fig1 shows a side view of a preferred child resistant attachment 100 of the present invention . attachment 100 is particularly well suited for use in conjunction with typical cylindrical pharmaceutical bottles and vials to dispense pharmaceutical products , such as tablets . attachment 100 comprises finish portion 1 and closure 2 . finish portion 1 and closure 2 are preferably injection molded of polypropylene , polystyrene , polycarbonate , or the like . finish portion 1 comprises attachment ting 4 and tab ting or collar 5 . bead 3 on attachment ting 4 is used to secure attachment 100 to a pharmaceutical package ( not shown ). tab collar 5 is interrupted by slots 6 , thereby forming a pair of opposed cantilevered pushtabs 7 , as shown in fig2 . fig2 is a cross - sectional view of attachment 100 taken through section line i -- i of fig1 . the closure securement ting includes first means for rotatably and releasably securing closure 2 to finish portion 1 . in the illustrated embodiment , the first means comprises helical threads 9 on the outermost surface of thread ring 10 . the closure 2 includes second means complementary to said first means for rotatably and releasably securing the closure to the closure securement ring . in the embodiment of fig2 the second means comprises threads 18 on the innermost surface of thread collar 17 on closure 2 . while any suitable releasable securement means , e . g ., a combination of lugs or screw threads , can be employed to rotatably and releasably secure closure 2 onto finish portion 1 , complementary screw threads 9 and 18 , respectively , as shown in fig2 are particularly preferred . the threads 9 on the exterior surface of thread ring 10 are preferably double lead threads . the pitch of complementary threads 9 and 18 is preferably such that closure 2 is fully seated onto finish portion 1 with approximately 180 ° of rotation . the collar 5 , thread ting 10 , and attachment ring 4 are preferably integrally molded and are generally concentric with one another . the top of each spring - like pushtab 7 has a vertical extension 8 which projects above the plane of the top edge of tab collar 5 . the vertical extensions 8 interlock with pawls 15 on the innermost surface of lock ting 16 of closure 2 when the closure 2 is fully threaded onto finish portion 1 . a channel 11 , formed between the inner surface of tab collar 5 and thread ring 10 , accepts thread collar 17 when closure 2 is threaded onto finish portion 1 . during assembly of closure 2 onto finish portion 1 , pawls 15 must rotate past vertical extensions 8 . however , vertical extensions 8 interfere with rotation of pawls 15 and cause pushtabs 7 to be resiliently deflected inwardly . gradual lead - in ramps on pawls 15 facilitate the deflection . in general it is preferred that the lead - in ramps exhibit a gradual inwardly directed taper so as to avoid a sudden increase in the reapplication torque required to fully seat the closure 2 onto the finish portion 1 . if desired , the mating surfaces of vertical extensions 8 may also be profiled , as generally shown in the cross - sections of fig2 a and 3a , to minimize the reapplication torque required to fully seat the closure 2 onto the finish portion 1 of the attachment 100 . both of these features help to ensure that the user will properly reapply the closure to restore child resistance to the package after the package has been opened . continued rotation of closure 2 causes pawls 15 to clear the vertical extensions 8 , thereby permitting vertical extensions 8 and pushtabs 7 to resiliently return to the latched condition shown in fig2 and 2a . the finish portion 1 may be molded so that the pushtabs 7 and vertical extensions 8 exhibit an unrestrained at rest position wherein the maximum exterior dimension , as measured across the opposed vertical extension 8 is substantially equal to or slightly less than the inside diameter of the closure lock ting 16 , as measured in the area where pawls 15 are not present . alternatively , the finish portion may be molded so that the vertical extensions 8 exhibit an unrestrained maximum exterior dimension which is somewhat greater than the inside diameter of the closure lock ting 16 . in this situation , application of closure 2 to finish portion 1 results in preloading of the vertical extensions 8 against the interior surface of lock ting 16 when the closure 2 is fully seated , as shown in fig2 a . the arrangement of threads 9 and 18 in conjunction with vertical extensions 8 and pawls 15 is such that latching of pawls 15 past vertical extensions 8 occurs nearly simultaneously with the seating of closure 2 onto finish portion 1 , at which point seal lip 20 preferably engages finish taper 25 to form a seal . this is readily achievable , since the thread 9 is integrally molded with the finish portion 1 that includes the integrally formed pushtabs 7 , vertical extensions 8 and finish taper 25 while the thread 18 is integrally formed with the closure 2 which includes pawls 15 and seal lip 20 . fig2 a is a cross - sectional view of attachment 100 taken along section line ii -- ii in fig1 . with pushtabs 7 in the position shown in fig2 and 2a , edges 30 of vertical extensions 8 impede counter - clockwise rotation of pawls 15 preventing attempts to reopen the attachment by rotating the closure 2 in the counter - clockwise direction indicated by the arrow &# 34 ; t &# 34 ;. clearance in channel 11 between the outer surface of thread collar 17 and the inner surface of pushtabs 7 noted as dimension &# 34 ; x &# 34 ; in fig2 permits sufficient inward deflection of pushtabs 7 from the position shown in fig2 and 2a that the vertical extensions 8 will clear pawls 15 when the user concurrently depresses pushtabs 7 and applies an unscrewing torque in the direction of arrow &# 34 ; t &# 34 ; to the closure 2 . fig3 is a view of attachment 100 taken at a point corresponding to section line i -- i of fig1 but with pushtabs 7 deflected inwardly . in order to unscrew closure 2 from finish portion 1 once the closure has been fully assembled , sufficient manual pressure must be applied to opposed pushtabs 7 in the direction indicated by arrows &# 34 ; p &# 34 ; in fig3 such that the vertical extensions 8 on pushtabs 7 disengage the pawls 15 on the innermost surface of lock ring 16 of closure 2 . the squeezing force required to depress pushtabs 7 is preferably great enough to be difficult for a child , yet low enough that people using the medication , such as arthritics , can readily depress the opposing pushtabs 7 while concurrently applying an unscrewing torque in the direction of arrow &# 34 ; t &# 34 ; in fig3 a to the closure 2 . the preferred squeezing force &# 34 ; p &# 34 ; for the pushtabs 7 to provide child resistance without imposing undue difficulty for adults with impaired manual dexterity is believed to be within the range of about 0 . 5 pounds to about 5 pounds . in addition , pushtabs 7 are preferably substantially flush with the outermost surface of tab ring or collar 5 when the closure 2 is fully secured in place so that simply grasping the collar about its entire periphery and squeezing is unlikely to permit both of the vertical extensions 8 on the opposed pushtabs 7 to become inadvertently disengaged from pawls 15 at the same time an unscrewing torque is being applied to the closure 2 . rather , a conscious decision to squeeze the opposing pushtabs 7 must be made by the user to initiate the opening process , and this must be accompanied by a concurrent application of unscrewing torque to the closure 2 to proceed further . this minimizes the chance that a child will be able to remove closure 2 simply by squeezing the entire periphery of tab collar 5 in his or her hand while trying to unscrew closure 2 . fig3 a is a cross - sectional view of attachment 100 taken at a point corresponding to section line ii -- ii of fig1 but showing the attachment 100 in the condition shown in fig3 i . e ., with pushtabs 7 deflected inwardly . vertical extensions 8 are thus shifted to a position wherein edges 30 no longer impede counter - clockwise rotation of pawls 15 on lock ting 16 in the direction indicated by the arrow &# 34 ; t &# 34 ;. the user of child resistant attachment 100 is then able to further rotate closure 2 in a counter - clockwise direction , thereby causing the closure 2 to rise above vertical extensions 8 and release the engagement of threads 9 and 18 on thread ting 10 and thread collar 17 , respectively . this permits closure 2 to be completely removed from finish portion 1 . fig4 shows an alternative embodiment of a child resistant attachment 200 of the present invention . attachment 200 comprises finish portion 201 and closure 202 . finish portion 201 further comprises attachment ting 204 and tab ring or collar 205 . attachment ring 204 includes bead 203 . tab ting or collar 205 is interrupted by slots 206 , thereby forming a pair of opposed cantilevered pushtabs 207 . fig4 a is a cross - sectional view of the child resistant container attachment 200 shown in fig4 said view being taken along section line iii -- iii in fig4 . descending ring 231 extends inwardly from horizontal closure wall 230 and is joined to an outwardly extending ascending ting 232 at the upper end of thread ting 217 . ascending ting 232 supports horizontal closure wall 233 . descending ting 231 and ascending ting 232 are separated by a circular channel 235 . thread ting 217 extends downwardly from the juncture of descending ring 231 and ascending ting 232 and includes threads 218 about its lower outermost surface . threads 218 are complementary to threads 209 on the interior surface of attachment ting 204 . the top of each spring - like pushtab 207 has a vertical extension 208 which projects above the plane of the top edge of the tab ting or collar 205 . the vertical extensions 208 interlock with pawls 2 15 on the innermost surface of lock ting 2 16 of closure 202 when the closure 202 is fully threaded onto finish portion 201 in substantially the same manner described with respect to the child resistant container attachment 100 shown in fig1 - 3a . during assembly of closure 202 onto finish portion 201 , pawls 215 must rotate past vertical extensions 208 . however , vertical extensions 208 interfere with rotation of pawls 215 and cause pushtabs 207 to be resiliently deflected inwardly . ramps on pawls 215 facilitate this deflection . further rotation of closure 202 causes pawls 215 to clear vertical extensions 208 , thereby permitting pushtabs 207 to resiliently return to the condition shown in fig4 and 4a . the arrangement of threads 209 and 218 in conjunction with vertical extensions 208 and pawls 215 is such that latching of pawls 215 past vertical extensions 208 occurs nearly simultaneously with the seating of closure 202 onto finish portion 201 , at which point seal lip 220 preferably engages finish taper 221 to form a seal . clearance in channel 211 between the outer surface of descending ring 231 and the inner surface of pushtabs 207 , noted as dimension &# 34 ; y &# 34 ; in fig4 a , permits sufficient inward deflection of pushtabs 207 to permit the vertical extensions 208 to clear pawls 215 when the user wants to apply sufficient unscrewing torque to remove the closure 202 from the finish portion 201 . with pushtabs 207 in the condition shown in fig4 and 4a , vertical extensions 208 impede counter - clockwise rotation of pawls 215 when attempting to remove closure 202 . in order to unscrew closure 202 from finish portion 201 once the closure has been fully assembled onto the finish portion , sufficient manual pressure must be applied to pushtabs 207 such that the vertical extensions 208 on pushtabs 207 fully disengage the pawls 215 on the innermost surface of lock ring 216 of closure 202 . the squeezing force required to depress pushtabs 207 is preferably great enough to be difficult for a child , yet low enough that people using the medication , such as arthritics , can readily depress the opposing pushtabs 207 while concurrently applying an unscrewing torque to the closure 202 . in addition , pushtabs 207 are preferably substantially flush with the outermost surface of tab collar 205 when the closure 202 and finish portion 201 are in a fully assembled condition so that simply grasping the ring about its entire periphery is unlikely to permit both of the vertical extensions 208 on pushtabs 207 from becoming inadvertently disengaged from pawls 215 . rather , a conscious decision to squeeze the opposing pushtabs must be made by the user to initiate the opening process . this minimizes the chance that a child will be able to remove closure 202 simply by squeezing the entire periphery of tab collar 205 in his or her hand while trying to unscrew closure 202 . in the particular attachment embodiment 200 shown in fig4 a , ascending ring 232 supports the closure &# 39 ; s horizontal wall 233 such that the plane of the top surface of horizontal closure wall 233 is coincidental with the plane of the top surface of horizontal closure wall 230 . channel 235 between descending ring 23 1 and ascending ring 232 may , if desired , be covered , as by a label 234 , so that a smooth uninterrupted surface is presented to the user of the package . the particular configuration of closure 202 shown in fig4 a accommodates the internally threaded configuration of finish portion 201 while still providing a seal at seal lip 220 and finish taper 221 and a flush upper surface for closure 202 . in addition , closure 202 is injection moldable as a single integral closure . the vertical location of horizontal closure wall 233 may , if & amp ; sired , be located at points lower on ascending ring 232 or even on thread ring 217 . in the latter case , ascending ring 232 could , if desired , be eliminated altogether . further , if a fluid tight seal at the junction of seal lip 220 and the finish taper 221 shown in fig4 a is not required , ascending ring 232 and descending ring 231 could both be eliminated , horizontal closure wall 230 could be extended inwardly , horizontal closure wall 233 could be positioned within thread ring 217 , and thread ring 217 could be upwardly extended until it intersected the innermost edge of the inwardly extended horizontal closure wall 230 . fig5 is a cross - sectional view of child resistant attachment 200 assembled onto a cylindrical vial 250 . attachment ring 204 is inserted into the open end of vial 250 and is secured in its assembled position by means of an external bead 203 which engages a groove 251 on the interior wall of vial 250 . the resulting child resistant package provides the benefits of improved resistance to opening by children without significantly compromising access by adults to containers of the type commonly used by most pharmacists to dispense prescription medications . because external bead 203 on attachment ring 204 and groove 251 in vial 250 permit unlimited rotation between the finish portion 201 of attachment 200 and the vial 250 , child resistance of the resultant packages is enhanced even further , since rotation of the finish portion 201 of attachment 200 relative to vial 250 will not permit removal of closure 202 . furthermore , pharmacists &# 39 ; habits and practices regarding handling , filling and labeling are not significantly affected when child resistant attachments of the present invention are employed , since they are completely compatible with cylindrical vials . fig6 is a cross - sectional view of another child resistant attachment 300 of the present invention assembled onto another cylindrical vial 350 . child resistant attachment 300 includes a pair of opposed resiliently deformable levers 307 having vertical extensions 308 and is generally similar in operation to child resistant attachment 100 shown in fig1 - 3a , but further includes a clamp collar 360 . clamp collar 360 comprises lead - in taper 362 and groove 361 for securing the attachment 300 to the cylindrical vial 350 . clamp collar 360 is generally concentric about attachment ring 304 . seal bead 355 at the opening of vial 350 is typical of most pharmaceutical vials currently used with simple snap caps . to assemble the attachment 300 onto the vial 350 , attachment ring 304 of child resistant attachment 300 is inserted into the mouth of vial 350 and is pressed into place such that clamp collar 360 deflects outwardly as lead - in taper 362 encounters seal bead 355 . once fully assembled , groove 361 of attachment 300 substantially engages seal bead 355 of vial 350 . if desired , clamp collar 360 may be interrupted by slots which separate the clamp collar into several segments so that tougher polymers such as polycarbonate may be utilized without requiring excessive assembly force . furthermore , one or more internal beads , such as bead 203 described for attaching child resistant attachment 200 to vial 250 , can be added to reduce even further the chance that child resistant attachment 300 could be removed from vial 350 once full assembly of the attachment onto the vial has taken place . fig7 shows another alternative embodiment 400 of a child resistant attachment of the present invention . child resistant attachment 400 is shown with its closure 402 unassembled to the finish portion 401 . closure 402 and finish portion 401 are shown in cross - section , while the front of bottle 450 is illustrated in fig7 . finish portion 401 is shown assembled onto bottle 450 . below the neck ring 451 , bottle 450 may be cylindrical or non - cylindrical , as desired . neck ring 45 1 of bottle 450 extends within the inner surface of thread ring 410 and includes a catch bead 452 for retaining the finish portion 401 of child resistant attachment 400 on bottle 450 . threads 409 on the outermost surface of thread ring 410 are complementary to threads 418 on the innermost surface of thread collar 417 and provide means for releasably securing closure 402 to finish portion 401 . the top of each spring like pushtab 407 has a vertical extension 408 which projects above the plane of the top edge of the tab ring or collar 405 . a channel 411 , formed between the innermost surface of tab collar 405 and the outermost surface of thread ring 410 , accepts thread ring 417 when closure 402 is threaded onto finish portion 401 . the opposed vertical extensions 408 interlock with pawls 415 on the innermost surface of lock ring 416 of closure 402 when the closure 402 is fully threaded onto finish portion 401 . in general , the operation of child resistant attachment 400 is similar to that previously described for child resistant attachment 100 . fig8 shows an enlarged exploded view of the unassembled child resistant attachment 400 prior to assembly of the finish portion 401 onto bottle 450 . neck ring 451 of bottle 450 includes a catch bead 452 which engages catch recess 453 at the upper end of the innermost surface of thread ring 410 when finish portion 401 is fully assembled onto neck ring 451 . the diameter of catch bead 452 exceeds the diameter of the innermost surface of thread ring 410 at its juncture with catch recess 453 . the interference between catch bead 452 and the upper innermost edge of thread ring 410 at catch recess 453 prevents removal of finish portion 401 from neck ring 451 of bottle 450 . the tapered surface 454 on finish portion 401 facilitates insertion of neck ring 45 1 on bottle into finish portion 401 . the tapered surface 454 may , if desired , be extended even further up the innermost surface of thread ring 410 so that interference between catch bead 452 and the innermost surface of thread ring 410 occurs closer toward catch recess 453 to further facilitate assembly of the child resistant attachment 400 onto bottle 450 . if desired , limited clearance may also be provided between the innermost surface of thread ring 410 and the outermost surface of neck ring 45 1 while still maintaining sufficient interference between catch bead 452 on bottle 450 and catch recess 453 located at the upper innermost edge of thread ring 410 to prevent a child from removing the finish portion 401 from neck ring 451 of bottle 450 . this enables the entire child resistant attachment 400 to be rotated relative to bottle 450 about axis 460 . the ability to rotate the entire child resistant attachment 400 relative to bottle 450 further frustrates attempts by children to obtain access to the contents of the bottle 450 without appreciably compromising the ability of an adult having impaired strength , manual dexterity or both from gaining access to the package &# 39 ; s contents . although shown applied to a bottle in fig7 rotatable attachment of a child resistant attachment of the present invention is not limited to bottles , but may be applied to nearly any other package form as well , e . g ., pharmaceutical vials . fig9 is a partially segmented side elevation view of still another alternative embodiment 500 of a child resistant attachment of the present invention . however , as can be seen from fig9 and 9a , finish portion 501 of child resistant attachment 500 is integrally molded as a single component with vial 550 . closure 502 is shown unassembled from finish portion 501 in fig9 . a portion of the tab collar 505 is shown partially segmented to expose channel 511 which accepts thread collar 517 of closure 502 . tab ring or collar 505 is interrupted by slots 506 to form a pair of opposed cantilevered spring - like pushtabs 507 . pushtabs 507 have vertical extensions 508 which project above the plane of the upper surface of tab collar 505 . fig9 a shows a cross - sectional view of child resistant attachment 500 and vial 550 with closure 502 in a fully assembled condition , said view be taken through the opposed pushtabs 507 . the lowermost end of attachment ting 504 is integrally molded to the uppermost end of vial 550 . complementary threads 509 and 518 on the outermost surface of thread ring 510 and the innermost surface of thread collar 517 , respectively , secure closure 502 onto finish portion 501 . vertical extensions 508 interlock with pawls 515 on the innermost surface of lock ring 516 . in general , operation of child resistant attachment 500 is similar to that described for child resistant attachment 100 . fig1 shows a side elevation view of yet another alternative embodiment 600 of a child resistant attachment of the present invention . again , finish portion 601 of child resistant attachment 600 is integrally molded with vial 650 . closure 602 is shown fully assembled with finish portion 601 in both fig1 and 10a . tab collar 605 is interrupted by slots 606 to form a pair of opposed cantilevered spring - like pushtabs 607 . fig1 a shows a cross - sectional view of child resistant attachment 600 and vial 650 with closure 602 fully assembled onto finish portion 601 , said view being taken through the opposed pushtabs 607 . the lowermost end of attachment ring 604 is integrally formed with the uppermost end of vial 650 . complementary threads 609 and 618 on the innermost surface of attachment ring 604 and the outermost surface of thread ring 617 , respectively , releasably secure closure 602 onto finish portion 601 . vertical extensions 608 interlock with pawls 615 on the innermost surface of lock ring 616 . in general , operation of child resistant attachment 600 is similar to that described for child resistant attachment 200 shown in fig4 and 4a . fig1 shows a side elevation view of still another alternative embodiment 700 of a child resistant attachment of the present invention . as with the embodiments 500 and 600 of fig9 and 10 , respectively , finish portion 701 of child resistant attachment 700 is integrally molded with bottle 750 . child resistant attachment 700 is shown in fig1 with its closure 702 unassembled to finish portion 701 . operation of child resistant attachment 700 is generally similar to that described for child resistant attachment 100 shown in fig1 - 3a . fig1 a shows a cross - sectional view of closure 702 unassembled from finish portion 701 and with the lowermost end of attachment ring 704 of finish portion 701 integrally molded to the uppermost end of a preform 750 &# 39 ;. this represents an intermediate condition which occurs in the production process . preform 750 &# 39 ; is further processed by polymer processing means typically referred to as injection / blow molding or reheat / blow molding to form a finished bottle , such as the bottle 750 , shown in fig1 . child resistant attachments of the present invention may be used with a variety of pharmaceutical or other containers . it is believed that the package designs and processes described herein and their attendant advantages will be understood from the foregoing description . it will , of course , be apparent to those skilled in the art that various changes may be made in form , construction , and arrangement without departing from the spirit and scope of the invention , and it is intended to cover in the appended claims all such modifications that are within the scope of this invention .