John Norton of North Massapequa faces up to 7 years in prison when he's sentenced on Sept. 12.
The jury reached its verdict on Thursday. It convicted him of criminal possession of a weapon and attempted assault.
The 60-year-old's lawyer planned to appeal.
Prosecutors say Norton struck and kicked his mother in December after she threatened to call 911. She managed to run to the house of a neighbor, who called police.
Prosecutors say Norton lived at his mother's house while on probation for a 2010 aggravated drunken-driving conviction.