Sintering furnace for components made of sintered material, in particular dental components

Patent metadata

Field	Value
Publication number	US-11306969-B2
Application number	US-201515116936-A
Country	US
Kind code	B2
Filing date	Feb 12, 2015
Priority date	Feb 12, 2014
Publication date	Apr 19, 2022
Grant date	Apr 19, 2022

Abstract

The invention relates to a sintering furnace (1) for components (15) made of a sintered material, in particular for dental components, comprising a furnace chamber (2) having a chamber volume (VK), wherein a heating device (5), a receiving space (9) having a gross volume (VB) located in the chamber volume (VK) and delimited by the heating device (5), and a useful region (10) having a useful volume (VN) located in the gross volume (VB), are disposed in the furnace chamber (2). The furnace chamber (2) has an outer wall (3) consisting of a plurality of walls having a wall portion (7) to be opened for introduction of a component to be sintered having an object volume (VO) into the receiving space (9). In the furnace chamber (2) the heating device (5) has a thermal radiator (6) having a radiation field (13) which is disposed on at least one side of the receiving space (9). At least the useful volume (NV) disposed in the receiving space (9) is disposed in the radiation field (13) of the radiator (6), wherein the maximum possible distance (d) of the component (15) to be sintered from the radiator (6) corresponds to at most twice the dimension (Dy) of the maximum useful volume (VN).

First claim

The invention claimed is:

1. A dental sintering furnace for one or more ceramic dental components to be sintered, comprising:
a furnace chamber with a chamber volume, the furnace chamber further including;
a heating device disposed within said chamber volume,
a receiving space disposed within said chamber volume and having a gross volume, said receiving space delimited by the heating device,
and a useful region with a useful volume disposed within the receiving space;

wherein the furnace chamber has an outer wall that includes a plurality of walls, and that has at least one wall portion, said at least one wall portion constructed to be opened for introduction of the one or more ceramic dental components into the receiving space, said one or more ceramic dental components having an object volume;
wherein the heating device has a radiator with a direct radiation field, said radiator disposed on at least one side of the receiving space;
wherein the useful volume is further configured to be disposed in the direct radiation field;
wherein the dental sintering furnace is constructed such that a ratio of the useful volume to the chamber volume is from 1:50 to 1:1 and a ratio of the useful volume to the gross volume is from 1:20 to 1:1 such that a maximum possible useful volume in relation to the gross volume is kept as small as possible so as to eliminate a need for a preheating of the dental sintering furnace and provide a relatively fast sintering of the one or more ceramic dental components as compared conventional furnaces, and
wherein the radiator is configured to be heated in an inductive fashion using an encircling coil,
wherein the radiator is made of SiSiC,
wherein the useful volume is at most 20×20×40 mm 3 .

2. The dental sintering furnace according to claim 1 , wherein the dental sintering furnace is constructed such that a ratio of the useful volume to the object volume is from 1,500:1 to 1:1.

3. The dental sintering furnace according to claim 1 , wherein the outer wall has a chamber inner wall that is impermeable to the direct radiation field and/or reflects it.

4. The dental sintering furnace according to claim 1 , wherein the useful volume is at most 20×20×40 mm 3 and that the dimensions of the useful volume are at most 20 mm×20 mm×40 mm.

5. The dental sintering furnace according to claim 1 , wherein the radiator is configured as a crucible.

6. The dental sintering furnace according to claim 1 , wherein the radiator is formed from two plate-shaped elements, which are heated by integrated coils and wherein the receiving space is configured to be between the two plate-shaped elements.

7. The dental sintering furnace according to claim 1 , wherein the radiator heated in an inductive fashion comes into direct contact with the one or more ceramic dental components during sintering.

8. The dental sintering surface according to claim 1 , wherein the dental sintering furnace includes an active water cooling inside the encircling coil.

9. The dental sintering furnace according to claim 1 , wherein the radiator is capable of achieving heating rates above 150° C./min.

Assignees

• Dentsply Sirona Inc

Inventors

• Fornoff Peter
• Schmidt Christian

Classifications

• F27B17/025 Primary

  for dental workpieces · CPC title

• A61C13/20

  Methods or devices for soldering, casting, moulding or melting {(A61C13/04, A61C13/081 take precedence)} · CPC title

• F27B14/10

  Crucibles · CPC title

• F27D1/0033

  Linings or walls comprising heat shields, e.g. heat shields · CPC title

• F27B17/02

  specially designed for laboratory use · CPC title