Method of Mixing and Extruding Viscous Materials and Gearbox for Dispensing the Same

Abstract

The present invention relates to a method of mixing and dispensing viscous materials, comprising the steps of: inserting a cartridge containing one or more viscous materials in a chamber; activating a first motor (1) to move a plunger from a first position to a second position within the cartridge and activating a second motor (2) to move the plunger from the second position further within the cartridge to dispense the material.

Description

BACKGROUND OF THE INVENTION[0001]1. Technical Field[0002]The invention relates to a method of mixing and extruding viscous materials, particularly relatively highly viscous or pasty materials, and to a gearbox, in particular to a superimposing gear drive, for transmitting high torque and / or high revolutions per minute to an output drive shaft without changing gears. The gearbox may particularly be used together with dispensing cartridges and mixer elements for mixing and dispensing multi-component dental impression materials.[0003]2. Description of the Related Art[0004]Dispensing devices with cartridges are often used in the field of dentistry for mixing and dispensing dental compositions of two or more components, such as impression materials, restoratives, adhesives, cements, etching gels, sealants and the like.[0005]In one type of dispensing device that comprises an applicator and a cartridge, the applicator has a plunger that is advanced either manually by the user or automatica...

AI Technical Summary

Benefits of technology

[0022]The invention provides the further advantage that both high torque at low speed and high speed with relatively low torque are provided at a first output drive shaft, and a third speed is provided at a second output drive shaft, without using a clutch and without changing gears. This is enabled by the use of a superimposing gear drive providing a permanent connection between the first output drive shaft and two motors as well as a permanent connection between the second motor and the second output drive shaft.

[0024]The invention is unique and different from prior art systems and advantageous in various aspects, wherein two motors serve three purposes. Firstly, high speed is provided by the first motor at the first output drive shaft for positioning the plunger in a short time to the desired position, in both directions, wherein only relatively low torque at the first output drive shaft is sufficient. Secondly, lower speed but with higher torque is provided by the second motor at the first output drive shaft. This is beneficial for driving the plunger or piston and dispensing the material with high viscosity under high pressure. Finally, a third speed is provided, preferably by the second motor at the second output drive shaft, wherein the speed of the second drive shaft has a fixed ratio to the speed of the first output drive shaft, when the first output drive shaft is driven with the second motor only. The third speed is preferable also a low speed for driving the mixing element in the mixer only during dispensation of the paste material. The fixed ratio of the third speed to the low speed is advantageous, since the low speed dispenses the material with a specific speed, and therefore the speed of the mixing tip should be correlated to this dispensing speed.

[0068]It may be provided that the gearbox is adapted that when the first output drive shaft is driven by the first motor and the second motor at the same time, the speed of the first output drive shaft is dominated by the first motor and high speed is applied to said first output drive shaft. This may occur for example if the plungers are positioned with low resistance so that the load on the motors is low.

[0072]It may be provided that the second output drive shaft is adapted for dispensing highly viscous material with higher torque at the first output drive shaft followed by the fast change of the direction of rotation at the first output drive shaft so that further undesired dispensing of highly viscous material is prevented.

Problems solved by technology

It is difficult to achieve both high torque at low speed, and also low torque at high speed, without changing gears.

It is also difficult to achieve highly different speeds, e.g., differing by a magnitude of 100, using a linear drive of any kind without changing gears or using clutch-like devices.

The changing of gears typically requires a complicated drive.

Furthermore, it is very difficult or sometimes even impossible to change gears under load.

Devices that can perform these functions can as a result be complicated and expensive.

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