Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
Lowe
1 AUTOMATIC TOOL CHANGER TAPPING LUBRICANT DISPENSER
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;
3 ~.225i~
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.
7 5~6~
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.
