|  | F |
SECTION F — MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING

LIGHTING; HEATING

|  | F27 |
FURNACES; KILNS; OVENS; RETORTS (specially adapted for a purpose covered by a single other class and specifically mentioned in that class, see the class in question, e.g. bakery ovens Fulltext... Hierarchy... Expanded...A21B, glass melting furnaces Fulltext... Hierarchy... Expanded...C03B, coke or gas-making apparatus Fulltext... Hierarchy... Expanded...C10B, Fulltext... Hierarchy... Expanded...C10J, apparatus for cracking hydrocarbons Fulltext... Hierarchy... Expanded...C10G, blast furnaces Fulltext... Hierarchy... Expanded...C21B, converters for making steel Fulltext... Hierarchy... Expanded...C21C, furnaces for heat treatment of metal Fulltext... Hierarchy... Expanded...C21D; furnaces for electroslag or arc remelting of metals Fulltext... Hierarchy... Expanded...C22B 9/00; enamelling ovens Fulltext... Hierarchy... Expanded...C23D; combustion apparatus Fulltext... Hierarchy... Expanded...F23; electric heating Fulltext... Hierarchy... Expanded...H05B) [4]

|  | F27 |
Note(s) This class covers: furnaces, kilns, ovens, retorts, open sintering apparatus and other similar apparatus for heat treatment of materials or articles, and details or accessories therefor, in general; the arrangement of electrical heating elements in or on furnaces. This class does not cover: combustion apparatus per se, i.e. apparatus for direct combination of oxygen gas and a burnable substance; [7] electrical heating elements per se; processes carried on within the furnaces. In this class, the following term is used with the meaning indicated: "furnaces" covers kilns, ovens, or retorts.

|  | F27B |
FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS

|  | F27B |
Note(s) Attention is drawn to the references and Notes following the title of class Fulltext... Hierarchy... Expanded...F27 and the Note III following the Contents of Section of section H.

|  | F27B |
Subclass index
FURNACES WITH STATIONARY CHARGE |
Shaft furnaces | 1/00
Horizontal furnaces | 3/00, 5/00
Bell-type furnaces | 11/00
With progression of heating | 13/00
Crucible furnaces, tank furnaces | 14/00
STATIONARY FURNACES WITH MECHANICALLY-MOVED CHARGE | 9/00
ROTARY FURNACES | 7/00, 13/00
OTHER FURNACES; COMBINATIONS | 15/00, 17/00; 19/00
OPEN SINTERING OR LIKE APPARATUS | 21/00

|  | F27D |
DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE (combustion apparatus Fulltext... Hierarchy... Expanded...F23)

|  | F27D |
Note(s) Attention is drawn to the references and Notes following the title of class Fulltext... Hierarchy... Expanded...F27 and Note III following the Contents of Section of section H.

|  | F27D |
Subclass index
CONSTRUCTIONAL FEATURES | 1/00
HANDLING AND SUPPORTING CHARGE | 3/00, 5/00, 15/00
PREHEATING CHARGE; COOLING; USING WASTE HEAT OR GASES | 13/00; 9/00, 15/02; 17/00
ARRANGEMENTS OF ELECTRIC HEATING ELEMENTS | 11/00
ARRANGEMENTS OF CONTROL AND SAFETY DEVICES | 19/00, 21/00
OTHER FEATURES; OTHER DETAILS | 7/00; 23/00