a` group to supply the desired grade to that feeding means. Y

12. An apparatus for supplying abrasive to sheet surfacing machines, comprising a supply tank, a conduit extending from the tank past the machines and discharging back mto the tank, means for forcing abrasive through the conduit, means for feeding abrasive from the conduit selectively to the` machines, a series f reservoirs for different grades of abrasive in suspension, means permitting replenishment of the abrasive circulating in the conduit and tank from the reservoirs, a series of grading tanks, means permitting discharging ofthe graded material from the grading tanks into the reservoirs, and means for conductin the used abrasive from the machines to t e grading tanks.

13. In an apparatus for supplying abrasives to grinding mechanisms, two series of grading tanks, means for alternately feeding abrasives in suspension to either series, a series of storage reservoirs into which the graded abrasives are withdrawn, a circulating system for feeding selected grades of abrasive to the grinding mechanisms,` and means permitting replenishment of the circulating system from the reservoirs.

14. In an apparatus for supplying abrasives to grinding mechanisms, two series of grading tanks, means for alternately feeding abrasives in suspension to either series, a series of storage reservoirs into which the graded abrasives are withdrawn, a circulating system for feeding selected grades of abrasive to the grinding mechanisms, means permitting replenishment of the circulating system from the reservoirs, and means for returning the abrasives used on the grinding machines to the grading-tanks.

i 15. An apparatus for supplying abrasive a series of grading tanks, means for discharg' yto a sheet-surfacing machine, comprising a supply tank and a conduit leading from the tank past the machine and back to the tank, means for permitting abrasive to be fed from the conduit to the machine, means for maintaining a continuous pressure l011 the abrasive in the conduit, a valve for intermittently closing communication. between the discharge end of the conduit and the tank, a. series of reservoirs for different grades of abrasive in suspension, and means permitting replenishment from the reservoirs the abrasive supply circulating in the tank and conduit.

' 16. An apparatus for supplying abrasive to a sheet-surfacing machine, comprising a supply tank and a conduit leading from the tank past the machine and back to the tank,

means for permitting abrasive to be fed from the conduit to the machine, means for maintaining a continuous pressure on the abrasive vin the conduit, a valve for intermittently closing communication between the discharge end of-the conduit and the tank, a serles 4of reservolrs for different grades of t abrasive 1n suspens1on, means permittlng replenishment from the reservoirs the abrasive supply circulating in the tank and conduit, a series of grading tanks and means for discharging graded abrasive from the grading tanks into the reservoirs.

17. An apparatus for supplying abrasive to a sheet-surfacing machine, comprising a supply tank and a conduit leading from the tank past the machine and back to the tank,

means for permitting abrasive to be fed from the conduit to the machine, means for maintaining a continuous pressure on the abrasive in the conduit, a valve for intermittently closing communication between the discharge end of the conduit and the tank, a series of reservoirs for different grades of abrasive in suspension, means permitting replenishing from the reservoirs the abrasive supply circulating in the tank and conduit,

ing graded abrasive from the grading tanks into the reservoirs, and means for conducting used abrasive from the machine to the grading tanks. Y

igned at Toledo, in the county of Lucas and State of 0hio, this 21st day of December, 1923.

JOSEPH P. CROWLEY.

Images