Automatic Injection Device With Delay Mechanism Including Dual Functioning Biasing Member

An automatic injection apparatus comprising a housing including a main body, a needled syringe with a plunger that has a plurality of latching prongs, the plunger prongs extending through at least one opening in a latchable element within the housing main body, a button rotatable between first and second angular positions relative to the housing main body and the plunger prongs, the prongs having latching surfaces in releasable engagement with the latchable element, the prongs including ramp surfaces, the button including at least one activating element for engaging the ramp surfaces during manual plunging of the button relative to the main body to cam the prongs so as to move the prong latching surfaces out of engagement with the latchable element such that the prongs can pass through the at least one opening in the latchable element, and at least one biasing element for moving the needled syringe within the housing, when the prongs are released from engagement with the latchable element, to extend the needle of the syringe beyond the housing with the prongs passing through the at least one opening in the latchable element, and to advance the plunger to force syringe contents through the needle for an injection, the improvement comprising:

• locking protuberances integrally formed with the prong ramp surfaces and projecting upwardly from the ramp surfaces toward the button, wherein upward tips of said locking protuberances are in spaced relationship with upward tips of the ramp surfaces to define radial gaps therebetween in which extend the at least one activating element of the button when the button is in the first angular position, whereby abutment of the at least one activating element of the button by the locking protuberances resists movement of the prong latching surfaces out of engagement with the latchable element;
• and
• the at least one activating element of the button further comprising clearance slots, said slots extending within the radial gaps when the button is in the second angular position, whereby the locking protuberances fit within the clearance slots to not resist movement of the prong latching surfaces out of engagement with the latchable element.