BAR FEEDER

Abstract: Bar feeder apparatus (10) comprising a cylindrical guide passage (16) defined by two elongate extrusions (18, 20). A yoke rodless cylinder (32) is provided extending parallel to the passage (16) and mounting a bracket (36) which extends through an opening (24) into the passage (16). The bracket (36) mounts a rod holding assembly (38) including a collet (44) which permits a rod to be moved by the cylinder (32).

Description: Ba r F eeder This invention concerns improvements in or relating to bar feeders. Bar feeders permit an elongate article such as a bar to be fed to a article working machine, usually a lathe and especially an automatic computerised lathe. Bar feeders generally comprise an elongate closed trough with a central passage in which the bar is rotatably held. The passage is substantially coaxial with the lathe. Oil is normally supplied into the passage for lubrication and to reduce noise. A pusher assembly is provided which grips the end of the bar remote from the lathe. The pusher assembly moves the bar into the lathe as is required. Once a bar has been used as fully as possible the pusher assembly pulls the remaining portion to the end of the feeder away from the lathe where it is dropped into a billet catcher. A further bar is then placed in the trough and gripped whilst a collet on the free end of the pusher assembly is pushed onto the end of the bar to grip same. The'pusher assembly is generally . driven by a chain and sprockets arrangement which is not wholly satisfactory. Firstly this arrangement is relatively noisy. Secondly this arrangement requires regular inspection and maintenance particularly as the chain will tend to stretch. Rodless cylinders comprise a piston and cylinder but no piston rods. The piston is connected by some means to a carriage outside of the cylinder and which normally rides along the exterior of the cylinder. The piston and carriage may be connected by mechanical or magnetic means. One type or rodless cylinder is described below which in this specification will be referred to as a yoke rodless cylinder. A yoke. rodless cylinder comprises an elongate cylinder with a longitudinal slot extending for substantially the whole length thereof. An internal pressure seal and an external dust seal are provided across the slot. A piston is provided in the barrel with means for supplying fluid, normally air, to either side of the . piston for moving same along the length of the barrel. A yoke is provided slidable along the slot and located between the internal .and external seals. The cylinder has a central portion of reduced diameter which accepts a part of the yoke such that the yoke moves with the cylinder. A carriage is provided on the exterior of the cylinder slidably movable therealong. A further part of the yoke engages with the carriage so as to be movable therewith such that movement of the cylinder moves the carriage. The carriage generally engages with grooves on the cylinder exterior. According to the present invention there is provided a bar feeder comprising means defining an elongate guide passage one end of which is alignable with an article working machine, a holding assembly selectively engagable with an elongate article located in the guide passage, and means for moving the holding assembly along the guide passage whereby to move the article toward or away from the working machine, the moving means comprising a rodless cylinder extending parallel to the guide passage. The moving means preferably comprises a yoke rodless cylinder as hereinbefore defined. The slot of the cylinder may face downwardly thereby reducing the possibility of ingress of contaminating material into the cylinder. The guide passage is preferably defined by a pair of engagable components which are selectively separable to permit an elongate article to be loaded in the passage. When engaged said pair of components preferably define a lateral opening extending from the guide passage through which the moving means is extendable. A seal is generally provided for said lateral opening which may be in the form of a brush. The holding means preferably comprises a collet engagable with the elongate article and rotatably mounted on a member connected to the moving means. A magazine is preferably provided permitting a plurality of elongate articles to be held prior to loading into the guide passage. The magazine is preferably automatically actuable so as to load an elongate article into the guide passage as is required. Clamp means may be provided for clamping an elongate member subsequent to loading into the passage to permit the collet to engage therewith. Means are preferably provided for supplying lubricant into the guide passage. Means are. preferably also provided for cleaning an article as it exits the guide passage adjacent the working machine. An embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:- Fig. 1 is a plan view of a bar feeder according to the present invention; Fig. 2 is a side view of the apparatus of fig. 1; Fig. 3 is a diagrammatic end view of the apparatus of fig. 1 ; Fig. 4 is a diagrammatic end view of part of the apparatus of fig. 1 ; Fig. 5 is a further end view of part of the apparatus of fig. 1 ; Fig. 6 is a still further end view of part of the apparatus of fig. 1; and Fig. 7 is a diagrammatic sectional side view of part of the apparatus of fig. 1. The drawings shown bar feeder apparatus 10 suitable for feeding metal bars into a computerised lathe (not shown). The apparatus comprises an elongate generally horizontally aligned casing 12 supported on two cabinets 14, the left hand one of which (as shown in fig. 2) locates a supply of lubricant for the apparatus, whilst the right hand one locates the electrical circuitry for the apparatus. A part of the casing 12 can be opened to permit inspection of the interior of the apparatus (as shown in fig. 3). The apparatus 10 comprises a cylindrical guide passage 16 defined by two elongate extrusions 18, 20. A lower one of the extrusions 20 is fixed whilst the upper extrusion 18 can be lifted away from the extrusion 20 about a pivotal mounting 22 (fig.5) whereby to permit a bar to be loaded into the passage 16. The extrusions 18, 20 are shaped to define an upwardly inclined lateral opening 24 extending from the guide passage 16. A brush 26 is provided across the exterior of the opening 24 to substantially close same. An oil supply system is provided connecting with the interior of the passage 16 to provide lubrication for a bar therein and an inlet 28 of the system is shown in fig. 5. The apparatus 10 also comprises a moving assembly 30. The assembly 30 comprises a yoke rodless cylinder 32 of the type described above. A carriage 34 is provided on the cylinder 32 and mounts a bracket 36. The bracket 36 comprises a shaped strip which extends through the opening 24 into the passage 16. The bracket 36 mounts on its free end a rod holding assembly 38. The assembly 38 comprises a sleeve 40 which rotatably mounts a shaft 42 which extends outwardly therefrom. A collet 44 is provided on the free end of the shaft 42 for selectively engaging a bar. The assembly 38 is movable anywhere between two extreme positions, a first position 46 (fig. 2) at the left hand end of the casing 12, and a second position 48 extending from the right hand end of the casing 12. Towards the left hand end of. the casing 12, a short distance from the position 46, are a pair of ram operated clamps 50 capable of clamping a bar such that the collet 44 may be pushed thereon to grip the bar. A magazine 52 extends from one side of the casing 12. The magazine 52 comprises a plurality of spaced pairs of arms 54 inclined downwardly towards the extrusions 18, 20. The spacing between the arms 54 may be adjusted using the arrangement illustrated in fig. 6. A finger 56 (fig. 5) is provided adjacent the lower end of the lowest arms 54 and is movable downwardly by a ram 58 to permit a bar 60 to pass thereover towards the extrusions 18, 20. A receptacle 62 is provided beneath the clamps 50 to accept billets i.e. the remainder of a bar 60 once ' the bar 60 has been used fully by the lathe. The billet being dropped from the collet 44. A bar cleaning assembly 64 is provided adjacent the right hand end (as shown in fig. 2) of the passage 16. The assembly 64 (fig. 7) comprises a pair of opposed upper and lower brushes 66 , 68, and a pair of opposed jets 70, 72 for squirting fluid onto the bar 60. In use, the spacing of the arms 54 is adjusted as required and a plurality of bars 60 are loaded between the arms 54. The extrusions 18, 20 are opened and a bar 60 is released from the magazine by lowering the finger 56 with the ram 58. The extrusion 18 is then lowered to close the guide passage 16. The bar 60 is initially held by the clamps 50 and the collet 44 pushed on to the end thereof. The bar 60 is then pushed by the moving assembly 30 towards the lathe as is required. The bar 60 will obviously rotate in the lathe along with the shaft 42. Once the bar 60 has been fully used the holding assembly 38 will be retracted and the remainder of the bar, the billet, is dropped into the receptacle 62. A further bar 60 will then be delivered from the magazine 52 and the process repeated. There is thus described a bar feeder of relatively simple construction which can thus be inexpensively and robustly manufactured. The use of a rodless cylinder considerably reduces the noise output of the apparatus. In many circumstance a plurality of such bar feeders will be provided in a room such that a reduction of noise is particularly important. The rodless cylinders are relatively inexpensive and are of simple construction therefore requiring little maintenance. The rodless cylinders provide a smoother and more accurate movement of the bars into and out of the lathe than chains and sprockets. These cylinders also provide a more instantaneous response than would be provided by conventional chains and sprockets. The apparatus may be automatically actuable and connected to the lathe such that the bars are moved as is required by the lathe and fresh bars are automatically loaded into the apparatus subsequent to a bar having been fully used. Various modifications may be made without departing from the scope of the invention. For example the slot of the rodless cylinder could be provided pointing downwardly thereby further reducing the chance of contaminating material entering the cylinder. Further a magnetic rodless cylinder could be used. A different magazine arrangement could also be provided. Whilst endeavouring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the Applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in the drawings whether or not particular emphasis has been placed thereon.

Claims: C l a ims : - 1. A bar feeder (10) comprising means (18,20) defining an elongate guide passage (16) one end of which is alignable with an article working machine, a holding assembly (38) selectively engagable with an elongate article located in the guide passage (16), and means (30) for moving the holding assembly (38) along the guide passage (16) whereby to move the article toward or away from the working machine, characterised in that the moving means (30) comprises a rodless cylinder (32) extending parallel to the guide passage (16). 2. A bar feeder according to Claim 1, characterised in that the moving means (30) comprises a yoke rodless cylinder (32) as hereinbefore defined. 3. A bar feeder according to Claim 2, characterised in that the slot of the cylinder (32) faces downwardly. 4. A bar feeder according to any of the preceding claims, characterised in that the guide passage (16) is defined by a pair of engagable components (18,20) which are selectively separable to permit an elongate article to be located in the passage. 5. A bar feeder according to Claim 4, characterised in that when engaged the pair of components (18,20) define a lateral opening (24) extending from the guide passage (16) through which the moving means (36) is extendable. 6. A bar feeder according to Claim 5, characterised in that a seal (26) is provided for the lateral opening (24). 7. A bar feeder according to Claim 6, characterised in that the seal is in the form of a brush (36). 8. A bar feeder according to any of the preceding claims, characterised in that the holding means (38) comprises a collet (44) engagable with the elongate article and rotatably. mounted on a member (40) connected to the moving means (36). 9. A bar feeder according to Claim 8, characterised in that clamp means (50) are provided for clamping an elongate member subsequent to loading into the passage (16) to permit the collet (44). to engage therewith. 10. A bar feeder according to any of the preceding claims, characterised in that a magazine (52) is provided permitting a plurality of elongate articles to be held prior to loading into the guide passage (16). 11. A bar feeder according to Claim 10, characterised in that the magazine (52) is automatically actuable so as to load an elongate article into the guide passage (16) as is required. 12. A bar feeder according to any of the preceding claims, characterised in that means (28) are provided for supplying lubricant into the guide passage (16). 13. A bar feeder according to any of the preceding claims, characterised in that means (64) are provided for cleaning an article as it exits the guide passage (16) adjacent the working machine.

Inventors: KRUPA JOHN THOMAS, KRUPA, JOHN, THOMAS
Applicants: STERLING MACHINES INC, STERLING MACHINES INC.
Application year: 1992
Main classification: B23B13
IPC codes: B23B13