Devised, researched
 and written
  Peter King Smith BSc

                                                         The mid-1960s, German-built multi-track tape recorder with FM/AM/SW radio

1st Main Patent

Patent no.: CH432038 

Tape recorder with continuous and/or selective playback of information, particularly music

Key facts:

  • Drawn up in German 
  • Applied to: Federal Office for Intellectual Property (IGE), Bern, Switzerland 
  • Applicant:  Standard Telephon und Radio AG, Zurich 
  • Applied:     7 July 1964 
  • Granted:   15 March 1967 
  • Includes:   9 earlier patent applications ("priority claims"for key Music Center inventions  
  • Includes:   10 diagrams, all of which had been originally registered with the DPA in Munich 

Priority claims

The following table shows nine
 priority claims that Standard Telephon und Radio AG annexed to, and described in, the first main patent, to the Federal Office for Intellectual Property in Bern on 7 July 1964 (see Summary).

Patent No. Earlier Patent
(priority no.)
Registered on Title of Invention Inventors
1 DE1891624U 16155 9-7-1963 Track-selecting mechanism for tape recorders None mentioned
2 DE1891625U 16169 10-7-1963 Track-selecting mechanism for tape recorders None mentioned
3 DE1891626U 16171 11-7-1963 Track-selecting mechanism for magnetic tape recorders with wide tape [1] None mentioned
4 DE1891627U 16231 26-7-1963 Mechanism for adjusting the sound/ erase heads in tape recorders Friedrich Knochenhauer
Hans-Georg Fuchs
5 DE1891628U 16230 26-7-1963 Tape-run indicator for tape recorders Friedrich Knochenhauer
Hans-Georg Fuchs
6 DE1891630U 16229 26-7-1963 Device for adjusting height/tilt of cabinet Friedrich Knochenhauer
Hans-Georg Fuchs
7 DE1891631U 16232 26-7-1963 Cabinet for tape recorder and radio Friedrich Knochenhauer
Günter Löffler
8 DE1187823 (Auslegschrift) 20910 IX 26-7-1963 Magnetic tape recorder for the continuous and/or selective replaying of information, particularly music Friedrich Knochenhauer
9 DE1208906 (Auslegschrift) 21304 IX 9-11-1963 Magnetic tape recorder with information starting in the middle of the tape's length [2] Alexander Boom

1. The service manuals for the Schaub-Lorenz Music Center use the term "wide band".
2. This patent refers retrospectively to Friedrich Knochenhauer's patent application no. DE1187823.

The patent family applications numbered 1-7 are patent registrations (
No.s 8-9 are registered, detailed descriptions of inventions (
It is not clear what the difference was between the first two priority claims in the table above.

The inventions

On the basis of the nine priority claims, the development team's key inventions were: 
  1. Track-selecting mechanism. 
  2. Mechanism for adjusting the sound/erase heads. 
  3. Tape-run indicator mechanism. 
  4. Device for adjusting height/tilt of cabinet suspended on an I-framed pedestal. 
  5. Cabinet for housing tape recorder and radio. 
  6. Method of recording information on multiple, parallel soundtracks on a wide tape. 
  7. Method of detecting the start/end of information/music recorded on a wide tape. 
  8. Mechanism for automatically switching to next track and rewinding tape. 

Patent claims

The following claims were made for this new tape-recorder invention: 
  1. A magnetic tape recorder with a wide tape fixed inside the recording device that is enclosed in a cabinet. 
  2. The tape contains multiple tracks on which information, particularly music, can be recorded and played back either selectively or continuously. 
  3. When selecting a track, a track-selecting mechanism locates the information recorded on a particular track at a point corresponding to the beginning of the [ed. recordable] tape. 
  4. When the end of the [ed. recordable] tape is reached, the tape device automatically rewinds the tape back to the beginning, and the playback head automatically switches (or can be switched manually) to the next track. 

The inventors
The first main patent application
CH432038 for this tape recorder recognises a team of five co-inventors:
  • Friedrich Knochenhauer 
  • Hans-Georg Fuchs 
  • Siegfried Apitz, Dipl.-Ing. 
  • Günter Löffler, Dipl.-Ing. 
  • Alexander Boom 

Although only Siegfried Apitz and Günter Löffler are shown as having the Diploma in Engineering qualification, research shows that all five of the team were in fact similarly qualified with a Dipl.-Ing.

Unlike all its patent antecedents (see Priority claims), this first main patent application CH432038 was submitted by Standard Telephon und Radio AG [1] of Zurich whose correspondence address was Gotthardhaus, Bubenbergplatz 11, Bern, Switzerland, and not by Standard Elektrik Lorenz AG of Stuttgart-Zuffenhausen [2]), was made to the Federal Office for Intellectual Property (IGE) [3], Einsteinstrasse 2, Bern, Switzerland, instead of to the usual DPA [4] in Munich, as occurred with its nine priority claims. The reason for this choice is presumably because SEL had moved its registered office to Switzerland.

1. Standard Telephon und Radio AG was International Telephone and Telegraph's (ITT) Swiss-based telecommunications division. (ITT was founded in New York in 1920).
2. Standard Elektrik Lorenz AG was parent company ITT's German-based consumer electronics division.
3. The IGE was renamed the Swiss Federal Institute of Intellectual Property in 1996.
4. DPA: Deutsche Patentamt, Zweibrückenstrasse 12, 8000 Munich 2, Germany.


The following ten diagrams (5 images):
  • Were submitted together with patent CH432038 
  • Are the same as the individual drawings submitted with the original nine priority claims 
  • Are listed chronologically in order of original application 
  • Are not in numerical order of the figures 
  • Indicate their respective priority claim numbers in brackets 

Fig. 5: Track-selecting mechanism (16155), showing heart-shaped disc cam.
Fig. 6: Track-selecting mechanism (16169).

Fig. 7: Track-selecting mechanism (16171).

Fig. 8: Sound/erase head adjustment mechanism - from above
[record/play heads: 403; erase head: 404] (16231).
Fig. 9: Sound/erase head adjustment mechanism - side view (16231).
Fig. 10: Tape-run indicator (16230)

                  Fig. 4: Device for adjusting height/tilt of cabinet (16229), and I-framed pedestal. [1]
                  Fig. 3: Cabinet for tape recorder and radio (16232) [2].

The patent describes all the attached drawings as 'examples' of how the tape-recorder invention would look, adding a rider that they could deviate from the final design, which indeed they did, in the following ways:
1. In Fig 4: 
  • It appears from the Dutch application for this main patent (NL 6407513; pag. 11, lines 25-50 ), which is translated directly from the main German-Swiss patent application (CH432038), that the inventors were planning a design for a cabinet that could be rotated on its horizontal axis as shown in the figure 
  • It had two fixed, threaded shafts (not drawn) protruding out from either side of the cabinet 
  • These two shafts would pass though a hole in two moveable plates that could be slid up and down the vertical I-frame 
  • The cabinet and plate could then both be fastened tightly to the I-frame using the two large threaded clamp-knobs [34] which wound around the threaded shafts, enabling the user to adjust the cabinet's height above the floor and the angle of tilt, to optimise ease of use and the acoustics 
  • As far as is known, this rotatable, height-adjustable pedestal never went into production (please advise the website author if you know otherwise) 
  • The I-framed pedestal [31, 32] with tiltable cabinet, differs from the final production model, which consisted of a rectangular metal frame horizontally mounted on four metal legs and fitted with four trolley wheels [a type known to the author] 
2. In Fig 3:
The positions of the receiver (radio/receiver) [25], control knobs [27] and tape-run indicator [26] in Fig. 3 all differ from the final production model (see main photo:

Fig. 1
: Information (on multiple, parallel magnetic soundtracks) on a wide tape;
F. Knochenhauer (20910 IX).

Fig. 2: Information (on multiple, parallel magnetic soundtracks), starting in middle
of a wide tape; an update of 20910 IX by A. Boom (21304 IX).

1. The correspondence associated with the patent family shows that the first seven antecedent patent applications listed in the table above were sent from the company's Pforzheim address in 1963.

2. Friedrich Knochenhauer describes the tape-recorder invention for the first time in his earlier, antecedent patent application (DE1187823).

3. Although registered as one of the five* co-inventors of the music center in the first main patent, Siegfried Apitz is the only inventor not cited as one of the inventors in any of its nine antecedent patents which describe the key components of the music center invention! This is odd as he was the most prolific of all the inventors (see Interview)

© Researched, translated and adapted by Peter K. Smith, 26 June 2008