Volume 24 (1872) (424 pages)

BY DEWEY & CO., Patent Solicitors, SAN FRANCISCO, SATURDAY, JUNE 8, 1872. VOLUME 3NXIV. Number 23. “Hydraulic Joints.” [Written for the Press by H. Waray Paivtos. Extonsive as the present application of hydranlic poweér is, there is no reason why it shonld not bo munch more so if two cansee of retardation were removed. The firat of theso is, that the extreme adaptability of hydraulic pressure to many operations roqniring but little power, is as yet not nnderstood. For instance, in very many casee a eteady and perfectly smooth motion, snch a3 can be regulated to any eneed, and also so arranged that the power cannot rise ahove a certain point, would be invaluable for smal] menafactnring purposes. Now if, as is generally the case, a screw, cam, or other ordinary mechanical means be used, the graduatien of speed, though simple enough in its first design, offers a difficulty in general when the machine is in motion. Fnrther, shonld any obstrnction occur, the power at onee hegins to accnmailate, till in many casee the force becomes eo great as to cause the destruetion of eome parts of the running gear. The practically perfect non-elasticity of water gives jnst the advantages reqnired, a motion of complete uniformity can be obtained, which, without stopping the machinery, cen be regulated to any desired extent from nothing to the most rapid velocity originally estimated in the designing of tbe machine. Should the resistance be increased hy any ohstructien, tbe machine will eimply stop, inetead of destroying any part of itself, or the attachments, suppesing always that ordinary care and knowledge are exercieed in proportioning the work, pressnre, and size of the macbine to its attachmente and the ultimate power to the ultimate resistance. But it may he objected tbat hydraulic power is enly applicable where very great resistance bas to he dealt with, and that it is not at all applicable where very emall degrees of power are required. Again it may he said that there is so mnch trouble) with the joints ae to render other appliances preferable. With tbe queetion of hydraulic joints—wby they are so much trouble, how they ought tobe made, and what amount of indurance may he expected from them, when properly.constructed, I propose to deal in a simple and practical manner, leaving the other question open for a future communication. To all intents and purpeses the joints, more particularly the working onee, are the vitals in arrangement of hydraulic mechanism. No matter hew perfect other parts of the macbine may he, if the joints are defective continued annoyance will assuredly ensue. How to make a thoroughly effective hydraulic joint is a secret poseessed by but few. No matter how well the leathers are made, or of what quality of material; no matter bow carefnlly they may be inserted or how correctly the recesees for them may be conetructed, if they are called upon to encounter onght hut a higbly polisbed surface, against which to work, they cannot last long. It muet be horne in miud that if an unpolished snrface is oondncive, in the case of a metallic packing moving in contact with it, to rapid wear, if ie, in the case of leather, nothing ehort of positive destrnetion. To leather, under high pressnre, tho very pores of the metal become so many pits, into which the leather ie forced, only tobe torn away in emall fragments. It might eeem smal] and nnnecessary to nrge this truth, were it not that I have Fig. I. known hnt too many cases where most costly results have followed from the nee of unpolished surfaces. Over and heyond these causes there ie stil] another, which ie, wo onght almoet to say, universal, so seldom ie care taken to avoid it, or rather, in fact, so deliherately Fig. I. is it, as it were, cultivated. I refer to the rapid destruction of leatbers, hy reason of the destructive mode of adjustment, formed only with a view of first cost, in euch a way as to positively insure the actnal cutting of tbe leatber. In making hydranlic joints three types of leatber are nsed, whicb are usnally designated as cup, cap and hat leathers, Fig. II. respectively. The enp leather is the most commonly used, and is of a form so well known as not to need any description bere. The cap leather ie not unlike a bat deprived of its rim and with a hole in its crown; and the hat leather resemhleea hat minns all the crown. Of conrse in each case the grain of the leatber, that is the outer side, mnet form the working surface of the hydraulie packing. It will then work to a smooth, evenly polisbed eurface, if proper care he taken in finishing tbe metal in contact witb it. French chalk mixed with a little of the best unsalted tallow, forme an excellent lubricating paste for the leathers. In preparing hydraulic leathers of varions kinds, the following mode of procedure will he found completely encceseful: The leather selected mnst be of the best tannage, t. e., oak bark tanned leather. The snitahle parts of the leather are the hard parts of the hntt, for large leathere, and the best shoulders for the small ones. On no account ehonld any of the belly leather he nsed. With a sharp knife tbe whole of the fleshing or soft inner portions Fig. IV. must he completely removed; great care heing taken to eut'the leather to an even enrface. The elightest cnt below the snrface will spoil the part so cut, as the leather when at work will then fail, and that soon. Having so prepared the inner surface of the leather, the outer grain must he turned uppermost, and very carefully examined for any ents or flawe, no matter Fig. V. how minute; with a pair of dividere the circles deecrihing washers of tbe sizes suited to prodnce the reqnired leathers must next he drawn. For cup and hat leathers an inner circle will he requisite to mark the place to he eut ont at the centre, When cut leathers are required with any holeein the crown, the leg of the diyiders muet not punctnre the leather; use a loose piece of leather to take a center from, or @ circular tin plate and ‘‘ ecribe” round it. After cutting the washers, overhan] them and eee whether the thickness ie exactly equal all over each. If it be not eo, then the leatbers will be drawn unequally in the die. Tbe hest way to make tbe waehers ie to cut them square; faeten hy the corner to wood, faced truein a latbe, and then turn them, firet toa proper even thickness; seeondly, cutting them to the right circnlar eize. Of conrse the graiu side mnet go towarde the face plate and the fastenings only pierce the waste corners. ed deeign for making cut leathere. After the washere are thne prepared, they are tohe steeped in eoft water till eoftand flexihle. When they are thoroughly softened they are ready for the dies, which I will deserihe:—First, a really good pair of dies ‘ought to be made for making cnp leather. The best material for dies ie goed hard gun metal, ae cast iron is affected by the tannic acid, and so becomes troublesome, so tbat the dies move in and ont of each other with considerahle friction. Besides the iron is apt to tear the leather, eince it becomee, as it were adhesive or grating on the eurface, and the leather does not elide easily with the recese of the dies. The eketch herewith ehowsin fig. la pair of dies of the latest and most improvThe fignre also includes the proper means of forcing bome the die when the leather is adjusted. A is the center piece of the die, baving a projecting epindle, A’, wbhicb acts asa guide to eenter the leather; the monlding ring, B, is the onter die, fitting accurately around A; the recess, D, is formed half in each die. When this constrnetion is not observed there is difiicnlty in removing the leatbers, and they are frequently injured. When very large nnmbers of leathere have to he made it is woith while to provide epecial means for removal from the dies. The hest means to accomplieb this consies of two rings of metal, a little deeper thau the dies. One ring shonld juet pass freely around the die, A, the other throngh the die, B, the elges of these dies must be smooth and rounded, the ringe merely resting on the form. When the diee are eeparated, tbe leather is very quickly removed from either dies hy meane of these ringe. Should tbe leather, as is the nenal case, be upon the die, A, this die is merely dropped into the ring belonging to it. If tbe die, B, ehonld carry the leather it is forced over the proper ring. If these rings are not provided, eome hlunt instrument muet be ueed. The hell, C, fitting upon the guide, A, is in every way euperior to the ring generally used for forcing the leather into the dies. The small boles ut 7/7, are outlets for the air. Thie arrangement for forcing home the dies is the same ae in auy hand puncb, and needs no description. Tbe best arrangement for forcing home the bell is hy bydranlic power itself. Whben a press is at hand the leatbers are hest prepared by placing the dies between the pattern, and then allowing merely a sligbt opening of the valve to produce jnst leakage into the cylinder, by means of which a elow motion is produced. After being forced home, the leather must he allowed thoronghly to set, when it becomee firm, the pressnre may be removed and tbe hell withdrawn; next witb a sharp knife pare off the leather level. If yon have no lathe, finish tbe leather in the dies and carefully trim them. It yon baye {Continued on page 857].

BY DEWEY & CO., Patent Solicitors, SAN FRANCISCO, SATURDAY, JUNE 8, 1872. VOLUME 3NXIV. Number 23. “Hydraulic Joints.” [Written for the Press by H. Waray Paivtos. Extonsive as the present application of hydranlic poweér is, there is no reason why it shonld not bo munch more so if two cansee of retardation were removed. The firat of theso is, that the extreme adaptability of hydraulic pressure to many operations roqniring but little power, is as yet not nnderstood. For instance, in very many casee a eteady and perfectly smooth motion, snch a3 can be regulated to any eneed, and also so arranged that the power cannot rise ahove a certain point, would be invaluable for smal] menafactnring purposes. Now if, as is generally the case, a screw, cam, or other ordinary mechanical means be used, the graduatien of speed, though simple enough in its first design, offers a difficulty in general when the machine is in motion. Fnrther, shonld any obstrnction occur, the power at onee hegins to accnmailate, till in many casee the force becomes eo great as to cause the destruetion of eome parts of the running gear. The practically perfect non-elasticity of water gives jnst the advantages reqnired, a motion of complete uniformity can be obtained, which, without stopping the machinery, cen be regulated to any desired extent from nothing to the most rapid velocity originally estimated in the designing of tbe machine. Should the resistance be increased hy any ohstructien, tbe machine will eimply stop, inetead of destroying any part of itself, or the attachments, suppesing always that ordinary care and knowledge are exercieed in proportioning the work, pressnre, and size of the macbine to its attachmente and the ultimate power to the ultimate resistance. But it may he objected tbat hydraulic power is enly applicable where very great resistance bas to he dealt with, and that it is not at all applicable where very emall degrees of power are required. Again it may he said that there is so mnch trouble) with the joints ae to render other appliances preferable. With tbe queetion of hydraulic joints—wby they are so much trouble, how they ought tobe made, and what amount of indurance may he expected from them, when properly.constructed, I propose to deal in a simple and practical manner, leaving the other question open for a future communication. To all intents and purpeses the joints, more particularly the working onee, are the vitals in arrangement of hydraulic mechanism. No matter hew perfect other parts of the macbine may he, if the joints are defective continued annoyance will assuredly ensue. How to make a thoroughly effective hydraulic joint is a secret poseessed by but few. No matter how well the leathers are made, or of what quality of material; no matter bow carefnlly they may be inserted or how correctly the recesees for them may be conetructed, if they are called upon to encounter onght hut a higbly polisbed surface, against which to work, they cannot last long. It muet be horne in miud that if an unpolished snrface is oondncive, in the case of a metallic packing moving in contact with it, to rapid wear, if ie, in the case of leather, nothing ehort of positive destrnetion. To leather, under high pressnre, tho very pores of the metal become so many pits, into which the leather ie forced, only tobe torn away in emall fragments. It might eeem smal] and nnnecessary to nrge this truth, were it not that I have Fig. I. known hnt too many cases where most costly results have followed from the nee of unpolished surfaces. Over and heyond these causes there ie stil] another, which ie, wo onght almoet to say, universal, so seldom ie care taken to avoid it, or rather, in fact, so deliherately Fig. I. is it, as it were, cultivated. I refer to the rapid destruction of leatbers, hy reason of the destructive mode of adjustment, formed only with a view of first cost, in euch a way as to positively insure the actnal cutting of tbe leatber. In making hydranlic joints three types of leatber are nsed, whicb are usnally designated as cup, cap and hat leathers, Fig. II. respectively. The enp leather is the most commonly used, and is of a form so well known as not to need any description bere. The cap leather ie not unlike a bat deprived of its rim and with a hole in its crown; and the hat leather resemhleea hat minns all the crown. Of conrse in each case the grain of the leatber, that is the outer side, mnet form the working surface of the hydraulie packing. It will then work to a smooth, evenly polisbed eurface, if proper care he taken in finishing tbe metal in contact witb it. French chalk mixed with a little of the best unsalted tallow, forme an excellent lubricating paste for the leathers. In preparing hydraulic leathers of varions kinds, the following mode of procedure will he found completely encceseful: The leather selected mnst be of the best

tannage, t. e., oak bark tanned leather. The snitahle parts of the leather are the hard parts of the hntt, for large leathere, and the best shoulders for the small ones. On no account ehonld any of the belly leather he nsed. With a sharp knife tbe whole of the fleshing or soft inner portions Fig. IV. must he completely removed; great care heing taken to eut'the leather to an even enrface. The elightest cnt below the snrface will spoil the part so cut, as the leather when at work will then fail, and that soon. Having so prepared the inner surface of the leather, the outer grain must he turned uppermost, and very carefully examined for any ents or flawe, no matter Fig. V. how minute; with a pair of dividere the circles deecrihing washers of tbe sizes suited to prodnce the reqnired leathers must next he drawn. For cup and hat leathers an inner circle will he requisite to mark the place to he eut ont at the centre, When cut leathers are required with any holeein the crown, the leg of the diyiders muet not punctnre the leather; use a loose piece of leather to take a center from, or @ circular tin plate and ‘‘ ecribe” round it. After cutting the washers, overhan] them and eee whether the thickness ie exactly equal all over each. If it be not eo, then the leatbers will be drawn unequally in the die. Tbe hest way to make tbe waehers ie to cut them square; faeten hy the corner to wood, faced truein a latbe, and then turn them, firet toa proper even thickness; seeondly, cutting them to the right circnlar eize. Of conrse the graiu side mnet go towarde the face plate and the fastenings only pierce the waste corners. ed deeign for making cut leathere. After the washere are thne prepared, they are tohe steeped in eoft water till eoftand flexihle. When they are thoroughly softened they are ready for the dies, which I will deserihe:—First, a really good pair of dies ‘ought to be made for making cnp leather. The best material for dies ie goed hard gun metal, ae cast iron is affected by the tannic acid, and so becomes troublesome, so tbat the dies move in and ont of each other with considerahle friction. Besides the iron is apt to tear the leather, eince it becomee, as it were adhesive or grating on the eurface, and the leather does not elide easily with the recese of the dies. The eketch herewith ehowsin fig. la pair of dies of the latest and most improvThe fignre also includes the proper means of forcing bome the die when the leather is adjusted. A is the center piece of the die, baving a projecting epindle, A’, wbhicb acts asa guide to eenter the leather; the monlding ring, B, is the onter die, fitting accurately around A; the recess, D, is formed half in each die. When this constrnetion is not observed there is difiicnlty in removing the leatbers, and they are frequently injured. When very large nnmbers of leathere have to he made it is woith while to provide epecial means for removal from the dies. The hest means to accomplieb this consies of two rings of metal, a little deeper thau the dies. One ring shonld juet pass freely around the die, A, the other throngh the die, B, the elges of these dies must be smooth and rounded, the ringe merely resting on the form. When the diee are eeparated, tbe leather is very quickly removed from either dies hy meane of these ringe. Should tbe leather, as is the nenal case, be upon the die, A, this die is merely dropped into the ring belonging to it. If tbe die, B, ehonld carry the leather it is forced over the proper ring. If these rings are not provided, eome hlunt instrument muet be ueed. The hell, C, fitting upon the guide, A, is in every way euperior to the ring generally used for forcing the leather into the dies. The small boles ut 7/7, are outlets for the air. Thie arrangement for forcing home the dies is the same ae in auy hand puncb, and needs no description. Tbe best arrangement for forcing home the bell is hy bydranlic power itself. Whben a press is at hand the leatbers are hest prepared by placing the dies between the pattern, and then allowing merely a sligbt opening of the valve to produce jnst leakage into the cylinder, by means of which a elow motion is produced. After being forced home, the leather must he allowed thoronghly to set, when it becomee firm, the pressnre may be removed and tbe hell withdrawn; next witb a sharp knife pare off the leather level. If yon have no lathe, finish tbe leather in the dies and carefully trim them. It yon baye {Continued on page 857].