CLEANING ROLL

Abstract

A method of making a cleaning-roll body having a core and a jacket on the core. The method has the steps of forming the core of a first polymer by injection molding in a first injection mold, removing the injection molded from the first mold, inserting the formed core into a second mold and overmolding the jacket on the formed core.

Claims

1. A method of making a cleaning-roll body having a core and a jacket on the core, the method comprising the steps of: forming the core of a first polymer by injection molding in a first injection mold; removing the injection molded from the first mold; inserting the formed core into a second injection mold and overmolding the jacket on the formed core with a second polymer.

2. The method according to claim 1, wherein the composition of the first polymer corresponds to at least 95% by weight with the composition of the second polymer.

3. The method according to claim 1, wherein the first polymer is identical to the second polymer.

4. The method according to claim 1, wherein the first polymer has the same density as the second polymer.

5. The method according to claim 1, further comprising the step of: cooling the core 3 before overmolding it with the jacket.

6. The method according to claim 1, wherein the first polymer and the second polymer are in a mass ratio between 1:2 and 2:1.

7. The method according to claim 1, the core is formed about a center axis and has an axial extent that is at least five times greater than a radial dimension of the core.

8. The method according to claim 7, wherein the axis radial dimension measured perpendicular thereto and radially of the center axis.

9. The method according to claim 7, wherein the center axis passes through a center of gravity of the core.

10. The method according to claim 7, wherein the core has a maximum diameter between 1.5 cm and 4 cm.

11. The method according to claim 7, wherein the core has a length measured parallel to the center axis of between 20 cm and 35 cm.

12. The method according to claim 1, further comprising the step of: imbedding bristles in the jacket.

13. The method according to claim 1, wherein the core is formed in the first mold with coupling bumps extending radially into the jacket when same is overmolded on the core.

14. The method according to claim 1, further comprising the step of: embedding a roller bearing rolling in the core in the first mold.

15. The method according to claim 7, wherein axially opposite ends of the core are formed in the first mold with axially oppositely open seats.

16. The method according to claim 1, further comprising the step before overmolding the jacket of: fitting a drive member to the core; and subsequently fixing the drive member on the core by overmolding of the jacket.

17. The method according to claim 1, wherein the core has anchor bodies for holding the drive member against rotation.

18. The method according to claim 1, wherein the anchor bodies are not of polymer and are embedded into the core in the first injection mold.

19. A cleaning roll comprising: a core made of a first polymer and extending along an axis; a jacket overmolded of a second polymer on the core, substantially surrounding the core, and adapted to carry a cleaning element.

20. A vacuum-cleaner nozzle having the cleaning roll defined in claim 18.

Description

BRIEF DESCRIPTION OF THE DRAWING

[0043] The above and other objects, features, and advantages will become more readily apparent from the following description, reference being made to the accompanying drawing in which:

[0044] FIG. 1A is a longitudinal section through the core and the first injection mold;

[0045] FIG. 1B is a side view of the core made in the first injection mold;

[0046] FIG. 1C is a perspective view of a detail of the core;

[0047] FIG. 2A is a longitudinal section through the roll body according to the invention in the second injection mold; and

[0048] FIG. 2B is a side view of the finished cleaning roll according to the invention.

SPECIFIC DESCRIPTION OF THE INVENTION

[0049] According to the process of the invention a cleaning-roll body 1 is produced in a multistage injection molding process. As can be seen from FIG. 1A a first injection mold 2 is filled with a first polymer to form a rigid core 3 constituted basically as a one-piece shaft or body of revolution centered on an axis x. The first injection mold 2 is formed in several parts, here as shown in FIG. 1A of two end pieces 2a and 2b and two side shells 2c and 2d. As handling aid for transport of the core 3 from the mold 2, ends are fitted with transverse T-section rods 4 in the mold 2. These rods 4 are secured by the polymer of the core 3 but can be removed at a later time with no harm to the core 3 by pulling out of the core 3 longitudinally of their transverse extent.

[0050] As shown in FIG. 2A the core 3 is subsequently put in a second closed mold 5 also formed of two end pieces 5a and 5b and two side shells 5c and 5d. A first polymer is injected into this mold to overmold the core 3 with a jacket 6. The sectional view shows that the jacket 6 completely externally surrounds the core 3 as shown in FIG. 2B, thereby forming the core body 1. This roll body 1 has external formations or outwardly open grooves 7 outside in which a cleaning element, for example a bristle strip, can be cemented.

[0051] To ensure good cohesion between the jacket 6 and core 3 as well as a uniform mass distribution, the core 3 and the jacket 6 are made of the same polymer, in particular of the same density. Here the mass of the jacket 6 makes up approximately two thirds of the mass of the core 3.

[0052] The roll body 1 as a whole (as well as the core 3 and the jacket 6) are bodies of revolution centered on the axis x. The roll body 1 has thereby axially, that is parallel to the axis x a longitudinal extension 1 that in is about ten times greater than the transverse dimension or diameter d perpendicular to the center axis x. Due to the rotation symmetry with respect to the x, this axis x also extends through the center of gravity of the roll body 1.

[0053] As can be seen from the FIGS. 1A and 1B the core 3 is formed on its outer surface 3a with axially and radially spaced bumps 8 that center the core 3 in the second mold 5 so the jacket is of a uniform radial thickness that is the same as the radial dimensions of the identical bumps 8.

[0054] For mounting the roll body 1 for its intended use, in particular in a vacuum-cleaner nozzle, it is provided with bearing pins that were seated in seats 9 of the end parts 5a and 5b on the axis. Thus during the overmolding step, these pins are anchored in the core 3.

[0055] FIG. 2B shows that, spaced between ends of the roll body 1 is a gear wheel 11 serving as a drive element. This is made possible in that metal plates 11 (FIGS. 1C and 2A) are embedded into the core 1 and project radially therefrom so that a metal ring gear 11 can be pushed axially over the body 1 and securely fixed on the body 1. Presuming the end pins 10 are held in bearings, a drive gear meshing with the gear 11 can rotate the entire roll body (and any cleaning element mounted thereon for instance in the grooves 7) about its axis.