fig1 illustrates a ventilated safety goggle similar to the goggle illustrated in u . s . pat . no . 3 , 141 , 172 . as described therein , the goggle includes a frame 10 having a rim portion 12 which encloses the periphery of the lens 13 , and a back portion or wall 14 extending rearwardly from the rim and terminating in a flange 15 for engaging the face of the wearer . the ventilators 20 , which are preferably identical in construction and located on opposite sides of frame 10 , are shown in detail in fig2 - 4 . each ventilator 20 includes a generally cup - shaped inner part 22 having a hollow tubular portion 25 adapted for insertion through a suitably sized ventilator aperture 28 formed in the goggle wall 14 . the inner part 22 is inserted into the aperture 28 from inside the goggle , and when so inserted , the outer end 30 of the tubular portion 25 extends outwardly and is spaced from the wall 14 . an integral annular flange 32 on the end of tubular portion 25 inside the goggle and opposite end 30 is sized to engage the inner surface of the goggle wall 14 , and when clamped firmly thereon is in sealing engagement with the wall . the inner part 22 thus provides a ventilating opening or air passage 33 connecting axially through the tubular portion 25 from outside the wall 14 into the interior of the goggle . ventilator 20 also includes a generally cup - shaped cap part 35 having an impervious outer end 37 , a cylindrical body portion 38 , and a peripheral flange 39 . body portion 38 is arranged to be assembled on the goggle in telescoping relation with tubular portion 25 , portion 38 providing axially inwardly extending sides which overlap the outer end 30 of the tubular portion 25 . as may be seen in fig3 portion 38 is proportioned to stand in spaced relation to the sides and outer end of tubular portion 25 to provide a ventilating space or passageway 40 between ventilator openings 42 formed through portion 38 and opening 33 which passes through the center of tubular portion 25 . openings 42 are located adjacent flange 39 and axially inwardly of the radial projection of the outer end 30 of the tubular portion 25 . in these respects , therefore , the ventilator of the present invention is similar to that in the above - noted u . s . pat . no . 3 , 141 , 172 , and similarly provides good ventilation for the goggles while protecting against intrusion of foreign solids and liquids . in order to hold the ventilators 20 on the goggle , each ventilator cap part 35 includes a pin 45 extending axially inwardly thereof from the end wall 37 and including a pilot portion 46 of reduced diameter and a peripheral rib or bead 47 of greater diameter than the inner end portion of the pin . in the assembled device , the pin 45 is received through a pin - receiving opening 50 in a web 53 which forms the end wall across the outer end 30 of the inner member tubular portion 25 . web 53 includes several perforations 55 which connect the axial ventilating opening 33 with the ventilating passageway 40 on the other side thereof . as illustrated in fig2 and 3 , the ventilator 20 is assembled quite easily onto the goggle wall 14 simply by inserting the inner member tubular portion 25 outwardly through the ventilation aperture 28 in wall 14 , and then forcing the cap pin 45 through the inner member pin - receiving opening 50 until the bead 47 passes through the opening to seat on the surrounding surface portion of the web 53 . pin 45 is then firmly held in interlocked relation to prevent the ventilator portions 22 and 35 from separating . as shown in fig3 and 5 , the web portion 53 acts somewhat as a spring since it is resiliently displaceable in the axial direction . thus the force with which the ventilator flanges 32 and 39 grip the goggle wall 14 may be controlled by the degree to which pin 45 is forced through opening 50 . it is thus easy to establish a permanent tension between these members to seal the ventilator flanges onto the goggle wall . as may be seen , therefore , the present invention provides numerous advantages . the ventilators may be assembled onto the goggle in minimum time and with minimum effort . the simplicity of their individual portions lends them readily to inexpensive mass production by injection molding . once assembled , the ventilators remain permanently affixed and provide a firm , liquid - tight seal between the ventilator flanges 32 and 39 and the goggle wall 14 . the present invention also lends itself to suitable modification where desired . for example , pin 45 might be proportioned or have a textured surface to enhance its frictional engagement within opening 50 , or vice versa , or the pilot end 46 of the pin opposite the outer end 37 of cap part 35 could be melted after the ventilator is assembled onto the goggle to enlarge the pin end 46 . the latter would prevent subsequent withdrawal of the pin through the pin receiving opening 50 . it should also be appreciated that a plurality of pins and pin - receiving openings may be used , and the pin or pins , and their openings , need not lie right on the ventilator axis . while the form of apparatus herein described constitutes a preferred embodiment of this invention , it is to be understood that the invention is not limited to this precise form of apparatus , and that changes may be made therein without departing from the scope of the invention .
a two - part goggle ventilator includes a pin on one part and a pin receiving opening in the other part providing for quick , convenient and reliable attachment of the ventilator in a complementary aperture in a goggle . when assembled on the goggle , the ventilator allows air to flow through the goggle but provides high resistance to intrusion of liquids and other foreign matter .