Summary of Significant Accounting Policies (Details Textual)	3 Months Ended	12 Months Ended
	Jun. 30, 2016 USD ($)	Jun. 30, 2016 USD ($) shares	Jun. 30, 2015 USD ($) shares	Jun. 30, 2014 USD ($) shares
Advertising Expense		$ 15,699	$ 32,675	$ 17,904
FIFO Inventory Amount	$ 2,286,022	2,286,022	2,383,104
Decreases In Cost Of Goods Sold		86,698	0	0
Inventory Valuation Reserves	$ 1,498,915	$ 1,498,915	1,472,956
Entity Number of Employees	236	236
Collective Bargaining Period Expiry Date	May 31, 2018
Health Care Insurance Accrued Liabilities	$ 175,000	$ 175,000	195,000
Gain Contingency, Description	Benefits from tax positions are measured at the largest amount of benefit that is greater than 50 percent likely of being realized upon settlement.
Research and Development Expense		$ 463,902	$ 528,285	$ 657,356
Weighted Average Number of Shares Outstanding, Basic | shares		8,027,147	8,027,147	8,027,147
Weighted Average Number of Shares Outstanding, Diluted | shares		8,027,147	8,027,147	8,027,147
Share-Based Compensation		$ 2,946	$ 4,956	$ 9,655
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized	$ 1,000	1,000
Employee Service Share-based Compensation, Tax Benefit from Compensation Expense		$ 1,000	2,000	4,000
Collective Bargaining Agreement [Member]
Entity Number of Employees	139	139
Minimum [Member]
Property, Plant and Equipment, Useful Life		3 years
Maximum [Member]
Property, Plant and Equipment, Useful Life		35 years
Warranty Service [Member]
Revenue Recognition, Multiple-deliverable Arrangements, Determination of Selling Price, Amount		$ 89,895	176,169	$ 113,209
Revenue Recognition Multiple Deliverable Arrangements Determination Of Liability Amount	$ 100,000	$ 100,000	$ 130,000