Hoop-casing device

Description

BACKGROUND

The invention concerns a hoop-casing device for hooping an object with a heat-sealable plastic strip placed around it.

Hoop-casing devices of the type mentioned above are multiply known, for instance from EP-0744342. They comprise a tool part and a counter-bearing part, the counter-bearing surfaces of which face each other and match each other and have a structure similar to a toothing to be able to grip the plastic strip as efficiently as possible during tensioning and friction-sealing.

In this context it is a drawback that it is work-expensive and costly to manufacture the desired structure similar to a toothing on the concave counter-bearing surface of the counter-bearing part.

SUMMARY

The object of the invention is to provide a hoop-casing device of the relevant generic type that does not have the above mentioned drawback.

According to the invention said object is attained in a hoop-casing device of the relevant generic type by providing a hoop-casing device for hooping an object with a heat-sealable plastic strip placed around the object; the hoop-casing device comprising a unit for tensioning the strip and for friction-sealing two overlapping strip parts of the tensioned strip; the unit comprising a tool part that can be rotatably driven about a rotation axis and having a generally cylindrical tool mantle surface, the unit further comprising a counter-bearing part having a counter-bearing surface facing the tool part and extending over a sector of the tool mantle surface and generally enclosing said sector; at least the counter-bearing surface of the counter-bearing part having a structure similar to toothing; the tool part and the counter-bearing part being mutually pivotable about a swivel axis that is parallel to the rotation axis to grip or release the overlapping strip parts between the counter-bearing surface and the tool mantle surface, characterized in that: the counter-bearing part comprises a multipart shoe made up of holding blocks arranged side by side in angular sequence about the rotation axis; and, the holding blocks having respective outer faces which taken together form an outer face of the shoe as well as the counter-bearing surface of the counter-bearing part.

In this embodiment according to the invention the concave counter-bearing surface of the counter-bearing part is composed of several portions of parts that are arranged side by side, namely, composed of the plurality of outer faces of the holding blocks, which in contrast with the prior art allows rather small areas of the concave counter-bearing surface to be machined individually and the machining costs to be correspondingly reduced.

Advantageous embodiments of the hoop-casing device according to the invention include making the outer faces of the holding blocks essentially planar and rectangular with edges parallel to the rotation axis and swivel axis.

More particularly, it is advantageous to provide that the holding blocks each are provided with an essentially planar and rectangular outer face, the edges of this outer face being parallel to the rotation axis and the swivel axis. Such holding blocks can then be machined economically and at the same time structured with an optimal toothing on one planar outer face. Moreover, when being mounted they are adapted to be arranged side by side and fixed on the shoe in such a way that they end up all located on the mantle surface of a prism having edges essentially parallel to the rotation axis and the swivel axis. Taken together, the holding blocks thus manufactured and mounted make up a counter-bearing surface of the counter-bearing part that approximately matches the generally cylindrical tool mantle surface of the tool part, which, in combination with the optimal toothing, allows the overlapping strip parts inserted therebetween to be well gripped and hold and to be applied high tensioning forces.

DESCRIPTION OF THE DRAWINGS

An exemplary embodiment of the invention is explained below with reference to the drawings.

FIG. 1

shows a side view of a hoop-casing device according to the invention together with a view of a partial domain of the hoop-casing device magnified by a factor of about six (magnifying glass view);

FIG. 2

shows a sectional view of the hoop-casing device cut along line A—A of

FIG. 1

together with a view of a partial domain of the hoop-casing device magnified by a factor of about one and a half (magnifying glass view);

FIG. 3

shows a perspective explosion view of parts of the hoop-casing device in order to illustrate the fixation and arrangement of holding blocks at the hoop-casing device;

FIG. 4

shows a perspective explosion view of the holding blocks of

FIG. 3

magnified by a factor of about two in comparison with

FIG. 3

;

FIG. 5

shows a top view of a part of the hoop-casing device shown in the magnifying glass view of

FIG. 1

, broken-off and magnified by a factor of about one and a half in comparison with said magnifying glass view, in order to illustrate the structural features and mutual arrangement of the holding blocks;

FIG. 6

shows the hoop-casing device in a view that is the same as in

FIG. 1

but for the plastic strip being inserted; and

FIG. 7

shows the hoop-casing device in a view that is the same as in

FIG. 2

but for the plastic strip being inserted.

In all figures, parts corresponding to each other are designated with same reference numerals.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The hoop-casing device according to the invention that is illustrated in the figures serves to hoop-case an object with a plastic strip placed around it and will be described with reference to an exemplary embodiment, it being understood that the invention must not be limited to this exemplary embodiment.

The illustrated hoop-casing device comprises, at a housing

1

, a unit

2

for tensioning a heat-sealable plastic strip

3

and for friction-sealing two strip parts

4

and

5

of this plastic strip

3

that overlap each other. The unit

2

comprises a tool part

7

that has a generally cylindrical tool mantle surface

8

and that can be rotated about a rotation axis

6

and driven. Additionally, the unit

2

comprises a counter-bearing part

9

that in turn is provided with a counter-bearing surface

10

facing the tool part

7

and extending over a sector of the tool mantle surface and generally enclosing the latter.

The counter-bearing surface

10

and, advantageously, the tool mantle surface

8

as well, are provided with structural features to allow to grip the plastic strip

3

as efficiently as possible. However, whereas the tool mantle surface

8

is conventionally provided with structural features similar to a ratchet toothing, the counter-bearing surface

10

is provided with a special toothing that will be described more in detail below and may best be perceived in

FIGS. 3

,

4

and

5

.

Either and alternatively to grip or release the overlapping strip parts

4

and

5

between the counter-bearing surface

10

and the tool mantle surface

8

, the tool part

7

and the counter-bearing part

9

can be swivelled relative to each other about a swivel axis

12

by means of a lever

11

, this swivel axis

12

being parallel to the rotation axis

6

.

The production of structural features of the counter-bearing surface

10

and the manufacturing of the counter-bearing part

9

are considerably facilitated by the fact that the counter-bearing part

9

comprises a separate shoe

13

that is made up of several parts. In the exemplified embodiment the shoe

13

is composed of three holding blocks

14

,

16

and

18

that are arranged side by side in angular sequence about the rotation axis

6

. These holding blocks

14

,

16

and

18

are provided with respective outer faces

15

,

17

and

19

adjacent to each other at edges

20

,

21

,

22

,

23

and that, taken together, form an outer face

24

of the shoe

13

and hence, the counter-bearing surface

10

of the counter-bearing part

9

as well.

In comparison with a conventional type of shoe that is three times larger, it is already easier to machine the three described smaller holding blocks

14

,

16

and

18

in order to provide their outer faces with structural features. The manufacture, however, is still further facilitated by the fact that the outer faces

15

,

17

and

19

of the holding blocks

14

,

16

and

18

are essentially planar and rectangular. Subsequently, to allow to grip the plastic strip as efficiently as possible the edges

20

,

21

,

22

,

23

are disposed parallel to the rotation axis

6

and swivel axis

12

, and the outer faces

15

,

17

and

19

are located on a prismatic mantle surface that encloses the tool mantle surface

8

. The thus formed counter-bearing surface

10

of the counter-bearing part

9

approximately matches the cylindrical tool mantle surface

8

of the tool part

7

and allows the overlapping strip parts

4

and

5

of the plastic strip

3

inserted therebetween to be sufficiently well gripped and hold.

How the shoe

13

or the holding blocks

14

,

16

and

18

, respectively, are fixed on the counter-bearing part

9

may best be perceived in

FIGS. 3 and 5

. The holding blocks

14

,

16

and

18

are located next to each other and resting against each other in a recess

25

of the counter-bearing part

9

with those edges

20

,

21

,

22

,

23

that are parallel to the rotation axis

6

and the swivel axis

12

constituting respective longer edges of the outer faces

15

,

17

and

19

, which are formed rectangular. In a direction parallel to the rotation axis

6

and the swivel axis

12

the holding blocks

14

,

16

and

18

terminate on each side thereof in projections

26

, each of which protrudes under one of two clamping blocks

27

and

28

. These clamping blocks

27

and

28

are fixed on the counter-bearing part

9

with the help of screws

29

, guide pins

30

and washers

31

and in turn hold the holding blocks

14

,

16

and

18

when the screws

29

are tightened at the counter-bearing part

9

.

The machining of the outer faces

15

,

17

and

19

of the holding blocks

14

,

16

and

18

eventually produces an embodiment with structural features such as for instance that which may best be perceived in

FIGS. 3

,

4

and

5

. The planar outer faces

15

,

17

and

19

of the holding blocks

14

,

16

and

18

allow and facilitate the machining of the holding blocks by milling or grinding in various directions essentially parallel to the outer faces while oriented at any desired angle to the longer edges

20

,

21

,

22

,

23

. In this manner the outer faces

15

,

17

and

19

of the holding blocks

14

,

16

and

18

are provided with any desired rows and patterns of diamond points

32

that are adapted to be pressed into the strip portion that rests against the counter-bearing part

9

and to hold it well during a clamping of the overlapping strip parts

4

and

5

of the plastic strip

3

between the tool part

7

and the counter-bearing part

9

.

Claims

1. A hoop-casing device for hooping an object with a heat-sealable plastic strip placed around the object;the hoop-casing device comprising a unit for tensioning the strip and for friction-sealing two overlapping strip parts of the tensioned strip; the unit comprising a tool part that can be rotatably driven about a rotation axis and having a generally cylindrical tool mantle surface, the unit further comprising a counter-bearing part having a counter-bearing surface facing the tool part and extending over a sector of the tool mantle surface and generally enclosing said sector; at least the counter-bearing surface of the counter-bearing part having a structure similar to toothing; the tool part and the counter-bearing part being mutually pivotable about a swivel axis that is parallel to the rotation axis to grip or release the overlapping strip parts between the counter-bearing surface and the tool mantle surface, characterized in that: the counter-bearing part comprises a multipart shoe made up of holding blocks arranged side by side in angular sequence about the rotation axis; and, the holding blocks having respective outer faces which taken together form an outer face of the shoe as well as the counter-bearing surface of the counter-bearing part.
2. The hoop-casing device according to claim 1, characterized in that the outer faces of the holding blocks are essentially planar and rectangular with edges parallel to the rotation axis and swivel axis.

Priority Claims (1)

Number	Date	Country	Kind
97 1119	May 1997	CH

PCT Information

Filing Document	Filing Date	Country	Kind
PCT/OH98/00137		WO	00

Publishing Document	Publishing Date	Country	Kind
WO98/51569	11/19/1998	WO	A

US Referenced Citations (8)

Number	Name	Date	Kind
3360017	Vilcins	Dec 1967	A
3442732	Stensaker et al.	May 1969	A
3586572	Ericsson	Jun 1971	A
4015643	Cheung	Apr 1977	A
4313779	Nix	Feb 1982	A
5133532	Figiel et al.	Jul 1992	A
5542239	Fujii et al.	Aug 1996	A
5632851	Young	May 1997	A

Hoop-casing device

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)

PCT Information

US Referenced Citations (8)