Karin,
I did a search of the 1940 Federal census records for Philadelphia and found 5 men with the name Charles Altman. 1 Charles Altman was born 1902 in Russia; 1 Charles Altman was born 1871 Austria; 1 Charles Altman was born 1889 in Austria; 1 Charles Altman was born 1915 in Sweden and 1 Charles Altman was born 1905 in Pennsylvania. In looking at the occupations, the only one that came close was the Charles Altman born 1871 was listed as an inspector, Government hat Dept. This Charles Altman was living in his son's household on South 57th Street. Given the dates of birth for these men they are all probably deceased, as the youngest born in 1915 would be about 105 years old now. Good luck with your search..