Green’s Dictionary of Slang

1. (US Und.) a till.

1914		Jackson & Hellyer Vocab. Criminal Sl. 23: chip [...] A cash-box; a till; a cash drawer without belling device. A cash receptacle with a belling device is called a ‘combination chip,’ or a ‘damper,’ or a ‘dinger’.
1950		Goldin et al. DAUL 58/2: Dinger. [...] 2. (Rare) Cash register.

2. (US) a bell.

1944		Slanguage Dict. Mod. Amer. Sl. 12: dinger, an alarm bell at the door of a bank.
1949		Monteleone Criminal Sl. (rev. edn) 52: cling the dinger To beg from house to house.
1950		Goldin et al. DAUL 58/2: Dinger. 1. An old-fashioned burglary alarm bell, once used outside banks, shops, etc. [...] 3. A bell or bell-like sound.

3. a telephone.

1984

Partridge DSUE (8th edn) 310/1: since early 1930s.

4. a railroad conductor.

1945

F.H. Hubbard Railroad Avenue 340: Dinger – Conductor (man who rings the bell).