US2762244A - Fluid feed devices for drill presses and other power tools - Google Patents

Description

S. D. REED Sept. 11, 1956 FLUID FEED DEVICES FOR DRILL PRESSES AND OTHER POWER TOOLS Filed Dec. 16, 1955 INVENTOR. SPENCER D. REED HIIHIHIH lHll HIIIII HI OI IHI M ATTORNEY Unite States FLUlD FEED DEVICES FOR DRILL PRES'SES OTHER PGWER T0615 Spencer D. Reed, Endicott, N. Y.

Application December 16, 1953, Serial N 398,555

6 Claims. (Cl. 7733.5)

This invention relates to fluid feed devices for drill presses and other power tools; and, more particularly, to improved means for pneumatically applying, to poweroperated cutting tools a resilient feed urge, and for establishing limits of extents of travel of such tools.

It is an important object of this invention to provide a device having arrangement and formation of parts such that the device may conveniently and expeditiously be assembled in operative relation to, and removed from, intended power tools.

It is another object to provide such a device having parts whereby it may readily be assembled with one or another of diverse types, forms or sizes of such tools.

It is a further object to provide, in such a device, structure suited for eflicient embodiment in a size suited for use on adjacent spindles of gang drills of types providing clearance between spindles insutficient to permit use of devices for similar purposes which have heretofore been available.

Certain devices heretofore available have utilized compressed air or other fluid for feeding power-operated cutting tools, together with dashpots containing liquids for controlling the speed of such feeding; but such prior devices have been of forms which have necessitated the use of features such as packings, stuffing boxes and glands for minimizing leakage around pistons in cylinders and/ or around relatively movable stems or rods.

The utilization of such features has involved frictional losses Which have objectionably added to the power required for feed actuation; and, still more objectionable, has tended to cause occasional extensive irregularities in operation, when there have been adhesions between such packings and relatively moving metallic surfaces, thereby causing what is termed jumpy action, after the impelling force has been sufficiently built up to efiect disengagements from such adhesions.

It is therefore, a still further object to provide, in such a device, structures and arrangements of a character which renders unnecessary the use of glands, stufiing boxes, packings and other features found objectionable in such prior devices.

A still further object is to provide a feeding device for power-operated tools comprising parts for effecting operation thereof by the use of a relatively compressible fluid (such as compressed air) and for governing rates and extents of such operation through use of dashpot structure containing a liquid (such as a suitable oil), all of which parts are so relatively formed and associated that both escape of operating fluid and loss of dashpot liquid will be avoided, Without reliance upon tightness of .joints between parts which are relatively movable incident to use of the device.

It is another object to avoid occasion for use of air filters and lubricators, suchas are found needful during long extended operation of piston and cylinder type of feeding devices, as by using an inflatable annular tube which is comparatively inexpensive and may readily be installed or replaced.

p, 2,762,244 g Patented Sept. 11, 1956 It is another important object of this invention to simplify the construction of such devices and to provide a device which can be more economically and conveniently manufactured, used and repairedthan devices for like purposes heretofore devised, and to provide a very rugged structure.

Other and more specific objects and advantages Will appear in the ensuing description or will be apparent therefrom to those skilled in this art.

In constructing this invention, in accordance with a broad aspect thereof, a collapsible chamber is provided having relatively movable opposing walls, together with parts for attaching one of such walls to a relatively stationary part, such as the frame of a drill press, and for attaching the other of said walls to a movable part, such as the quill of a drill press.

An inflatable member, such as a bag, tube or bellows, is placed between the opposing walls of said chamber, and provision is made for connecting the interiorof said member to a suitable valve for alternatively applying fluid pressure to and for exhausting such pressure therefrom.

For a better understanding of this invention and of its more detailed features, illustrative embodiments thereof are shown in the accompanying drawing, in which Figure l is a side elevational view, partly in section and with some parts broken away, of a device embodying this invention, as applied to a drill press of a conventional well known construction;

Figs. 2 and 3 are fragmentary views of alternative formations of certain of the parts shown in Fig. 1, whereby to maintain peripheral enclosure of the expandable cham her during extensive vertical distensions thereof;

Fig. 4 is an enlarged sectional view of a fragment of the piston of Fig. 1, showing one of the valves which facilitate transfer of liquid from the upper to the lower side thereof; and

Fig. 5 is a top plan view of the upper or bell-shaped disk of the collapsible chamber of Fig. 1 together with certain of the parts carried thereby.

Referring now particularlyto Fig. 1, an embodiment of this invention is here shown as applied to a generally conventional form of vertical drill press, having a frame including the arm 21, a quill 22 longitudinally movable in said arm, and a splined spindle 23 revoluble within and moving lengthwise with said quill; together with a conventional drill chuck 24 carried by the lower end of said spindle.

The bell-shaped disk 25 is firmly attached to the lower part of the tubular portion 26 of the arm 21, as by the adapter attachment 27; and the disk 28 is likewise attached to the lower end of the quill 22, as by the attachment 29.

From the foregoing, it will be apparent that the disks 25 and 28 provide the upper and lower walls of a collapsible chamber. Between said Walls there is provided a vertically inflatable member 30, here shown as an annular bellows, but which may be in the form of a bag or tube which may constitute less than a complete ring. Such member may be of soft rubber or other suitable material, and should be of a form and character of material such as to be capable of an extent of axial expansion sufficient to provide for a suitable intended maximum drill travel.

A threaded fitting 31 makes provision for establishing a flexible conduit channel between the interior of said member 30 and a valve or other structure for exhausting the pressure fluid from said member and for admitting such fluid into said member from a suitable source of pressure.

In as much as a device having parts constructed in accordance with this invention provides littIe if any op- '7 of said cylinder. 7

portunity for appreciable escape of the pressure fluid, the

7 control of the member 30 may be accomplished by a foottreadle or by hand or electrically operated structure having a chamber subject to actuation for eflecting both collapse and expansion thereof; so that, when the fluid in such chamber is compressed, the member 30 will be expanded,

and when such chamber is contracted, a partial vacuum will be established so as to eflect quick withdrawal of fluid from the member 30.

A downwardly extending peripheral flange 32 is carried'by the disk 25, Within which flange the disk 28 freely moves. The height of this flange is such that, during intended longitudinal travel of theyquill 22, the disk 28 will not pass below the lower edge of this flange. The purpose of this flange is to prevent excessive peripheral-wise expansion of the member 30. It will be understood that may be supplemented by use of an upwardly extending flange carried by the disk 28, such as the flange 33 shown 'in Fig. 2. If the use of such a flange 33 would fail to 7 provide for desired drill travel, a corresponding flange 33', as shown in Fig. 3, may be further supplemented by one or more telescopic sections 34.

The disk 25 has a central opening 35 therethrough, (best shown'in Fig. the diameter of which opening should not only be suflicient to permit the quill 22 to freely pass therethrough, but should also be large enough to pass the chuck 24, inorder to enable the device to be applied to and removed from desired drill presses without. occasion for removing chucks. A like opening 35' is provided in the disk 28.

Rate-of-feed governing structure, generally indicated by the number 41, interconnects the disks 25 and 28 for I at times adjustably retarding relative movements therebetween.

Said structure provides a cylinder 42 lengthwise of which the piston 43 freely moves.

A rod 47 has the lower end thereof fixed in the piston 43, and said rod is of length such that, after passing through the cylinder cap 48, it may extend upwardly therefrom a distance suficient to provide for adjustments of piston travel suitable for desired drilling operations, as hereinafter more fully explained. Suitable means is provided for holding said cylinder cap in place; as, for example, screws 48, 48' (Fig. 5) which pass through ears forming part of said cap and extend into the walls A channel 44 is provided in said structure from the lower end to the upper portion of said cylinder 42.

A needle-valve is provided for regulating the flow of I liquid from said ,channel44 into the cylinder 42.

This valve comprises a rod 45 having a portion near 7 one end thereof passing through and in threaded engageend of said valve rod, which valve is aligned with the valve seat 46 provided in an opening in the substantially opposite'cylinder wall, which opening communicates with J the upper portion of the channel 44. e

. The formation of the portion of said opening situated between said seat and the interior surface of said cylinder 7 is such that liquid may .freely flowaround the body of said valve'rod during discharge thereof into. said cylinder;

and such that in so doing, such liquid will be caused to move ina substantially horizontal path, so as not to impinge against the lower. surface of the cap 48.

A post 49 is attached to the upper surface of the disk 28 and extends therefrom through the disk-25, and thence upwardly adjacent and parallel with the piston rod 47.

A fixture 50 is mounted upon the post 49 for moving longitudinally thereon and carries a set screw 51 for retaining it in desired settings along the length of said post;

An eye 52, forms part of said fixture 50 and encloses the piston rod 47, permittingsaid rod to freely move therethrough. a j c Rings 53 and 53 are situated on the piston rod 47, respectively above and below the eye 52; and, preferably, said rings are in threaded enegagement with said rod. These rings carry set screws for maintaining settings thereof upon said rod.

One or more valves are provided in the piston 43 for permitting fluid to freely pass from the upper to the lower side thereof. Each such valve involves an opening 54 having a restricted diameter upper portion 55 and containing a ball 56 and a spring 57 urging said ball toward said restricted diameter portion. An arrangement of ballvalve parts, such as just described, is shown on an enlarged scale in Fig. 4.

Liquid 58 (such as a suitable oil) is provided within the cylinder 42. The amount of such liquid should be such as to fill said cylinder to a height at least as great as the maximum travel of drills during cutting action, for reasons which will be hereinafter more fully explained.

The adapter attachment 27 consists of a substantially U-shaped piece having the arms 61 and 62 (best shown in Fig. 5) and an interconnecting portion 63. A slot 64 in said portion 63 is provided in order to facilitate'a needful extent of relative movement between said arms( The distance between said arms 61 and 62 should be such that the tubular portion 26 of the arm 21 of an intended drill press may be snuggly received therebetween; and a bolt 65 passes freely through said arm 61.. near the free end thereof and threadedly enegages said arm 62, so that said arms may be drawn together by tightening said bolt, to thereby firmly secure said attachment to the tubular portion 26 of an intended drill press.

Threaded studs 66, 66 are secured to the disk 25, and extend through openings provided therefor in the attachment 27; in which attachment they are firmly secured by the nuts 67, 67. a

For use with drill presses which do not have a tubular portion 26 which extends below the horizontal part of the arm 21, use of the bolt 65 and of the slot 64 may be dispensed with, and the attachment may be otherwise secured to such arm, as by the use of set screws such as the screw 65 shown in Fig. 1, which screws pass through threaded holes in respective ones of the arms 61 and 62. Or, as an alternative, the distance between the arms 61 and 62 may be reduced so as to be only sufficient to permit the quill 22 to freely pass therebetween, and the attachment then secured to the lower face of the arm 21, as by the use of machine screws or bolts passing through the attachment into tappedholes provided therefor in the lower surface of said arm 21. 7

Other suitable methods of attaching the disk 25 to the frame of a drill press will readily suggest themselves to those skilled in this art, although the improved methods just described will be found most eflicient and desirable in most instances.

It will also be understood by thosejskilled in the art that extra attachments (such as the attachments 27 and 29) may be provided for any device constructed'in accordance withthis invention, to thereby facilitate the association of such device with one or another of several drill presses having parts of diverse dimensions and forms.

Itis assumed that drill presses to which. this invention is applied are equipped'with the usual means for urging the quills 22 of such presses upwardly, such. as a suitable. spring; and that such urge is of suflicientforce to cause the disk 28 to act upon the member 30 to force air or other fluid therefrom when a path of escape therefor is provided through the fitting 31.

Should it be desired to limit the extent of upward movement of the disk 28 (and hence of the quill 22) a threaded lug 68 may be provided, carrying a screw 69 situated above the post 49. Said lug may be attached to the frame of the drill press in a manner analogous to that provided for securing the attachment 27 thereto, or said lug may be carried by said attachment 27.

When it is desired to assemble a device constructed in accordance with this invention upon a given drill press, attachments, such as 27 and 29, should be utilized, which 'have been suitably prepared for respective attachment to the arm and quill of such drill press, in a manner such as hereinbefore explained. The suitable one of said attachments should then be firmly secured to the lower part of the portion of the frame of such drill press adjacent the point of emergence therefrom of the quill 22. The assembled disks 25 and 28, with the member 30 therebetween, should then be applied over the chuck 24, and the studs 66, 66 passed through openings provided therefor in the attachment 27. The nuts 67, 67 should then be tightly fastened to said studs.

The disk 28 should then be pressed upwardly as far as it will go, while the quill 22 is at a height not less than such that an intended drill in the chuck 24 would be so positioned as to facilitate placement and withdrawal of work pieces. The attachment 29 should then be secured to said quill.

The piston rod 47 should next be moved downwardly so as to bring the piston 43 near or at the lower end of its stroke, the ring 53" positioned on said rod against the cap 48, and the screw in said ring tightened to maintain the setting.

While said piston rod and said ring 53" are positioned as just described, the screw 51 should be loosened, the quill and chuck moved downwardly to the end of the desired cutting stroke, and the fixture 50 moved downwardly on the post 49 so that the eye 52 will rest upon the ring 53". The screw 51 should then be tightened to retain this setting.

The quill should next be raised, so as to bring an intended drill to a level facilitating placement and withdrawal of work pieces, and the ring 53' should then be moved into engagement with the upper surface of the eye 52. The screw in said ring should then be tightened to retain this setting.

The quill should next be lowered so as to bring the point of an intended drill to the level where cutting should commence, the piston rod 47 then raised so as to bring the ring 53 against the eye 52, and while the piston rod is held in that position, the quill should be further raised to a level facilitating placement and withdrawal of work pieces, the ring 53' positioned against the upper surface of the eye 52, and this setting retained by tightening the screw in said ring.

The screw 69 (if used) may then be adjusted to prevent further upward movement of the post 49.

Attachment may then be made to the threaded fitting 31 of a flexible conduit providing a channel to a valve or other means for effecting withdrawal of pressure fluid from and for the admission of such fluid into the member.

The valve rod 45 may now be turned, in one direction or the other, for obtaining a desired rate of cutting feed for such drill as is to be carried by the chuck 24.

With adjustments and setting of parts just described, it is evident that, when fluid pressure is applied through the fitting 31, rapid downward movement will be imparted to the chuck 24 and the post 49 until the eye 52 reaches the ring 53", whereupon further downward movement of said chuck will be at the speed established by the setting of the valve rod 45. When the drill has cut for the intended depth, the ring 53" will encounter the cylinder cap 48; thereby terminating downward movement of parts 6 moving with said ring, inclusive of the eye 52 and the chuck 24.

Thereafter, when the fluid is permitted to escape from or is sucked out of said member 30, through the fitting 31, the chuck 24 will be moved rapidly upward until said member 30 is fully collapsed or until the post 49 encounters the screw 69; and the liquid 58 which had accumulated on the upper side of the piston 43 will meanwhile force the balls 56 downwardly in the openings 54 provided therefor and be transferred to the lower side of said piston.

When drilling considerable distances in certain materials it is desirable to occasionally withdraw the drill, in order to clear it of chips and shavings. This can be readily accomplished in the use of the device herein described by alternatively decreasing and then restoring the pressure of the fluid within the member 30. When this is done, the drill will be withdrawn as desired from the work, and cutting may be quickly resumed by reapplying pressure fluid into the member 30. However, inasmuch as some of the fluid in the cylinder 42 will have been transferred to the lower side of the piston 43, during withdrawal of the drill, both through the channel 44 and, more particularly, through the openings 54 in said piston, the speed of the downward return movement of the drill will be reduced just before it again reaches cutting level. This is of distinct advantage when using a comparatively small drill, especially if the quill and parts moving therewith are of such mass as might otherwise reapply the drill with an objectionable force, so great as to frequently cause breakage of drills.

When grinding holes through glass, it is often desirable to vary the pressure on the drilling tool quite rapidly, but it is likewise important that, should the tool be lifted an appreciable distance above the glass, it shall not thereafter be brought against the glass at a speed so great that the momentum of parts would be likely to cause breakage of the glass. Such undulation of cutting pressure may be readily obtained in the use of this device, particularly, if a treadle or other device is employed which tends to establish somewhat of a vacuum whenever the fluid pressure in the member 30 has been reduced below the atmospheric level.

Other procedures for utilization of this invention will readily suggest themselves to persons skilled in this art.

It should be understood that many matters of arrangement and design or form of parts may be modified without departing from this invention, the specific embodiment shown in the accompanying drawing and hereinbefore described having been selected for the purpose of making clear the nature and the objects of this invention; and it is the purpose to claim all novelty inherent to this invention as broadly as is permissible in view of the prior art.

What is claimed is:

l. A feed device for the holder of a power-operated cutting tool, which holder is carried by a spindle journaled in a quill supported by a relatively stationary frame for longitudinal movement with reference thereto and involving means for urging such movement in one direction, a part suited for readily detachable connection to said frame, another part suited for readily detachable connection to said quill independently of the connection of said first named part, said parts having opposing faces convergently and divergently movable incident to aforesaid quill movement whereby to provide walls of a collapsible chamber, the functional relationship of said walls to other parts being such that divergent relative movement of said walls will effect longitudinal movement of said quill with reference to said frame in the direction opposing its aforesaid urge, an inflatable member situated between said faces, said member of substantially annular form and its substance so distributed with reference to said spindle, quill and faces that inflation of said member will cause application of urge for divergent relative movement of 7 such faces in a manner such that said urge will be distributed with substantial uniformity on respective sides of said spindle and quill, and means for establishing a connection between the interior of said member and structure for governing inflation and deflation of said member.

2. A device as claimed in claim 1, in which there is pro- ,vided means for alternatively establishing various speeds of diverging chamber wall movements, said means com- 4. A device as claimed in claim 1, in which there is provided means for effecting retardation of divergent chamberwall-movements, said last named means comprising parts situated so that they are constantly accessible for efiecting manual revisions of adjustments without occasion for dismantling any of the other parts of the device, whereby to establish desired ones of diverse extents of such retardation and for determining portions which are less than all of such movements in which such retardation will be effective.

5. A device as claimed in claim 1, inwhich' the associating means comprises substantially U-shaped attachments, the arms of one of said'attachments being spaced for receiving therebetween a suitableportion of the frame and the .arms of the other of said attachments suitably spaced for receiving the quill therebetwcen, and means for securing said attachments to said frame portion and to said quill, respectively. V a a I p 6.' A device as claimed in claim 1, in which thereis provided means for efiecting any one of various degrees of retardations of the aforesaid divergent movements, said means comprising parts for adjustably rendering greater or less portions of divergent wall movements subject to retardation, manually adjustable parts of said means situated so that they are constantly accessible for manual revision of conditionings without occasion for dismantling any of the other parts of the device.

References Cited in the file of this patent' UNITED STATES PATENTS

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