US796211A - Stuffing-box for hydraulic cylinders. - Google Patents

Description

' v T B. HOLMES. 1 STUFFI-NG BOX FOR HYDRAULIC CYLINDERS.

APPLICATION FILED DEC. 5, 1904.

PATBNTED AUG. 1,1905.

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UNITED STATES THOMAS EDMUND HOLMES, OF SHEFFIELD, ENGLAND, ASSIGNOR OF ONE-HALF TO DAVY BROTHERS LIMITED, OF SHEFFIELD, ENGLAND,

AN INCORPORATED COMPANY.

STUFFlNG-BOX FOR HYDRAULIC CYLINDERS- Specification of Letters Patent.

Patented. Aug. 1, 1905.

Application filed {December 5, 1904:. Serial No. 235,511. I

To all whmnl it may concern.-

Be it known that I, THoMAs EDMUND HOLMES, engineer and chief draftsman, a subject of the King of Great Britain, residing at 63 Sheldon road, Shefiield, in the county of York, England, have invented certain new and useful Improvements in Stuffing-Boxes for Hydraulic Cylinders, of which the following is a-specification. I g

In a hydraulic cylinder wherein a ram or plunger, both of which are hereinafter referred to as the ram, is fitted to work through a stufiing-box packed with a leather collar it is usually necessary when the leather requires to be changed either to withdraw the ram from the cylinder or to dismount the cylinder itself, both of these operations being not only diflicult, (especially in the case of large steamintensifiers used in connection with hydraulic presses and some types of hydraulic pum pingengines, accumulators,&c. but also involving a great waste of time. I

The object of this invention is to obviate the necessity of either withdrawing the ram.or

dismounting the cylinder in order to allow of the leather being renewed, the construction whereby this end is attained also permitting of the use of leather packing in situations wherein, owing to the impracticability of dismounting the cylinder or withdrawing the ram, hemp or other readily renewable packing has been heretofore employedin place of leather packing, notwithstanding the fact of the latter being preferable in itself.

The accompanying drawing represents in longitudinal section the stufiing-box and adjacent portion of a hydraulic cylinder'constructed according to this invention, the ram being shown as at the end of its outward stroke.

In the drawing, a is the cylinder, 6 the ram, and c the stuifing-box serving to retain in position the leather d. In such cylinders as usually constructed the joint e between the cylinder at and stufiEing-box 0 is so situated that the end f of the ram 6 does not pass said joint when at the limit of its outward stroke. Consequently I the breaking of the joint at e and the slipping of the stufling-box 0 along the ram 6 so as to permit of the leather d being exposed does not enable the leather to be removed by being passed over the end f of the ram.

According to the present invention the joint 0 is situated at such a distance inward of the total length of the cylinder at and stuffing-box 0 as to be within and clear of the end f of the ram to an extent greater than the length of the leather d and its retaining or distending ring g, either separately or conjointly, when the ram is at the limit of its outward stroke. Consequently when the ram is in this position by breaking the joint 6 between the cylinder at and stuffing-box 0 and slipping the latter along the ram I; so far as to expose the end f of the ram the leather cl and ring Q can be got out side wise through the clearance then existing between the outer end of the cylinder and the inner end f of the ram.

In carrying the invention into effect the leather d is held between the usual shouldered bush 72. and the retaining-ring g, the latter being adapted in the well-known manner to hold the leather distended against the ram I; and the wall of the stuffing-box, which is chambered out. Between the base of the ring -g and the end of the cylinder at is interposed a distance-ring 7', of a length approximately equal to the conjoint length of the leather d and ring 9 and (similarly to said conjoint length) less than the clearance provided between the end of the cylinder and the end f of the ram when the latter is at the limit of its outward stroke. By this means when the stulfing-box c is retracted, as before described, first the'distance-ring j and then the distending-ring g and leather d can be readily got out sidewise in succession and replaced in reverse order. 7

In order to prevent the leather OZ from being injured by being nipped .too tightly between the bush h and ring 9 when the stufling-box 0 is drawn up into position by the bolts 70, the length of thering j is made slightly less than the distance between the base of the ring 9 and the end of the cylinder (0, as indicated. The joint 6, between the cylinder and stuffing-box, is provided with a spigot and recess in order to maintain the correct alinement of the parts, and in order to support the stuffing I box when withdrawn in the case of a vertical cylinder at least two of the bolts I; are made sufiiciently long, as indicated at Z, to permit of the stufling-box when lowered resting on the nuts, which need not in'such case be detached from the bolts.

I claim 1. A hydraulic cylinder having a removable stufiing-box forming a joint therewith and I having a bore substantially coinciding with the bore of said cylinder, removable packing within said stuffing-box, and a ram, said stufiing-box and ram being arranged so as to enable the ram to move beyond said joint and into said stuffing-box.

2. In combination, a hydraulic cylinder, a ram fitted to reciprocate in said cylinder, a detachable end portion forming a closure for the cylinder around the ram and jointed to the body portion of the cylinder at a point in the length thereof inward of the end of the ram When the latter is at the limit of its out- Ward stroke, said detachable portion having an annular cavity in the inner wall thereof, extending from the joint to a point outward beyond the end of the ram when the latter is in the aforesaid position, a packing device for the ram received in the outer end ofthe cavity and extending inward of the end of the ram when the latter is in the aforesaid position so far as to leave a clearance-space not less than its own length between its inner end and the joint, and a ring fitting the said clearancespace, the arrangement being such that when the ram is at the limit of its outward stroke and the end portion is retracted from the body of the cylinder the distance-ring and packing may be successively removed, substantially as specified.

THOMAS EDMUND HOLMES.

Witnesses:

LUTHER J. PARR, VVILFRED H. SLATER.

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