Method for wrapping an article

FIELD OF THE INVENTION

The present invention relates to a wrapping machine for wrapping five surfaces of an article except the bottom thereof, and a method to do the same. More particularly, the machine and the method of the present invention are useful for wrapping an article having a variable length such as a bundle of lumber, plywood or the like, or a pile of other products, or a single article.

BACKGROUND

A very significant proportion of lumber and construction panels are currently shipped and stored in bundles or piles wrapped in a waterproof envelope in order to provide a protection against alterations due to weather conditions and stabilise the humidity level.

Traditionally, the placement and folding of the wrapper sheet has mostly been carried-out in a semi-automatic fashion, a web like material being supplied from a material roll positioned above the article to be wrapped. Also, prefabricated plastic envelopes (bags) are currently used to speed-up the wrapping operation. The bag is generally installed from the top of the bundle, thus protecting the top and the sides of the bundle, while allowing some air circulation through the bottom. In this latter case, the envelope is manually secured to the bundle by stapling into the wood pieces. In this case, the operation is still quite expensive since extensive manpower is still required and the cost of the envelopes is relatively high.

Many automated solutions have been proposed in the prior art to wrap pelletised articles in a plastic film or web. However, most of these solutions perform the wrapping operation by rotating a narrow plastic film roll around the load on a spiral path. Such techniques are not practical for elongate articles such as lumber bundles and do not provide automatic installation of a top web member nor yield a neat result.

It is also known in the art to use an automated system to slide a bundle of lumber into a bag that is then manually closed and sealed at one end. The economic performance of that process is still limited since expensive large prefabricated bags are required in a wide range of sizes, thus also resulting in inventory concerns.

Also known in the art, there is the U.S. Pat. No. 5,657,608 which discloses a fully automated method for wrapping a parallelpipedly shaped article such as a bundle of lumber, using a web like material supplied from a roll located over the article. The wrapper material is dispensed and folded around the article in a continuous process by the relative movements of a backing means and the article, plus the movement of the article with respect to spring loaded rollers as folding members. The principal embodiments of that invention as described show several limitations and drawbacks. The main drawback is certainly the fact that the process must be continuously, so that a new set-up is required after each time an incoming article does not require wrapping, that situation occurring frequently since only a part of lumber shipments must be wrapped. It shall also be noted that the folding caused by the rollers is not precisely controlled and will generally yield a poor looking result and very visible folding lines on the long sides of the article. That poor looking result is also subject to be emphasised by the presence of static electricity in plastic based wrapper material. Moreover, it is worth indicating that it is generally not acceptable to apply adhesive all over the article to hold the web in place. Another obvious limitation of that process is that the article is moved back and forth a few times to complete the wrapping. Since the contemplated articles are long and heavy, a lot of time and energy is required.

SUMMARY OF THE INVENTION

The present invention is directed to a wrapping machine and a related method that overcome the above-mentioned drawbacks.

In accordance with the present invention, there is provided a wrapping machine for wrapping an article located in a wrapping area, comprising:

web delivering means for delivering a web;

first clamping means for clamping a first end of the web extending from the web delivering means;

first moving means for moving the first clamping means;

cutting means for cutting the web extending from the web delivering means and therefor providing a web piece for wrapping the article;

second clamping means for clamping a second end of the web piece that is a free end opposite to said first end;

second moving means for moving the second clamping means;

fastening means for fastening the web piece on the article; and

a controller for controlling the web delivering means, the first and second clamping means, the first and second moving means, the cutting means, and the fastening means following a predetermined sequencing program in such a way that, in operation, the web piece is moved and put down over the article by means of the first and second clamping means and the first and second moving means, and is fastened to the article by means of the fastening means.

In accordance with the present invention, there is also provided a method for wrapping an article, comprising the steps of:

a) delivering a web by means of a web delivering means;

b) clamping a first end of the web extending from the web delivering means by means of a first clamping means;

c) moving said first end away from the delivering means by means of the first clamping means;

d) after step (c), cutting the web extending from the web delivering means and therefor providing a web piece for wrapping the article;

e) clamping a second end of the web piece that is a free end opposite to said first end by means of a second clamping means;

f) moving and putting down the web piece over the article by means of the first and second clamping means; and

g) after step (f), fastening the web piece on the article.

Advantageously, the machine and the method of the present invention provide an automatic adjustment of the length of the article.

According the method and the machine of the invention, it is not necessary to move the article during its wrapping which is very advantageous for heavy article.

The present invention has also the advantage of providing a fully automated machine with a very high level of control and accuracy.

A preferred embodiment of the invention has a further advantage of providing a clean and neat appearance of the wrapped article with the web folded only at the ends of the article and no apparent folding line.

The invention and its advantages will be better understood after reading the non restrictive description of a preferred embodiment of the present invention. This description is given with reference to the appended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1

a side view of a wrapping machine according to a preferred embodiment of the present invention, with the working environment.

FIG. 2

is a top view of the wrapping machine shown in

FIG. 1

which does not have the crane-and winch assembly.

FIG. 3

is a front view of the first assembly of the machine shown in

FIG. 1

, where the first pivoting frame is missing for sake of clarity.

FIG. 4

is a front view of the first pivoting frame of the first assembly of the machine shown in FIG.

1

.

FIG. 5

is a side view of the first pivoting frame shown in FIG.

4

.

FIG. 6

is rear view of the second assembly of the machine shown in

FIG. 2

, where the second pivoting frame is missing for sake of clarity.

FIG. 7

is a front view of the second pivoting frame of the second assembly of the machine shown in FIG.

1

.

FIG. 8

is a side view of the second pivoting frame shown in FIG.

7

.

FIG. 9

is a side view of the third assembly of the machine shown in FIG.

1

.

FIG. 10

is a rear view of the web delivering means, the cutting means and a portion of the third assembly shown in FIG.

9

.

FIG. 11

is a top view of the web delivering means shown in FIG.

10

.

FIG. 12

is a side view of a portion of the web delivering means shown in

FIGS. 10 and 11

.

FIG. 13

is a side view of the second assembly of the machine shown in

FIG. 1

, where the second pivoting frame is in an horizontal position.

FIG. 14

is a side view of the second assembly shown in

FIG. 13

, except that the second pivoting frame is in a diagonal position.

FIG. 15

is a side view of the second assembly shown in

FIG. 13

, except that the second pivoting frame is in a vertical position.

FIG. 16

is a side view of the first assembly of the machine shown in

FIG. 1

, where the first pivoting frame is in an horizontal position.

FIG. 17

is a side view of the first assembly shown in

FIG. 16

, except that the first pivoting frame is in a diagonal position.

FIG. 18

is a side view of the first assembly shown in

FIGS. 16 and 17

, except that the first pivoting frame is in a vertical position.

FIG. 19

is a front view of a portion of the third assembly shown in

FIGS. 9 and 10

, showing a portion of the retractable supporting means.

FIG. 20

is a side view of a portion of the third assembly shown in

FIG. 10

, showing the retractable supporting means being in an horizontal position in relation with the cutting means.

FIG. 21

is a side view of a portion of the third assembly shown in

FIG. 9

, where a tension relief roller is in a back position and in a front position.

FIG. 22

is a side view of a clamp of the first clamping means shown in

FIGS. 16

,

17

and

18

, where a jaw of the clamp in is an open position and a closed position.

FIG. 23

is a top view of the clamp shown in FIG.

22

.

FIG. 24

is a side view of a clamp of the second clamping means shown in

FIG. 13

, where two jaws of the clamp are in open position and in closed position.

FIG. 25

is a top view of the clamp of FIG.

24

.

FIG. 26

is a diagram of the controller.

FIG. 27

is a perspective view of a wrapping machine according to a preferred embodiment of the present invention, showing the article partially covered by the web and the working environment.

FIG. 28

is a perspective view of a wrapping machine according to a preferred embodiment of the present invention, showing the article partially wrapped by the web piece and the working environment.

FIG. 29

is a perspective view of a wrapping machine according to a preferred embodiment of the present invention, showing the article completely wrapped by the web piece and the working environment.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION

Referring to

FIGS. 1

,

2

,

27

,

28

and

29

, we will now generally describe a wrapping machine

10

for wrapping an article

1

located in a wrapping area

17

. The wrapping machine

10

according to the present invention comprises web delivering means for delivering a web

9

; first clamping means for clamping a first end

14

of the web

9

extending from the web delivering means; first moving means for moving the first clamping means; and cutting means for cutting the web

9

extending from the web delivering means and therefor providing a web piece

12

for wrapping the article

1

. The machine

10

further comprises second clamping means for clamping a second end

15

of the web piece

12

that is a free end opposite to said first end

14

; second moving means for moving the second clamping means; fastening means for fastening the web piece

12

on the article

1

; and a controller

50

illustrated in FIG.

26

. The controller is for controlling the web delivering means, the first and second clamping means, the first and second moving means, the cutting means, and the fastening means following a predetermined sequencing program in such a way that, in operation, the web piece

12

is moved and put down over the article

1

by means of the first and second clamping means and the first and second moving means, and is fastened to the article

1

by means of the fastening means.

We will now describe three assemblies of the machine

10

that are structurally in relation with the above mentioned means and indicated in

FIGS. 1

,

2

and

29

.

More particularly, the first moving means comprise a first assembly

100

on which the first clamping means is mounted, and a first sliding means for sliding the first assembly

100

along the wrapping area

17

. The first sliding means are controlled by the controller

50

illustrated in FIG.

26

. The second moving means comprise a second assembly

200

on which the second clamping means is mounted, and a second sliding means for sliding the second assembly

200

. The second sliding means being controlled by the controller

50

. The machine further comprises a third assembly

300

on which the web delivering means and the cutting means are mounted.

Referring to

FIGS. 1

,

2

,

3

and

29

, the first sliding means for sliding the first assembly

100

comprise a pair of rails

4

parallel to opposite sides of the wrapping area

17

, and sliding members

102

mounted under the first assembly

100

and for slidably engaging the rails

4

. The sliding motion of the first assembly

100

on the rails

4

is driven by the motor

6

.

Referring to

FIGS. 1

,

2

,

6

and

29

, the second sliding means for sliding the second assembly

200

comprise a pair of rails

5

parallel to opposite sides of the wrapping area

17

, and sliding members

202

mounted under the second assembly

200

for slidably engaging the rails

5

. The sliding motion of the second assembly

200

on the rails

5

is driven by the powered cylinder

326

indicated in FIG.

1

.

We will now describe staplers which are among many tools that could be used to fasten the web piece

12

to the article

1

shown in

FIGS. 28 and 29

. It should be noted that the wrapping machine

10

of the invention has been designed for wrapping a pile of lumbers and, consequently it is not a problem to stable a web to the pile of lumbers. However, the machine

10

of the invention is very useful to wrap many other type of article on which it may not be suitable to staple. In this case, other fastening means may be used such as adhesive material, fusion processing with heat stem, thermosealing, or the like.

Referring to

FIGS. 1

,

4

,

5

and

28

and

29

, the fastening means comprise a front stapler

137

mounted on the first assembly

100

for stapling the web piece

12

to a front surface

20

of the article

1

, and a third moving means for moving the front stapler

137

along the front surface

20

of the article

1

. The third moving means are mounted on the first assembly

100

, and comprise a first powered cylinder

118

for moving horizontally the front stapler

137

, and two second powered cylinders

114

et

115

for moving the same vertically and being perpendicular to the first powered cylinder

118

. The third moving means further comprise front stapler detecting means for detecting a position of the front stapler

137

along each of said cylinders. The front stapler detecting means comprises one detector

133

shown in

FIG. 4

, for detecting the position of the front stapler

137

along the cylinder

118

, and another detector

134

for detecting the position of the front stapler

137

along the cylinders

114

and

115

. Both detectors

133

and

134

provide an output signal to the controller

50

illustrated in FIG.

26

.

Referring to

FIGS. 1

,

7

,

8

,

28

and

29

, the fastening means further comprise a rear stapler

239

mounted on the second assembly

200

for stapling the web piece

12

to a back surface

21

of the article

1

, and a fourth moving means for moving the rear stapler

239

along the back surface

21

of the article

1

. The fourth moving means are mounted on the second assembly

200

, and comprise a first powered cylinder

219

shown in

FIG. 7

, for moving horizontally the rear stapler

239

, and two second powered cylinders

221

and

222

shown in

FIG. 8

, for moving the same vertically and being perpendicular to the first powered cylinder

219

. The fourth moving means further comprise rear stapler detecting means for detecting a position of the rear stapler

239

along each of said cylinders. The rear stapler detecting means comprise one detector

234

shown in

FIG. 7

, for detecting the position of the rear stapler

239

along the cylinder

219

, and another detector

233

for detecting the position of the rear stapler

239

along the cylinders

221

and

222

. Each detector and powered cylinder mentioned above and hereinafter are preferably a linear encoder and a pneumatic rodless linear cylinder with magnetic piston. Both detectors

233

and

234

provide an output signal to the controller

50

illustrated in FIG.

26

.

Referring to

FIGS. 1

,

3

,

28

and

29

, the fastening means further comprise two side staplers

135

and

136

mounted respectively on opposite sides of the first assembly

100

for fastening side portions

16

of the web piece

12

to side surfaces

22

of the article

1

.

Referring again to

FIG. 1

, we will now describe article detectors of the machine

10

further comprises a conveyor

2

controlled by the controller

50

for conveying the article

1

within a wrapping area

17

, and first detecting means

8

mounted on the second assembly

200

, for detecting a back surface

21

of the article

1

and providing an output signal to the controller

50

illustrated in FIG.

26

. The controller

50

, in operation, controls the conveyor

2

to align the back surface

21

of the article

1

with a proper location in the wrapping area

17

. The machine further comprises second detecting means

143

mounted on the first assembly

100

, for detecting a front surface

20

of the article

1

and providing an output signal to the controller

50

which, in operation, controls the first moving means to move the first clamping means away from the web delivering means at a specific distance which is in relation with the length of the article

1

so that the cutting means is in a proper position to cut a web piece

12

having a size adapted to cover a top surface

23

, a front surface

20

, a back surface

21

and two opposite side surfaces

22

of the article

1

.

The article

1

may slide on the conveyor

2

. Consequently, it is planned that the machine

10

can comprise an alignment system for aligning the article with the conveyor

2

before conveying it in the wrapping area

17

.

Since the machine

10

is designed for wrapping a bundle of lumbers among others and such bundle may has an end of wood extending out, it planned that the machine

10

can comprises a trimming system for cutting such end of wood. A end of wood extending out the article

1

could interfere with the wrapping processing.

We will now describe different elements mounted on the third assembly

300

. Referring now to

FIGS. 1

,

2

,

9

to

12

, the web delivering means has a roll support composed of two cradle rollers

306

and

307

, for supporting a roll of web

305

from which the web

9

is delivered.

Referring more particularly to

FIGS. 27 and 28

and according to the preferred embodiment of the invention, the web

9

in the roll

305

has two opposite side portions

30

fold under a central portion

31

thereof, where the central portion has a width determining the width of the roll

305

which is slightly superior to the width of the top surface

23

of the article

1

. The fold side portions

30

of the web

9

fold under the central portion

31

of the web

9

are indicated on the roll

305

in

FIG. 28

with dotted lines. It should be understood that the web

9

can be in a roll without being fold as explained above. In such a case, the roll of web would be as long as the width of the web and adapters could be provided for avoiding interference between the web from the roll and the second assembly

200

. It should be understood also that it is not necessary that the web is delivered from a roll, since the web could be fold up in a pile or in any other form.

Referring to

FIGS. 1 and 9

, the machine preferably further comprises an over head crane-and-winch assembly

304

for supplying a spare roll of web

323

to a base

327

. It is to be understood that other lifting apparatus can be used in replacement of the crane-and-winch assembly

304

such as an elevator. The base

327

is pivotally mounted on the third assembly

300

and can be raise up by means of the powered cylinders

328

and

329

for pushing the spare roll of web

323

on the cradle rollers

306

and

307

.

Referring more particularly to

FIGS. 9 and 21

, the web delivering means comprises advantageously a tension relief roller

308

to make sure that the web

9

is delivered equally from side-to-side of the roll

305

. The tension relief roller

308

has a sliding bushing

338

on each extremity thereof, which is slidably engaged on a guiding shaft

339

and is driven by the powered cylinder

337

.

Referring now to

FIGS. 9 and 12

, the web delivering means further comprise a motorised upper drive roller

309

and a lower roller

310

for squeezing the web

9

extending from the roll

305

between them and pulling out the web

9

from the roll

305

by the motion of the motorised upper drive roller

309

. The web delivering means also comprise a shelf

313

for separating the central portion

31

of the fold web

9

from the side portions thereof. Such separation is particularly useful for allowing the first and second clamping means to clamp only locations on the central portion

31

of the web

9

.

Referring to

FIGS. 10

,

12

,

19

,

20

and

28

, the cutting means is preferably a circular rotary blade

317

, and the shelf

313

of the web delivering means has a slot

320

for allowing the rotary blade

317

to go through. Since the central portion

31

of the web

9

slides above the shelf

313

and the rotary blade

317

engages the slot

320

, the central portion

31

is cut all way long when the rotary blade

317

is moved from side-to-side of the shelf

313

. The rotary blade

317

is driven laterally along the powered cylinder

319

shown in

FIGS. 10

,

11

and

12

.

To make sure that the side portions

30

of the web

9

, shown in

FIG. 28

, is cut at the same time than the central portion thereof, the third assembly

300

is provided with retractable supports

324

and

325

and powered cylinders

334

and

335

for driving them as illustrated in

FIGS. 10

and

19

. The retractable support

324

and

325

have an upper concave surface

340

which is align with the path of the rotary blade

317

so that, when the retractable supports

324

and

325

are raised up against the shelf

313

, the blade

317

engages the concave surface

340

and cut the side portions

30

of the web

9

slid between the shelf

313

and the retractable supports

324

and

325

.

We will now describe clamps of the machine

10

. Referring now to

FIGS. 4

,

27

and

28

, the first clamping means comprise a pair of clamps

104

and

105

for clamping two points on the first end

14

of the web

9

that are spaced apart by a distance corresponding to a width of the top surface

23

of the article

1

and centrally located along the first end

14

of the web

9

.

Referring to

FIGS. 7

,

27

and

28

, the second clamping means comprise a pair of clamps

204

and

205

for clamping two points on the second end

15

of the web piece

12

that are spaced apart by a distance corresponding to the width of the top surface

23

of the article

1

and centrally located along the second end

15

.

Referring now to

FIGS. 24 and 25

, the second moving means also comprise third pivoting means for pivoting the clamps

204

and

205

around an horizontal axis parallel to the back surface

21

of the article

1

shown in FIG.

1

.

FIGS. 24 and 25

show only clamp

204

since clamps

204

and

205

are preferably identical. More particularly, the third pivoting means comprise a powered rotary cylinder for each jaw of each clamp

204

and

205

. Each clamp

204

,

205

has a longer jaw

224

and a shorter jaw

225

which are driven respectively by the powered rotary cylinder

227

and

228

.

FIGS. 22 and 23

show only clamp

104

since clamps

104

and

105

are preferably identical. Each of clamps

104

,

105

has a fixed jaw

145

, a pivoting jaw

144

and a powered rotary cylinder

146

for driving the pivoting jaw

144

.

We will now describe different elements mounted on the first assembly

100

. Referring more particularly to

FIGS. 1

,

16

,

17

and

18

, the first moving means comprise preferably a first pivoting frame

106

pivotally mounted on the main frame

101

of the first assembly

100

, and first pivoting means for pivoting the first pivoting frame

106

between an horizontal position (shown in

FIG. 16

) higher than the height of the front surface

20

of the article

1

and a vertical position (shown in

FIG. 18

) parallel to the front surface

20

of the article

1

. An intermediate position of the first pivoting frame

106

is illustrated in FIG.

17

.

As shown in

FIG. 4

, the first pivoting frame

106

has a “C” shaped frame on which are mounted the first clamping means, the front stapler

137

and the third moving means for moving the front stapler

137

.

The main frame

101

of the first assembly

100

has a substantially “H” shape as illustrated in the side views of

FIGS. 16

to

18

. The main frame

101

constitute two “H” shaped frames interconnected by an upper part and a lower part thereof as shown in the front view of FIG.

3

. The first pivoting frame

106

is pivotally mounted on each opposite “H” shaped frame of said main frame

101

by means of bracket

103

which may rotate around the pivot

109

. The rotation of the brackets

103

is driven by the first pivoting means which comprise two powered cylinders

107

and

108

on the opposite “H” shaped frames of the main frame

101

respectively.

Referring more particularly to

FIGS. 5 and 16

, the first moving means further comprise translating moving means for translating the clamps

104

and

105

of the first clamping means along the first pivoting frame

106

. The translating means comprise a powered cylinder

116

or

117

for translating each clamp

104

or

105

respectively.

We will now describe different elements of the second assembly

200

. Referring more particularly to

FIGS. 1

,

13

,

14

and

15

, the second moving means comprise preferably a second pivoting frame

206

pivotally mounted on the main frame

201

of the second assembly

200

, and second pivoting means for pivoting the second pivoting frame

206

between an horizontal position (shown in

FIG. 13

) higher than the height of the back surface

21

of the article

1

and a vertical position (shown in

FIG. 15

) parallel to the back surface

21

of the article

1

. An intermediate position of the second pivoting frame

206

is illustrated in FIG.

14

.

As shown in

FIG. 7

, the second pivoting frame

206

has a “C” shaped frame on which are mounted the second clamping means, the rear stapler

239

and the fourth moving means for moving the rear stapler

239

.

The main frame

201

of the second assembly

200

has a substantially “b” shape as illustrated in the side views of

FIGS. 13

to

15

. The main frame

201

constitute two “b” shaped frames interconnected by an upper part and a lower part thereof as shown in the front view of FIG.

6

. The second pivoting frame

206

is pivotally mounted on each opposite “b” shaped frame of said main frame

201

by means of a bracket

203

which may rotate around the pivot

209

. The rotation of the brackets

203

is driven by the second pivoting means which comprise two powered cylinders

207

and

208

on the opposite “b” shaped frames of the main frame

201

respectively.

Referring more particularly to

FIGS. 1

,

6

and

13

, the second moving means further comprise fifth moving means for moving the second pivoting frame

206

vertically with respect to the second assembly

200

. The fifth moving means comprise vertical threaded shafts

235

and

236

passing through the opposite “b” shaped frames of the main frame

201

respectively. The fifth moving means further comprise a motor

238

for driving the threaded shafts

236

and indirectly the threaded shafts

235

.

Referring now more particularly to

FIGS. 6 and 13

, it should be understood that the dimensions the machine

10

, shown in

FIG. 1

, may vary in order to wrap different sizes of article

1

. It is also contemplated that the machine

10

can adapt itself to a variable width and height of the article

1

to be wrapped could also be constructed. The pivots

109

and

209

could be mounted on linear jacks or the like such as electric motorized screws so that the pivots

109

and

209

can be aligned with the top surface

23

of the article

1

detected by an optical or proximity sensor. Should the variations of the dimensions of the article

1

be such that the width of the web

9

would need to be reduced to avoid the web

9

to exceed below the article

1

, the machine

10

can comprise a pair of laterally adjustable rotary blades installed under the shelf

313

to cut the excess of web

9

symmetrically on side portions

30

of the web

9

, shown in FIG.

28

. With the machine

10

being so adapted, it can comply with a wide range of article sizes, since the width of the web

9

is selected with respect of the width of the article

1

to be wrapped.

We will now describe the blowers of the machine

10

according to the preferred embodiment of the invention. Referring to

FIG. 28

, the machine

10

comprises folding means for folding the web piece

12

around the article

1

so that the resulting wrapped article has a clean and neat appearance. The folding means hereinafter described are designed more particularly for wrapping a parallelpipedly shaped article

1

.

Referring to

FIGS. 3

,

16

,

17

,

18

,

28

and

29

, the preferred folding means comprise two blowers

131

and

132

mounted respectively on the opposite “H” shaped frames of the main frame

101

of the first assembly

100

for blowing corners

18

of the first end

14

of the web piece

12

towards each other while the clamps

104

and

105

of the first clamping means having the first end

14

of the web piece

12

clamped therein move from an initial position to a final position located on a lower edge of the front surface

20

of the article

1

. The final and fold position of the corners

18

is shown in FIG.

29

and the diagonal dotted lines illustrate folded lines

13

in the web piece

12

. The movement of the clamps

104

and

105

between the initial position and the final position located on a lower edge of the front surface

20

is essentially driven by the powered cylinders

107

and

108

which pivot the first pivoting frame

106

around the pivot

109

and is illustrated the sequence of

FIGS. 16

,

17

and

18

.

Referring to

FIGS. 6

,

13

,

14

,

15

,

28

and

29

, the preferred folding means further comprise two blowers

231

and

232

mounted respectively on the opposite “b” shaped frames of the main frame

201

of the second assembly

200

for blowing corners

19

of the second end

15

of the web piece

12

towards each other while the clamps

204

and

205

of the second clamping means having the second end

15

of the web piece

12

clamped therein move from an initial position to a final position located on a lower edge of the back surface

21

of the article

1

. The movement of the clamps

204

and

205

between the initial position and the final position located on a lower edge of the back surface

21

is essentially driven by the powered cylinders

207

and

208

which pivot the second pivoting frame

206

around the pivot

209

and is illustrated the sequence of

FIGS. 13

,

14

and

15

. Basically, the action of the blowers

131

,

132

,

231

and

232

is push the corners

18

and

19

under a central portion of the first and second ends

14

and

15

located between the clamps

104

,

105

and the clamps

204

,

205

respectively. The movement of the clamps

104

,

105

,

204

and

205

sandwiches the corners

18

and

19

under the central portions of the first and second end

14

and

15

. After the web folding, the web piece

12

is fasten to the article

1

as above described.

Many types of folding means may be designed without departing from the scope of the invention to carry out the folding of the web piece

12

such as using retractable arms or the like for folding the corners

18

and

19

of the web piece

12

as described above.

We will now describe the anti-static electrode

312

of the machine

10

, shown in

FIG. 1

, according to the preferred embodiment of the invention and we will refer more particularly to

FIGS. 9

,

12

an

20

. Many kinds of web

9

, as shown in

FIG. 27

, may be used, such as fabric, plastic film and the like. The choice of the type of web

9

depends on the type of article

1

to be wrapped and the necessity to be permeable, semi-permeable or impermeable. Using certain kinds of web

9

with the wrapping machine

10

can result in creation of static electricity. Such static electricity is mainly generated by the web delivering means and can interfere with positioning and folding of the web piece

12

over the article

1

. In order to overcome this inconvenience, the machine

10

further comprises an anti-static electrode

312

located at an exit point of the web

9

from the web delivering means. Thus, the contact of the web with the electrode

312

is done just before the web

9

leaves the web delivering means. More particularly, the electrode

312

is located at an external extremity of the shelf

313

. Other devices can be used to overcome this inconvenience such as static eliminating brush and tinsel. A grounded tinsel wire in conductive copper strands has been used for such purpose.

Referring to

FIG. 26

, the controller

60

receives input signals from the detector

8

for detecting the front surface

20

of the article

1

, the detector

143

for detecting the back surface

21

of the article

1

, the detectors

133

and

134

for detecting the position of the front stapler

137

, the detectors

233

and

234

detecting the position of the rear stapler

239

.

Still referring to

FIG. 26

, the controller

50

transmits output signals to the motor

7

of the conveyor

2

, the motor

6

for sliding the first assembly

100

, the cylinders

107

and

108

for pivoting the first pivoting frame

106

, the cylinders

116

and

117

for the translation of the clamps

104

and

105

, the rotary cylinders

148

of the clamps

104

and

105

, the first cylinder

118

for moving horizontally the front stapler

137

, the second cylinders

114

and

115

for moving vertically the front stapler

137

, the front stapler

137

, the side stapler

135

and

136

, the cylinder

326

for sliding the second assembly

200

, the cylinders

207

and

208

for pivoting second pivoting frame

206

, the rotary cylinders

227

and

228

of the clamps

204

and

205

, the first cylinder

219

for moving horizontally the rear stapler

239

, the rear stapler

239

, the second cylinders

221

and

222

for moving vertically the front stapler

239

, the blowers

131

,

132

,

231

and

232

, the motorized upper drive roller

309

, the cylinder

334

and

335

for pivoting the retractable support

324

and

325

, the circular rotary blade

317

and the cylinder

319

for sliding the blade

317

.

The present invention also provides a method for wrapping an article

1

which will be now described with references to

FIGS. 9

,

27

,

28

and

29

. The method of the invention is preferably perform with the machine

10

above-described. The machine

10

necessitates an initial preparation for being ready to perform the method for wrapping. Referring to

FIG. 9

, the initial preparation includes installing a roll

305

of web

9

of the cradle rollers

306

and

307

, slipping the web

9

from the roll

305

between the cradle rollers

306

and

307

, in front of a guiding roll

330

, behind the tension relief roller

308

, between the lower roller

310

and the motorized upper drive roller

309

, and around the shelf

313

where the fold side portions

30

of the web

9

is slid under the shelf

313

and the central portion

31

thereof is slid over the shelf

313

.

Still referring to

FIG. 9

, the method is fully automated and comprises the step (a) of delivering a web

9

by means of a web delivering means. The action of the motorized upper drive roller

309

pushes the web

9

until it extends out the shelf

313

.

Referring to

FIG. 17

, the method further comprises the step (b) of clamping a first end

14

of the web

9

extending from the shelf

313

by means of the clamps

104

and

105

, and the following step (c) of moving away from the shelf

313

, the clamps

104

and

105

having the first end

14

clamped therein. According to a preferred embodiment of the invention, in the step (c), the first end

14

is moved away from the shelf

313

at a specific distance which is in relation with the length of the article

1

so that the rotary blade

317

is in a proper position to cut a web piece

12

having a size adapted to cover a top surface

23

, a front surface

20

, a back surface

21

and two opposite side surfaces

22

of the article

1

. For practical purpose, the second pivoting frame

206

is raised up by means of the motor

238

and the threaded shafts

235

and

236

, shown in

FIGS. 13 and 27

, in order to clear a sufficient space for allowing the first assembly

100

to slide under it and the clamps

204

and

205

to reach the web

9

extending out the shelf

313

and perform step (b).

Referring to

FIGS. 9 and 20

, the method further comprises the step (d-

4

), executed after step (c), of cutting the web

9

extending from the lower roller

310

and the motorized upper drive roller

309

and therefor providing a web piece

12

, shown in

FIG. 28

, for wrapping the article

1

. Advantageously, the clamps

204

and

205

are also used to stabilize the web

9

during the cutting step (d-

4

). To do so, the method further comprises, before step (d-

4

), the step (d-

1

) of moving the clamps

204

and

205

in proximity of the rotary blade

317

; and the step (d-

2

) of squeezing the second end

15

of the web piece

12

between the longer jaws

224

(shown in

FIGS. 24 and 25

) of the clamps

204

and

205

and the shelf

313

by engaging the two cavities

321

and

322

(shown in

FIG. 11

) provided in the shelf

313

. Therefor, the method further comprises the step (d-

3

) of maintaining the squeezing action of step (d-

2

) for stabilizing the web

9

during the cutting action. It should be understood that the step (d-

1

) of moving the clamps

204

and

205

in proximity of the rotary blade

317

comprises the step of lowering the second pivoting frame

206

since it has been raised up for allowing step (b).

Referring to

FIG. 27

, the method further comprises the step (e) which follows step (d-

4

), of clamping a second end

15

of the web piece

12

that is a free end opposite to said first end

14

and that has been generated by the cutting step (d-

4

) with the clamps

204

and

205

. In the case that the step (d-

3

) is performed, the shorter jaws

225

, kept in the open position, are ready to pivot towards the respective longer jaws

224

and therefore clamp the second end

15

in order to perform step (e).

Referring to

FIGS. 13

to

18

,

27

and

28

, the method further comprises the step (f), which follows step (e), of moving and putting down the web piece

12

over the article

1

by moving the clamps

104

and

105

and moving the clamps

204

and

205

. According to a preferred embodiment of the invention, the step (f) comprises the sub-step (f-

1

) of pivoting the clamps

104

and

105

to bring the first end

14

of the web piece

12

at a lower edge of the front surface

20

of the article

1

; and the sub-step (f-

2

), which is performed during step (f-

1

), of blowing corners

18

of the first end

14

of the web piece

12

towards each other while the clamps

104

and

105

having the first end

14

of the web piece

12

clamped therein move from an initial position to a final position located on a lower edge of the front surface

20

of the article

1

. In sub-step (f-

1

), it should be understood that the action of pivoting the clamps

104

and

105

is executed by pivoting the first pivoting frame

106

by means of the powered cylinders

107

and

108

. The step (f) further comprises the sub-step (f-

3

) of pivoting the clamps

204

and

205

to bring the second end

15

of the web piece

12

at a lower edge of the back surface

21

of the article

1

; and (f-

4

), which is performed during step (f-

3

), of blowing corners

19

of the second end

15

of the web piece

12

towards each other while the clamps

204

and

205

having the second end

15

of the web piece

12

clamped therein move from an initial position to a final position located on a lower edge of the back surface

21

of the article

1

. In sub step (f-

3

), it should be understood that the action of pivoting the clamps

204

and

205

is executed by pivoting the second pivoting frame

206

by means of the powered cylinders

207

and

208

. For practical purpose, the sub-step (f-

3

) comprise a prior step of moving the second assembly

200

away from the third assembly

300

by means of the powered cylinder

326

in order that the shelf

313

would not interfere with the second pivoting frame

206

when it pivots. Advantageously, the sub-steps (f-

1

) and (f-

3

) are executed simultaneously in order to reduce time consuming.

Referring to

FIGS. 3

,

14

,

17

and

28

, the method further comprises the step (g), executed after step (f), of fastening the web piece

12

on the article

1

. Still according to the preferred embodiment, the step (g) comprises the sub-step (g-

1

) of fastening the web piece

12

to the front surface

20

and back surface

21

of the article

1

by means of the front stapler

137

and the rear stapler

239

; the sub-step (g-

2

) of conveying the article

1

away from the wrapping area

17

; and the sub-step (g-

3

), executed during sub-step (g-

2

), of fastening the web piece to the two opposite sides of the article by means of the two side staplers

135

and

136

. An other way to fasten the web piece

12

to the side surfaces

22

of the article

1

could be to slide the first assembly

100

towards the back surface

21

of the article

1

. As above mentioned, it is not necessary to move the article

1

for wrapping it. However it is less time consuming the fasten side surfaces

22

thereof while conveyed out the wrapping area

17

.

It should be understood that the steps of the above described method may be executed in a different sequence and some of them may be executed simultaneously.

While embodiments of this invention have been illustrated in the accompanying drawings and described above, it will be evident to those skilled in the art that changes and modifications may be made therein without departing from the essence of this invention. All such modifications or variations are believed to be within the scope of the invention as defined by the claims appended hereto.

Number	Name	Date
1734351	Sevigne et al.	Nov 1929
3469368	Churchhill et al.	Sep 1969
3808767	Reid	May 1974
4400929	Iwaki et al.	Aug 1983
5314286	Bolejack et al.	May 1994
5657608	Parviainen et al.	Aug 1997
6138438	Michell et al.	Oct 2000

Method for wrapping an article

Information

Patent Number

Date Filed

Date Issued

Inventors

Original Assignees

Examiners

Agents

CPC

US Classifications

Field of Search

US

International Classifications

Abstract

Description

Claims

Priority Claims (1)

US Referenced Citations (7)

Foreign Referenced Citations (1)