US3586157A

US3586157A - Wrapping machines

Info

Publication number: US3586157A
Application number: US796375A
Authority: US
Inventors: Matthew Parker; Edwin Hall Lazenby
Original assignee: Rose Forgrove Ltd
Current assignee: Rose Forgrove Ltd
Priority date: 1968-02-06
Filing date: 1969-02-04
Publication date: 1971-06-22
Anticipated expiration: 1988-06-22
Also published as: GB1198021A; DE1905403A1; CH502920A

Abstract

Article-feeding mechanism which advances a procession of articles continuously towards a positioning stop and includes reciprocating leading and trailing grippers, and means for closing these grippers to engage respectively the leading and the next article in the procession after the leading article has contacted the stop, then advancing the grippers to feed the articles forward, the leading gripper imparting a larger forward movement to the leading article than is imparted to the next article by the trailing gripper, then opening the grippers to release the articles with a space between them and finally returning the grippers.

Description

United States Patent Inventors Appl. No.

Filed Patented Assignee Priority Matthew Parker Leeds;

Edwin Hall Lazenby, Bardsey, near Leeds, both 01, England Feb. 4, 1969 June 22, 1971 Rose Forgrove Limited Leeds, England Feb. 6, 1968 Great Britain 5835/68 WRAPPING MACHINES 5 Claims, 6 Drawing Figs.

US. Cl......

Int. Cl

............................................... res/21s,

mss 25/04 Field of Search;

[56] References Cited UNITED STATES PATENTS 3,262,541 7/1966 De Gain 198/19 Primary Examiner-Richard E. Aegerter Attorney-Wats0n, Cole, Grindle & Watson ABSTRACT: Article-feeding mechanism which advances a procession of articles continuously towards a positioning stop and includes reciprocating leading and trailing grippers, and means for closing these grippers to engage respectively the leading and the next article in the procession after the leading articlehas contacted the stop, then advancing the grippers to feed the articles forward, the leading gripper imparting a larger forward movement to the leading article than is imparted to the next article by the trailing gripper, then opening the grippers to release the articles with a space between them and finally returning the grippers.

BQSSBJST PATENTED JUN22 I9?! SHEET 1 OF 4 v wi #TTOf/MEKS waarsuso Mscrrrsias It is often necessary when feeding articles to be wrapped into a wrapping machine to space them apart from each other, for example, when they are of irregular shape and would tend to overlap or interlock and so impede the feed.

The invention provides a feeding mechanism for achieving such spacing of the articles automatically.

The invention provides apparatus for feeding articles to a wrapping machine comprising feed mechanism for advancing a procession of articles continuously towards a positioning stop, reciprocating leading and trailing grippers, and means for closing these grippers to engage respectively the leading and the next article in the procession after the leading article has contacted the stop, then advancing the grippers to feed the articled forward, the leading gripper imparting a larger forward movement to the leading article than is imparted to the next article by the trailing gripper, then opening the grippers to release the articles with a space between them and finally returning the grippers.

If desired, the leading gripper may have a pushing face which, on its next closing movement upon the second article, engages the leading article to advance it to a disposal position. Alternatively the leading article may be removed from the procession at the position to which it is advanced by the aforesaid forward movement. I

The leading article may be fed directly into the wrapping machine from either of said positions, e.g. by a prong on a chain conveyor running at right angles to the direction of advance of the feed mechanism. However, once the leading article has been separated from the others it can be disposed of and conveyed to the wrapping machine in any desired way.

Preferably the stop remains in the path of the articles and prevents gripper closure if no article is in the correct position to be gripped. This ensures that the positions of articles placed at random in the procession are later corrected, so that feeding, especially when starting up, is simplified.

The invention is particularly suitable for the feeding of chocolate bars of irregular outline. During normal running, all the chocolate bars in the feed channel leading to the stop, except that in the leading gripper, may move at an average speed very little more than the width of a bar per cycle, the period of arrest of the bars by the stop being only just enough to ensure that the leading bar is correctly positioned. The advantage of this very short dwell is that scuffing of the undersides of the chocolate bars is minimized.

Having determined that the leading chocolate bar is in position, the stop quickly moves clear to allow passage of the bar and then returns, behind the leading bar and in front of the second bar, i.e. into the gap later entered by the pushing face of the leading gripper upon its return and closure; and is so timed that it will safely limit the movement of the bars in the feed channel when the grippers are open.

The function of the trailing gripper is to prevent displacement of a correctly positioned second bar during movement away from it of the leading bar, so that the gap between the bars is always as intended, both in amount an position. As the stop is inoperative at this time the operator could, but for the trailing gripper, when pushing bars along the feed channel to catch up with those already feeding upset the correct positioning and cause the stop and pushing face to collide with a chocolate bar occupying the space into which they should return. Thus, wrong positioning of the bars is always prevented, for if the operator pushes them when the grippers are open, this can only advance their arrival at the stop, and result in a momentary excess of skid as the feed member slides ineffectively under them.

A constantly moving belt may constitute the feed mechanism, but we prefer to use a system of bars, as described later, arranged to give a somewhat similar action to that of the well-known cakewalk" motion.

These feed bars are capable of emptying the feed channel of chocolate bars, whereas the dead plate needed to support the chocolate bars immediately the belt begins to round the pulley, if a feed belt is used, invariably holds back several of the bars and so reduces feeding space. Also, stainless steel bars are much easier to keep clean than is a belt.

One embodiment of the invention is illustrated in the accompanying drawings, in which: a

. FIG. 1 is a side elevation of mechanism for feeding chocolate bars to a wrapping machine with the front plate removed,

FIG. 2 is a plan view partly broken away,

FIG. 3 is an end elevation,

FIG. 4 is a section on the line IV-IV in FIG. 1,

FIG. 5 is an enlarged view of a trip mechanism looking in the direction of the arrow X in FIG. 1, and

FIG. 6 is a corresponding plan view.

As shown in the drawings articles, in the case illustrated chocolate bars 100, are placed manually in a feed channel constituted by three feed bars I, 2, and 3 and

side guides

4, 5 supported on plates 104, I05, the articles extending transversely to the feed bars as shown in FIG. 3. The

outer feed bars

1 and 3 perform a substantially horizontal reciprocating movement while the center feed bar performs a cakewalk motion, receiving both a horizontal and a vertical reciprocating movement.

The center bar 2 receives a substantially horizontal movement from a cam 6 (FIG. 4) through the agency of a cam lever 7, a link 8, and a lever 9 (FIG. 1), which oscillates levers 10 fixed to a rear shaft 11 and pivoted by pins 12 to a bracket 14 on a support 13. Similar levers l0 and a similar bracket 14 are provided near the front of the support 13, the levers 10 being fixed to a shaft IS. The front and rear pins 12 carry levers 17, 16 respectively, which are joined by a link 18; the levers l7, 16 being oscillated by a cam 19 (FIG. 4), through the agency of

levers

20, 21, pivoted respectively to the shafts 15 and 11, and

links

22, 23 thereby imparting a small vertical movement to the center bar 2, which is fixed to

brackets

24, 25 on the levers l6, 17.

The

bars

1 and 3 are given a substantially horizontal movement only from a cam 26 (FIG. 4) through the agency of a lever 27 and a carrier 28 having three pillars 29, one fixed to the bar 1 and the others to the bar 3. The rear ends of the

bars

1 and 3 are supported by pillars 30 on

brackets

31, 32 pivoted to a lever 33 which rocks on a shaft 34.

Apart from small increments at the beginning and end of the leftward movement of

bars

1, 2, and 3 for acceleration and deceleration, the motion is at uniform speed, and the distance moved by each bar at this speed is just over half the width of a chocolate bar. The

bars

1 and 3 begin to decelerate near the end of their leftward movement at the moment when the bar 2, having just accelerated up to speed from the beginning of its leftward movement, comes level with

bars

1 and 3, after lifting about one-sixteenth inch. This upward motion continues for about another one-sixteenth inch, so that the articles previously being carried leftward by the

bars

1 and 3 now continue, still at the same unifonn speed, to move leftward on the bar 2, and the

bars

1 and 3 return below the articles. The bar 2 begins to decelerate, near the end of its leftward movement and halfway through its total downward movement, and at this moment the bars l and 3 have just accelerated up to speed from the beginning of their leftward movement, so that again the articles continue to move uniformly leftward, having transferred back to the bars I and 3, the bar 2 meanwhile returning below the articles.

The conjoint cakewalk motion of the bar 2 and horizontal reciprocating motions of the

bars

1 and 3 are thus effective to impart a continuous feed to the articles 100, moving them in procession towards a positioning stop 53.

The articles in the procession are engaged in pairs by leading and trailing grippers, which close on the first two articles in the procession after the leading article has contacted the stop 53. These grippers then advance the first two articles by different amounts to provide a definite spacing between them, release the articles, return, and afterwards again grip a pair of articles.

The trailing gripper is constituted by a gripper jaw 36 pivoted by a stud 35 to be support 13 so that the jaw 36 partakes of the horizontal movement of the center bar 2 which acts as a cooperating lower gripper when a lever 37, pivoted on the shaft 115 and having a runner 137 coacting with a cam 38, is permitted by the cam 33 to descend under the action of a spring 63 and so to cause a cam piece 39 on the lever 37 to allow a runner 40 on the jaw 36 to descend under the action of a spring 431, to close the jaw 36 on the article 1008 behind the leading article NBA on the feed bars 1-3 just after the center bar 2 has begun to lift all the articles from the

bars

1 and 3. At the moment it is gripped the article 100B is correctly positioned, i.e. touching the leading article 100A which is now in contact with the stop 53 and gripped by the

jaws

42, 43 of the leading gripper 101. The jaws d2, 43 are mounted on

pivot pins

47, 48 on a lever 45 pivoted on a shaft 46 and are interconnected by meshing gear segments M3, 144. The leading gripper 101 is operated by the cam 6 and the lever 7 through a link 44 and the lever 45, and opening and closing movement of the

jaws

42, 43 is controlled by a cam piece 49 on the lever 37, a runner 50 on the jaw 42 and a spring 51 connected between the jaws.

As they are both operated by the cam 6 the leading and trailing grippers move together, but the lever ratios are such that the leading gripper is caused to move a greater distance than the other, so that on arrival at the extreme leftward position, as shown in HO. 1, the leading article 100A and the immediately following article 1098 are an appreciable distance apart and the lever 37 has lifted to its uppermost position, causing the

jaws

36, 42, and 43 to open and thus release the leading article 100A on to a platform 52, which is cut away for the entry of the jaw 42 and also to free the next article 1008,

. which cannot however be displaced to an unsafe position because the stop 53, which is pivoted to the lever 37 at 54, is interposed between it and the leading article 100A.

As the grippers and the center bar 2 return, the article 1008 is moved by the feed. bars l and 3 up to the stop 53, leaving sufficient room for an upstanding pushing face 142 on the jaw 42 to rim, after retraction of the grippers by the center bar 2, into the space 102 between the article 1008 and the leading article 100A as the grippers close, the pushing face 142 preventing unsafe displacement of the article 1008 until closure is completed and while the stop 53 descends well below the feed level.

It is evident that a third article will now be held by the gripper 36 and is thus restrained from following the article 1003 except at the prescribed rate.

The leading article 100A is pushed from the platform 52 to position 55 by the upstanding face 142 on the jaw 42 upon the next leftward movement of the closed grippers, from which position it will normally be moved into the wrapping machine by a prong 56 on a chain conveyor. A light spring 57 holds a trip pin 58 (F I08. and 6) against a stop 59 and overlapping a trip wedge 60 to prevent downward movement of the lever 37 under the pull of the spring 63 unless an article overcomes the spring 57 by pressing against the stop 53, to which is fixed an arm 61 carrying the pin 58. Movement of the pin 58 to the right as seen in FIG. 1 is limited by an angle piece 62 which forms with the trip wedge 60 a channel for controlling the pin 58 and the stop 53 during movement of the lever 37. The stop 53 thus always obstructs the feed channel and the grippers stay open unless an article trips the stop.

It is not essential that the articles should be moved at uniform speed along the feed channel, and the

bars

1 and 3 need not move the articles through exactly the same distance as the bar 2. Chocolate bars having irregular bases, e.g. bars containing projecting nuts, may require the bars l and 3 to have-vertical movement as well as the bar 2 to ensure clearing the projections during the return of the bars.

The above-described apparatus can also be used to feed groups of articles, which tends to be uneconomical when performed by hand because of the concentration required over long periods to ensure that the correctnumber of articles per group I8 assembled and placed in the mfeed of the wrapping machine and extra feeders may be needed to keep up with the speed of the machine. If the articles referred to above as second and third" articled are considered themselves each to consist of two or more chocolate bars, the ready adaptation to group feeding can be appreciated, e.g. if the apparatus is set up to feed single 1 inch wide bars, then a wide bars will be fed by it in groups of four, the only special conditions being that the leading gripper must safely hold all of the first four bars, and that the trailing gripper must safely hold at least the foremost one of the following bars.

When the apparatus is used to feed groups of chocolate bars, it is more convenient to move the articles directly into the wrapping machine from position A instead of from position 100, e.g. by conveyor prongs similar to those indicated at 56. In this case no pushing face M2 is required on the jaw 42.

The apparatus may also be used to count articles, e.g. by inserting a pusher after every n cycles of gripper closure into the gap left by the pushing face M2 on the jaw 62, after gripper opening, so that groups of N objects can be pushed clear in an identifiable manner. This is often useful, e.g. to deal with wrapped objects being discharged from a wrapping machine.

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

1. Apparatus for feeding articles to a wrapping machine comprising feed mechanism for advancing a procession of articles continuously towards a positioning stop, reciprocating leading and trailing grippers, and gripper-actuating means operatively associated with said grippers and effective first to close the grippers so that they engage respectively the leading and the next article in the procession after the leading article has contacted the stop, to advance the grippers to feed the articles forward, the leading gripper imparting a larger forward movement to the leading article than is imparted to the next article by the trailing gripper, then to open the grippers to release the articles with a space between them and finally to return the grippers.

2. Apparatus as claimed in claim 1, in which the leading gripper has a pushing face which, on its next closing movement upon the second article, engages the leading article to advance it to a disposal position.

3. Apparatus as claimed in claim 1 which includes a trip mechanism for preventing closure of the grippers unless an article is in contact with the stop.

4. Apparatus as claimed in claim 3, which includes a spring loaded lever movable under the control of a cam to permit of closing of the grippers, and a stop pin attached to the stop and biased to a position to prevent such movement of the lever, the stop being pivoted to the lever and movable by pressure of an article to overcome the bias and free the lever for movement to cause closure of the jaws.

5. Apparatus as claimed in claim 1, in which the feed mechanism comprises a first feed bar which performs a cakewalk motion and a pair of feed bars which reciprocate in a substantially horizontal direction and feed the articles forward while the first feed bar is in a lowered position and performing a return stroke.