CA1225260A - Automatic toolchanger tapping lubricant dispenser - Google Patents

Abstract

ABSTRACT
AUTOMATIC TOOLCHANGER TAPPING LUBRICANT DISPENSER
A tapping lubricant dispenser apparatus is provided for use in numerically controlled automatic toolchanger machining systems to dispense tapping lubricant into a prev-iously drilled hole before tapping. The tapping lubricant is usually a viscous tapping compound of the consistency of paste, grease or the like. The apparatus includes a tool-holder of the type to fit into the machine spindle, a reser-voir for a supply of lubricant -- typically sufficient to run unattended for several complete cycles, e.g. at least one shift -- and a reciprocating pump means that dispenses the lubricant responsive to actuation by the numerical control system when the toolholder of this apparatus is fitted into the machine tool spindle. The reservoir reloads the pump after each dispensing action. The numerical control and toolchanger system is programmed to select the apparatus, put it in the spindle, align same with the hole to be tapped, and causes pump reciprocation and dispensing and then remove the apparatus from the spindle. Usually a drilling program is employed whereby the motion to advance the drill into a hole instead advances this apparatus thereby placing in the hole a body of lubricant.

Description

Lowe This Invention relates to an automatic tool changer tapping lubricant dispenser. One aspect of the invention relates to a dispensing means. An aspect of the invention relates to a dispensing means for dispensing lapping lubricant in a numerically controlled automatic tool changer system. An aspect of the invention relates to means for dispensing a viscous fluid, preferably in a metered or measured quantity.
Producing a tapped hole in a metal body requires the metal cutting operations of drilling followed by tapping.
Numerically controlled (NC) automatic tool changer tapping has evolved a problem of automatically providing a lubricant as part of the tapping operation in an unmanned operation desirably by placement of tapping lubricant in the hole before tapping as automatically and as reliably as other NC operations.
Failure to provide proper tapping lubricant leads to reduced tool life of the tap, increased danger of tap or tool breakage in the hole requiring an expensive manual operation to remove same, poor finish on the threads, quality loss US
the tap rapidly dulls, and related problems. One attempted solution to tapping lubrication, especially when cutting in steel, has been to direct cutting fluids at the vicinity of the tapping operation and hope enough jets into the hole along the flutes of the tap to achieve some l lubrication. In some

2; intoners, the NC program galls Son increased cutting fluid or coolant volumes during tapping. This is a best partially sa~isSactory because the fluid concerned is not delivered sufficiently within the hole where the tapping is going on.
Furthermore, the preferred lubricant for tapping steel has the consistency of grease or paste and heretofore has been used in tarring by manual placement within the hole prior to tapping.
Such substance may be a commercially available tarring lubricant such as What sold under the brand name Cl~ITAP and manufactured by Cincinnati Micron ]ndusLries, no or a su]ph~Jr based lubricant galled "eye umber 5" commercially available from Soulful Concentrate, worth Tenoned, eye or * trade mark 2 ii2~1~

1 The present invention provides a dispenser or Libra-actor that as part of a NC program automatically places a body of tapping lubricant of the desired kind within the hole prior to tapping, normally placing same between drilling and tapping operations. my so delivering this body of very viscous fluid within the hole, the fluid moves down the hole with the tap and lubricates in the immediate vicinity of the actual thread forming operation. The present invention includes a lubricator and a tool holder that is manipulated as one of the tools by the tool changer. Lubricating with the present invention is preferably done by repeating the drill instructions ox the NC
whereupon the tapping lubricant is delivered in measured quantity within a hole by pressing together the instant Libra-actor and the workups having a hole to be tapped and then repeating the same for each hole as required by the NC program.
When all the holes have been lubricated, the tool changer removes the present apparatus, replaces it with a tap, and proceeds to tap in accordance with the NC program.
The present invention provides an apparatus for applying tapping lubricant, useful and handled as a tool in a numerically controlled automatic tool changer system which comprises tool holder means combined with a reservoir of a size sufficient to store lubricant for many operations, e.g., a quantity for four hours or possibly even an entire eight hour shift, a dispensing means including a dispensing pump actuated by reciprocation of the apparatus relative to the workups, and means to transfer material into the pump means from the reservoir.
Other objects, advantages and features of the invention may be realized by the reader from this specification when read in conjunction with the annexed claims and drawings wherein:
Fig. 1 is a schematic perspective view in pertinent Hart of an apparatus according to the invention hying placed by a too changer arm into a rotating spindle in working relationship with a partly cutaway workups mounted on the machine tool pallet or worktable;

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l Figs. 2 and 3 are cross-sectional side views of an apparatus according to the invention with no lubricant in the reservoir and when fully charged with lubricant, respectively;
Fig, 4 is similar to Fig. 2 and 3 buy shows the parts as positioned when dispensing (e.g. check valves open);
Figs. 5, 6, and 7 are sections through the apparatus of Fix" 2 as seen on sections 5-5, 6-6 and 7-7, respectively;
Figs. 8 and 9 are side and end views of another embodiment of tip;
lo Fig. lo shows a representative tool holder with the dispenser of the instant invention in ghostliness and Fig. if is a thrust bearing detail along section if-if of Fig. 5.
Numerically controlled (NC) automatic tool changer machining systems are by this time well-known in the state-of-the-art. The following teach NC controlled automatic toolchan~er systems and are representative of this art; United States 3,990,585 "Article Exchange Mechanism', United States 3,803,704 IlMachine Tool", and United States 3,719,987 IlToolchange Apparatus".
Referring first to Fig. 1, there is shown in pertinent part the tool changer arm l in the position where it is in-sorting a lubricator apparatus 3 according to toe present invention in the machine tool spindle 4 (or renlovir) same from the spindle, as the case may be) in ju.~:tal>osition with the workups 5 having a plurality of holes I, some on each side, which haze been drilled and are now to be aped. the York-piece 3 is, of course, mounted by conventional means Trots clamps, etc.) on the worktable 8 or on a pellet 9 associated with the worktable of the machine tool 7. Toe machine tool spindle 4 may at this time be still, i.e., not rotating, or it may be or remain rotating from the previous cycle. In the preferred embodiment, the machine tool spindle 4 is still rotating (called a live spindle) because rotational power it still applied thereto and once the instant disrencing apparatus 3 is secure in the spindle, the NC stem moves the dispenser and warps relative to each other, finally pressing them ~2~6~
1 together and causing a body lo of lubricant 10 (see Fig. 4) to be dispensed into the hole 6 to be tapped. Dispenser 3 and workups S are then moved apart. The operation may then be repeated on other holes. Then the tool changer arm 1 removes the instant tapping lubricator 3 replacing it with a tap and the tapping operation it commenced. The instant lubricator as well as other tools (drill, tap, end mill) are drawn from and returned to a tool store or tool matrix (not shown).
The dispensing apparatus 3 includes as seen in Figs.
1-4, 10 a tool holder 113 an elongated housing assembly 12 secured to said tool holder and defining a reservoir 14 at the end adjacent the tool holder; a pump chamber 15; and a pump plunger assembly 16 and its outermost dispensing end tip assembly 17 extending out of the housing 12 at the end 18 of the apparatus remote or opposite from the tool holder. The tool holder 11 illustrated is preferably one of the well-known (see Anal specification 5.10 "Machine Tapers" and B-5.18 "Spindle Noses and Tool Shanks...") kinds having a tapered or frusto-conical spindle-engaging surface with the drubber stud and clamping groove at the distal end for locking into the spindle, a pair of spaced-apart flanges with (usually) face keys (not illustrated) and locating surfaces thereon. Other toolho]der structures for NC are embraced within the present invention, e.g. cylindrical spindle surface. The tooled the tool holder has recess 35 to receive the mounting shank. A set screw oh is provided to foot; the two together. The tool holder construction shown is a conventional construction of the kind used to hold an end mill cutting tool or the like.
The housing assembly preferably comprises a body 38 I of a one-piece aluminum casting Lotte contains the reservoir 14 and pump chamber 15 and which is sealed at toolho]der end by a cap 40 from which the mounting shank 42 extends into the Tudor recess 35. The cap 40 is secured in place to the tlt)using b) a purity of bolts 43 pre~trabl) of the alien head type and has a stepped pull thaw provides a scaling circuit 44 that engages tile inner Hall of the reservoir end a spring boss 45. the housing howdy interior defining the 2~2~i~
l reservoir 14 is a hollow circular and cylindrical member that ends at a partition 48 which separates it frorc the pump chamber 15 on the opposite end of the housing. Within the reservoir is a reload biasing means, preferably a helical mainspring 50 with closed ground flat ends, one of which is located by being positioned around the spring boss 45 and the other end of which engages the backside of a reloading piston 52 which likewise has a piston spring boss on its back face. The reloading piston 52, of course, is a cylindrical member having lo a sliding fit within the reservoir and serves the function of pushing tapping lubricant lo from the reservoir into the pup chamber 15.
Tapping lubricant 10 is pumped into the reservoir through the ordinary grease fitting 55 of the kind made the Zonk Company and commonly found on automobiles and other such places. The grease fitting 55 is secured in one end of a filling passage 56 formed in the housing in the region rimmed-lately adjacent the partition 48. There may be more than one grease or filling fittings provided.
The partition 48 has formed therein an exit passage 60 in which is situated a first check valve means 62 to prevent flow from the pump chamber back in the reservoir but to permit flow upon a pressure rise Iron the reservoir into the pump chamber. Preferably exit passage 60 is formed to have at least diameter 63 in the end communicating with the reservoir, a tapered seat 64 to cooperate with the ball check, and a threaded end 65 adjacent the pump chamber. Check means 62 is a sprint 66 and ball 67 are positioned within exit passage 60 and retained there by a plug 63 screwed into place and through which a passage is likewise bored. A hexagonal recess 69 or receiving an alien wrench or the like is pro-tenably provided in the pug so that a flush surface 70 is provided at the end of the pump chamber.
The pump chamber 15 is a much smeller recess formed in the housing and contains a pump bias means comprising helical pump spring 73 with ground iota ends and a spider 74 to support one end of the pump spring, a pump plunger 16 6 .52~i~

1 consisting of a hollow tube 75 combined with a piston or support flange 77, and a thrust beaning assembly 79 in the form of a steel ball (also numbered 79) to support the pump plunger against the spider. The pump chamber it closed by a pump closure cap 80 with an opening or bearing 81 in which the pump plunger tube is revolvable supported. The pump plunger 16 can also reciprocate relative to the cap and along the axis 83 (Fig. 3,10) of the dispensing assembly. The cap I is held in place by a plurality of bolts 84 extending into the housing wall through the outermost flange of the cap. The chamber side of cap 80 contains a pilot shoulder I and a sealing surface 87. The housing walls are suitably contoured to receive both the pump cap and the reservoir cap.
The spider 74 (Fig. 6) is a disc with holes 88 and a central hole that provides thrust bearing 79 and pump spring 73 support. As shown, it to a flanged disc having a pump spring locating boss 89 on one side and a centrally located thrust bearing recess 90 (Fig. 11) on the other. The thrust bearing recess conveniently comprises a hole drilled through the spider and countersunk to provide tapered shoulders to receive the ball.
The pump plunger comprises 16 (Figs. 6,11) Hoyle tube 75 with a longitudinal passage 92, the innermost end 93 of which is Lucy countersunk to provide thrust bearing shoulders immediately adjacent the thrust bearing a plurality of holes 94 are drilled through the assay of this tube into the central longitudinal passage 92 so that risque can flow into the passage 92 and out through the tip 17 as described elsewhere herein. Secured to a central portion of the pump I plunger 16 is the piston 77. Preferably, it is machined in one piece with the tubular body of the punier, but it could be made of a separate member and secured to tube 75. The outboard end of piston 77 is ground or otherwise ~ell-finished on the periphery US of Its outboard face to prude a Good Sweeney surface in cooperation high the opposite situate elan face 87 on the pump closure cap.

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l Pump chamber 15 has a relief passage 99 fitted with a relief valve 10 at its mid-portion to eliminate lubricant in event of a malfunction.
The dispensing tip 17 preferably comprises a machined nylon member of generally cylindrical shape having a dispensing passage 102 figs. 3-6) there through and a second check valve 104 located in said passage to permit flow out through the tip from within the pump chamber. Check valve 104 is preferably a spring and ball check located in an enlarged portion of the passage and sealing against the end of the pump plunger 2. As illustrated, the tip 17 is threadedly secured to the pump plunger with passage 102 aligned with plunger passage 92 and the check 104 retained by the plunger end in passage 102.
The outboard end of the dispensing tip may be of various shapes. Preferably, it has an outwardly converging 7 (Fig. 2) slight taper. Also, the outboard end contains grooves 108 extending from the dispensing passage exit opening 109 to the outer surface of the tip. This provides a relief passage so excess lubricant can escape when the volume of the lubricant exceeds the volume of the hole, e.g., when a blind hole is being serviced.
Another shape of tip 17 is shown in Figs. 8 and 9 and have generally the same mechanical features. The end of the tip is hemispherical and may not have a relief groove but preferably does. The tip does not have to enter the hole --it merely has to contact the surface outside of the hole (eye.
Fix. if).
A description of the operation follows: The instant apparatus 3 is filed in a tool store or matrix in a numerically controlled automatic tool changer equipped machine tool. One or more holes 6 is/are to be drilled and then tapped. Servicing of only one hole will be described.
The reservoir 14 of the lubricator 3 is first tilled completely with Lapsing lubricant I throllgh the grease tilting 55 and phony passage 56 to the point where the reservoir sprint So is substantially compressed and the piston 52 is driven to the left as seen in Fig. 3. Moreover the filling 8 ~2~526~

l pressure and/or spring 50 bias also urges the first check valve 62 open and fills the pump chamber 15 with lubricant 10 in the volume between check valve 62 and the pump piston 77.
Pump spring 73 urges pump piston 77 against the pump cap.
Compression of the respective check valve springs, especially that in the tip, has been adjusted so that at this time the tip check valve assembly 104 is in the Figs. 2, 3 position --not opened under the pressure of filling from the reservoir.
The hole 6 is first drilled whereupon the NC tool-lo changer removes the drilling tool from the machine tool and replaces it as shown in Fig. 1 with the tapping lubricant dispenser 3 of the present invention. The NC system then brings together the workups 5 containing the hole 6 and the tapping lubricator 3: relative motion is indicated by the arrows 110 (Fig. 1 only). As noted, a drill program can be used for this inasmuch as the workups and tool have to be advanced toward each other with the axes of hole 6 and Libra-actor preferably coincident. When the tip 17 engages the outer surface of the workups adjacent hole 6 -- for instance as in Fig. 4,11 -- a very high pressure is built up in the pump chamber 15 because the pump piston 77 and the inner end of the plunger displace volume and push on the body of viscous lubricant 10 therein to shut first check valve 62 in the partition US and with the continued moven7ent of the piston into the pump chamber the pressure continues to build until the tip check valve 104 is forced open and body of lubricant lo is ejected into the hole 6.
It is preferred to let the machine tool spindle 4 continue to rotate during use ox this ]uhricator. thus! the entire lubricator is rotating during the aforesaid proceedings.
However, the lubricator tip 17 ceases to rotate when it engages the workups but the rest of the lubricator 3 continues to rotate. use, there is relative rotation between the lubricator housing, etc. arid the pull wronger and tip. thus, the pump closllre cap 80 must provide bearing support to the pump punier for both rotation and sliding operation. Simi]zrl~, as to the en~agenlent between the pump piston and the inner 9 ~225~
1 surfaces 114 of the pump chamber. So Allah some rotational as well as thrust support must be expressed by the pump thrust bearing. The tapping lubricant serves to lubricate the various bearings.
After the lubricant lo has been ejected, the work-piece and lubricator are separated in response to the NC
control program. This causes the tip check valve 104 to slam shut, thus preventing dribbling and unnecessary loss of Libra-cant. Rotation between the pump plunger and the remainder of the housing and pump stops in response to this separation --even though, as noted above, the spindle 4 may be continuing to rotate the entire lubricator 3. Further, at this time the reservoir spring 50 responds to the loss of lubricant from the pump chamber by expanding to push reloading piston 52, opening the first check valve 62 in the partition, and forcing lubricant 10 through the refilling passage into the pump chamber until the pump piston assumes its full position against the closure cap shoulder.
Although longer strokes and smaller quantity lo are preferred, strokes of the plunger as short as 0.090 inches have been used. Reservoir capacity of 44 cubic inches has provided tapping compound sufficient for two shifts of unmanned operation without a refill but the unmanned running time is extremely variable and unpredictable overall being dependent on number and size of holes.
At this point, the NC program can order a repeat of the above events to place lubricant in one or more additional holes or, alternatively, it can rewove the lubricator to a tool store, replacing it with a tap and then proceed with a tapping operation.

Claims (11)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY OR
PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. An apparatus for applying tapping lubricant into a hole to be tapped by using a numerically controlled automatic toolchanger system to remove such apparatus from a tool store, insert it in a revolvable spindle, manipulate it to dispense tapping lubricant, and then return the apparatus to the tool store wherein the apparatus comprises:
toolholder means at one end of said apparatus for connection with such revolvable spindle in a machine tool;
pump plunger means at the other end of said apparatus with a dispensing end outermost;
an elongated housing extending between said toolholder and plunger that has walls defining therewithin a reservoir adjacent said toolholder means, a pump chamber adjacent said other end, and an exit passage between said reservoir and said pump chamber;
first valve means responsive to pressure increase in said pump chamber to close said exit passage;
reload biasing means for urging material out of said reservoir past said valve means through said exit passage and into said pump chamber;
said pump plunger means extending into said pump chamber through said housing from said dispensing end supported for rotation and reciprocation relative to said housing and having a length sufficient to permit reciprocation relative to said chamber while maintaining outside of said housing a portion of such length that includes said dispensing end at said other end;
that end of said pump plunger means within said pump chamber forming a pump piston to reciprocate with said plunger within said pump chamber;
a pump conduit within said plunger establishing communication between said dispensing end and said chamber upstream of said piston;
plunger bias means for urging said pump plunger away from said toolholder; and second valve means disposed in said pump conduit, normally closed but openable in response to fluid pressure increase within said chamber.

2. An apparatus according to claim 1 further comprising a thrust bearing means within said chamber that includes said plunger biasing means for receiving thrust loads from said plunger.

3. An apparatus according to claim 2 wherein said thrust bearing means includes a perforate piston slidable in said chamber and disposed between said plunger biasing means and said plunger and for receiving rotary loads from said plunger.

4. An apparatus according to claim 1 further comprising a filling passage through said housing wall at that end of said reservoir adjacent said exist passage.

5. An apparatus for applying tapping lubricant into a hole to be tapped by using a numerically controlled automatic toolchanger system to remove such apparatus from a too]. store, insert it in a revolvable spindle, manipulate it to dispense tapping lubricant, and then return the apparatus to the tool store wherein the apparatus comprises:
toolholder means at one end of said apparatus for connecting with a toolholder which is insertable in the revolvable spindle of a machine tool;
elongated housing assembly secured to said toolholder and defining therewithin a reservoir adjacent said toolholder and a pump chamber at that end of the housing most remote from said toolholder and having a partition separating said pump chamber from said reservoir;
a reload passage through said partition connecting said reservoir to said pump chamber;
first check valve means disposed within said reload passage to prevent flow from said pump chamber into said reservoir;
a pump plunger means extending out of said pump chamber through said housing assembly;
a pump piston mounted on said pump plunger means within said pump chamber and engaging slidably the walls of said pump chamber;
a thrust bearing means engageable with the end of said pump plunger means disposed within said chamber that moves with said plunger means;
a dispensing tip secured on the outermost portion of said pump plunger means and outside of said chamber;
said pump plunger means having therewithin an exit passage communicating within said pump plunger means on the upstream side of said piston to the exit passage in said tip.

6. An apparatus according to claim 5 further comprising a check valve means disposed in one of said pump plunger exit passage or tip exit passage for normally opposing flow from within said pump chamber out through said tip.

7. Apparatus according to claim 5 further comprising as part of said thrust bearing a perforate piston disposed within said pump chamber adjacent one end of said pump plunger.

8. Apparatus according to claim 5 further comprising a perforate piston disposed within said pump chamber adjacent one end of said pump plunger, said thrust bearing connected between said pump plunger and said perforate piston, and means biasing said perforate piston and thrust bearing against said pump plunger means.

9. Apparatus according to claim 5 further comprising said thrust bearing means being disposed in said pump chamber to support said pump plunger for rotation and reciprocation relative to said pump chamber.

10. Apparatus according to claim 5 further comprising a dispensing tip at the end of said pump plunger means having radial grooves extending to its periphery from its exit passage.

11. Apparatus according to claim 1 further comprising a dispensing tip at the end of said pump plunger means having radial grooves extending to its periphery from its exit passage.

It