US2903120A

US2903120A - Planetary transfer machines

Info

Publication number: US2903120A
Application number: US655073A
Authority: US
Inventors: Alan P L Thomas
Original assignee: EDWARD J SKINNER Ltd
Current assignee: EDWARD J SKINNER Ltd
Priority date: 1956-04-13
Filing date: 1957-04-25
Publication date: 1959-09-08
Anticipated expiration: 1976-09-08

Description

sept. 8, 1959 A. P. L; THQMAS A 2,903,120

PLANETARY TRANSFER MACHINES Filed April 25, `1.95"? 4 Sheets-Sheet 1."

iNvENT'oR 4 Sheets-Sheet 2 A. P. -L. THOMAS F IG PLANETARY TRANSFER MACHINES Sept. 8, 1959 'Filed April 25, 1957 INVENTOR ALAN PLTHOMAS ATTO N Y A. P. L. THoMAs PLAETARY TRANSFER MACHINES Sept. 8, 1959 4 Sheets-Sheet 3 Filed April 25, 1957 Sept 8, 1959 l A. P; L. THOMAS 2,903,120

PLANETARY TRANSFER MACHINES INVENTOR ALAN P. L. THOMAS United States Patent .O

PLANETARY TRANSFER MACHINES Alan P. L. Thomas, Solihull, England, assignor to Edward J. Skinner Limited, Solihull, Warwickshire, England Application April 25, 1957, Serial No. 655,073

5 Claims. (Cl. 198-19) This invention has reference to planetary transfer machines ofthe kind comprising a number of platens which are displaceable internally and at timed intervals along a iixed bed and each of which is provided with a clamp or equivalent tting for holding a workpiece thereon so that, as the platens are displaced upon the bed to and through a succession of different stations, the workpieces held thereon may be subjected to a predetermined sequence of operations, such as drilling, boring, reamering and/or cleansing, by tools or appliances installed and operating at the said stations.

The principal object of the present invention is to provide an improved planetary transfer machine in which the predetermined sequence of operations may be performed on each workpiece held upon a platen, at any number of dilerent positions anywhere around the workpiece, during a single progression of the said workpiece through the several stations and without having either to alter the position of the workpiece on the platen or to turn the platen upon the bed of the machine.

, Further objects of the invention are to provide a ma chine wherein the iirst and final stations of .each progression are adjacent one another so that a single operator may remove and replace a treated workpiece by a fresh workpiece between two successive displacements of the corresponding platen; to minimise the total number of platens that need be provided in the machine to enable a predetermined sequence of operations to be performed on each of the workpieces; to enable the number and the arrangementof the stations to be varied as desired, and to minimise the floor space occupied by the machine.

In accordance with the present invention, a planetary transfer machine of the kind referred to comprises a number of identical platens which are disposed in a common plane with each platen occupying a different one of a number of stations arranged around the periphery of a polygonal area having at least four straight sides, each side being of a length equal to, a multiple of a platen dimension and the number of platens being one less than the number of stations so that one station is unoccupied by a platen and the platens are adapted to be progressed from station to station along each of the sides in succession.

Preferably, the unoccupied station is located at a corner of the polygonal area so that all the platens occupying the remainder of the stations in one of the two sides converging at the corner, may be displaced simultaneously thereby removing the platen from the station at the opposite end of the said one side; consequently, the platens in the next adjacent side may be displaced simultaneously and so on around the whole of the said area until all the platens have been displaced from one station to the next adjacent station in the direction of progression.

The bed of the machine may be built up from a number of identical corner units and a number of identical intermediate units so that by varying the number and/or arrangement of the said units, the number and arrangement of the stations may be varied as desired.

lCC

In order that the invention may more readily be under' stood and carried into practice, reference will now be made to the accompanying drawings, wherein:

Figure 1 is a perspective view of a planetary transfer machine, some of the control apparatus and work-treating mechanism having been omitted for the sake of clarity. Figure 2 is a plan of the machine shown in Figure l,

all the control apparatus and work-treating mechanism having been omitted.

Figure 3 is an underside perspective view on an enlarged scale, of a platen.

Figure 4 is a sectional elevation, on the same scale as eight identical units 3 which are of the same depth as.

the corner units and two of each of which are located in the bed intermediate two of the said corner units',

The` units are secured together in face-to-face abutment each two abutting faces being formed with registering keyways both of which are engaged by a correspondingv key 5 (see Figure 4) to ensure that the units in each-ofA4 the four sides of the bed are in exact alignment.

The machine also comprises eleven platens 4 eachof.

which is supported upon the head of a corresponding one of the corner or intermediate bed units 2, 3, is provided with a clamp, jig or equivalent fitting (not shown) adapted to receive and locate a workpiece on the upper face of the platen, and is capable of being displaced upon guide or keeper plates 6 of uniform thickness, secured upon the top of the corner and intermediate units 2 and 3, from one unit on to an adjoining unit. Since the said corner and intermediate units are of the same depth and the plates 6 are of uniform thickness, the platens are located in a common horizontal plane.

Each corner and intermediate bed unit forms part of a different work-treating station, each of which (with one exception) also includes mechanism or apparatus, with` one or more electrically-driven drills or other machine tools 7 (see Figure l) and/or washing or similar workcleansing means 8, and a master control cabinet 9 or subsidiary control cabinet 10; the station 1a which does not include any such mechanism or apparatus is a loading station where the workpieces are mounted in and removed from the clamps or like fittings on the platens, by an operator working at the said station, from where he is also able to operate push-button switches 11 of the master' control cabinet.

Since there are twelve separate stations and only elevenl is occupying a corresponding one of the said stations, the' twelfth station is not so occupied. Consequently, by displacing a platen from an adjacent station into an unoccupied station, each of the platens may be progressed to and through each of the twelve stations in succession and in sequence. Further, if, as shown in Figures 1 and 4, the unoccupied station is always one of the four corner stations, then all the platens in either of the two sides of the machine which converge to the corner at which the said unoccupied station is situated, that is the platens on the three remaining bed units in the said side, may be displaced simultaneously by displacement of the platen occupying the corner station at the opposite end of the side;

as a consequence, during each cycle of operations, the.

platens are progressed through the several stations in 3 cycle; beingf the trailing platen in the group displaced at the'end'of the cycle. The successive displacement of the four separate groups is initiated and timed by the master control cabinet which also controls the subsidiary cabinets in'- such a-manner that, atA the termination: ofI the displacementof each group, the machine tool or tools and/-or other work-treatingv apparatus v included inthe three stations intowhich-theplatens are displaced, areput into operation for periods controlled by therespecti'vesubsidiary cabinets 10: Aseach platen'A carrying atreated workpiece movesintolthelloading station- La; the-saidvworkpiece is removed bythe operator-andreplaced by afresh untreated workpiece so that as the platen supportingthe fresh workpiece islprogressedf to and throughrthe remaining'elevem stations in succession, it is subjected to one or more drilling; bor-y i'ng, reamering, washingA or similar treatments during each^- cycle off operations. As each platen and its supported workpiece is displaced into each cornerh station, a diierentl zoneof theI periphery of theI said workpiece is presented to the external periphery of the bedv and is', thereforeeaccessible' tothe machine tools, such as the drills7, mounted uponthe cabinets Band/or 10 around and externally of the said bed. Since an overhead machineftool, such as the drill 7u may be included in the apparatus installed at any of the several stations, the tops of'y the workpieces may also be subjected to any desired number oftreatments as the platens progress through thetsevera'l stations from and back to the loading station 1a.-

Each of.V the bed units 2 and 3 is` a hollow structure andis formed'with an internal transverse partition 12 (see Figures 4 and' 5) in the vicinity of its upper end so that' the unitV is divided into an upper compartment 13 and a lowercompartmentv 14. partition, vertical walls 15 and horizontal walls 16 i'solate auxiliary chambers 17'fromv the lower compartment; in each' intermediate unit, the two auxiliary chambers extend respectivelyV along the inner and outer walls of the unit andV open to both transverse walls; in each cornery unit; one auxiliary chamber extends along the two adjacent' outer walls of the unit and opens to the other two transverse walls, whereas the other auxiliary chamber extends between and'opens to the two transverse walls at the converging ends of the latter., Hence, the chambers form two continuous ducts which extend respectively around but inside the internal and external peripheries of the bed' for accommodation of. electric wiring and/ or compressed airlines, the units being formed with windows or apertures 18' (see Figure 1") to permit access tothe said ducts,

Flanges 19` extending inwardly of andy alongvthe length of the upper edges ofl the internalY walls of each intermediate unit, provide supports for the keeper or guide plates which are of the same length as and are fixed.- upon the said anges; the plates are wider than the anges,

and"l overhang the inner edges of. the latter. Similarly, plates 6 are ixed upon the upper edges of the twotonter walls of each corner unit and upon a pillar 20 provided in the angle between the converging ends of the other two, transverse walls; the plates of the corner units also overlap their respective flanges and posts.

Each platen (see Figures 3-5) consists of aV square crown 21 which is of the same dimensions as, the top of each bed unit and has wear plates 22 embedded in the peripheral zone of its underside, which wear plates seat upon and are adapted to slide along the upper faces ofthe keeper plates 6. A square block 23 depends from the underside and centrally of the crown 21, ythe block being of smaller area than the crownl and having a groove 24 formed@ in and along each of its four sides. The block passes between the adjacent edges of the keeper plates 6 and the overhanging portions of the plates engagethe grooves in opposed sides oi the block thereby retaining the platen upon the bed of the machine in a manner which preventsthe platen from rotary movement relatively to thelsaidbed but permits thesaid platen to` slide alonglthe,

Immediately below theV a plates from station to station and to change its direction of travel through ninety degrees as it is displaced from each corner station.

As shown in Figure 3, two pairs of

pockets

25, 25a are formed in the underside of each platen block, the pockets of each pair being located in a different diagonal of the block. A female coned seat 26 is secured within each pocket and each bed unit is provided with two vertical plungers 27 each having a tapered head 27a; the jalungers are reciprocable. within liner. bushes 285 29 providedon the partition 12 and chamber walls 15 respectively and their lower ends are connected by cranked links 30 and straight links 31 to the outer end of the piston rod' 32 of a double-acting pneumatic cylinder 33 journalled upon a. xed platformy 34l provided in and diagonally of the lower compartment 14. The plungers are so located within the corresponding bed unit that when driven upwardly by displacement of the. piston ro'd inwardly ofthe cylinder, and' when a platen is dis,- placed on to the top of" the said'unit, the tapered plunger heads engage respectively with the tapered seats of one ofthe pairs of pockets thereby locating the platen in a predetermined position relatively to the bed unit and to the tool or tools and/0r other work-treating apparatus included. on the same station. The tapering of the seats facilitates the engagement of the plungers with the seats and compensates for any wear that may take place between their mating surfaces. The arrangement of the cranked and straight links is such that the links are locked' against return movement so that the plungers are unable to recede until admission of compressed air to the cylinder forces the piston rod outwardly of the said cylinder. The provision ofthe two pairs ofpockets in.` each platen enables the plunger bushes to be located in. identical relative positions in each corner unity and each intermediate unit because as each platen progresses from. one side ofthe bed` intoan adjacent side in which the.- bed units are turned through ninety degrees relatively to the units in the preceding side, the plungers are adapted to engage a differentone. ofthe. two pairs of seats, see Figure 2).

For displacing the groups. of platens along the sides ofV the bed, two parallel walls 35 are provided upon the upper face of. the transverse partition of each bed unit so-as to form. achannel 36 symmetrically ofone of.' the transverse centre lines of the unit. The channel ends open: respectively tov opposed side walls of each upper compartment 13-and in three adjacent bed units (namely the two intermediate units and" one corner unit) of each side of the bed, the channels are arranged in longitudinal alignment (see. Figure 4) and house a corresponding doublefacting pneumatic cylinder 37 of which the piston rod 38v has secured on its` free or outen end, a` plate'39 of whichv the upper, edge is provided with a hook or lug 40 adapted: to engage behindl anedgel of. the block om the underside V of theplatenlocated on the4 corresponding. cornert unitwhenv the pistonrodl isdriven to the limit of.its1travelfoutwardlyI of the cylinder. Consequently,` when. the pistony isl forced'inwardly of the cylinder by the admission of compressed air to the said cylinder,. the. platen; located on the said corner unit is adapted to betdisplaced, after the retractionI of the plungers from tlieftaperedy seats,A along the saidv side of' the bed on to the adjacent. intermediate unit. The plungers engaging the platens ontheA two intermediate'units are retractedA simultaneously with the. plungers engaging the platen on thecorner'unit, witht thev resultthat. the displacement of thel latter platen alsofdispla'cesthe other twoplatens and. theleading. platen is, progressed on.- to the previously unf occupied corner; platen in the next adjacent side of the bed. A groove 411 formed in andV lengthwise, of each channel is engaged by the lower edge of the plate'39 to ensurel that, the plate travels along a straight path` within. the channel,

Although the invention has 1 been4 described with.- refer ence to a` planetary transfer machine comprising four? corner bed units and eight intermediate bed units ar-` ranged along the four sides of a square floor space area and surmounted by eleven platens, it isl'to be' understood that it is not restricted to sucha machine since the number of units in its sides may be increased or decreased as desired depending upon the numberof treatments to which each workpiece is to be subjected, and/or the units may be arranged along lthesic'ies of a polygonal oor space area having more than four straight sides.

Since all the platens are located in a common plane upon the top of the machine bed and are displaced intermittentl'y to and through each of the stations in succession from and back to the loading station 1a, they and the workpieces carried thereon are -always visible and readily accessible; also, a separate workpiece may be mounted lupon each and every one of the platens and each and every one of the said workpieces may be subjected to one or more treatments during each operational cycle. Further, since the bed of the machine is disposed around a polygonal oor space, the area occupied by the machine is reduced to a I claim:

1. A planetary transfer machine comprising a bed defining a polygonal area having straight sides of which adjacent sides are at right angles to one another, said bed consisting of a number of corner units which are identical to one another and a number of intermediate units which are identical to one another, each unit having a square platen supporting head, the heads of the said units being disposed in edge-to-edge abutment in and along the sides of the said area, a number of identical square platens less than the total number of corner and intermediate units, each platen being supported upon a corresponding one of the heads, being ofthe same area as each of the said heads and coinciding with said corresponding head, means for displacing the platens from bed-unit to bed-unit along each of the said sides in succession, and means for individually locking the platens upon said heads between successive displacements.

2. A planetary transfer machine comprising a number of square platens and a bed defining a polygonal area having straight sides of which each adjacent two sides are at right angles to one another, and are equal in length to a multiple of the length of a platen, said bed consisting of a number of corner units which are identical to one another and a number of intermediate units which are identical to one another, each unit having a square head of equal area to each of said platens, the said heads being disposed in a common plane and in edge-to-edge abutment in straight lines around the sides of said area, each head having flanges projecting inwardly of the head from opposed edges to form a guideway and support the platens, rails secured to said flanges, each platen having a square dependent projection which engages in said guideway, a groove formed around the root of each projection, said groove being engaged by said rails to retain the platens on said bed but permit a displacement thereon, means for displacing said platens in groups consisting of platens disposed on the heads of each one of said sides, and means for locking each platen between successive displacements.

3. A planetary transfer machine comprising a bed and a number of platens supported on said bed, all of said platens 'being square, identical with one another, formed with a dependent square projection, having a groove formed around the root thereof four pockets formed respectively in corners of the projection and opening to the face thereof, said bed consisting of a number of corner units identical to one another and disposed respectively at the corners of a polygonal area, and a number of intermediate units identical to one another and disposed between corner units along the sides of said area, said sides being equal in length to a multiple of the length of a platen, each of the units having a square platen-receiving head of equal area to each of said platens and flanges extending inwardly from opposite'sides to form a guideway into which one of said square projections is received, rails secured to said flanges and engaging insaid grooves, to retain the platen on the head but permit displacement therefrom onto the next adjacent head, the number of platens being less than the total number of units, means for displacing said platens along said bed in groups to move a leading platen of a vgroup onto a vacant corner unit and remove a trailing platen of. said group from a corner unit so as to vacate said corner unit, and means comprising a pair of plungers disposed in each unit registrable with one of said pockets, and displaceable by a pressure-Huid cylinder for locking said platens individually and relatively to said bed between successive displacements.

`4. A planetary transfer machine comprising a bed made up of a number of corner units identical with one another and a number of intermediate units identical with one another, each unit having a square head formed with flanges extending inwards from opposite sides thereof to define a guideway therein, a channel in each head between said anges, and rails secured to and overhanging said channel, said machine further comprising a number of square platens identical with one another, each having a square projection dependent from one face, a groove formed around the root of said projection, a pocket formed in each corner of said projection, and opening to the face thereof, said number of platens being less than the total number of units, each platen being of equal area to each of the units, supported on and coinciding with the head of a corresponding one thereof, said projection being received in the guideway between iianges and said rails engaging in said grooves, all of the units being arranged with their heads in edge-to-edge abutment so as to form an endless support for said platens and an endless guideway for the projections therefrom around the periphery of a polygonal ligure, each side of said figure being equal in length to a multiple of the length of a platen and at right angles to adjacent sides, means comprising a pair of reciprocable plungers provided in each unit for engage ment with one of said pockets so as to lock a platen supported on each of said units to said units individually, and means for displacing the platens along the guideway from bed-unit to bed-unit comprising double-acting pres sure uid cylinders disposed in the channel formed in the several heads of the units, one of such cylinders being disposed in each of the sides, and a plate secured to the piston rod of each of said cylinders for engagement with the projection from the trailing one of a line of platens which is to be displaced so that by movement of a piston Within the corresponding cylinder said trailing platen may be displaced from a corner unit on to the next adjacent unit and the leading one of said line of platens being moved onto the next corner unit.

5. A planetary transfer machine comprising a bed deiining a polygonal area having straight sides of which each adjacent two sides are at right angles to one another, and a number of square platens, the bed consisting of a number of corner units identical to one another and a number of intermediate units identical to one another, said units all having square heads, said heads being arranged in edge to edge abutment in straight lines around the sides of said area, each of said lines of length equal to a multiple of the length of said platens each side being at right angles to adjacent sides, said heads lying in a common plane, a guideway formed around said area in said heads, each platen having a square projection engaging in said guideway lbeing of equal area to each of said units, coinciding with a respective one thereof and being displaceable around said bed from unit to unit, a pocket formed adjacent each corner of said projection, means for displacing said platens, and means for individually locking said platens between successive displacements comprising a double-acting pressure fluid cylinder mounted in each unit, a pair of plungers reciprocable in 7 the:l head of wehunit,. aj-pair oflinkspivotedte the free end ofthev piston rod of each cylinder,Y a-pair ofcranked` links individually pivoted in each unit, one' endof each ofsaideranked'- links being pivoted to the free end ofcorresponding onel of said piston-rod pivoted links and the etherends being pivoted respectively tp said plunger,the latterbeingmovablefby the corresponding-piston` rody into engagement with one ofsaid `pockets to lock` the platens to the bedand beingimmovable from the locked position until the;v piston rod is returned,u different ones of said poeketslbein'g'engaged inV adjacent sides of the=bed.

'lftafe'revcles Cited in the 'le nf this patent UNITED STATES PATENTS 1505213459l Schwnz Feb'. 25:, 1913*: 25392,'169 Mn'seld lan. l, 1946 y l y 'R'IG'N' PATENTS'. 311-,446 t Switzerland Jan?. 3l,- 1.956