GB2065622A

GB2065622A - Improvements in or relating to application heads for closure applying machines

Info

Publication number: GB2065622A
Application number: GB8036545A
Authority: GB
Original assignee: Metal Closures Ltd
Current assignee: Arconic Closure Systems International UK Ltd
Priority date: 1979-11-26
Filing date: 1980-11-13
Publication date: 1981-07-01
Also published as: GB2065622B

Abstract

An application head for a closure machine comprises a cylinder block 11 in which two pistons 21, 22 are arranged in tandem, a support member 31 suspended from the pistons and mounted for vertical sliding movement in a guideway, a hollow vertical shaft 34 carried in bearings in the support member, and a hollow spindle 42 disposed within shaft 34 and fixed to the support member 31. Shaft 34 has elongate gear teeth 36 enabling it to be driven in rotation and carries at its lower end a rotary headset equipped with forming rollers 39, 40. The spindle carries at its lower end a closure reforming die. Rollers 39, 40 are actuated by respective pistons mounted for radial movement in cylinders 52, compressed air being supplied to the cylinders along the hollow spindle 42. <IMAGE>

Description

SPECIFICATION Improvements in or relating to application heads for closure applying machines This invention relates to application heads for closure applying machines.

According to this invention there is provided an application head for a closure machine comprising a cylinder block which is carried by a supporting structure and which provides two coaxial cylinders arranged endto-end with their common axis vertical, said cylinders being separated by an intermediate wall, two pistons respectively slidably disposed in the cylinders and rigidly interconnected by a piston rod slidingly and sealingly engaged in a bore in the intermediate wall, the cylinders being connected to be supplied with pressure fluid so as to operate the pistons in tandem, a support member which is suspended from the piston rod and guided for vertical sliding movement but which is restrained from rotation about the cylinder axis, said support member carrying bearings for a vertical shaft which is adapted to be driven in rotation about its lengthwise axis but is held against movement lengthwise of itself relative to the support member, and a non-rotary spindle connected to the piston rod, co-operating tools of a closure application headset being respectively mounted on the lower ends of said shaft and said spindle.

In a preferred construction, the cylinder block is slidably mounted in a guideway for vertical movement lengthwise of the cylinders and is suspended from a cam roller engaged in a cam track whereby a cyclic vertical movement is transmitted to the cylinder block.

In a preferred construction said shaft is formed with external axially elongate gear teeth for sliding driving engagement with an axially fixed driving gear.

One embodiment of the invention will now be described by way of example with reference to the accompanying drawing showing in axial section an application head according to the invention. The application head operates on a metal closure blank in the form of an inverted cup resting on the externally screw threaded neck of a container. The application head presses the blank down on the container neck and deforms the skirt of the blank into sealing contact with the neck and into conformity with the screw thread on the neck in the well-known manner.

Referring to the drawing, the application head shown is one of several which are mounted in circumferentially spaced relation on a carrier which is driven in rotation about a fixed vertical central spindle (not shown), the application heads being mounted in respective guideways (not shown) on the carrier for vertical sliding movement. The application head has at its upper end a cylinder block 11 suspended by arm 1 2 from a roller 1 3 which is rotatably mounted on a pin 1 3a secured in the upper end of the cam and which engages in a fixed endless cam track (not shown) extending about the said central spindle.The carrier and application heads are driven round the fixed central spindle and the engagement of the roller 1 3 in the cam track causes the application heads to carry out a cyclic up and down movement in the known manner to bring their respective headsets 15 into and out of engagement with caps carried by bot tles.

The arm 1 2 is formed in one piece with an end member 1 6 of the cylinder block 11. The block 11 provides two cylinders 18, 1 9 dis posed in vertical alignment with each other and separated by an intermediate wall 20.

The two cylinders are made in cup form and are secured base to base by screws, the base of the upper cup having a central boss which is located in a recess in the base of the lower cup. These bases together form the wall 20.

Pistons 21, 22 are respectively mounted in the two cylinders 18, 1 9 and are rigidly interconnected by a piston rod 23 which is encircled by a distance sleeve 26 slidingly and sealingly engaged in a bore in wall 20, and which has an extension 23a projecting downward from the lower cylinder 1 9. Com pressed air can be fed into the cylinder spaces above the upper piston 21 from an airline 24 connected to the end member 1 6 and is fed from that space into the cylinder space above the lower piston 22 through an axial drilling 25 and radial drilling 27 in the piston rod.

The pistons thus operate in tandem. A vent passage extends from the lower end of each of the two cylinder spaces to atmosphere.

The piston rod extension 23a terminates in an annular flange 28 suspended by an offset arm portion 29. The central aperture in flange 28 accommodates an annular boss 30 at the upper end of a support member 31 which is mounted for vertical sliding movement in one of the previously mentioned guideways (not shown) in the rotary carrier. Screws 32 secure the support member to the flange. The cylin der block 11 is slidingly mounted in the upper end portions of the same guideway as mem ber 31. A shaft 34 is mounted for rotation in bearings 35 at the upper and lower ends of the member 31 and its middle portion is formed with axially elongate gear teeth 36. A large aperture in the side of member 31 enables a drive pinion (not shown) mounted on the carrier to mesh with the gear teeth 36 and to remain in mesh therewith during the sliding movement of the application head.

The lower end of the shaft 34 projects below the support member and terminates in an enlargement 34a by which the headset 1 5 is secured to the shaft by a nut 37. The headset is keyed at 38 to the end of the shaft 34 so as to rotate with the shaft. The headset is provided with forming rollers 39, 40 constructed, arranged and operated in the manner described more fully in our Patent Specification No. 1 369793, to deform the skirt of the closure blank which is disposed on the mouth of the container. Compressed air for actuating movement of the forming rollers is passed down a hollow spindle 42 disposed concentrically within the shaft 34.The upper end of the spindle projects through the boss 30 and is screwed into a threaded bore 43 in the piston rod extension, to permit adjustment of the height of the spindle relative to the shaft 34. A nut 44 on the threaded upper end portion of the spindle is tightened against the boss 30 to lock the spindle in the selected position of adjustment. At its lower end the spindle 42 carries a die 53 which presses the closure blank down on the top of the container and reforms the radially outer portions of the top of the closure into sealing engagement with the container.

The upper end of the central hollow of the spindle is sealed by a threaded plug45 and compressed air is supplied to the interior of the spindle through an air-line 46 connected to the support member, a passage 47 in the support member and an annular recess 48 and radial passages 49 in the spindle. The lower end portion of the spindle 42 houses a valve member 50 which is operated by a spring-loaded probe 1 5 disposed on the axis of rotation of the shaft and projecting downward from the lower end of the spindle. If a container presented to the headset has no closure blank in position on its neck, the valve member remains in its initial position and blocks the flow of air through the spindle to the air-cylinders 52 which actuate the forming rollers, so that the rollers are not moved into direct contact with the bottle neck. If a closure blank is in position, the probe strikes it during the downward movement of the application head and moves the valve member 50 to initiate the supply of air through the spindle to the air-cylinders.

Claims

1. An application head for a closure machine comprising a cylinder block which is carried by a supporting structure and which provides two coaxial cylinders arranged endto-end with their common axis vertical, said cylinders being separated by an intermediate wall, two pistons respectively slidably disposed in the cylinders and rigidly interconnected by a piston rod slidingly and sealingly engaged in a bore in the intermediate wall, the cylinders being connected to be supplied with pressure fluid so as to operate the piston in tandem, a support member which is suspended from the piston rod and guided for vertical sliding movement but which is restrained from rotation about the cylinder axis, said support member carrying bearings for a vertical shaft which is adapted to be driven in rotation about its lengthwise axis but is held against movement lengthwise of itself relative to the support member, and a non-rotary spindle connected to the piston rod, co-operating tools of a closure application headset being respectively mounted on the lower ends of said shaft and said spindle.

2. An application head as claimed in claim 1, wherein said shaft is formed with external axially elongate gear teeth for sliding driving engagement with an axially fixed driving gear.

3. An application head as claimed in claim 1 or claim 2, wherein said spindle has a central lengthwise extending bore which serves to conduct compressed air to the headset for operating the tools thereof carried by said shaft.

4. An application head as claimed in claim 3, wherein a valve means is mounted in said bore of the spindle and is operated by a probe on the lower end of the spindle to operate the valve means to supply compressed air to operate the tools carried by the shaft only if a closure blank is present on a container disposed under the headset.

5. An application head as claimed in any one of claims 1 to 4 wherein, in operation, compressed air is continuously applied to the cylinder spaces above the two pistons, the cylinder spaces below the pistons being permanently vented to atmosphere.

6. An application head for a closure machine, which application head is substantially as hereinbefore described with reference to and as illustrated in the accompanying drawing.