US 4,538,950 AGranted

Automatic system for conveying works in a machine shop

AssigneeMurata Kikai Kabushiki Kaisha

InventorsTadataka Shiomi, Kouichi Nabika, Takashi Kawagoe

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Abstract

A system is disclosed for automatically transporting works between an automated warehouse and a machine tool, and for maintaining the works in a precise position with respect to the machine tool. The system includes an automated warehouse, a pallet for precisely holding works, a truck for carrying the pallet, the truck moving along rails between the warehouse and a work exchanging apparatus adjacent to a machine tool table, and a device for positioning the pallet on the machine tool table precisely with respect to the machine tool. The work exchanging apparatus operates to transfer a pallet which holds unmachined works from the truck to the machine tool table and to transfer a pallet holding machined works from the machine tool table to the truck. The pallet, machine tool table, truck and work exchanging apparatus include means to position the pallet so that after a work is initially positioned on the pallet, the work will be precisely positioned with respect to the machine tool. The truck includes means for positioning the truck along the rails with respect to the warehouse and work exchanging apparatus.

Claims4

Dependent claims

An automated system for conveying a pallet on which a work is securely positioned between a pallet warehouse and a machine tool table, the pallet of the type having a body which includes upper and lower surfaces and side faces, the system including:

(1) a conveyor truck movable along a path laid on the ground between a loading station adjacent to the warehouse and an automatic work exchanging apparatus provided adjacent to the machine tool table, said conveyor truck including:
(a) a truck positioning device for positioning the truck with respect to the ground at a predetermined position on the path, the truck positioning device comprising:
(i) cone bodies secured on the ground at positions on the ground for the truck to be stopped,
(ii) an engaging device provided on the truck, the engaging device including cone plates attached to the lower end of a piston rod slidably engaged within a cylinder fixedly and vertically mounted on the truck, and
(iii) switch means for detecting upper limit and lower limit positions of the cone plates, said piston rod having connected thereto a disc-shaped dog which can engage with upper and lower limit switches of the switch means, said cone plates being engaged with the cone bodies by actuation of the engaging device cylinder when the truck stops, wherein the truck is set and positioned at a predetermined position with respect to the ground when the dog engages with the lower limit switch, and
(b) a pallet positioning device for positioning and supporting the pallet on the truck;
(2) an automatic work exchanging apparatus for transporting the pallet between the conveyor truck and the machine tool table, the automatic work exchanging apparatus having means for positioning the pallet on the automatic work exchanging apparatus by guiding a conveying surface provided on the undersurface and side faces of the pallet thereby controlling the position of the pallet when the pallet is transferred from the machine tool table to the conveyor truck;
and
(3) pallet positioning means for positioning and fixing a pallet on the machine tool table, said pallet positioning means including:
(a) a reference surface on the lower surface of the pallet, and
(b) a reference surface on the machine tool table, wherein intimate contact of the pallet reference surface and the machine tool table reference surface precisely positions the pallet on the machine tool table.

8 more elements

(1) a conveyor truck movable along a path laid on the ground between a loading station adjacent to the warehouse and an automatic work exchanging apparatus provided adjacent to the machine tool table, said conveyor truck including:
(a) a truck positioning device for positioning the truck with respect to the ground at a predetermined position on the path, and
(b) a pallet positioning device for positioning and supporting the pallet on the truck;
(2) an automatic work exchanging apparatus for transporting the pallet between the conveyor truck and the machine tool table, the automatic work exchanging apparatus comprising:
(a) positioning means for positioning the pallet on the automatic work exchanging apparatus by guiding a conveying surface provided on the undersurface and side faces of the pallet thereby controlling the position of the pallet when the pallet is transferred from the machine tool table to the conveyor truck,
(b) a four cornered truck laterally displaceable along circularly sectioned straight rails laid on the ground adjacent to the machine tool table,
(c) a platform vertically movable along supports positioned at the four corners and center of said truck, the platform being connected to piston rods of cylinders mounted at two positions on the truck, the vertical stroke of the platform being adjustable by positioning nut members on the corner supports so that the uppermost and lowermost positions of said platform can be defined by engagement of blocks fixed on the platform with said nut members,
(d) a pallet displacing device positioned on said platform, said pallet displacing device operating to transfer a pallet between the platform and the machine tool table, and p2 (e) driving means for driving the pallet displacing device;
and
(3) pallet positioning means for positioning and fixing the pallet on the machine tool table, said pallet positioning means including:
(a) a reference surface of the lower surface of the pallet, and
(b) a reference surface on the machine tool table, wherein intimate contact of the pallet reference surface and the machine tool table reference surface precisely positions the pallet on the machine tool table.

9 more elements

(1) a conveyor truck movable along a path laid on the ground between a loading station adjacent to the warehouse and an automatic work exchanging apparatus provided adjacent to the machine tool table, said conveyor truck including:
(a) a truck positioning device for positioning the truck with respect to the gound at a predetermined position on the path, and
(b) a pallet positioning device for positioning and supporting the pallet on the truck;
(2) an automatic work exchanging apparatus for transporting the pallet between the conveyor truck and the machine tool table, the automatic work exchanging apparatus comprising:
(a) a four corner truck laterally displaceable along circularly sectioned straight rails laid on the ground adjacent to the machine tool table,
(b) a platform vertically movable along supports positioned at the four corners and center of said truck,
(c) a pallet displacing device positioned upon said platform, said pallet displacing device operating to transfer a pallet between the platform and the machine tool table, the pallet displacing device comprising:
(i) a slidable member having two ends and guided by guide rails disposed on the platform, the slidable member movable along the guide rails in a direction perpendicular to the ground rails adjacent to the machine tool table,
(ii) two slidable member pinions supported at either end of the slidable member for pulling or pushing the pallet, said slidable member pinions being engageable with a rack provided on the lower surface of the pallet,
(iii) switch means for detecting the position of the slidable member with respect to the platform, and
(iv) a driving device for moving the slidable member along the guide rails, said driving device having a slidable member rack provided on a lower face of the slidable member and a platform pinion driven by a motor mounted on the platform, the platform pinion engageable with the slidable member rack, wherein one of the two slidable member pinions is driven by a motor and wherein the other slidable member pinion is driven by a chain provided between a sprocket coaxial with the former pinion and another sprocket connected to the latter pinion so that said two slidable member pinions are rotated in a same direction with an identical speed, and
(d) driving means for driving the pallet displacing device;
and
(3) pallet positioning means for positioning and fixing the pallet on the machine tool table, said pallet positioning means including:
(a) a reference surface on the lower surface of the pallet, and
(b) a reference surface on the machine tool table, wherein intimate contact of the pallet reference surface and the machine tool table reference surface precisely positions the pallet on the machine tool table.

13 more elements

Dependencies are inferred from the claim text.