Patented Sept, 24, 1946 _ 2,408,346 -¿ , . „ UNITED, V"S'I'ATÉS '.eÀTEiNrÍoFLFieE Kave A. Smith, Overland, Mo., assignor to Lincoln Engineering Company, St. Louis, M0., a corporation of Missouri . y vApplication October -7, 1944,’¿Serial’No. .557,587 5 Claims. (C1. 3094-4) l . This‘invention relates to -pistonaand with re ~ 2 |3‘wl1ich hug the inside 'of the cylinder 3. 'One metal'head lof the piston is shown at i5 andan other at Il. Each head I5 andv I1 carries a sliding hub I9. The `hubs are oppositely directed gard to certain morespeciñc'features, to follower , pistonsffor lubricant containers and the like, being an improvement over the ’piston shown `in-> the copending U. S. patent application of k'Lutwin CpR'otter and Victor G. Klein, Serial No. 435,966, now Patent Number 2,394,488, ‘ñled May 7, 1943. ' to 'accommodate the resilienthub I I of the pack-V ing. Each head >I5 and Il is also provided with `an edgewise beveled portion 2| Vfor accommodat ing the lips I3, these beveled portions beingalso for Lubricating apparatus. , ~ Among the several objects of the invention may oppositely directed. benoted "the provision of a piston which great _ ' The head I5 is Nprovided with preferably dia 1y simplifies assembling Yprocedure and reduces metrically opposite holes 23v for accommodating the cost of manufacture; and the provision of a the straight shanks 25 of a pairof holding studs. The >shanks >pass through said `'openings 23 and also through aligned openings `2l' in the-packing El.v The openings 21 are of’a size adapted to grip and seal around the shanks 25. piston Lof the class described which veliminates several unhandy fasteners, whereby'replacement in the ñeld of its packing member may readily 15 be accomplished -entirely without tools. Other objects will be in part obvious and in 'part point ed out hereinafter. Each shank, beyond the diaphragm 9, >is grooved, as shown at 29. What may be called a head kportion 3| is preferably of the same di » -The invention `accordingly comprises the -ele ments and combinations of elements, features 20 ameter as shank 21. The grooves 29 are ar of construction, and arrangements of parts which rangedin a plane next to ¿one face of the pack will be exempliñed in >the structureshereinafter ing 9, said planer being the one which the »head described, and the scope of the >application of |‘1 isto assume. » which will be indicated in the following claims. As indicated in Figs. 1 and 3., the head l1 is In `the accompanying drawing, in lwhichis il 25 provided with keyhole openings 33. The small lustrated one of various possible embodiments of ends’or notches 35 of `these openings are prefer the invention, . ' . ably opposite and must be centered with the open Fig. 1 is a plan view of one side of..my new ings 23 in the opposite head I5. The enlarged piston; . _ portions 3l of the openings 33 are opposite but Fig. 2 is a plany viewof the opposite side of 30 not diametrically opposite. Thus the directions the'piston; ' ~ of the keyholes are opposite since the left-hand Fig. 3 is a View similar to Fig. l showing a keyhole in Fig. 3 points counterclockwise and the preliminary assembly .or disassembly operation; right-hand hole 33 Vpoints clockwise. Each en larged end 31 of each hole 33 freely-accommo Fig. 4 is a vertical section taken on line 4-4 of Fig. 1 but showing also the cylindric lubri 35 dates a head 3|; whereas the small notched part cant compartment of a lubricant pump, for which 35 accommodates only the grooved portion 29. the piston is adapted; and Assembly or disassembly is quite easily carried Fig. 5 is an explodedv view of the piston , parts out as is añirmed byfcomparing Fig. 3 and Fig. 1. shown partially disassembled. ` In Fig. 3 the studs 25 have been inserted through Similar reference characters indicate corre 40 the'openlngs in the head I5 (see also the left sponding parts throughout the several views of hand part of Fig. 5). Next, the packing-is assem the drawing. Y bled'by inserting the studs 25 through the open ings 2l Vin the packing. Then as shown in Fig. 3, the large portions 3l of the keyhole openings 33 Referring now more particularly to Figs. 1, 2 and 4, numeral | indicates my new piston assem bled for insertion into a cylinder, the latter being shown at numeral 3 in Fig. 4. This piston is intended to actk as a lubricant follower, on lubri are applied axially over the heads 3|. Then the head |1 is slipped laterally into the position shown in Fig. 1, wherein the small ends 35 of the notches cant carried beneath and in the cylinder 3. To 33>are keyed into the recesses 29. , this end it Aslides upon a retractor rod 5 and is ~ The piston thus assembled may be applied to biased by means of a spring "_I. Sometimes fol 50 rod 5 and inserted into the'cylinder 3 and there lowers of this type are used'in cylinders without after the head |'| cannot slip back into the Fig. 3 rods such as 5. position because the rod 5 prevents any substan The invention has to do with the piston per tial misalignment between the head I1 and the se. 'I‘his consists of an lintermediate resilient packing 9 to the extent that would be required packing diaphragm 9, consisting _preferably of synthetic rubber or the like which is chemically resistant to attack by lubricants, such as for 55 for disassembly. example, “neoprene” This packing has an elon gate hub part II which hugs the retractor rod 5. On its periphery are opposite edgewise lips 60 It will be noted that one rea son for this fact is that the keyhole openings 33 are not pointed -in the same direction around the clock. If they were, the head I1 could, even in the cylinder 3, twist around to a disassembling position. ' . Y e 2,408,346 3 It will be noted that for disassembly purposes the lengths of the small portions 35 of the keyhole 4 passing through said openings, a second head on the opposite side of said packing member, said studs having grooves in the plane of said second head and adjacent to the packing,` and keyhole openings in the second head having notched ing 9 which is greater than the misalignment which will be permitted by the rod 5 or the cylin- j 1 . portions cooperating only with said grooves and y, oppositely directed with respect to the clock, said der 3 in which the piston I operates. notched portions being diametrically opposite one To disassemble the piston is quite easy for all another, >said keyhole openings having enlarged that needs to be done is to remove it from cylinder vportions accommodating the non-grooved por 3 and rod 5 and then move the head l'l `from the tions of said studs beyond the grooves, said heads position shown in Fig. 1 to that shown in Fig. 3; and packing being adapted to be maintained in After this it may be removed axially as suggested slots 33> are enough to require a degree of mis alignment between the head .l1 and the pack alignment by the interior wall of the cylinder in in Fig. 5. Removal of the packing diaphragm which said piston is used. from the unthreaded studs 25 is then quiteeasy 3. A piston comprising an intermediate pack 15 and may be Iaccomplished without damage. From the above it will be seen that the inven tion avoids all threaded studs, nuts, washers and the like, and that assembly and disassembly may ing member, a head on one side of said member having diametrically opposite openings, `said packing having openings aligned therewith, studs vpassing through said openings, a second head tools. It also simpliñes assembly and disassem 20 on the opposite side of said packing member, said studs having grooves in the plane of saidv second bly and reduces the cost of manufacture. It will head adjacent to the packing, and keyhole open be noted that a part of the reason for the simpli ings in the second head having notched portions fication accomplished is the use of the rod 5 (on cooperating with said grooves and oppositely di which the piston operates) for preventing work rected with respect to a radius of the piston, ing loose of the head l'i. In other words, the readily be accomplished entirely by hand, without said keyhole openings having enlarged portions head I1 needs to pass through a sequence of posi - accommodating the non-grooved portions of said tions for disassembly which the rod 5 will not studs beyond the grooves, the length of said permit when the piston is thereon. It Will be notched portions of the keyhole openings being understood that in cases where the follower is used in a cylinder without a rod such as 5, the 30 such as to require for disassembly a misalign ment between the head in which they are lo heads I5 and I1 are made without central open cated and the packing member which is greater ings and that in such cases it is the cylinder than that which ris permitted by the cylindric such as 3 which prevents the head I1 from pass member in connection with which the piston co ing through a sequence of positions which would cause its disassembly in the cylinder. Broadly 35 operates. 4. A piston- comprising an intermediate pack considered, either cylinder 3 and/or rod 5 may be ing member, a head on one side of said _member considered to be a cooperating cylindric member having an opening, said packing having an open in connection with which the piston operates, ing aligned therewith, a stud passing through 40 said opening, a second head on the opposite side conditions. of said `packing member, said stud having a‘ While a single keyhole slot andY one stud could be used, two or more with a symmetrical rela groove in the plane of said second head adjacent tionship between the stud positions is preferable to the packing, and a keyhole opening in the for a balanced holding action by the studs. second head having a notched portion cooperat In View of the above, it will be seen that the ing only with said groove, said keyhole opening several objects of the invention are achieved and having an enlarged portion accommodatingthe other advantageous results attained. I groove of said stud, the length of said notched As many changes could be made in the above portion of the keyhole opening being such as _to constructions without departing from the scope require for disassembly a-misalignment between of the invention, it is intended that all matter the head in which it is located and the packing contained in the above description or shown in member which is greater than that which is the accompanying drawing shall be interpreted as permitted by the cylindric member in connec whereby is prevented disassembly under Working illustrative and not in a limiting sense. I claim: _ ~ tion with’which the piston cooperates. i 1. A piston comprising an intermediate packing member, a head on one side of said member hav ing openings, said packing having ropenings aligned therewith, studs passing through said openings, a second head on the opposite side of said packing member, said studs having recesses in the plane of said second head and adjacent to the packing, and keyhole openings in the ,5. A piston comprising an intermediate pack 55 ing member and a pair of heads between which the packing member is disposed, a post project ing from one head through an ope-ning in said packing member, and through a keyhole open ing in the other head, said keyhole opening be ing formed to provide an aperture larger than saidpost and a smaller notched> portion extend ing therefrom, said post having a groove in the second head having notched portions cooperat plane of said other head adjacent the packing ing only with said recesses respectively and be ing oppositely directed with respect to the clock, 65 member, said notched portion cooperating with said groove to prevent axial lseparation ofV the said keyhole openings having enlarged portions heads and packing member and being- ofv such accommodating the non-grooved portions of said length and extending from said aperture in such studs beyond the grooves, said heads and pack direction as to prevent both relative rotation and ing being adapted to be maintained in alignment by the interior wall ofl the cylinder in which said 70 separation of said other head when the heads and packing member are maintained in align piston is used. ment by the cylindric member in connection with 2. A piston comprising an intermediate pack ing member, a head on one side of said member having diametrically opposite openings, said packing having openings aligned therewith,_studs which the piston is used. ' - » ., KAVE A. SMITH.