US3530827A - Machine for applying a locking patch to a threaded element - Google Patents

Description

United States Patent Inventor George F. C. Burke,

Beverly, Massachusetts Appl. No. 810,913

Filed Mar. 20, 1969 l Continuation of Ser. No. 672,347, Oct. 2, 1967 Patented Sept. 29, 1970 Assignee USM Corporation Boston, Massachusetts a corporation of New Jersey MACHINE FOR APPLYING A LOCKING PATCH TO A THREADED ELEMENT 14 Claims, 5 Drawing Figs.

US. Cl 118/620, 118/62, 118/308, 118/319 Int. Cl 1305c 5/00 Field 01' Search 1 18/620,

[56] References Cited UNITED STATES PATENTS 309,243 12/1884 Patch 1l8/502X 1,153,679 9/1915 Elliot 118/230 1,334,017 3/1920 Cooley 118/62 2,198,999 4/1940 Jeffery ll8/319X 2,422,417 6/1947 Hutchinson l 18/620UX 3,291,631 12/1966 Smith 1 18/308 3,306,309 2/1967 Pahl et a1. 3,323,492 6/1967 Mellar et al. 3,416,492 12/1968 Greenleaf 1 18/620 Primary E.raminer lohn P. McIntosh At!orneysW. Bigelow Hall and Richard A. Wise ABSTRACT: A machine for applying a locking patch to elements, the machine having a rotatable wheel with a plurality of removable holders to carry the elements sequentially and individually through a heating station, a patch applying station and a removal station.

MACHINE FOR APPLYING A LOCKING PATCH TO A THREADED ELEMENT BACKGROUND OF THE INVENTION This application is a continuation of application Ser. No. 672,347, filed Oct. 2, I967.

This invention relates to improvements in a machine for applying a retarder patch" to a threaded element. The patch is designed to increase the frictional engagement between the threaded element and its mating threaded surface and is applied by the method disclosed in U. S. Pat. application Ser. No. 628,683 filed Apr. 5, 1967 in the name of R. J. Duffy.

It has been proposed heretofore to apply a retarder patch" to a threaded element by depositing a plastic material in the desired location on the fastener by positioning, contiguous with the fastener, an apparatus such as a die, filling the cavity with the plastic and thereafter heating the die, fastener and plastic to fuse the plastic material to the thread surface of the fastener.

It has further been proposed to utilize an open cavity in a suitable non-conductive material with the electrically charged fastener resting therein. The exposed surface of the fastener is appropriately shielded to define the shape of the desired patch and a particulate plastic material is electrostatically disposed thereon. The entire assembly is then heated to cause a fusing between the fastener and the plastic material.

Although a plastic patch applied by either of these methods provides a locking action between mating threaded elements, the steps of bringing each fastener element into register with the receptacle, supplying the plastic and then heating the entire combination, has proven to be both time consuming and expensive.

A through feed apparatus for applying locking patches to headed, threaded fasteners is the subject matter of U. S. Pat. application Ser. No. 640,639 filed May 23, I967 in the name of George F. C. Burke et al. This machine carries the fasteners through a series of work stations by suspending the fasteners by their heads between a pair ofbelts.

The prior Burke apparatus, while eliminating to a large extent the shortcomings of the other methods is limited in the fact that only headed fasteners may beprocessed.

SUMMARY OF THE INVENTION It is an object of this invention to provide a mechanism by which a locking patch may be applied to a threaded fastener whether or not they are headed and in an inexpensive and rapid fashion.

In accordance with this object and as a feature of this invention, there is provided a manually fed machine which will carry a threaded fastener through a plurality of stations which prepare the fastener to receive the patch and apply the patch.

It is another object ofthis invention to provide a machine to handle fasteners of the socket type and to apply a locking patch thereto.

in accordance with this object as another feature of this invention there is provided a rotating wheel having a plurality of radially extending pins which are ofa size suitable to securely hold a socket type fastener with the socket placed over the pin. These pins are easily removable and they can be replaced witha pin of a different size when a different size fastener is being used.

Other and further objects are to provide a machine which will provide a socket type threaded fastener, of either the headed or headless type, with a plastic coating sufficient in size and form to provide the necessary self-locking torque with a complementary threaded mating element. The processed fasteners need have no more than standard dimensional limits and the plastic coating will form without the application of shaping or molding pressures, a patch of plastic material securely bonded to the root flank and crest surfaces throughout a limited angular extent and for a predetermined number ofthreaded convolutions.

Yet, another object of this invention is to provide a machine which will rapidly and easily apply a patch to any socket headed element.

A further object of this invention is a machine to provide a locking patch to a socket type threaded element without resort to auxiliary apparatus such as heaters or the like.

The above and other features of the invention including various novel details of construction and combinations of parts will now be more particularly described with reference to the accompanying drawings and pointed out in the claims.

It will be understood that the particular machine embodying the invention is shown by way of illustration only and not as a limitation of the invention. The principles and features of this invention may be employed in varied and numerous embodiments without departing from the scope of the invention.

DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevational view of an illustrative patch applying machine embodying the present invention;

FIG. 2 is a view partly in section on an enlarged scale of an element holding pin and its fastening means;

FIG. 3 is a sectional view of the pin with an element mounted thereon showing the relationship of the element with the heater taken along lines III-Ill of FIG. 1;

FIG. 4 is a sectional view of the pin mounted thereon showing a relationship of the element of the patch applying means taken along lines IVIV of FIG. I; and

FIG. 5 is a sectional view of the pin with an element mounted thereon showing the relationship with the discharge means along lines V-V of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The illustrative machine as seen in FIG. 1 comprises a frame 2 upon which is mounted for rotation a shaft 4 supported by journals 6. Frictionally mounted upon the shaft 4 is a circular frame disc 8 having a plurality of clamps 10 mounted near its periphery. Suspended beneath the frame two and connected to the disc 8 by means of pulleys 12, I4 and belt 16 is a motor 18. Mounted above the frame 2 is a vertically adjustable induction heater coil 20 to be described in greater detail later. Adjacent the heater along the direction of feed is the patch applying station which is mounted upon a vertically rigid shaft 32 but is adjustable along said shaft by means of a bracket and bolt assembly 34. Briefly, the patch aapplying station comprises a motor 36 which drives a belt 38 which turns a screw feed (not shown) within a hopper 40 to meter the plastic material held within the hopper to the fasteners 22 as they pass by thenozzle 42 of the applying station.

The fasteners 22 which are treated by the patch applying apparatus are carried through the various work stations mounted upon the outer end of pins removably mounted in the clamps 10. An operator places a fastener which has' a socket head upon the outer end of the pin 50 as the wheel 8 rotates at a suitable pace under operator control. The fastener which has been properly prepared is then carried through the field of the induction heater coil 20 whereat it is heated to the appropriate temperature. The fastener then passes by the nozzle 32 of the patch station 30 whereat the plastic material is disposed upon the heated, threaded surface. The pins 50 continue to carry the threaded fasteners 22 in a circular path until the removal station 52 is reached whereat a steady stream of air is fed through tube 54 a pair of nozzles and then directed in a generally radial direction outwardly blowing the fastener 22 off the pin 50 into receptacles or perhaps upon a moving belt for further coiling.

Since the apparatus is manually fed, the disc 8 rotates at a relatively slow rate and further included for safety is a friction drive between the pulley I2 and the shaft 14 allowing the operator, if necessary, to stop rotation of the disc without endangering his person or damaging the machine.

As can thus be seen in FIGS. 2 and 3, the clamps 10 which are mounted upon the disc 8 comprise a pair of U-shaped inwardly sprung members mounted in parallel relation along a radius of the disc 8 and which receive one pin 50. The pin in turn, comprises a main body portion of a suitable heat resistant material such as treated asbestos which tapers to a hollow truncated point into which is placed an insert 60 of any suitable material such as a ceramic or an appropriate metal. It should again be emphasized that the pins 50 are readily replaceable so that if it is desired to place the patch upon screws having a different sized socket, all that the-operator need do is remove the pins 50 and replace them with ones of an appropriate size.

FIG. 3 illustrates the relationship between the disc 8, a pin 50, a fastener 22, and the heater coil while the pin is passing through the heating station. The heater coil 20 is found in a loop having segments 20a and 20b The fasteners 22 pass between the segments which are curved (see FIG. 1) to conform to a mean circular path of fasteners of different lengths. The loop is vertically adjustable through a selected range to accommodate the different length fasteners without interference. It is to be noted that the fastener 22 is removably seated upon the pin 60 and extends upwardly to a position directly between the two arms of the heater coil 20. In the event that the fastener was one of the greater length, the heater assembly need only be adjusted along its vertical shaft to apply heat to the fastener at the appropriate lengthwise position.

FIG. 4 illustrates the relationship of the fastener 22 as it passes the nozzle 42 of the patch applying station. The particulate plastic material is forced through nozzle 42 and impinges the heated portion of the fastener 22 whereat it becomes viscous and adheres tothe threaded surface. A vacuum mouth 66 is placed directly opposite the nozzle 42 to recover any of the particulate plastic which does not adhere to the plastic.

FIG. 5 illustrates relationship of the fastener 22 at the removal station whereat a pair of nozzles 70 connected by tube 54 to a standard air supply presents sufficient outwardly directed force to the fastener 22 to remove it from the end of the pin 50. V

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States isz l. A machine for applying locking patches to threadedelements comprising a rotatable wheel, means for holding a plurality of threaded elements on said wheel and adjacent the periphery thereof with a threaded portion of each element extending outwardly from the wheel, a plurality of work stations disposed adjacent the periphery of said wheel including a station having an arcuate heater located for heating the threaded portion of an element on said wheel, a station having means for applying a locking patch to a threaded portion of an element held on said wheel, a station having means for automatically ejecting an element located thereat from said wheel, and

means for rotating said wheel such that an element so retained by said holding means is passed seriatim through said heating station, said patch applying station and said ejecting station.

2. The machine set forth in claim 1 wherein said holding means comprises a mounting piece which is readily removable from said wheel for receiving a threaded element to be provided with a locking patch.

3. The machine set forth in claim 2 wherein said threaded elements are fasteners having socket-type heads and said mounting piece comprises a pin having an end portion adapted for insertion into the socket of a threaded element to be provided with a locking patch.

4. The machine set forth in claim 3 wherein said mounting pin is disposed on said wheel with said end portion extending radially outwardly from said wheel.

5. The machine set forth in claim 4 wherein said mounting means further includes a clip having an opening provided for receiving said mounting pin in readily removable engagement.

6. A machine for applying locking patches to threaded elements comprising a rotatable wheel, a plurality of radially extending pins mounted adjacent the periphery of said wheel for receiving the threaded elements thereon, an arcuate heater mounted adjacent said wheel, means mounted adjacent said wheel for applying a locking patch to a threaded portion of an element received on said wheel, and an ejector means disposed adjacent said wheel, rotation of said wheel being effective to carry threaded elements placed on said pins in a predetermined path wherein an element is subjected to said heater, said patch applying means, and then automatically ejected from the pins, readying each pin to receive another element for processing.

7. A machine as in claim six and further including means for detachably retaining said pins on said wheel.

8. A machine as in claim 7 wherein said retaining means comprises a plurality of clips.

9. A machine as in claim 6 wherein the heater is of the induction type.

10. A machine as in claim 9 wherein the heating station comprises a coil which is curved to conform to the mean circular path of different length fasteners.

11. A machine as in claim 6 wherein the heating station comprises a coil having two arcuate segments spaced on either side of the path of the fastener.

12. A machine as in claim 6 wherein the pins are of a heat resistant material.

13. A machine as in claim 6 wherein each pin has a truncated conical end portion having an insert which extends beyond the truncated surface.

14. A machine as in claim 6 wherein the ejector means comprises an air nozzle directed in a radial direction with respect to the wheel and which directs a stream of air approximately parallel to the pins.

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