Method Of Providing A Lubricant To Braided Cord

Abstract

This disclosure relates to the method of impregnating a packing material with a lubricant. The impregnant is extruded by pulsations into a central portion of braided packing as it is being formed.

Description

BACKGROUND OF THE INVENTION

Prior to this invention, braided packing, hose packing, or the like was provided with a lubricant during the forming process by means such as (1) permitting the strands to wipe across a surface wetted by a lubricant, (2) dripping a supply of lubricant on the strands at the time of braiding, (3) passing the finished product through a bath, (4) pickling or (5) providing a supply of lubricant in the vicinity and adjacent the strands being braided. In each of the above instances, the process relied upon adsorption by fibrous strands used in forming the body. Pickling or passing the finished braided packing cord, etc. through a bath has not generally been a satisfactory process. As background, the following patents are listed by way of examples: U.S. Pat. Nos. 1,094,879; 1,098,257; 1,204,065; 1,797,249; 1,861,146; and 2,025,038.

BRIEF SUMMARY OF THE INVENTION

This invention is concerned with providing a lubricant into or among strands being braided into a packing cord. More specifically, the impregnating lubricant or the like is deposited by pulsation directly into the center or apex of the braid at a predetermined rate and quantity.

An object of this invention is to provide a process for impregnating braided packing with a lubricant.

Another object is to provide a process for depositing the lubricant by pulse feed directly at the center or apex of the strands being braided into a packing cord.

Another object is to provide an arrangement whereby the pulse feeding or delivering of impregnating lubricant is adapted to a predetermined rate and quantity.

DESCRIPTION OF THE DRAWINGS

The invention will be more fully understood and further objects and advantages thereof will become apparent when reference is made to the following detailed description of the preferred embodiment of the invention and the accompanying drawing in which:

FIG. 1 is a representation of apparatus for forming braided packing and discloses means for discharging a lubricant directly at the juncture of the strands being braided,

FIG. 2 is an enlarged showing of the braiding apparatus in more detail and with a minor variation,

FIG. 3 discloses structure corresponding to the representations in FIG. 1 and in more detail.

DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 is a representation of the arrangement of apparatus for practicing the invention disclosed and claimed herein. The apparatus and process manufacture a braided packing material wherein an impregnant such as a heavy grease or graphite is extrudedly deposited in pulsations at the internal juncture of the strands being braided.

Numeral 10 designates generally the braiding apparatus while numeral 11 designates generally the impregnating feed system for providing a lubricant to the braid being formed. The apparatus of the braider comprises a table 16 having central opening means for the upward passage of core yarn 18 (when a core yarn is used) and a conduit 20 for carrying lubricating impregnant. Table 16 is not shown in detail in either FIG. 1 or FIG. 3, but it does include mechanism known in the art for moving spools 22 in planetary motion thereabout for braiding packing material 12 which is temporarily collected under light tension about slowly revolving capstan 14. Thereafter, it passes on to a container. Like numerals are applied to the more detailed arrangement in FIG. 3 to identify corresponding elements or parts.

The impregnating feed system, designated generally by the numeral 11 and which will be fully disclosed in more detail later in this specification, provides a lubricant under pressure through pipe or conduit 20 to nozzle 26 just beneath die 24 of the braider. This nozzle is positioned and directed so as to discharge a lubricant centrally into the strands being braided. A feed cup 28 is provided beneath the nozzle to aid in catching or retaining excess lubricant. In order that core yarn 18 may pass to the central portion of the braid, holes may be provided in the feed cup to permit their passage.

The braider 10 operates in a manner known in the art to form braided packing 12 which passes through die 24 after braiding for compacting and refining to final desired cross-sectional shape. A wiper 25 of flexible sheath or the like wipes excessive lubricant from finished braided packing material 12 as it passes upwardly therethrough.

The cooperating apparatus defining the impregnating feed system 11 is shown on the left hand side in FIGS. 1 and 3. The impregnant or lubricant in the form of grease or the like is fed in intermittent pulsations at a predetermined rate to nozzle 26. The impregnant supply 32 is normally a very heavy grease-like substance capable of retaining its body form and characteristics at elevated temperatures in service of over 400.degree. F. An air supply 36 at about 100 p.s.i. passes to regulation 38 where it is reduced to a constant outlet pressure of about 15 p.s.i. for operating pump 34. Lubricant is thereby drawn from supply 32 and discharged into line 20. It passes a pair of accumulators 40, 42 which are adapted to maintain a substantially constant pressure on the lubricant to solenoid 44. This solenoid included a valve for permitting or preventing passage of the lubricant therethrough. The solenoid is electrically connected to and controlled by a timer 46 for permitting passage of lubricant therethrough to line 20 for delivery to nozzle 26. Timer 46 can be selectively set for desired control of solenoid 44 thereby admitting lubricant to nozzle 26 at timed intermittent pulses. The timer is electrically operated through transformer 50 and switch 52 as shown in FIG. 3.

The disclosure in FIG. 3 is in substantially more detail and pictorial representation than that of FIG. 1 to include such items as a drain 54 and shut-off valve 56 in delivery line 20. Additionally die 24 is shown connected with an adjustable yoke 58 for positioning the die to the desired vertical location with relation to the spools and impregnant nozzle for the desired braiding.

A more detailed showing of the braiding operation is shown in FIG. 2. It will be noted herein that a spill collector 60 may be provided to be adjustably secured around conduit 20 to the desired height. Strands from spools 22 normally pass on the outside of collector 60, but core yarn may pass through opening therein (not shown) at a location closer to conduit 20. The braided packing passes through die 24 where the final cross-sectional shape of the braided cord is assured its passage through a die is formed thereon as by slight deformation or extrusion.

In the manufacture of braided packing, specifications may vary considerably as to weight, shape and size. Likewise, the desired quantity of lubricant varies. By the basic nature of the heavy lubricant, it is difficult to handle for delivery of the desired quantities, especially at low volume. Accordingly, it has been found that control can be obtained by the arrangement disclosed herein where lubricant is intermittently delivered through a nozzle directly into the braid in pulses of duration and at intervals determined by the opening and closing of solenoid 44 by electrical command from timer 46.

Claims

What I claim:

1. In a process for making packing material wherein a plurality of fibrous strands are brought together and braided to form an elongate body of packing material and impregnated with a lubricant during the process, the improvement comprising:

a. extruding under intermittent pulsating pressure a heavy lubricant through a nozzle terminating at the internal juncture of the fibrous strands being braided whereby the lubricant is effectively forcibly distributed in a direction axially of and among the strands at the center of the packing material.

2. The claimed subject matter of claim 1 wherein the intermittent pulsations are controllable both as to duration and interval.

3. In a process for making packing material wherein a plurality of fibrous strands are brought together and braided to form an elongate body of packing material and impregnated with a lubricant during the process, the improvement comprising:

a. providing a nozzle terminating at the internal juncture where the fibrous strands are being braided,

b. providing a supply of lubricant to the nozzle under pulsating pressure whereby a heavy lubricant is intermittently forcibly deposited directly internally among braided fibrous strands at the center of the packing material and in general axial alignment therewith.

4. The claimed subject matter of claim 3 wherein the intermittent delivery of lubricant is controllable by duration of pulsation and interval therebetween.