US2987861A

US2987861A - Wrapping machines

Info

Publication number: US2987861A
Application number: US855719A
Authority: US
Inventors: Brook Leonard
Original assignee: Forgrove Machinery Co Ltd
Current assignee: Forgrove Machinery Co Ltd
Priority date: 1958-11-28
Filing date: 1959-11-27
Publication date: 1961-06-13
Anticipated expiration: 1978-06-13

Description

June 13, 1961 L. BROOK WRAPPING MACHINES 3 Sheets-Sheet 1 Filed Nov. 27, 1959 June 13, 1961 L. BROOK 2,987,861

WRAPPING MACHINES Filed Nov. 27, 1959 s Sheets-Sheet 2 June 13, 1961 L. BROOK 2,987,861

WRAPPING MACHINES Filed Nov. 27, 1959 3 Sheets-Sheet 3 Patented June .13, 1961 ice This invention relates to bunch wrapping machines. In the conventional type of bunch wrapping machine, the articles to be wrapped are lifted in succession each carrying a wrapper with it, through an annular brush into jaws on a carrier head which rotates intermittently on a vertical axis. As the result of passage through the brush, the wrapper is folded around the top and sides of the article and depends in irregular pleats from the base of the article. The carrier head then conveys the articles in succession to a tucking station, where the depending portions of the wrapper are folded against the base of the article, then to a heater which forms a heat sea-l at the base of the article, then over a cooler and finally to a dischargestation.

The present invention provides a bunch wrapping machine comprising a number of pocketed wrapping elements mounted on a rotary carrier head so as to be carried thereby past successive wrapper feed, loading, tucking, sealing and discharge stations, means on eachwrapping element for receiving a wrapper supplied at the wrapper feed station and holding it across the mouth of the pocket in the wrapping element, a pusher at the loading station for introducing articles in succession into the pockets of the wrapping elements as they arrive at the loading station, each article carrying a wrapper with it as it enters the pocket, and means at the discharge station for discharging wrapped articles from the packets.

In this machine, the wrapper is accordingly folded around one end and the sides of the article as it is pushed into the pocket of the wrapping element carrying the wrapper with it. The projecting skirt of the-wrapper is folded against the other end of the article'at the tucking station and the overlapping folds of the wrapper at'this end of the article are subsequently sealed 'at'the sealing station.

Preferably the carrier head is rotated continuously and means are provided for momentarily decelerating the wrapping elements as they pass the'wrapper feed, loading and discharge stations. Preferably also the carrier;head

rotates about a horizontal axis and the articles'arefed to it by the pusher at the loading station from recessesin a continuously rotating feed wheel which-also rotates about a horizontal axis.

One specific embodiment of bunch wrapping machine according to the invention will now bedescribed in more detail, by way of, example with reference to the accompanying diagrammatic drawings, in which:

FIG. 1 is a front .elevationof the carrier head and associated mechanisms with the wrapper feedmejchanism omitted,

FIG. 2 is a corresponding vertical section,

FIG. 3 is .a section on the .line III-{II in FIG. 1 showing the wrapperjfeed mechanism,

FIG. 4 is a side view, partly in section, of the mechanism for actuatingthe transfer pusher, .and

FIG. 5 is a.section on theline V.V- in FIG. 4.

In the construction illustrated, the carrier head is constituted by a wheel 10 mounted on a horizontal shaft 11 which is rotated continuously by a motor (not shown) in a clockwise direction as seen in FIG. 1. The carrier head carries a number of wrapping elements, each constituted by a block 12 formed with an article-receiving pocket 13. The wrapping elements are traversed in succession by rotation of the carrier head past a wrapper feed station A, a loading station B, a tucking station C, a sealing stationD, a cooling station E and a discharge station F.

The wrapping elements 12 are pivoted to the wheel 10 wrapping'element is formed with a cranked arm 15 carrying 'a runner 16 engaging a cam track 17 in a fixed cam 18 concentric with and situated behind the wheel 10. So long as the runners 16 engage a concentric portion of the cam track the wrapping elements rotate at the same angular velocity as the wheel. The cam track is, however, so shaped at the points 17A, 17B and 17F as to provide momentary deceleration of the wrapping elements when they reach the wrapper feed station A, the loading station B and the discharge station F and subsequently to accelerate them again to their normal angular velocity.

A web 19 of wrapping material is fed continuously, asshown in FIG. 3, in a vertical plane and at an angle of some 30 towards the front face of thewheel near the top thereof by continuously rotating feed rollers 20. The leading end of the web is fed between guides 21 against the front face of the moving wrapping element 12 situated at the top of the wheel, Wrappers are severed in succession from the web by a rotary knife 22 coacting with a fixed knife 23, and the front end of each wrapper is gripped immediately after severance by a pair of grippers which hold the wrapper to the face of the wrapping element 12 in position over the pocket 13 therein. The grippers are constituted by outwardly

bent fingers

24, 25 on

levers

26, 27 pivoted at 28, 29 to the side face of the wrapping element and urged by springs 30 to the closed position. The lever 27 has a projection 31 engaging a slot 32 in the lever 26 and is formed with an extension 33 carrying a runner 34, which coacts with a fixed cam piece 35 as the wrapping element approaches the wrapper feed station A, causing the

grippers

24, 25 to open momentarily to allow the leading end of the wrapper to pass between them and the face of the wrapping element and then close to hold the wrapper to the wrapper element. As will be apparent from FIG. 2, when the roller 34 rides up the face of the cam 35, the lever 27 will be rocked anticlockwise about its pivot 29 to lift the finger 25 from the face of the element 12. During such movement the projection 32 rocks the lever 26 about its pivot 28 to lift the finger 24 from the element 12. As soon as the roller 34 clears the fixed cam 35, the springs 30 return the parts to the position shown in FIG. 2.

Since the uniform rotation of the wheel moves the wrappingelements 12 approximately 3 /8" per cycle, and the web 19 of wrapping material is also being fed continuously but at theuniform rate of approximately 2" per cycle, it will beobviousthat the wrapping elements must .beslowed upat thisperiod in order to allowthe leading edge of the web to overtake and be inserted .beneath the

grippers

24, 25. The cam track 17'is so shaped at-17A that .each wrapping element, as it traverses the wrapperfeedmechanism, travels ata suitable speed to allow this to take place.

The articles'to be'wrapped, in the case in question round tablets 50, are fed by any conventional feed mechanism into a vertical magazine 36 in which the tablets stand on edge, one above the other. From this magazine successive tablets fall by gravity into peripheral recesses 37 in a feed wheel 38 driven by a continuously rotating horizontal shaft 39. The feed wheel 38 is situated im mediately below the magazine 36 and immediately in front of the wheel and rotates on a horizontal axis at a uniform speed less than the uniform speed of rotation of the carrier head. Suitable guides 40' are provided for preventing the tablets from falling out of the recesses 37 in the feed wheel 38. Since the recesses 37 in the feed wheel are close together the articles are gently removed by the feed wheel from the magazine 36.

At the loading station B which is situated some 45 beyond the Wrapper feed station A, a recess 3-7 in the feed wheel 38 is brought into regitser at each cycle with the pocket 13 in one of the wrapping elements 12. The reciprocating pusher 41 then moves inwardly from the front as described later to deliver the tablet from the recess in the feed wheel into the pocket in the wrapping element, the tablet taking with it the wrapper held by the grippers 24, against the face of the wrapping element. At this time the follower 34 associated with the grippers encounters another fixed cam piece 42, which causes the grippers to open momentarily to release the wrapper.

It is desired that the angular velocity of the feed wheel and the particular wrapping element to be loaded should coincide for a reasonable period of time in order that the pusher 41 may transfer the tablet with its piece of wrapping material into the receiving pocket in the wrapping element. Therefore the wrapping element is again slowed down by suitably shaping the portion 17B of the track in the control cam. This is necessary since the pitch of the recesses 37 in the feed Wheel is considerably less than the pitch of the pocket 13 in the wrapping elements. a

To effect the transfer the pusher 41 is moved backwards and forwards by suitable movement of a rod 43 supporting it, but it is also swung sideways to match the rotational velocities by a rocking movement imparted to said rod. The mechanism for imparting these movements to the pusher is illustrated in FIGS. 4 and 5 and is of the following construction: The rod has attached to it a small gear quadrant 60 engaging with a similar quadrant 51 mounted on a shaft 52 extending parallel to the rod. This shaft carries a cam lever 53 coacting with a cam 54 to give a rocking action to the shaft 52. This is transmitted to the

gear quadrants

51, 60 to give a sideways swinging action to the pusher 41. The gear teeth on the quadrant 51 are sufficiently wide to allow for the longitudinal movement of the rod 43, and this longitudinal movement is imparted through trunnion block 55 on the end of the rod engaging with trunnions 56 mounted on a bell crank lever 57. The bell crank lever 57 in turn coacts with another cam 58 in order to give the necessary loading action to the pusher 41. The major part of the sideways movement imparted to the pusher 41 by the cam 54 matches the speed and direction of the recess 37 and the pocket 13 over the small arc of movement during which the tablet is being pushed from the recess 37 into the pocket 13 as the result of the reciprocating movement imparted to the pusher by the cam 58. The pusher 41 receives in addition a small extra sideways movement to allow it to withdraw without fouling. Since there is no appreciable relative arcuate movement of the

elements

37, 13 and 41 during the said small sideways movement, it is possible to eifect the transfer of the tablet without momentarily stopping the wheel 38 or the wheel 10.

When a tablet is inserted into apocket 13 in a wrapping element it is supported at the rear by a friction plunger 44 slidably mounted in the pocket. The wrapper covers the rear surfaceof the tablet, is pleated in a random fashion round the periphery and stands forward in a kind of skirt from the face of the carrier element. At station C, which is situated approximately 30 below the horizontal, rotary tuckers indicated diagrammatically at 45 and co-acting with a stationary tucking piece 46 complete the folding, and the folds then pass over a heated segment 47 at station D and a cooling segment 48 at station E in order to complete the wrapping.

Soon after this the wrapping elements are again momentarily slowed by the portion 17F of the cam track 17 in order that the wrapped tablet may be discharged at station F by means of the friction plunger 44. The friction plunger receives its stroke from a tappet rod 49 actuated by a cam, not shown.

What I claim as my invention and desire to secure by Letters Patent is:

l. A bunch wrapping machine comprising a number of wrapping elements mounted on a rotary carrier head so as to be carried thereby past successive wrapper feed, loading, tucking, sealing and discharge stations, said wrapping elements being constituted by blocks formed with open-mouthed pockets extending into them in a direction parallel to the axis of rotation of the carrier head, means on each wrapping element for receiving a wrapper supplied at the wrapper feed station and holding it across a face of said wrapping element across the mouth of the pocket in the wrapping element and a pusher at the loading station for introducing articles in succession into the pockets of the wrapping elements as they arrive at the loading station, each article carrying a wrapper with it as it enters the pocket, and means at the discharge station for discharging wrapped articles from the pockets.

2. A wrapping machine according to claim 1 which includes driving mechanism for imparting continuous rotation to the carrier head and means for momentarily decelerating the Wrapping elements as they pass the wrapper feed, loading and discharge stations.

3. A wrapping machine according to claim 1 in which the wrapping elements are displaceably mounted on the carrier head and comprising means for rotating the carrier head continuously and at a uniform speed, means for feeding wrappers continuously to the wrapper feed station at a uniform rate less than the normal peripheral speed of the wrapping elements and means for momentarily decelerating each wrapping element as it reaches the wrapper feed station. V

4. A wrapping machine according to claim 1, in which the wrapping elements are displaceably mounted on the carrier head and comprising means for rotating the carrier head continuously and at a uniform speed, a feed wheel mounted for rotation about an axis parallel to that of the carrier head and having peripheral recesses located closer together than the pockets in the wrapping elements, means for rotating the feed wheel continuously at a uniform speed to bring its recesses successively into register with the pockets of the wrapping elements at the loading station, means for introducing articles in succession into the recesses of the feed disc, and means for momentarily decelerating each wrapping element as it reaches the loading station.

5. A wrapping machine according to claim 2 in which the carrier head is mounted for rotation about a horizontal axis and which includes a recessed feed wheel arranged to rotate continuously about a horizontal axis and a magazine for charging articles into the recesses of the feed wheel, the feed wheel bringing its recesses successively into register with the pockets in the wrapping elements at the loading station to permit of transfer from the recesses to the pockets by the pusher.

6. A wrapping machine according to claim 2 wherein the wrapping elements are pivotally mounted on the carrier head for movement about axes parallel to the axis of rotation of the carrier head and carry followers coacting with a fixed track shaped to provide the required deceleration of the wrapping elements.

7. A wrapping machine according to claim 2 wherein each wrapping element carries wrapper grippers which are spring urged to position to hold a wrapper against the wrapping element and comprising fixed cam pieces which coact with the wrapper grippers to open them momentarily as each wrapping element passes through the wrapper feed and loading stations.

References Cited in the file of this patent UNITED STATES PATENTS Rose Oct. 31, 1922 FOREIGN PATENTS Germany Apr. 3, 1958