US2643501A - Wrapping machine - Google Patents

Description

June 30, 1953 RUSSELL 2,643,501

WRAPPING MACHINE Filed Feb. 4, 1952 5 Sheets-Sheet l 3.9 40 C 2;. O o '1 I 11 0 I! Q) x I D o 42 4! June 30, 1953 A. RUSSELL WRAPPING MACHINE 5 Sheets-Sheet 2 Filed Feb. 4, 1952 June 30, 1953 A. RUSSELL WRAPPING MACHINE 5 Sheets-Sheet 5 Filed Feb. 4, 1952 M M, m W

June 30, 1953 A. RUSSELL 2,643,501

WRAPPING MACHINE Filed Feb. 4, 1952 s Sheets-Sheet 4 June 30, 1953 A. RUSSELL 2,643,501

WRAPPING MACHINE Filed Feb. 4, 1952 s Sheets-Sheet 5 Patented June 30, 1953 WRAPPING MACHINE Alexander Russell, Leeds, England, assignor to The Forgrove Machinery Company Limited, Leeds, England, a company of Great Britain Application February 4, 1952, Serial No. 269,884 In Great Britain February 15, 1951 6 Claims.

This invention relates to machines for wrapping shaped blocks of plastic materials, such for example as butter, margarine or the like, of the kind described for example in U. S. Patent No. 2,379,655, comprising an intermittently rotating wrapping wheel having a number of pockets arranged to be brought in succession to a receiving station, and a lifting member for lifting into each pocket, while it dwells at the receiving station, a block of plastic material together with a wrapper, which is fed into position between the pocket and the block and folded in U formation about the block as it is lifted into the pocket.

It has been the customary practice in such machines to provide each pocket of the wrapping wheel with a fixed base plate and a pair of pivoted side jaws. The use of a fixed base plate, however, has the disadvantage that wrinkles may form in the portion of the wrapper adjoining the top of the block as the latter is lifted into the pocket. Furthermore, correct register of the wrapper in relation to the block is dependent solely upon adhesion between the wrapper and the block during the lifting of the block into the pocket, and this adhesion is sometimes insufficient.

This invention provides a wrapping machine of the above kind, in which each pocket of the wrapping wheel comprises a movable base plate at the receiving station and simultaneously opening the side jaws preparatory to arrival of the block in the pocket, and thereafter raising the base plate and gradually closing the side jaws on the block as the latter is lifted into the pocket.

In this way I ensure that the wrapper will lie smoothly on the upper surface of the block and that the wrapper will be tightly folded in U- formation against the sides of the block.

Preferably, the base plate of each pocket is resiliently mounted on a bar which, on arrival of the pocket at the receiving station, is moved up and down in relation to the wrapping wheel by a cam mechanism and is linked to the side jaws so as to impart opening and closing movements thereto. This allows the initial impact of the top of the block against the base plate to be taken up together with the amount of acceleration required by the bar to enable it to reach, on its up stroke, the same speed as the 22 speed of upward movement of the lifting member. The flexible mounting of the base plate also allows for vibration in the height of the block of plastic material.

One specific embodiment of wrapping machine according to the invention will now be described. in detail, by way of example, with reference to the accompanying drawings, in which:

Fig. 1 is a front elevation of the wrapping wheel and associated lifting plunger,

Fig. 2 is a sectional elevation, on a larger scale, showing the pocket of the wrapping wheel at the receiving stage and in position to receive the block of material to be wrapped,

Fig. 3 is a view similar to Fig. 2, but showing the jaws of the pocket closed, this figure being a section on the line IIIIII in Fig. 4,

Fig. 4 is a side elevation of part of the wrapping wheel, looking from the right hand side of Fig. 3,

Fig. 5 is a section on the line V-V in Fig. 3, and

Fig. 6 is an enlarged detail perspective view, showing the spring mounting of the base plate.

Like reference numerals denote like parts II, meshing with another gear (not shown) driven by a Geneva mechanism (also not shown),

which imparts intermittent movement to the wrapping wheel Ill. The wrapping wheel Ill is attached to the gear wheel l2 by a sleeve [3 having at its ends bearing bushings which fit the shaft, and the resulting unit is disposed on the shaft between a collar [4 and a circular member 15, both of which are fixed to the shaft II. The wrappin wheel has four pockets I 6 which are brought successively, by rotation of the wrapping wheel, to a bottom receiving station A (Fig. l), a folding station B, a top pressing station C and a discharge station D, these stations being spaced apart.

As each pocket I6 dwells at the receiving station A, a block I! of plastic material is lifted into the pocket by a lifting member [8 (Fig. 1), which is reciprocated by a linkage l9 deriving movement from a cam 20 as described in U. S. Patent No. 2,379,655. A pusher 2| feeds the blocks in succession onto the top of the lifting member l8 while it is dwelling in the bottom position shown in Fig. l. Wrappers 22 are fed in succession into the path of the lifting member I8, as described in U. S. Patent No. 2,374,838, so that a wrapper is folded in U-formation about each block as the latter is lifted into the pocket, by the base plate 23 and side jaws 24 of the pocket which will be described later. Prior to arrival of the pocket at the folding station, the depending ends of the wrapper are folded against the base of the block. At the folding station B, side tucks are formed in the projecting ends of the wrapper and these ends are folded against the surface of the block remote from the centre of the wrapping wheel. During the travel of the block to the top pressing station C it passes between fixed end plates having slots which fold down against the ends of the block the projecting triangular wings of the wrapper which are left projecting at the folding station. At the top pressing station, a top presser descends onto the top of the block to ensure correct shaping thereof and finally, at the discharge station D, the block is discharged from the pocket in a direction parallel to the base plate thereof. The operations taking plate at the stations B, C and D will not be described in more detail as they form no part of the present invention.

The base plate 23 of each pocket is carried on a bar 25 mounted in guides 2t on the wrapping wheel so that it may slide radially in relation to the wrapping wheel. The base plate 23 is resiliently supported on the bar 25 by compression springs 21, which tend to hold the base plate projected from the bar. As will be clear from Fig. 6, a bracket 28 is attached to the base plate 23 and fixed by bolts 29 to a plate 39 formed with a cavity embracin a waisted portion 25 of the bar 25. The lower ends of the springs 21, which lie one on each side of the bar 25, are accommodated in tubular bosses 3| in the bracket 28 and the plate 30 respectively, while their upper ends are accommodated in tubular bosses 32 on plates 33 fixed by a bolt 34 to the bar 25. The springs 21 normally hold the base plate projected beyond the lower end of the bar 25 as shown in Fig. 2. The springs 21, however, can yield when necessary to permit of limited upward movement of the base plate in relation to the bar.

A stud 35, passing through the upper ends of the plates 33 and the bar 25 and extending parallel to the shaft H of the wrapping wheel, carries a roller 36 (Fig. 5) which runs in an annular track 3'! in the circular member 15. Each side jaw 24 of each pocket is mounted on a pivot pin 38 extending parallel to the shaft ll of the wrapping wheel and is integral with an upwardly extending arm 39 connected by a link 40 to an arm 4| integral with one of the plates 33. Consequently, as the bar 25 and base plate 23 move outwardly on the wrapping wheel, from the position of Fig. 3 to that of Fig. 2, the side jaws 24 will be opened, and vice versa.

A section l5 of the circular member adjoining the receiving station A, which section contains part 3! of the annular track, is movable in relation to the rest of the circular member and is attached by a bolt 43 (Fig. 5) a lever 42, pivoted at 44 (Fig. 1) to the machine frame and actuated by a cam 45. Normally, the section I5 occupies the position shown in Fig. 3 in which its portion 3'! of the track 31 is aligned with the remainder of the track. Each time, however, a pocket approaches the receiving station A, and after the roller 36 on the stud of that pocket has entered the portion 31 of the track in the movable section l5 of the circular member 15, the cam 45 moves the movable section [5 into the position shown in Fig. 2 and thereby slides the bar 25 and base plate 23 downwards and opens the side jaws 24 of the pocket. The movement is timed to open the side jaws 24 to the maximum and to depress the base plate 23 to its lowest position, in which it is disposed immediately above the wrapper 22, as shown in Fig. 1, as the pocket begins to dwell at the receiving station.

The block I! of margarine pushed upwards by the lifting member l8 first contacts the wrapper 22 and then contacts the base plate 23 of the pocket immediately afterwards. This flattens the wrapper over the whole of the top surface of the block and prepares the way for clean tight folding of the wrapper round the block. As the block rises into the pocket, the cam 45 gradually returns the movable section I5 to its normal position. The resulting gradual closing of the side jaws 24 as the block rises into the pocket ensures tight folding of the wrapper onto the sides of the block.

As already noted, the flexible mounting of the base plate 23 on the bar 25 allows for the initial impact of the top of the margarine block plus the amount of acceleration required by the operating movement to reach the same speed as the block lifter movement.

After return of the pockets to the position shown in Fig. 3, the wrapping wheel commences its movement to carry the partially wrapped block to the folding station B. During the remainder of the rotation of the wrapping wheel, and until the pocket in question again reaches the receiving station A, the annular track 3'! coacts with the stud 36 to maintain the bar 25 in the retracted position and the side jaws 24 closed on the block of plastic material. In this position, as shown in Fig. 3, the inner face of the base plate is closely adjacent to shoulders 50 on the side jaws. Consequently, when the block is pressed at the top pressing station C, the

resilient connection between the base plate and the bar can only yield to a very slight extent and the full pressure of the top presser is taken by these shoulders 50.

The circular member [5 has been described as having a simple annular track 31 and but one movable section l5 adjacent the receiving station A, and this will be sufficient because the soft mass of the margarine or butter permits discharge, at the discharge station D, of the blocks from the pockets in a direction parallel with the base plate 23 without it being necessary to open the side jaws 24 at the discharge station. If desired, however, the track 31 may have an offset portion, in the vicinity of the discharge station D, which will operate to displace the roller 36 and bar 25 in the direction to give a small opening to the side jaws 24 as the pocket arrives at the discharge station D.

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

l. A machine for wrapping shaped blocks of plastic material, comprising a wrappin wheel disposed with its axis horizontal and having a number of pockets, each comprising a movable base plate and pivoted side jaws, means for imparting intermittent rotation to said wrapping wheel to bring said pockets in succession to a receiving station said pockets extending downwardly when at said receiving station, an intermittently operating lifting member for lifting into each of said pockets as it dwells at the receiving station a block of plastic material with a wrapper folded in U-iormation about it, and mechanism, operating in timed relationship with the lifting member, for movin downwardly the base plate of the pocket at the receiving station and simultaneously opening the side jaws of said pocket preparatory to arrival of the block in the pocket and thereafter raising said base plate and gradually closing said side jaws on the block as the latter is lifted into the pocket.

2. A machine for wrapping shaped blocks of plastic material, comprising a wrapping wheel disposed with its axis horizontal and having a number of pockets, each comprising a bar movable radially in relation to the wheel, a base plate resiliently mounted on the end of said bar, a pair of pivoted side jaws and linkages for imparting pivotal movement to the side jaws from said bar, means for imparting intermittent rotation to said Wrapping wheel to bring said pockets in succession to a receiving station said pockets extending downwardly when at said receiving station, an intermittently operating lifting member for lifting into each of said pockets as it dwells at the receiving station a block of plastic material with a wrapper folded in U formation about it, and mechanism, operating in timed relationship with the lifting member, for operating the bar of the pocket at the receiving station to lower the base plate and open the side jaws of said pocket preparatory to arrival of the block in the pocket and thereafter to raise said base plate and gradually close said side jaws on the block as the latter is lifted into the pocket.

3. A machine for wrapping shaped blocks of plastic material, comprising a wrapping wheel disposed with its axis horizontal and having a number of pockets, each comprising a bar movable radially in relation to the wheel, a base plate on the end of said bar, a pair of pivoted side jaws and linkages for imparting pivotal movement to the side jaws from said bar, means for imparting intermittent rotation to said wrapping wheel to bring said pockets in succession to a receiving station said pockets extending downwardly when at said receiving station, an intermittently operating lifting member for lifting into each of said pockets as it dwells at the receiving station a block of plastic material with a wrapper folded in U formation about it, a fixed member adjoining and coaxial with the wrapping wheel, said fixed member having therein an annular track and comprising a movable portion adjoining the receiving station, studs on the bars of all the the side jaws thereof and thereafter, as the block rises into said pocket, to raise said base plate and close said side jaws.

l. A Wrapping machine as claimed in claim 3 comprising springs between each base plate and the associated bar for permitting limited upward movement of the base plate in relation to the bar while the block is being lifted into the pocket.

5. A wrapping machine as claimed in claim 4, in which the side jaws of each pocket have, on the inner faces of the jaws and near the pivots thereof shoulders which, when the side jaws are closed, coact with thebase plate to prevent any substantial inward movement thereof in relation to the bar.

6. A machine for wrapping shaped blocks of plastic material, comprising a wrapping wheel disposed with its axis horizontal and having a number of pockets, each comprising a movable base plate and pivoted side jaws, means for imparting intermittent rotation to said Wrapping wheel to bring said pockets in succession to a receiving station, said pockets extending downwardly when at said receiving station, an intermittently operating lifting member for lifting into each of said pockets as it dwells at the receiving station a block of plastic material with a wrapper folded in U-formation about it, mechanism, operating in timed relationship with the lifting member, for first moving downwardly the base plate of the pocket at the receiving station into position close to the Wrapper and thereafter raising said base plate as the lifting member lifts the Wrapper and block into the pocket, and linkages connecting said base plate to said side jaws and arranged to open said side jaws as said base plate moves downwards and gradually to close said side jaws as said base plate moves upwards.

ALEXANDER RUSSELL.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 727,554 Phillips May 5, 1903 2,077,431 Neumair Apr. 20, 1937

Images