US3078632A - Wrapping machine - Google Patents

Description

Feb. 26, 1963 H. M. FORMAN WRAPPING MACHINE 4"Sh ets-Sheet 1 Filed March 6, 1961 INVENTOR. HAROLD M. FORMAN I, II]

' A TTORNE Y Feb 26, 1963 4 Sheets-Sheet 2 Filed March 6, 1961 lOl b 2 3 4 2 W 8 1 L 2 4 3 mm s 6 M6 3 I 3 3 r H I 7 .m 2 m Q ll 9 3 1 m 4 W m A B FIG. 2.

INVENTOR. HA ROLD M. FOR MAN A TTORNE Y Feb. 26, 1963 H. M. FORMAN WRAPPING MACHINE 4 Sheets-Sheet 3 Filed March 6, 1961 INVENTOR HAROLD M. FORMAN FIG. 3.

ATTORNEY Patented Feb. 26, 1953 3,078,632 WRAPPllNG MACHINE Harold M. Format], Philadelphia, Pa., assignor, by mesne assignments, to Formatran, Inc, Philadelphia, Pin, a corporation of Pennsylvania Filed Mar. 6, MM, Ser. No. 93,424 4 Claims. (Cl. 53222) This invention relates to the wrapping of articles in sheets of wrapping material and it is more particularly concerned with a machine for carrying out the Wrapping operation.

There are a number of products, such as small boxes of potatoes, oranges, fruits and vegetables of various kinds, books, candies, cakes, etc. that are so irregular in shape that it is difficult to place a wrapper around them that will fit snugly, stay in place and look attractive. One procedure for overcoming this problem is to Wrap the article in a heat shrinkable plastic sheet and then, by subsequent treatment, shrink the wrapper to conform to the shape of the article. Prior methods and devices for accomplishing this are inefficient, cumbersome and ditlicult to use.

An object of the present invention is the provision of a wrapping machine for the purpose mentioned which comprises a novel combination of parts that results in an improved operation over previous types of wrapping machines.

Another object of the invention is the provision of such a machine which is efiicient, simple and easy to operate and which functions substantially automatic.

A further object of the invention is the provision of a wrapping machine which envelopes an article to be wrapped with a section of a sheet of wrapping material from a larger sheet, seals the section in place about the article, severs the section from the remaining portion of the sheet, and then positions the severed end and succeeding portion automatically for operation on a succeeding article to be wrapped.

A still further object of the invention is the provision of such a machine which is adaptable and adjustable to different sizes of articles to be wrapped.

These and still further objects, advantages, and features of the invention will appear more fully from the following description, considered together with the accompanying drawing in which an embodiment of the invention is described and shown by way of illustration, but not by way of limitation.

,In the drawing:

FIG. 1 is a vertical sectional view of the embodiment along the line 11 of FIG. 3.

FIG. 2 is a view similar to FIG. 1 with the movable parts of the embodiment in a different phase of the cycle of operation.

FIG. 3 is a side elevational view of the embodiment as Viewed from the right of FIG. 1.

FIG. 4 is a sectional view along the line 44 of FIG. 1.

FIG. 5 is a sectional view along the line 5-5 of FIG. 4.

FIG. 6 is a plan sectional view along the line 6-6 of FIG. 1.

FIG. 7 is a sectional view along the line 77 of FIG. 1.

FIGS. 8 and 9 are fragmentary sectional views of a portion of FIG. 2 on a larger scale with the movable parts in different phases of the cycle of operation, respectively.

Referring With more particularly to the drawing in which like numerals designate like parts throughout the several views, the embodiment illustrated comprises a wrapping table 11 supported on a suitable frame structure, including legs 12 (only one shown) connected by bracing members 13 and 14 welded or otherwise secured to the legs.

A loading ledge 15' is disposed alongside of and spaced from the table 11 at a slightly higher elevation and it is supported on a suitable frame structure, including legs 16 connected by bracing members 17 and 18. The frame structures of the table and ledge are rigidly connected together by cross bracing members, including members 19, 2b, and 21.

A vertical wall 22 is secured to the legs 16.

The loading ledge 15 is adapted to receive and support an article, such as a box of produce 23 preliminary to its being wrapped on the wrapping table 11. The ledge has a transverse slot 24 therein to slidably receive the upper end of a vertical rocker arm 25. The lower end of the arm 25 is rigidly secured to a rocker shaft 26 mounted in bearings 27 and 28 at the bottom of the wall 22.

An offset bar 29 is set parallel to the bottom section of the arm 25 and its lower end is likewise secured to the rocker shaft 26. The upper end of the bar 29 is connected to the arm 25 by means of a tie rod 30 secured by bolts 3]. or by any other suitable means.

The upper end of the arm 25 projects through the slot 24 and carries a pusher bar 32 which is adapted to contact the article to be wrapped on the loading table, such as the box of produce 23, and move it transversely to the wrapping table ll. The initial position of the box 23 relative to the wrapping sheet is set by means. of an adjustable abutment member 33 on the ledge, the adjustment being provided by a slot 34 in the bottom plate at right angles to the slot 24 engaging a bolt 35 in the ledge. A wing nut 36 carried by the bolt releasibly secures the plate in different positions in the direction of the slot.

The arm 25 is biased to its outer or initial position by means of a lever 37 having one end secured to the shaft 26. The other end projects inwardly and upwardly from the shaft and is connected to one end of a tensioned coil spring 38. The other end of the coil spring is secured to an anchor post 3% on a suitable stationary part of the frame of the device.

The arm 25 is actuated by power from an electric motor 4% which drives the intake shaft 41 of a gear box 4-2 by means of pulleys 43 and 44 connected by a belt 4-5. The take-off shaft 46 of the gear box has a crank arm 47 secured thereto for corotation. The outer end of the arm 47 is pivoted to one end of link 48 and the opposite end of the link has a longitudinal slot 49 which slidably engages a pin 50 on the bar 29.

The take-off shaft 46 is provided with a second crank arm 51, the outer end of which is pivotally connected to a pitman 52. The upper end of. the pitman is pivotally connected to a bracket 53 of a horizontal yoke 54 forming part of the carriage hereinafter more fully described.

The yoke 54 comprises a cross bar 55 and two side arms 56 and 57 at the ends thereof connecting the cross bar to slide bars 58 and 5'9 set in channel grooves 69 and 61 of vertical members 62 and 63 extending downwardly and inwardly from the inner edge of the top of the table 11 to the horizontal bracing members 19 and 26 at the bottom.

The slide bars 8 and 59 extend upwardly above the wrapping table 11 and the upper ends thereof are connected by a cross bar 64'. Below the cross bar 64 there is disposed a vertical floating plate 65 which is mounted on the bars 58 and 59 by means of bolts 66 and 67 on the bars engaging vertical slots 68 and 69, respectively, of the plate. The plate is biased to a downward position by means of a pair of coil springs 79 and 71 between the plate and anchors 72 and 73 therebelow on the bars 58 and 59, res ectively.

A thermal bar or sealing iron 74 is secured in spaced parallel relation to the plate 65 with its lower edge upwardly offset from the lower edge of the plate. (See FIG. 4) The sealing iron includes electrical heating elements (not shown) of any conventional type which is connected to a source of electric power by conductors symbolized in the drawing by the wires 75.

Between the sealing iron 74 and the anchors 72, 73 there are secured to the bars 58 and 59 mounting plates or brackets 76 and 77, respectively. These plates face each other and are provided with vertical slots 78 and 79, respectively, in which thereare disposed the threaded ends of a horizontal bar 80. The bar 80 is non-rotatably secured to the plates'by means of wing nuts 81 and 82 on the outside of the plates and abutment nuts 83 and 84, respectively, onthe inside. By these means the bar 80 may be vertically adjusted in the slots to provide for different size packages, as will be explained more fully hereinafter.

Thebar 80 carries a group of rollers 85, 86 and 87in longitudinal spaced relation. These rollers are each straddled by the ends of a weak spring-88, 89 and 90, respectively. The endsof these springs are anchored to the bar '80, the purpose of which will be explained hereinafter.

Across the upper ends of the plates 76 and 77 there is disposed an electrical resistance or hot wire 91 above the lower edge of the sealing iron 74. (See FIG. 4.) This wire is connected to a' source of electrical current (not shown) through electrical conductors symbolized by the lines 92 to cause it tobecome hot for the purpose of severing thewrapping sheet.

The inner edge of the wrapping table 11 has an upstanding lip 93. Below the vertical plate 65 there is disposed on the table 11 a strip 94 having a vertical flange 95 parallel to the lip 93. Between the flange 95 and the lip 93' an anvil 96 is disposed directly below the sealing iron- 74. The space 97 betweenthe anvil 96 and the lip 93 is directly below the hot wire 91, and the space 98 between the anvil and the flange 95 is directly below the plate 65. Accordingly, when the carriage is moved downward, the lower edge of the sealing iron abuts the anvil 96, the hot wire 91 enters the space 97 and the. lower end of the plate 65 enters the space 98.

The wrapping sheet is supplied from a roll 99 secured to a roller 100 for rotation therewith. The ends 101 and 102 of the roller 100 are cradled in slotted end brackets 103 and 104 on a pair of spaced horizontal arms 105 and'106, respectively, which are secured cantileverwise to upright supports 107 and 108, respectively. These supports are secured to the frame structure of the device at any convenient place (not shown).

The cantilever arms 105 and 106 are provided with diagonal notches 109 and 110, respectively, for the pivotal engagement of pins 111 and 112. These pins. are attached to rocker bars 113 and 114, the corresponding ends of which are connected together by the rods 115 and 116 these rocker bars and tie rods forming a teeter frame 117. The rod 115 rotatably carries a roller 118 over which the web of wapping sheet passes first from the roll 99 and thence downwardly between a small press roller 119 and a relatively larger ratchet or brake roller 120 directly beneath it.

A bar 121 is secured across the outer ends of the cantilever arms 105 and 106 and a canvas loop 122 extends between this bar and the rod 115 to limit the rocking motion of the frame 117.

Secured to the bar 121 is one end of a canvas strap 123. The other end of the strap 123 carries a weight 124 and it passes over a friction drum 125 secured to the roller 100. A counterweight 126 is carried by the rod 115. Secondary counterweights are provided in the form of arms 113A and 114A which are welded to the bars 113 and 114 as shown, adjacent the pins 111 and 112. These secondary counterweights permit the machine to. operate on a lighter package and provide. a smooth drawing oif of the wrapping sheet.

A pair of cantilever arms 127 and 128 extend parallel to each other from the cross bar 64 to which they are attached,- by rivets or other suitable means, over the wrapping table and they are provided with longitudinal slots 129 and 130, respectively. A pair of vertical bars 131 and 132 are supported on the arms 127 and 128, respectively, by means of bolts 133"and 134 passing through the slots 129 and and wing nuts 135 and 136 for releasibly clamping them in adjacent position along the slots. The lower end of the bar 131 is riveted to one end; of a flexible horizontalstrap 137, such as of canvas. The opposite end of the strap extends toward, but short of, the bar 132 and isconnected to it by means of a tensioned coil spring 138. (See FIG. 7.)

The roller 119 is biased toward the ratchet roller 120 by means of coil spring 139 and 140 betweenthe respective shafts 141" and 142 on which they are mounted; re-

spectively. A ratchet gear'143 is secured to the shaft 142 and it is engaged with an escapement pawl or detent 144 that is pivoted to the frame member 108.

In the initial position, the members of the embodiment are disposed with the carriage in the upper position, the article 23 tobe wrapped on theledge 15, as shown in FIG. 1 in broken lines, and with the' lower end-of the wrappingsheet hanging below the'ratchet roller 120, also A shown in the broken lines of FIG. 1. The ledge has an overhanging vertical portion 145 on the inside which lies alongside thelower end of the wrapping sheet and to'whichthe sheet normally clingsby virtue of thestatic electricity,

which develops therebetween, the wrapping sheetbeing preferably a conventional type of transparent heat seal able synthetic'material, such-as Plio film, and'the portion' 145 being of a materiahsuch as aluminum, stainless steel,"

et'c-., which develops and holds an electrostatic charge.

As the shaft 46 rotates, the operation of the machine from this initial position is first to pull the lever 25 to the-left, as viewed in FIGS.-l and 2 which causes the pusher 32 tomove thearticleto be wrapped against the" adjacent portion 146 of the sheet'of wrapping material hanging between the table and the ledge and then onto the table. This portion of the sheet is thus caused to partially envelop'the article by virtue of thehorizontal loop formed therein, as shown by the full lines in FIG. 1,

a section thereof lying above and a section lying below" the article. As the shaft 46 continues to' rotate, the pusher 32 is returned to its initial position and the carriage is pulled downward to the position shown in FIG..

2. As the carriage moves downward to this position a deepreverse loop 147 is formed in the sheet around the rollers 85, 86 and 87 which causes the portion of the wrapping sheet between the roller 147 and the lip 93to bend upwardly the'springs 88, 89and 90. (See FIG. 8.) As thecarriage continues to move downwardly, the bottom edge of the floating plate 65. holds overlapping parts of the wrapping sheet sections together until the sealing bar 74 has. descended far enough to press them together on the anvil 96'and heat seal them to each other. Continued movement of the carriage causes the hot wire 91 to engage the. plies over the space 97 and sever them, whereupon the'springs 88, 89 and 90 force the severed free end of the sheet outward and downward ('see FIG. 9) to the initial position in. preparation for the wrapping of the succeeding article.

The severing also results in the separation of a small end portion 148 of the underlying section. This portion 148 due to the heat of the wire 91 clings to the free end. of the sheet. Each succeeding cycle provides a similar end portion which clings to the previous end portion. A canvas chute 149 is draped between the bottom of the table 11 and the bottom edge of an opening 150 in the plate 22. During the cycle of operation, the back of this-canvas chute is kicked by the movement of the crank arm 51 and link 52 which forces the end of the sheet containing these end portions out through the opening 150 whereupon, the attendant, when a sufiicient amount of'these end pieces have thus collected, removes them manually.

As the article to be wrapped encounters the wrapping sheet in moving from the ledge 15 to the table 11, it

draws a sufficient portion of the sheet from the supply to envelop the article. The ratchet roller 120, being free to rotate clockwise, as viewed in FIG. 1, the effect is to cause the teeter frame 117 to tilt to the position shown in FIG. 2. When this force is released, the counterweight 126 on the frame returns it to its initial position of FIG. 1. However, since the roller cannot rotate counterclockwise, because of the ratchet mechanism, the return of the rocking frame to its initial position causes an additional amount of the wrapping sheet to be withdrawn from the roll 99. The parts are so proportioned that this additional amount is substantially equivalent to that needed for the wrapping of each article. Adjustment for different size packages is made by changing the position of the bar 80.

As the carriage moves downward from the position shown in FIG. 1 to the position shown in FIG. 2, the strap member 137 which is adjusted to a position directly over the place on the table where the articles are to be wrapped, descends to contact the portion 146 of the wrapping sheet above the article and push it downward in contact with the article until the sealing and severing operations are completed. This results in the article being held firm- 1y during the sealing and cutting operations.

Having thus described my invention, I claim:

1. A wrapping machine comprising a table for supporting articles to be wrapped, a ledge adjacent said table for receiving the articles, said ledge being in spaced relation to said table, a member slidably mounted on the ledge for engaging an article thereon and moving it across the space between the table and ledge onto the table, means for supporting a supply of wrapping sheet material above said table, means for holding and vertically positioning an end portion of the sheet material in the space between said table and ledge, whereby when the article to be wrapped is moved by said slidable member from the ledge to the table, the article encounters and becomes partially enveloped in said portion between an upper section and a lower section thereof, a carriage unit mounted for vertical reciprocation between a position above and a position between said ledge and table, means for reciprocating said carriage between said positions, a horizontal member carried by said carriage for engaging during its downward movement an area of the said upper section of the wrapping sheet portion and bringing it in contact with a corresponding underlying area of the lower section, means for sealing said areas to each other, means for severing said portion from the remaining part of the wrapping sheet supply, and a resilient holding member carried by the carriage for contacting the upper section of the wrapping sheet portion and holding it against the article during the sealing and severing operations, and a pair of vertical arms secured to the carriage in spaced relation and to the ends of said resilient member.

2. A wrapping machine comprising a table for supporting articles to be wrapped, a ledge adjacent said table for receiving the articles, said ledge being in spaced relation to said table, a member slidably mounted on the ledge for engaging an article thereon and moving it across the space between the ledge and table onto the table, means for supporting a supply of thermally scalable wrapping sheet material above said table, means for holding and vertically positioning an end portion of the sheet material in the space between said table and ledge, whereby when the article to be wrapped is move-d by said slidable member from the ledge to the table, the article encounters and becomes partially enveloped in said portion between an upper section and a lower section thereof, a carriage unit mounted for vertical reciprocation between a position above and a position between said ledge and table, means for vertically reciprocating said carriage, a horizontal member carried by said carriage for engaging during its downward movement an area of the said upper section of the wrapping sheet portion and bringing it in contact with a corresponding underlying area of the lower section, a thermal sealing iron carried by said carriage, an anvil on said table directly below said iron, whereby when the sealing iron descends it presses and seals said areas together, means for separating the end portion from the re mainder of the sheet material supply, a bar carried by the carriage for contacting a part of the wrapping sheet adjacent the said end portion and forming therein a U-shaped loop as the carriage moves downwardly between the table and the ledge, a resilient member carried by the bar, said member being normally in a protracted position opposing the formation of said loop and being retractable from the normal position by the sheet when the loop is formed therein, whereby when the said portion is severed from the adjacent part the retracting force is released and said resilient member returns to its normal position and unfolds the loop in preparation for the wrapping of a succeeding article.

3. A wrapping machine as defined by claim 2 and means for vertically adjusting the position of said bar on the carriage.

4. A wrapping machine as defined by claim 2 in which the ledge has a vertical plate adjacent the locus of formation of the loop, said plate having electrostatic properties to attract the said adjacent portion.

References Cited in the file of this patent UNITED STATES PATENTS 2,651,444 Casey Sept. 8, 1953 2,672,268 Bower Mar. 16, 1954 2,741,885 Allison Apr. 17, 1956 2,860,466 Ingram Nov. 18. 1958

Claims (1)

1. A WRAPPING MACHINE COMPRISING A TABLE FOR SUPPORTING ARTICLES TO BE WRAPPED, A LEDGE ADJACENT SAID TABLE FOR RECEIVING THE ARTICLES, SAID LEDGE BEING IN SPACED RELATION TO SAID TABLE, A MEMBER SLIDABLY MOUNTED ON THE LEDGE FOR ENGAGING AN ARTICLE THEREON AND MOVING IT ACROSS THE SPACE BETWEEN THE TABLE AND LEDGE ONTO THE TABLE, MEANS FOR SUPPORTING A SUPPLY OF WRAPPING SHEET MATERIAL ABOVE SAID TABLE, MEANS FOR HOLDING AND VERTICALLY POSITIONING AN END PORTION OF THE SHEET MATERIAL IN THE SPACE BETWEEN SAID TABLE AND LEDGE, WHEREBY WHEN THE ARTICLE TO BE WRAPPED IS MOVED BY SAID SLIDABLE MEMBER FROM THE LEDGE TO THE TABLE, THE ARTICLE ENCOUNTERS AND BECOMES PARTIALLY ENVELOPED IN SAID PORTION BETWEEN AN UPPER SECTION AND A LOWER SECTION THEREOF, A CARRIAGE UNIT MOUNTED FOR VERTICAL RECIPROCATION BETWEEN A POSITION ABOVE AND A POSITION BETWEEN SAID LEDGE AND TABLE, MEANS FOR RECIPROCATING SAID CARRIAGE BETWEEN SAID POSITIONS, A HORIZONTAL MEMBER CARRIED BY SAID CARRIAGE FOR ENGAGING DURING ITS DOWNWARD MOVEMENT AN AREA OF THE SAID UPPER SECTION OF THE WRAPPING SHEET PORTION AND BRINGING IT IN CONTACT WITH A CORRESPONDING UNDERLYING AREA OF THE LOWER SECTION, MEANS FOR SEALING SAID AREAS TO EACH OTHER, MEANS FOR SEVERING SAID PORTION FROM THE REMAINING PART OF THE WRAPPING SHEET SUPPLY, AND A RESILIENT HOLDING MEMBER CARRIED BY THE CARRIAGE FOR CONTACTING THE UPPER SECTION OF THE WRAPPING SHEET PORTION AND HOLDING IT AGAINST THE ARTICLE DURING THE SEALING AND SEVERING OPERATIONS, AND A PAIR OF VERTICAL ARMS SECURED TO THE CARRIAGE IN SPACED RELATION AND TO THE ENDS OF SAID RESILIENT MEMBER.

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