Note: Descriptions are shown in the official language in which they were submitted.
~x~
ITE~ LOCATOR. ~IXTUR~, AND ~ORK ~ET~OD
B~CKGRoUND OF T~E INVE~TION - FIELD OF APPLICATION
This application relates to work facilitators; and more
particularly, to item locators, fixtures and work methods.
BAC~GROU~D OF THE INVE~TION - DESCRIPTION OF THE PRIOR ART
Quite often when work must be accomplished for, on, or with
respect to an item it is important to position or locate the
item in a particular manner.
me item may be a part, sub-assembly, assembly or the like;
10 and the work to be accomplished upon the ltem may involve
r~lachining or other metal working or treatment; assembly, dis-
assembly, or some form of inspection, servicing, or other
operation re~uired by or for the item. In many instances it is
il~portant to locate the item with some degree of accuracy, rom
1~ a re~erence point or points, so that the work on the item may
be done at a specific location on the item. This is especially
the situation wl~en the item is progressing automatically from
work station to work station, and the work is being partially
or fully accomplished by automated tools, machinery, e~uipment,
or robots or the like. It is also important in many instances
to securely locate the item to be worked on so that the item
~aintains its position when the work is accomplished, whether
it be by-machine or a person~
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It is often desirable to per~orm assembly or other
operations on an item of equipment when the item is disposed on
a pallet or sub-base which facilitates moving the item along ~
conveyor line from worX station to work station where successive
S assembly or o~her operations take place. I~ is also desirable to
fasten th~ item to the pallet in such a manner that it can be
accurately positioned to allow such operations to be performed
by automatic machines, robots, etc.. Such arrangements generally
provide for fastening the item to the pallet very accurately and
1~ dictate a necessity for accurate surfaces on the pallet to
position the pallet against stops at the work station so that
the ite.~ is held in proper position for the required operation.
This procedure requires: that accurate tolerances be held in
positioning the item on the pallet~ and for fastening it
thereto; an accurate location of the fastening devices in
relation to the body o the pallet; and that an accuracy b~
maintained i~ the body of the pallet itself so that the whole
assembly can be gauged frorn the outside surfaces of the palle
when located against stops.
However, to accomplish the above, while at the same time
being able to secure the item in position without the use of
special tools, extremely complex fixtures and highly trained
operators, seems to be a challenge not easily met by existin~
equipment and devices. Furthermore, the more complex the
~5 existing locating devices are in order to accurately and
.
7~
securely position the item; the more difficult and time
consu~lin~ it usually is to so locate the item for its movement
through the one or more work stations. Additionally, removal of
the item, once the work has been accom~lished, is also usually
S equally as difficult a~d ti~e consuming for such work locators.
SUM~'~RY OF THI IN~ TION
It is thereore an object of this invention to provide a
new and improved work locator.
It is another object of this invention to provide a new and
improved locator for use in positioning items to be worked on.
It is still another object of ~his invention to provide a
new and i~proved locator for use in securely and accurately
positioning an item to be worked on.
It is yet another object of this invention to provide a new
~nd improved fixture.
It is yet still another object of this invention to provide
a new and improved fixture for locating an item to be wo~ked
on.
It is a further object of this invention to provide a new
and improved fixture ~or securely and accurately positioning an
item to be worked on.
It is yet a further object of this invention to provide a
new and improved method of locating an item to be worked on.
It is a fur~her object of this invention to provide a new
~J5 and improved item locator and fixture for locating an ite;~ to
be worked on at a work station.
It is a further object of ~his invention to provide a new
and improved work positioning arrangement for locating an item
to be worked on at a work station.
It is a further object of this invention to provide a new
and improved work positioning arrangement for locating an item
to be worked on in an automated manner, as by a robot.
It is still a further object of this invention to provide a
new and improved method of accurately and securely positioning
an item to be worked on.
It is yet still a further object of this invention to
provide a new and improve~ method of positioning an item for
movement through one or more automated work stations.
This invention involves item locators, fixtures and
positioners and work methods involvins same, and contemplates:
accurately combining a pair of item locators with a locator
carrier, such as a pallet, to thereby form a fixture for u6e i~
accurately and ~ecurely locating an item (part, sub-assembly,
assembly, ctc) which is to have work performed thereon;
constructing each item locator or coaction with the item and so
that, by an easy manipulation of a detented locating assemb]y,
the item will either be locked in place and accurately located
on the ~ix~ure, or released for ready removal of the item from
the fixture; positioniny the fixture and ite~ carried thereby
at a work station so that work can be performed on the itëm by
automated robot type equip~ent; and providing a method of
1~7~6~
constructing and combinin~ an it~m locator, fixture, positioner
and ite-~, so that item is positioned by the locators on the
fixture at a work station to facilitate performing work Gn, for,
or with respect to such ite~s.
Other o~jects, features and advantages of the invention in .
its details of construction and arrangement of parts will be
seen from the above, from the following description of the
preferred embodimen~ when considered with the drawing and from
the appended claims.
BRI~F DESCRIPTION OF T~E INVENTION
.
In the drawing:
FIG. 1 is a sche~atic perspective view of a plurality of
~or~ fixtures, each of which incorporates the instant
inYention, moving on a conveyor to and through an automated
robot type work station;
FIG. 2 is a perspective view of one of the work fixture~
with an item base located thereor positioned at the worl; station
of FIG. 1, but with the rest of the item removed from the ~ase;
C FIG. 3 is a sectional view taken on line 3-3 or FIG.~ o an
item locator embedded in a fixture pallet to form the fixtures
of FI~S. 1, with parts displaced from normal to better show
details thereof;
FIG. 4 is an exploded perspective view of the item locator
of FIG. 3 removed from the pallet and with parts cut away and in
section to better show details thereof;
PIG. 5 is a sectional view similar to that of FIG. 3, but
with so~e item loca~or parts rotated to a position between O and
90 degrees;
FIG. ~ is an exploded perspective view of one of the item
locators of FIG. 2 ln position for coation with the coopera-ing
part of an item base;
FI&. 7 is a perspective view of the other item locator of
FIG. 2 but with the item base locked in position on the fixture
by the item locator;
1~ FIG. 8 is a partial section view taken along line 8-~ of
FI&. 3 but showing the fixture and work station positioners as
they wo~ld be when a fixture arrives at a work station;
~ I~. 9 is a view similar to that of FIG. 8 but showing the
work station positioners in positions of coaction with the item
loc~tors;
FIG. 10 is a view similar to that of FIG. 9 but showing the
'work st~t~on positioners and item locators rotated through 90
degrees; and
FIG. 11 is a partial section view of a plurality of item
loca~ors in position in thei,r carriers and stacked o,ne upon the
other.
DESCRIPTIOM OF THE PREFERRED EM~ODIMENT
.. .. _ .
For convenience the invention will be described as applied
to a plastic fixture. pallet formed about a pair of item
locators, disposed in the pallet at predetermined locations Gne
with respect to the other, and with the item locators disposed
for cooperation with an item base upon which is disposed an item
that i5 to be moved, by belt conveyor, to and through a work
station where an automatic compu~er controlled robot i5 to
S perform an operation on the item. It should be understood,
nevertheless, that without departing from the scope of this
invention: ~hat the fixture pallets may be formed o~ other
material such as metal or wood; that the item locators may be
otherwise secured on, to, or into the fixture pallet; that the
10 flxture and item may be otherwise moved to or through a work
station or work stations; that the work to be done at the work
sta~ion can be assembly, disasser~bly, repair, rebuilding,
inspection, machining, or any other type of work, and that other
~orms of automatic machines and controls may be employed, or for
~hat matter, the work on the item may be accomplished by a
person.
With reference to FIG. 1, there is generally shown at 20 a
work station where an automated machine in the form of a robot
22 controlled by a computer 24 is performing a manufacturing
~ype operation on an item of work 26 located on an item ~ixture
28 ~FIGS. 1 and 2) through the use of a pair of item locators
30, 32. Robot 22 is positioned at work station 20 which is
disposed along the path of movement of a conveyor line 33.
Conveyor line 33 utilizes a conveyor 34 which may be automated
in its movements to pick up (or receive) a number of fixtures
7~
28 each with an item 26 located thereon. Each item 26 is
assembled to a base 35 to which item 26 is secured by threaded
members (not shown) which extend through holes in part 37 (FIG.
1~ and into appropriate internally threaded holes in base 35.
I~ is i~portant that item part 37 be accurately located on base
35. Base 35 may also be an integral part of item part 37; and
the entire item 25 may, in fact, be a single part upon which a
work operation is to be performed. After leaving work station
20 items 26 are moved to successive work stations ~not shown)
until the work being performed on each item 26 is completed.
In this partieular example, the work being performed on item
26 is an assembly opera~ion to build up item 26 into a complete
operative piece of equipment. Item 26 may just as well be a
s~-assembly undergoing its assembly operation; or it may be an
assembly or sub-assembly being disassembled for purpose o~ being
repaired and/or rebuilt. Item 26 may also be merel~ a piece part
undergoing a manufacuting operation such as machining, grinding,
shaping, forming, welding or other similar operation. There are,
relatively speaking, an inflnite number of jobs that can be done
2~ on item 26 when carried by fixture 28.
Item locators 30~ 32 are identical in construction and are
received through openings 34, 36 ~FIG. 2) respectively in item
~2~ irl
base 35 as will be hereinafter explained. Since item locators
30, 32 and their respective fixture pallets 28 are identical
only one such item locator 30 and fixture pallet 28 will be
described.
S A base pla~e 40 (FIGS. 3 and 4) is formed with four open-
ings 42 ~FI~. 4) located to be in alignment with corresponding
ope~ings 44 in an upper bushing ring 46; and with opening 48 in
a lower bushing rir.g 50. A pair of alignment holes 60 are also
formed through plate 40, for alignment and cooperation with
holes 62 (only one shown) in upper bushing ring 46 and holes 64
formed in lower bushiny ring 50. A dowel pin 70 is pressed into
each set of aligned holes 62, 60, 64 to hold upper bushing ring,
plate 40, and lower bushing ring S0, in alignment one with the
other. Threaded ~embers 72 ~FIG. 3) are inserted through each
lS set of openings 44, in upper bushing ring 46, and aligned
openings 42, in plate 40; to be thereafter threaded into
internal thre3ds 76 of openin5s 48 of lower bushin~ i~irg 50 ~o
securely hold plate 40, and bushings 46, 50 together as a sub-
assembly.
2Q The sub-assembly 78 of plate 40, upper bushing ring 46 and
lower bushing ring 50, when so assembled together by dowel pins
70 and threaded members 72, is thereafter positioned for
71~S
-10--
incorporation into fixture pallet 28. This i5 accompli.shed b~
locating the axial center of sub-asse~bly 78 on fixture pallet
28 in a generally central position with respect to side edges
ao, 82 (FIG. 2) thereof, but in a position so that a similar
S s~b-assembly can be positioned for locator 32. If fixture
pallet 28 is to be formed of plastic and so as to have plate 40,
and asse.mbled rings 46t 50 embedded, in situ, into fixture
pallet 28, then the pair of sub-assembly 78 are suitably
positioned in a mold and the plastic ~aterial poured thereabout
to mold ~he parts in place and form pallet 28. Openings 84 are
~o~ed through plate 40 to permit the material from which pallet
2~ is being molded to flow through during the molding process.
This will fir~ly hold plate 40, upper bushing ring 46 and lower
bushing ring 50 in place in pallet 28.
1~ m e assembled plate, upper bushing and lower busning for
l~cator 32 may be si~nilarly embedded in the plastic of fixture
pallet 28. However, such aispo5ition i5 to be made at a
predeterrnined location with respect to locator 30.
A l.ocating and locking pin 100 ~FIGS. 3 and 4) is formed
with a lower ledge 102 (FIG. 4) having an outside diameter
prvviding a clearance fit within a central opening 103 of lower
bushing ring 50. Four detent pressure springs 104 are disposed
in four ~oles 106, formed through ledge 102, and located
d~ j7~
equi-distant thereabout. A spring retainer ball 110 (onl.y two
shown) is disposed at the lower extremity of each hole 106, and
each such retainer ball is staked in place at that position~
A hardened steel washer 120 i5 disposed around locking and
locating pin 100 on top of springs 104 and the entire sub-
asser~bly ~pin 100, washer 120, springs 104 and balls 110) are
inserted into opening 103 of lower bushing ring 50 from the
bottom up so that washer 120 sits up against the lower surface
of plate 40. The asse~bly is then placed on a flat surface, and
lO a pair of detent balls 122 are inserted down through a central
opening 124, of upper bushing ring 46 each into one of a pair
of notches 126 formed through plate ~0O A central opening 128
forr~ed through plate 40 receives a middle section 130 formed on
l~cator pin 100.
A detent ring 140 is formed with an outside diameter to
facilitate a slide fit w.ithin central opening 124 of upper
bushing ring 46, and an inside diarneter requiring that ring 140
be pressed down over upper portion 142 of pin 100. The inside
diamter of ring 140 includes a relatively smooth lower Fection
~0 144 (PIG. 4~, a vertically serrated upper section 146, and an
intermediate groove 148. Detent ring 140 i5 also formed with
four detent notches 150 (only two shown) and four lands 152
disposed therebetween. Detent ring 140 is positioned on pin 100
with its notches 150 facing detent balls 122, and with two
6~
notches 150 in alignrnent with detent balls 122. When pressed
down about pin 100 into its position on top of balls 122
serrations 146 are so sized that they deform the metal on tlle
outside surface of pin 100; and a portion 156 ~FIG. 3) of the
deformed metal swells into groove 148 to hold ring 140 in place
on pin 100.
A cross pin 160 is then pressed through an opening 162
for~led through the top of pin lOG. An axial hole 164 is formed
all the way throuyh locating and locking pin 100. This is to
~ssist in avoiding problems with de~ris lodging in the internal
tapered portion 166 of pin 100 when it is used as a loca.ing
device and a male pin tnot shown) is inse~ted up into hole 1~4.
Al~hough hole 164 is partially blocked by cross pin 160 it does
allow passage of a jet of compressed air which would be used to
; 15 assist removal of debris in a cleaning operation.
A ~ross opening 170 extends up into tapered section 166 of
pin 100 from a lower edge ~hereof on opposite walls thereof.
Opening 170 is sized in width and depth to accommodate cross
pin 160 ~hen two or more pallets 18 are stacked one upon the
other, as will be hereinafter explained.
Sub-assembly 7~, of upper bushing 46, plate 40, and lower
bushing 50, may also be formed as a unitary and integral part OL
a height and ~hickness equivalent to that of sub-assembly 78.
Extension or other means could be formed on such an inteyral
part for embedding in the plastic of pallet 28. In a~dition,
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1~7~KS
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the outside configuration of such a member need not be
~ylindrical but it can be square, rectangular or of any other
suitable configuration; as long as the central opening of such a
me~ber is cylindrical and sized to guide the movement of pin
100. O~viously, forming an equivalent for sub-assembly 78 by
utili~ing two parts whicil are secured together and thereafter to
pallet 28 is also contemplated herein.
An appropriate guide for pin 100 may also be provided by
utilizing a section of cylindrical pipe of appropriate height
and wall thickness. Such a pipe section would be embedded, or
otherwise secured to vr fabricated into pallet 28. In fact,
depending upon the degree of accuracy desired for the locator,
pin 100 may be merely inserted into an appropriately sized
~ylindrical opening molded into, or otherwise provided in pallet
2~.
~ o ~atter how sub-assembly 7~, or its equivalent, is
f~bricated or provided for pall~t 28, it must incl~de
appropriate means to position detent balls 122 for coaction with
detent ring 140. This may be accomplished, for instance, by
securing detent ball seats within the central cylindrical
portion of such a sub-assembly to support detent balls 122 in
the positions shown in FIG. 3 for detent balls 122.
6S
-14-
It should be noted that openings 34, 36 formed in item base
35 are each formed with a central open space and a pair of
opposed notches. A central open space i72 (FIG~ 6) for opening
36 ~FIG. 6) is circular and sized to snugly receive the outside
diameter of upper portion 142 of pin 100 of locator 32. As such,
when locator 32 is disposed in opening 36 it is tightly
positioned therewithin. A pair of opposed notches 180, 182
~FIGS. 2 and 6) extend out from the central open space 172 of
opening 170 to permit passage of item base 35 over cross pin 160
of locator 32 and down against the surface of pallet 2~.
A c~ntral open space 186 (FIG. 7) for openina 34, ho~ever,
is formed with an elongated configuration. The side to side
spacing of the narrow dimension of space 186 is selected so as
to provide a snug sliding fit with upper portion 142 of pin 100
of locator 30. The end to end spacing for the elongated
dimension of space 186 is selected to allow for normal tolerance
variations in t~e spacing o~ openings 34, 36 and i;~ the
positioning of locator 30 with respect to locator 32 (FIG. 2).
pair o~ notches 190 (FIG. 7) 192 are formed at the respective
~0 elongated ends of opening 34 to permit passage through opening
34 of cross pin 160 of locator 30 as item base 35 is moved into
position on pallet 2~.
When putting ixture Z8 into use one neeA only place it upon
an appropriate support surface. An item base 35, to receive an
7~;5
item part 26, is thereafter placed on fixture 28. In doing so,
cross pin 160 of locators 30, 32 should be disposed for
alignment with notches 180, 182, 190, 192 formed in openings 34,
36 respectively.
When pins 100 and ~ross pins 160 have passed through
openings 34 and 36 base 35 is locked in place on top of
fixture 28 by rotating locators 30, 32 ninety degrees. As this
is accomplished the sides of notches 150 of detent ring 140 will
ride ~p on detent balls 122 and locating pin 100 will move from
its FIG. 3 disposition to its FIG. 5 disposition. Thereafter,
lands 152 of detent ring 140 will ride on detent balls 122;
~ntil another set of notches lS0 are disposed over balls 122 of
which time ring 140 will return to its FIG. 3 disposition.
This action raises up cross pin 160 above the upper surface
- 15 of item base 35 and permits rotatlon of locator 30 from its item
base receiving disposition (FIG. 6) (wi~h cross pin 160
aligned with notches 1~, 182 in o~ening 186) to its item base
locating and locking position (FIG. 7) (with cross pin 160
~cross opening 186 perpendicular to notches 190, 192). I~len so
raised up pin 160 will not score or otherwise damage the surface
of item base 35; or be damaged thereby.
The rotation of a locator (30, 34 )from its FIG. 6
disposition to its FIG. 7 disposition is against the bias of
springs 104 while notches 150 of ring 140 are climbing up on
2~ detent balls 122, and under the urging of springs 104 when
locator 100 returns to its FIG. 6 and FIG. 3 positions.
-16-
When pallet 28 arrives at work station 20 its forward
movement is arrested by conventionally available means (not
shown) so that lo~er tapered portion 166 is disposed in at
lea~t approximate alignment with fixture positioners 200, 20'2
(FIGS~ ~-10~ whi~h are disposed for up and down movement in
openings 204, 206 ~FIG. 9) formed at work station 20. Openings
204, 206 are located at work station 20 with sreat accuracy;
and ~ixture positoners 200, 202 are guided for movement in said
openings and otherwise positoned with great accuracy. The
corresponding positions of fixture positioners 200, 202 are, in
turn, stored in robot control computer 24 and are utilized
$hereby to control the movement of robot 22 witll great
accuracy; and to thereby insure similar accuracy in the work
operations performed by robot 22 upon item 26.
Fixture positioners 200, 202 are formed with an upper
portion of a shape and configuration to fit within tapered
p~tion 166 of item locators 100, 102 respectively and so as to
position locators 100, 102 and base 35 in an accurate location
; with respect to robot 24. h cross pin 210 212, siml]ar to cross
pin 160 of locator 100, is carried by positioners 200, 202
respectively. Cross pins 210, 212 are sized, positioned and of a
confiugration to seat in cross opening 170 formed in the boitom
~f locator pins 100.
A positioner actuator 220, carried by worX station 20l
coacts with fixture positioners 200, 202 to move then in an
upward direction with respect to work station 20 90 as to
~i71~5
-17-
extend therefrom; and to withdraw positioners 200, 202 back into
work s~ation 20 so that a fixture pallet 28 can pass through. A
power drive arrangement 222, suitably powered, is connected to
actua$or 200 to operate same to so move positioners 200, 20~.
Power drive 222 and actuator 220 are also operable to rotate
po~itioners 200, 202 through successive angles of ninety
degrees.
Thus, upon actuation of power drive 222 and actuator 220
positioners 200, 202 will be extended up through the surface of
work station 20 and into tapered sections 166 of item locators
30, 32 respectively. This will accurately position locators 30,
32 and item base 35 carried by.pallet 28 for work at work
station 20.
If desired, when the work is accomplished or at any other
~elected time, power drive 22Z is actuated to operate actuator
220 to turn positioners 200, 202 through an angle of ninety
degrees~ Actuation of power drive 222 may be under control of
cornputer 24 if desired; and would especially be so for an
automated process.
As ~ositioners 200, 202 are rotated cross pins 210, 212
thereof which are seated in cross openings 170 will rotate their
respective locator pins 100 through an angle of ninety degrees.
Such movernent.of loca~ors 100 will move their cross pins 160
through the same angle; from their positions in FIG. 8 and 9
tseCuring item base 35 against the surface of fixture pallet 28)
to their positions as shown in FIG. 10. In the FIG. 10 position
cross pin 160 of locator 32 will be in alignment
i'71~i5
-18-
with notches 180, 182 and cross pin 160 of locator ~0 wlll be in
alignment with notches 190, 192; and as such item base 35 may be
lifted off of fixture pallet 28. If cross pins 160 are initially
in their FIG. 10 positions then an item base may be placed ~pon
5 fixture pallet 28 and power pack 222 actuated to rotate locators
30, 32 throu~h ninety degrees to secure item base 35 in place
upon pallet 28~
In FIG. 11, there is shown a number of fixture pallets 28
stacked one upon ~he other. The tapered lower portion 166 of
each locator pin 100 fits on top of the tapered upper portion of
the locator pin on the next lower fixture. Each cross pin 160
seats in the notch 170 provided in the lower portion of the pin
100 just above. As such, fixture pallets 18 may be securely and
compactly stacked one on top of the other.
Several variations of the locator pallet 2~ are possible to
allow other types of construction. For instance, lf pallet ~8 is
~ormed o1 sheet ~netal or sheet plastic instead of being a rnolded
section, plate 40, previously described as being molded into the
plastic section, could be formed as a part of the sheet metal
~0 pallet or sheet plas~ic pallet with the appropriate holes being
punched into the pallet itself.
De~ent pressure springs 104 could be replaced by one or ~ore
wavy spring washers or some other compressible device to serve
the same function.
7~
--19--
From the above description it will thus be seen that there
has been provided a novel and improved work locator, work
fixture, fixture positioners and method of locating an item to
be worked on; which locator, fixture, fixture positioners and
method are relatively simple in construction, operation and use
but effective to securely locate and accurately pOSitiOll an item
to be worked on.
It is understood that althoush I have shown the preerred
~or~ of my invention that various modifications may be made in
the details thereof without departing from the spirit as
comprehended by the following claims.
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