US2995878A

US2995878A - Wrapping machines

Info

Publication number: US2995878A
Application number: US833836A
Authority: US
Inventors: Brook Leonard; Walker Rowland
Original assignee: Forgrove Machinery Co Ltd
Current assignee: Forgrove Machinery Co Ltd
Priority date: 1958-10-14
Filing date: 1959-08-14
Publication date: 1961-08-15
Anticipated expiration: 1978-08-15

Description

Aug. 15, 1961 L. BROOK ErAL WRAPPING MACHINES 5 Sheets-Sheet 1 Filed Aug. 14. 1959 Aug- 15, 1951 l.. BROOK Erm. 2,995,878

WRAPPING MACHINES Filed Aug. l4 1959 5 Sheets-Sheet 2 Aug. 15, 1961 L. BROOK ETAL 2,995,878

WRAPPING MACHINES Filed Aug. 14. 1959 5 sheets-sheet :s

A? /Mw/ gj MMM www Aug. 15, 1961 L. BROOK ETAL 2,995,878

WRAPPING MACHINES Filed Aug. 14. 1959 5 sheets-sheet 4 Aug. 15, 1961 1 BRooK ETAL 2,995,878

WRAPPING MACHINES Filed Aug. 14. 1959 5 sheets-sheet 5 nited States Patent 2,995,878 WRAPPING MACHINES Leonard Brook, Bramhope, near Leeds, and Rowland Walker, Dewsbury, England, assigno'rs to The Forgrove Machinery Company Limited, Leeds, Yorkshire, England, a company of Great Britain Filed Aug. 14, 1959, Ser. No. 833,836 Claims priority, application Great Britain Oct. 14, 1958 6 Claims. (Cl. 53--73) This invention relates to wrapping machines of the type comprising a conveyor, e.g. an intermittently rotating horizontal feed disc, formed with article receiving pockets and serving to feed the articles in succession to a loading station, means at the loading station for transferring the articles in succession from the pockets of the conveyor to a wrapping mechanism and wrapper feed mechanism for feeding wrappers in succession into the path of travel of the articles so that each article carries a wrapper with it into the wrapping mechanism.

It is -necessary to provide in such machines a trip mechanism for testing the presence, or otherwise, of articles in the pockets of the conveyor as they approach the loading station and disabling the Wrapper feed mechanism, when necessary, so as to prevent a wrapper from being fed into the path of the transfer mechanism whenever the latter fails to deliver an article to the wrapping mechanism.

Normally the trip mechanism comprises a trip arm carrying at one end a detector linger integral with the arm, a cam lever for rocking the trip arm to cause the finger to move towards each pocket of the conveyor as it approaches the loading station, a spring for maintaining the cam lever in operative relationship with an operating cam, the spring yielding whenever the ringer is prevented by an article from entering a pocket in the conveyor and means for disabling the wrapper feed mechanism whenever the nger moves into an empty pocket in the conveyor. The spring must be strong enough to prevent the runner of the cam lever from leaving the profile of the cam and in the case of a machine designed for high speed wrapping (erg. in which the cam shaft rotates at 350-500 rpm.) the detecting finger moves with considerable impact into contact with the articles, e. g. confectionery tablets, in the pockets of the conveyor, and this results in broken and distigured tablets. 'Ihe object of the invention is to avoid this disadvantage.

The invention provides a Wrapping machine of the above type in which the trip mechanism comprises a cam mechanism, an associated cam lever, a trip arm operable by the cam lever through the agency of a spring which can yield in the event of obstruction to movement of the trip arm, a trip member coacting with the trip arm and movable to alternative positions in one only of which it obstructs movement of the trip arm, means for disabling the wrapper feed mechanism whenever the movement of the trip arm is obstructed by the trip member, and a detector nger movable by the cam mechanism under the control of a light spring to test the presence of articles in the pockets of the conveyor, the detector finger being coupled to the trip member and ensuring that it will :occupy its obstructing position when and only when the detector finger moves into an empty pocket in the conveyor.

The trip member may be arranged to occupy normally its non-obstructing position and to be moved into its 4obstructing position whenever the detector nger is able to move into an empty pocket of the conveyor. Alternately the trip member may be normally in its obstructing position and arranged to be moved therefrom whenever an article obstructs movement of the detector linger into a pocket in the conveyor.

Two embodiments of the invention will now be described in more detail, by Way of example, with reference to the drawings, in which:

FIG. 1 is a side elevation of the iirst form of trip mechanism,

FIG. 2 is a corresponding plan view,

FIG. 3 is an end elevation looking from the left hand side of FIG. 1,

FIG. 4 is a side elevation of the second form of trip mechanism,

FIG. 5 is a corresponding plan view, and

FIG. 6 is a detail View showing part lof the mechanism of FIG. 4 in a displaced position.

Like reference numerals indicate like parts throughout the gures.

The embodiment shown in FIGS. 1-3 will first be described. In this, the presence or otherwise of articles in the pockets 11 of an intermittently rotating horizontal feed disc 12 is tested by a detector linger 12 shortly before the pockets arrive at a loading station 13, at which the articles are lifted in succession in known manner by an `elevator 139 into a wrapping wheel. The linger 12 is mounted on an arm 15 fixed to a rocking shaft 14. Also fixed to the shaft 14 are a trip operating lever 16 and an actuating lever 1K7. A spring 18 holds the lever 17 in Contact with ya roller 19 on a control arm 20. Adjacent the lever 16 is a trip member 21 pivoted on the rod 22 and normally held against a stop 23 by a spring 24 extending between the

parts

21 and 16.

A cam 25 on a cam shaft 26 actuates a 4follower 27 on a cam arm 28 rotatably mounted on a rocking shaft 29 and integral with the arm 20, which is thus periodically rocked by the cam. When the arm 2i) is rocked anti-clockwise as seen in FIG. 1, the linger 12 is moved by the light spring 13 into a pocket in the `feed disc, the extent of movement being determined by the presence or otherwise of an article 3b in the pocket.

The cam 25 also coacts with a follower 3i on a cam lever 32 which is free on the shaft 29. A strong compression spring 33 is mounted between the cam lever 32 and a lever 34 fixed to the shaft 29. Also xed to the shaft 29 are a Itrip arm 35 and an upwardly extending lever 36. Pivoted at 37 on a member 38 fixed to the cam shaft 26 is a pawl 39, the nose of which is normally maintained by a spring 40 in engagement with a ratchet 4i on a sleeve 42 rotatably mounted on the cam shaft and serving to drive the wrapper feed mechanism. This, being of conventional construction, is not illustrated.

When the finger 12 y(operated as above described by anti-clockwise movement of the arm 20) is arrested by the presence of an article 36 in the pocket under test, the nger 12 and lever 16 are prevented from moving further under the action of the spring 18 and the trip member 21 remains unmoved in the position shown in full lines in FIG. l. The trip arm 35 and lever 36 are accordingly rocked to their full extent by the cam 25 to a position also shown in full lines in which the lever 36 is clear of a roller 43 on the tail of the pawl 39. The pawl is accordingly effective to actuate the wrapper feed mechanism. When, however, the pocket tested is empty, the spring 13 is able to rock the arm 15 and lever 16 clockwise to an extent such that the lever 16 displaces the trip member 21 anti-clockwise into the position shown in chain dotted lines. The trip member 21 then arrests the nip arm 35 and lever 36 in the positions shown in chain dotted lines in FIG. l, the spring 33 yielding to permit of further movement of the cam lever 32. As the result, the lever 36 contacts the tail of the pawl 39 to disengage it from the ratchet 41 and disable the wrapper feed mechanism, thereby preventing a wrapper from being ed into position at the loading station 13 above the empty pocket in the feed disc.

The compression spring 33 can be made of sufficient strength to ensure full control over the trip arm 35 and lever 36 at high machine speeds, whereas the spring 18 may be made light so that the impact of the detector tinger 12 in the `articles is small. f Y

In the construction shown in FIGS. 4-6, the cam 25, as before, periodically rocks a cam lever 32 free on the shaft 29 and thereby rocks, through a strong compression spring 33, a lever 34 fixed to the shaft 29. Also fixed .to the shaft 29 is a lever 36 for lcoaction With a pawl 39 which is normally eiective to drivel the wrapper feed mechanism, this drive being imparted lthrough the agency of a gear 142 on the sleeve 42. The nger 12 is, however, differently operated from that in the construction previously described. Y

Fixed to the rocking shaft 29 is a trip arm 35 having pivoted at 50 at its free end a subsidiary trip arm 135 carrying the detecting iinger 12. A light spring 51 connected in tension between the

arms

35, 135 normally maintains an adjustable screw 52 on the subsidiary trip arm 135 in contact with an abutment 53 on the trip arm 35, as shown in FIG. 4.

An arm 54 fixed to the subsidiary trip arm 135 extends downwardly from the pivot 50 thereof and carries a pin '55 engaging a slot 56 in a lever 57, pivoted at its lower end on a fixed pivot 58 iand carrying a trip plate 124 normally located, as shown in FIG. 4, beneath a cooperating trip plate 125 on the undersurface of the trip arm 35 The cam rocks the

arms

35, 135 so as to move the detecting finger 12 towards each pocket 11 in the feed disc as the pocket approaches the loading station. When the pocket contains an article 30 the downward movement of the finger 12 is arrested and, as shown in FIG. 6, the subsidiary trip arm 135 is rocked against the tension spring 51, thereby causing the pin 55 to shift the lever 57A and move the trip plate 124 clear of the trip plate 125 on the trip arm 35. The latter is accordingly free to complete its stroke, with the result that the lever 36 moves into a position clear of the pawl 39.

Whenever, however, the hnger 12 fails to detect an article 30 it can move down into the pocket 11 in the feed disc, the subsidiary trip arm 135 is not rocked and the trip plates 124, 125 coact to limit the movement of the trip arm 3'5. Consequently the lever 36 is arrested in a position which it coacts with the pawl 39 to disengage it from the ratchet 41, thereby disabling the wrapper feed, continued movement of the cam lever 32 compressing the spring 33 without imparting further movement of the rotating shaft 29.

As in the construction of FIGS. l-3, the compression spring 33 can be made of suicient strength to give full control over the trip arm 35 at high machine speeds, Whereas the tension spring 51 may be light so that the impact of the detector nger 12 on the articles is small.

What we claim as our invention land desire to secure by Letters Patent is:

1. In a wrapping machine comprising a conveyor formed with article-receiving pockets for feeding articles in succession to a loading station, means at the loading station for transferring the `articles in succession from said pockets, wrapper feed mechanism for feeding wrappers in succession to the machine, a normally operative driving member for driving said wrapper feed mechanism, said driving member moving in a predetermined path, and a trip mechanism for testing the presence of articles in said pockets as they approach the loading station and controlling the wrapper feed mechanism accordingly, the improvement which consists in that said trip mechanism comprises a cammechanism, a cam lever actuatable thereby, a trip arm, a spring between said cam lever and said trip arm for imparting movement to said trip arm, said spring yielding in the event of obstruction to movement of said trip arm, a trip member coacting with the trip arm and movable from a position in which it obst-ructs movement of said trip arm to an alternative position in which it is clear of said trip arm, means controlled by said trip arm for intercepting said driving member and thereby disabling the Wrapper feed mechanism Whenever the movement of the trip arm is obstructed by the trip member, a detector finger movable by said cam mechanism to test the presence of articles in said pockets, a light spring coupled to the detector iinger and controlling its movement towards the pockets, and means coupling said detector linger to said trip member for causing said trip member to occupy its obstructing position when the `detector finger moves into an empty pocket and its alternative position when movement of said detector finger is arrested by Ian article in a pocket.

2. A wrapping .machine according to claim 1, wherein said trip member normally occupies its alternative position and said trip mechanism comprises a control arm coacting with said cam mechanism and with said detector ringer and actuatable by said mechanism to permit of periodic movement of the detector finger towards the pockets by said light spring.

3. A Wrapping machine according to claim 2, comprising a shaft, an arm xed to said shaft and carrying the detector finger, an actuating lever fixed on said shaft and urged by said light spring into contact with the control arm, and a trip operating lever also fixed to said shaft and connected to the trip member to control the position thereof.

4. A wrapping machine according to claim 1, wherein said trip member normally occupies its obstructing position and wherein said trip mechanism includes a subsidiary trip arm pivotally mounted on the trip arm and coupled thereto by the light spring, the subsidiary trip arm being capable of moving against the light spring to shift the trip member away from its obstructing position whenever movement of the nger into a pocket in the conveyor is obstructed by an article.

5. A wrapping machine according to claim 4, wherein said trip member is constituted by a trip plate and said trip mechanism includes a pivotally mounted lever carrying said trip plate and an arm attached to the subsidiary trip arm and engaging said lever to move said trip member to its `alternative positions'.

6. A `wrapping machine according to claim 1, wherein said `conveyor is an intermittently rotating horizontal feed disc.

References Cited in the tile of this patent UNITED STATES PATENTS 1,555,596 Miller Sept. 29, 1925 1,875,974 Alm Sept. 6, 1932 2,144,265 Milmoe Jan. 17, 1939 2,601,636 Rose et al. June 24, 1952 2,656,906 Van Haandel Oct. 27, 1953 2,676,441 Brook Apr. 27, 1954 2,720,068 Brook Oct. l1, 1955 FOREIGN PATENTS 386,955 Great Britain 1933