US3551239A

US3551239A - Box covering method and apparatus

Info

Publication number: US3551239A
Application number: US708705A
Authority: US
Inventors: Ernest J Newton
Original assignee: ERNEST J NEWTON
Current assignee: ERNEST J NEWTON
Priority date: 1968-02-27
Filing date: 1968-02-27
Publication date: 1970-12-29
Anticipated expiration: 1987-12-29

Description

Dec. 29, 1970 E. J. NEWTQN BOXCOVERING METHOD AND APPARATUS 4 Sheets-Sheet 1 FIG.

Filed Feb. 27

FIG.

INVENTOR.

ERNEST J. NEWTON BY M'JWIJI ATTORNEYS Dec. 29, 1970 E. J. N'EWTON BOX'COVERING METHOD AND APPARATUS 4 Sheets-Sheet 2 Filed Feb. 2'7 1968 FIG. 2

INVENTOR. ERNEST J. NEWTON BY W MQ- ATTORNEYS Dec. 29, 1970 Filed Feb. 27 1968 4 Sheets-Sheet 3 A |o4- I04 FIG. 4

' INVENTOR. ERNEST J. NEWTON BY [W7 ATTORNEYS 1970 E. J. NEWTON BOX COVERING METHOD AND APPARATUS 4 Sheets-Sheet 4 Filed Feb. 27, 1968 FIG. 5

FIG. l2

INVENTOR. ERNEST J. NEWTON BY Mm- ,JIM 1440mm ATTORNEYS United States Patent 3,551,239 BOX COVERING METHOD AND APPARATUS Ernest J. Newton, 3795 Wilson Ave., Montreal, Quebec, Canada Filed Feb. 27, 1968, Ser. No. 708,705 Int. Cl. B29c 17/04 US. Cl. 156-213 14 Claims ABSTRACT OF THE DISCLOSURE This invention is a machine and method for covering box shells with a deformable thermoplastic sheet material in which the material is first softened, then drawn down over a movable support for the box shells so as to cover the outside surfaces thereof, and to form tents over the shells, suction is applied to the inside of the tents to draw the sheet material tightly against the outside surfaces of the box shells and against a tucking member adapted to fit inside the shell, and then the shell is between the box shells and the aforementioned tucking 0 member to transfer and lay the material against the inside surfaces of the box shell.

BACKGROUND OF INVENTION It has been known in the art for some time that it is possible to cover objects with a heat sensitive thermoplastic material by first heating the materials so that they become stretchable, and then stretching them around the object to be covered. Many machines and methods for doing this have been devised, but basically they fo low the same pattern in that either the object to be covered is stationary and the material is brought around it and held in the enveloping position until the material cools, or the sheet of plastic material is held in a top position over the article to be covered, and then the article to be covered is moved into the sheet in order to draw the sheet around the article. It is to be noticed that in these several methods, it is always the outside of the article that is being covered.

There also have been machines developed which are basically adapted to covering the inside of an article with a plastic sheet, and again such machines first heat the plastic material and then by means of a form fit the stretchable material inside the article whose insides are to be covered.

In the manufacture of jewelry boxes where box shells are to be covered. It has long been desired to use a plastic material, such as vinyl, in which the material may imitate other materials such as leather, cloth, etc. Using the machinery and methods of the prior art, it has been possible to cover either the outsides or the insides of these box shells relatively easy, but to date it has not been possible to cover both the outside and the inside surfaces of the walls of the box shells in an automatic single operation.

The reason for desiring to cover the inside surfaces of the shell walls is that in a jewelry box, a pair of pads are used one of which covers the bottom of the box and one of which covers the top of the box. The pads are ornamental and serve not only to mount jewelry within the box, but also as a covering means to cover up the raw ice appearance of the material of the box shells themselves and any raw edges. In such a box, therefore, it is high- 1y desired to extend the covering material down on the inside surfaces of the walls of the box shell at least far enough so that when the pad is inserted, it covers up the edges of the covering material, with the result that when one opens the box and looks at it, what one sees is the ornamental pad and completely covered walls. To date, any covering of the inside walls with plastics have been a hand operation and therefore relatively ineflicient.

In summary, it is the purpose of this invention to provide a machine which when once loaded with a plurality of box shells, simultaneously covers that plurality of box shells both on the outside and then on the inner surfaces of the Walls of the box shells.

Therefore, among the several objects and advantages of the invention may be noted the provision of apparatus for covering both the outside of the box shell and the inside surfaces of the walls of the shell by at least a semiautomatic operation, the covering taking place automatically once the apparatus has been loaded with the shells to be covered and the covering material.

Another object of the invention is to provide apparatus of the above kind in which means are provided for heating the covering material in order to render it ductile prior to the covering operation, all operations thereafter being automatic.

A further object of the invention is the provision of apparatus of either of the above kinds in which means are provided for drawing a tent around the box shell to be covered, creating a diiferential pressure between the inside of the tent and the outside, and while maintaining said differential pressure, causing a relative motion between the shell and a tucking means so that material is tucked inside the box and laid against the inside surface of the box walls.

Yet another object of the invention is to provide apparatus of any of the above classes in which means are provided for guiding the box shells during the above operations, the guiding means being extended at the start of the automatic operations, but being retractable during subsequent steps in order to allow the tucking operation to take place.

A still further object of the invention is to provide a method of covering a box shell which results in a fast operation of covering both the outside and inside walls of the box shell on at least a semiautomatic basis.

A further object of the invention is the provision of any of the apparati set forth above or methods, which are simple to construct, easy to use, and economical in their operation.

The invention therefore accordingly comprises the elements and combinations of elements, features of construction, arrangements of parts, manipulation of the apparatus, the steps and sequence of steps and features of operation, all of which will be exemplified in the structures and methods hereinafter set forth, and the scope of the application of which will be indicated in the appended claims.

In the accompanying drawings, in which one of the various possible embodiments of the invention is illustrated:

FIG. 1 is a plan view of one embodiment of the invention;

FIG. 2 is a front elevation of the embodiment of FIG. 1;

FIG. 3 is a sectional elevation of a portion of the FIG. 1 embodiment, taken in the directionof sight lines 33 on FIG. 1 and showing an initial position of operating elements;

FIG. 4 is a sectional elevation similar to FIG. 3, but taken in the direction of sight lines 44 on FIG. 1 and showing a second stage in the operation of the apparatus;

FIG. is a view similar to FIG. 4, but showing the operating parts in a third stage of the operation;

FIG. 6 is a view similar to that of FIGS. 4 and 5, but enlarged thereover, to show a final position of the operating elements of the embodiment;

FIG. 7 is an illustration of a support element of the apparatus;

FIG. 8 is an illustration of an alternate support element of the apparatus;

FIG. 9 is an illustration of a tucking element used in the invention;

FIG. 10 is an illustration of a combined support and guide member used in the apparatus for certain box-shells;

FIG. 11 is a sectional elevation of the support element of FIG. 10 in combination with a tucking element; I

FIG. 12 is an illustration of a portion of a U-shaped, ornamental fastening-frame used to assist in holding a covering on a box; and

FIG. 13 is an illustration of a box shell showing the use of the FIG. 12. fastening frame.

Throughout the drawings, dimensions of certain of the parts as shown may have been modified and/or exaggerated for the purposes of clarity of illustration and understanding of the invention. Throughout the drawings, similar reference characters indicate corresponding parts.

Referring first to FIGS. 1, 2 and 3, there are shown a plan view, a front elevation, and a sectional elevation of one of several possible embodiments of the invention. In this embodiment, there is shown a heating structure indicated generally by numeral 2, the structure being a sliding framework or box containing an ohmic heating element indicated by the dotted lines 4. The heating element 4 is connected in conventional manner to a source of electrical power (not shown). Heater 2 is an open-faced box structure 6, for example, with the structure facing downwardly so that element 4 may radiate its heat directly downwardly. Heater 2 is supported by means of round side rails 8, the latter sliding in the half round tubes 10 which are mounted, conventionally, one on each side of the machine or supports 7. An upright handle 12 is fastened to the heater 2 so that the heater structure as a whole may be pulled forwardly on the machine into a position in which the radiated heat from heating element 4 will heat a sheet of plastic which is to be used to cover box-shells.

Attached to the front end of the box 6 is a curved strap 14 which serves, when the heater 2 is pulled forward, to actuate a switch 16- in conventional manner. Switch 16 starts a timing element which may be set to a given number of seconds or minutes. At the end of the set period of time, the timer provides an indication that the period is ended, and then the heating element 4 is shut off and the box 6 is moved back to the position of FIG. 1.

Attached to the front of the apparatus is the covering mechanism proper, indicated generally by numeral 18. It comprises a plate bed 20 having dependent therefrom the side walls 22 and a bottom plate 24, the sides and bottom plate 24, the sides and bottom plate forming a chamber 23 beneath the bed plate 20. Plate 20 and its dependent chamber 23 are suitably supported on a platform 90 which in turn is supported by the legs 28 in conventional manner. A heat shield is fastened to the back of platform 90 and serves to protect the plate 20 from any stray radiation from heater 2.

Mounted against the underside of the bottom 24 is one end 30 of an air cylinder 32 which is of the double acting kind. That is, introduction of air at one side of the piston of the cylinder will move the piston out, and introduction of air at the other side of the piston (with simultaneous exhaust of air on the first side) will move the piston in the other direction. The cylinder 32 has a bottom plate 34 attached to its other end, and to this plate 34 is attached the mounting plate 36 of a second air cylinder 38. Cylinder 38 is, like cylinder 32, of the double-acting kind.

The piston rod 40 of cylinder 32 extends upwardly through a suitably provided aperture in the plate 24, and the upper end of the piston supports and actuates a platform 42 so that operation of the cylinder 32 will move the plate 42 upwardly and downwardly.

Slidably mounted in the bed plate 20 through suitable apertures 44 therein are the supporting shafts or plungers 46. Plungers 46 are moved upwardly and downwardly by motion of plate 42 to accomplish certain useful operations of the apparatus, as will be described below.

Referring to any of FIGS. 3-8, and particularly FIG. 7, a plunger 46 is shown in greater detail. Provided in the side of the plunger itself is a keyway 48. Mounted at the top of the plunger 46 is a guide plate '50, each guide plate comprising a body portion 52 and a plurality of fingers 56 which are swiveled in conventional manner on the body as shown. The guide plate is held onto the top of the plunger 46 by means of a screw 58.

The function of the guide plates 50 is to guide and align a box shell (which is to be covered) on top of the plungers 46, so that when the plunger and its guide plate are lowered, the box shell will fit down over a skirt or tucking element 60 on the base 20, now to be described.

Mounted on the bed plate 20 are a number of the above mentioned tucking elements 60, each element comprising a base portion 62 and the upstanding skirt portion 64. The skirt portion 64 is made smaller in size than the inside dimensions of a box shell to be covered, but has the same cross-sectional shape as the box shell. The size difference is preferably sufiicient to accommodate slightly more than two thicknesses of the material being used to cover the box shell. As shown in FIG. 6, when the platform 42 has been moved down so that the plungers 46 are fully downward, the guide plates 50 are completely enclosed within the skirt portion 64, the fingers folding upwardly and inwardly in order to accommodate this downward motion of the guide plates. On the other hand, while the guide plates are in their extended position, it will be noticed (see FIGS. 4 and 5) that the fingers 56 extend outwardly sulficiently to contact the side walls of the box shell 66 and thus guide the box shell centrally on the plunger 46 and in position to be moved downwardly over the upstanding skirts 64.

Where the construction of the box permits it, instead of using the guide plates 50, a box support and guide element 70 may be used, this box support element being slightly smaller than the inside dimensions of the box shell and small enough to fit down into element 60. Preferably, if the box shell is rounded, the top of the box guide 70 is rounded in similar manner. In general practice, particularly in regard to jewelry boxes, it is the practice for the box shell used as the base to have a flat, bottom. For such a flat bottom box shell, it will be found that the guide plates 50 are the ones to be used for guiding of the shell on the plungers 46. On the other hand, in jewelry boxes, it is quite conventional to use a domed top box shell, and in such instances, the box support 70 will be sufiicient to centralize such a dome shell on the respective plunger 46 so as to be aligned with the skirt members 60.

There will be instances, however, where the box shell to be covered is of such depth that both the guide plate and the support 70 will need to be used. In this instance, the support 70* governs the vertical position of the box shell during the covering operation, and the guide plate 50 determines the lateral position of the box shell so that the latter will be centered over the skirt 60. A reference to FIGS. 10 and 11 illustrate the use of the combination of the top support 70 and a finger plate 50 with a skirt member 60, FIG. 11 showing the plunger 46, guide plate 50 and top support 70 being withdrawn completely in the skirt 60. As illustrated the shell 66 rests down on top of the skirt 64, and the tucking and lay-up features of the covering material 122 are clearly shown.

Referring again to the tucking element 60, a pin 76 extends laterally into therein to intersect with the aperture 78 through which slides the plunger 46. The pin 76 engages the keyway 48 in order to prevent the plunger from turning within the tucking element. In order to permit air to be drawn from the top of the plate downwardly through the plate and into the chamber 23, a suitable groove 80 is provided in the periphery of the aperture 78.

A plurality of elements 60 is provided and each is held to the base 20 by means of conventional machine screws 65.

It is also to be noted (see FIG. 6) that in order to make chamber 23 relatively airtight around its peripheral joints, the plate 20 is mounted on the side walls 22 by means of screws 82 and by the use of a rubber gasket 84. The rubber gasket 84 is not necessary if a sufliciently large vacuum pump is used, but is preferred. In similar manner, the plate 24 is mounted to the underneath side of the walls 22 by means of the conventional screws 86, and again, a rubber gasket 88 may be used to effectuate a rela-- tively tight seal of the plate 24 to the walls. Also, if

necessary though not shown, the piston rod 40 may extend through a suitable packing gland in the plate 24.

The piston 100 of the cylinder 38 is attached to a thrust plate 102 on which are mounted the four sulpport shafts 104. These shafts extend upwardly and pass through suitable apertures in the platform 90 so as to clear the bed plate 20.

Mounted at the top of the shafts 90 is a framework indicated generally by numeral 106 which may be made of any suitable material and comprises two aligned

frames

108 and 110. The opening within the two frames, which are in alignment, is just sufficient to clear the bed plate 20 when the frames are lowered down to platform 90 by the shafts 104, as will be described below. The upper frame 110 is suitably hinged to the frame 108 along one edge so that the upper frame may be swung upwardly. The top surface of the lower frame 108 is covered with a rubberlike material 112, and the lower face of the upper face 110 is in like manner covered with a rubberlike material 114.

Stretched across the bottom plane of the upper frame 108 are a pair of wires 116, these wires being held tightly to the frame and in stretched condition by any suitable means. In the present embodiment, since only four of the tucking elements 60 are shown, only a pair of wires is needed, these wires intersecting about the middle of the open face of the frame to form four spaces defined by the wires and inside edges of the frames. Of course, if more than four individual covering units are described, then sufficient additional wires are used so that each covering unit is associated with such an opening formed by the wires or the wires and the edges of the

frames

108 and 110.

The thrust of the piston 100 is sufiicient so that when the piston is extended, the

frames

108 and 110 are drawn down past the bed plate 20 and come to rest against the apron or platform 90. In order to provide an airtight seal, a rubber gasket 120 is fastened to the bottom surface of the frame 108, and contact of the gasket 120 with the top of plate 90 will provide a sutficiently airtight seal. It will be noticed that when the frames 108-110 are thus drawn downward, the wires 116 are drawn tightly down against the top of the bed plate 20.

The use and operation of the device thus described is as follows: With the heating element 2 in its retracted position as shown in FIG. 1, and platform 42 raised to its up position by actuations of piston 40, box shells are placed on the supports 50 (see FIG. 3). Upper frame 110 is then raised upwardly from frame 108, the frame carrying with it the wires 116. A sheet of covering material 122 is then laid across the lower frame 108, and then the upper frame 110 is brought back to rest against the sheet, thus clamping the sheet between the

rubber gaskets

112 and 114. It will be observed, that in this position, the wires 116 overly the sheet. Suitable locking means, such as the pivoted lever or latch bar 123 is used to lock frame 110 to frame 108 in conventional manner.

Next, the heating device 2 is pulled forwardly by means of the handle 12 to come above the

frames

108 and 110, thus overlying the plastic material, FIG. 3 showing the parts in this position. At the same time, the heating element 4 is connected to a source of electrical power by means of a conventional switch. Upon pulling the heating element 2 forwardly, the switch 16 is actuated which starts the aforesaid timer operating. After a given interval of time (for example, seven seconds) it will be found that the radiated heat from the heating element 4 has been sufiicient to heat the plastic to its stretching and forming point. For example, where a vinyl material is used, it will be found that when the material is raised to approximately a temperature of 200 the material will have sufficient ductility for the remaining covering operations. Because of the timer, this point will be indicated when the bell of the timer or other indicating means is activated. At that point, power is shut off the heating element 4, and the whole heater mechanism 2 is pushed back to its position shown in FIG. 1.

With the plastic covering material still in a flexible condition, the cylinder 38 is actuated, for example, by means of the double acting valve 130, to move the piston downwardly, and thus move the shafts 104 so as to pull the frames 108-110 downwardly until they come to rest in the position shown in FIG. 4.

In view of the fact that the shells 66 are in the upward position, when the framework 108-110 is moved downwardly by means of shafts 104, the vinyl plastic 122 is also drawn downwardly by means of the Wires 116 and the frame so as to form tents 124 (see FIG. 4) over each of the box shells 66 and the element 60 below it. It will also be noted that the wires 116 are pulled tightly enough against the top of the bed plate 20, and the frame 108 is held tightly enough against the apron 90, so that virtually an airtight seal is created within the several tents (four, in the embodiment shown in FIG. 1). With the frames 108110 held in this position, a valve 134 is actuated, one side of the valve being connected by tubing 136 to a suitable vacuum pump (not shown) and the other side of the valve being connected by tube 138 to a suitable aperture 139 in the bottom 24. As a result, the chamber 23 is evacuated, and this sucks air from within the tents 124 as thus formed, with the result (see FIG. 5) that the covering material 122 forming the tents 124 is drawn inwardly to lie against the walls of the skirts 64, and it will be observed that at the points indicated by numeral 140 the plastic covering material has been drawn inwardly to overly the top perimeters of the skirts.

While maintaining the frames 108-110 and the plastic material 122 in the downward position shown in FIGS. 5 and 6, and while maintaining the vacuum, a doubleacting valve 132 which controls cylinder 32 is now actuated to one of its positions, with the result that air cylinder 32 retracts its piston 40. This retracts the platform 42, and the individual plungers 46 descend. This operation lowers the shells down over the skirt 64, and it will be observed that as the shells are so lowered, the skirts act a tucking agents to lay-up the material which formerly was against their sides over against the inside surfaces of the walls of the box shells. See FIG. 6.

In order to retain the material in place, one may coat the inside surface of the shells with a suitable heat activated adhesive, prior to loading the box shells into the machine. The plastic 122 will still retain enough of its heat to activate the adhesive, thus causing the covering material to stick to the inside surfaces of the box shell walls. Or, an adhesive may be used which is self-curing without heat.

The material will shortly have cooled down to the point that the frames 108-110 may be lifted upwardly by suitable actuation of the valve 130, the vacuum having been broken by opening the valve 134. The frame 110 is now pivoted upwardly, and the shells together with their covering material may be withdrawn from the machine.

At this point, further shells are put on the supports, another sheet of plastic material is laid across the frame 108, and the operations given above are repeated. While this set is being covered, the covered shells of the first set are severed from the rest of the sheet material by any convenient method, either mechanical or by hand.

Due to an adherent memory of a plastic material such as vinyl, there may be a tendency for the covering material to draw backwards, and thus possibly pull the covering material away from the inside of the box shell sides. In order to eliminate this, as mentioned above a suitable adhesive may be used which will cover not only the outside of the box shell but the insides of the box shell walls. When this adhesive is set, it will be sufficiently strong to prevent any such retraction. On the other hand, the withdrawal may be prevented by clamping the plastic covering material about the edge of the box. This is conveniently done by using, for example, a typical ornamental U-shaped framework 140 illustrated in FIG. 12. FIG. 13 show a box having been covered and the framework in place, the framework being clamped against the covering material in conventional fashion in order to more firmly secure the covering material to the box wall. If desired, both adhesive and the clamping frame 140 may be used.

Throughout the description, little mention has been made of the materials from which the various components are to be made. This is within the engineering skill of the art, and steel and brass may be used where a designers choice indicates that they should be used. The elements 60 may be formed out of metal, which is preferred; or if desired for economy, they may be molded from a suitable plastic material such as an epoxy resin.

Other means may be used to guide the box shells so that they will fit nicely down over the several elements 60. Whatever the means used, it is important to notice that in the method of covering described herein, the box shells are held away from the tucking mechanisms 60 while a tent of the plastic covering material is formed over the box shell. Air is then withdrawn from within the tent in order to cause the covering material to fold inwardly. At that point, a relative motion between the box shell and the tucking element is caused to occur, whereby the tucking element telescopes up within the shell. By doing this, material which has hitherto been caused to lay-up against the outside of the tucking element, due to the vacuum, is caused to be transferred to the inside walls of the box shells, whereat the material is secured in place either by a simple adhesive or by a member which is clamped around the edge of the box shell.

In view of the above it will be seen that the several objects of the invention are achieved and other advantageous results attained.

It is to be understood that the invention is not limited in its application to the details of construction, and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practiced or carried out in various ways. Also, it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.

As many changes could be made in the above construc tions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings, shall be interpreted as illustrative and not in a limiting sense, and it is also intended that the appended claims shall cover all such equivalent variations as come within the true spirit and scope of the invention.

Having described the invention, what is claimed is:

1. The method of covering with a covering material an open-faced hollow article having a bottom and a plurality of side walls extending therefrom, comprising the steps of supporting the article by its bottom on a support on a base with the open face of the article facing on one 8 direction, and the support being movable relative to the base;

supporting a sheet of covering material adjacent the outerface of the bottom of the article;

supporting on the base a tucking element projecting therefrom toward said open face, said element having the same cross-sectional shape as that of the article but being smaller and thereby being adapted to move into the hollow article;

stretching the sheet of covering material over the article and toward the base to form a tent of said material over the article;

causing a differential pressure to exist between the air pressures on the outside and inside of said tent with the air presssure inside the tent being less than that outside, whereby the sheet is pressed snugly against the outer surface of the article and against the outer surfaces of said tucking element;

While maintaining said differential pressure, moving the article and tucking element toward each other until said element at least partially enters the open face of the article, whereby said material is pulled from the outer walls of said element and laid against the inside surfaces of said sides to cover at least a portion thereof; and

thereafter causing said material to be held tightly at least to the edge portions of the sides of the article.

2. The method of claim 1 in which said sheet of covering material is supported at its border in a frame movable toward said base.

3. The method of claim 1 in which said sheet of covering material is supported at its periphery by a frame, and including a grid of elongated members overlying the plastic sheet and forming a plurality of openings large enough to pass over said article, said members drawing said sheet over the article by passing over the article and against said base, thereby to form said tent.

4. The method of claim 1 in which the differential air pressure is caused by sucking air from within said tent.

5. The method of claim 1 in which the step of causing the said material to be held tightly against the sides of the article includes the step of applying, over said material covering the edges of the sides, a framework of stiff material having a U-shaped cross-section, the framework clamping the material against said edge portions.

6. The method of claim .1 in which the inside surfaces of said sides are covered with an adhesive, said adhesive tightly binding the covering material to the inside surfaces as the material is laid thereon during relative motion between said element and the article.

7. The method of claim 1 in which said covering material is a thermoplastic resin.

8. The method of claim 7 including the step of heating the material prior to forming said tent, to make said material more ductile.

9. The method of claim 8 in which the plastic resin is vinyl.

10. Apparatus for covering an open-faced hollow article with a layer of covering material, the article having a bottom and a plurality of sides upstanding therefrom comprising:

a base;

a support for the article mounted on the base and adapted to move toward and away from the base;

a tucking element upstanding from the base and extending toward the support, said element having the same cross-sectional shape as the article but being small enough to fit into the open face of the latter, whereby upon motion of the support toward the base the article is adapted to fit over said element;

means for forming a tent of said material over the article with the latter on the support, said base constituting the bottom of the tent and the article being at the top of the tent;

means for causing the air pressure outside the tent to be greater than that inside the tent, thereby to force said material against the outer surfaces of the article and said element; and

means for moving said support and article toward said element sufiiciently far so that at least a portion of said element enters the article while maintaining the outside air pressure greater than the inside air pressure, whereby said material removed from the sides of said element and is laid against at least portions of the inside surfaces of said sides.

11. The apparatus of claim 10 in which said support is mounted on the base by means of a plunger slidable through the "base, the apparatus including movable means workable against the free end of the plunger to move said support.

12. The apparatus of claim 11 including guide means mounted on the plunger and movable therewith, the guide means constituting a flat plate so shaped as to fit within said element when the support moves toward the latter; said plate having fingers pivoted thereto at its periphery, the fingers being adapted to fold upon entry of the plate into said element; and the envelope defined by the free ends of the fingers being the shape and size of the crosssection of the interior of the article, whereby, when the article is On the support prior to its motion toward said element, said fingers are extended and center the article with respect to said element.

13. The apparatus of claim 10 in which the means for forming said tent comprises:

a frame adapted to hold a sheet of the material initially over an article on the support;

a grid of elongated members overlying said material and forming openings large enough to pass over said article, the grid being movable toward the base far enough to draw the material over said articles when on the support, and down against the base.

14. The apparatus of claim 10 including means for heating said material to render it stretchable prior to forming said tent.

References Cited UNITED STATES PATENTS 2,621,142 12/1952 Wetherell 156-216X 3,146,143 8/1964 Bolesky et al. 156216X 3,147,172 9/1964 Wesa et a1 156-216X 3,325,329 6/ 1967 Bolesky 156216X 3,329,545 7/1967 Hamilton 156213 SAMUEL W. ENGLE, Primary Examiner US. Cl. X.R.

3 3 3 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,551,239 Dated December 29, 1970 Inventor(s) Ernest J. Newton ppears in the above-identified patent It is certified that error a hereby corrected as shown below:

and that'said Letters Patent are Column 3 lines 57 and 58, cancel the phrase "the sides and bottom plate 24,".

Column 5, line 47 "described" should read "desired".

Signed and sealed this 23rd day of March 1971 (SEAL) Attest:

EDWARD M.FLETCHER,JR. WILLIAM E. SCHUYLER, JR.

Commissioner of Patents Attesting Officer