CA1183491A - Technique of forming a riffled pad by coiling and securing a flexible strip - Google Patents
Technique of forming a riffled pad by coiling and securing a flexible stripInfo
- Publication number
- CA1183491A CA1183491A CA000377641A CA377641A CA1183491A CA 1183491 A CA1183491 A CA 1183491A CA 000377641 A CA000377641 A CA 000377641A CA 377641 A CA377641 A CA 377641A CA 1183491 A CA1183491 A CA 1183491A
- Authority
- CA
- Canada
- Prior art keywords
- stripping
- pad
- spiral
- molded part
- strips
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C33/00—Moulds or cores; Details thereof or accessories therefor
- B29C33/38—Moulds or cores; Details thereof or accessories therefor characterised by the material or the manufacturing process
- B29C33/3842—Manufacturing moulds, e.g. shaping the mould surface by machining
- B29C33/3857—Manufacturing moulds, e.g. shaping the mould surface by machining by making impressions of one or more parts of models, e.g. shaped articles and including possible subsequent assembly of the parts
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
- B03B—SEPARATING SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS
- B03B5/00—Washing granular, powdered or lumpy materials; Wet separating
- B03B5/02—Washing granular, powdered or lumpy materials; Wet separating using shaken, pulsated or stirred beds as the principal means of separation
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
- B03B—SEPARATING SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS
- B03B5/00—Washing granular, powdered or lumpy materials; Wet separating
- B03B5/68—Washing granular, powdered or lumpy materials; Wet separating by water impulse
- B03B5/70—Washing granular, powdered or lumpy materials; Wet separating by water impulse on tables or strakes
- B03B5/72—Washing granular, powdered or lumpy materials; Wet separating by water impulse on tables or strakes which are movable
- B03B5/74—Revolving tables
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C33/00—Moulds or cores; Details thereof or accessories therefor
- B29C33/38—Moulds or cores; Details thereof or accessories therefor characterised by the material or the manufacturing process
- B29C33/3842—Manufacturing moulds, e.g. shaping the mould surface by machining
- B29C33/3857—Manufacturing moulds, e.g. shaping the mould surface by machining by making impressions of one or more parts of models, e.g. shaped articles and including possible subsequent assembly of the parts
- B29C33/3892—Preparation of the model, e.g. by assembling parts
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C39/00—Shaping by casting, i.e. introducing the moulding material into a mould or between confining surfaces without significant moulding pressure; Apparatus therefor
- B29C39/02—Shaping by casting, i.e. introducing the moulding material into a mould or between confining surfaces without significant moulding pressure; Apparatus therefor for making articles of definite length, i.e. discrete articles
- B29C39/026—Shaping by casting, i.e. introducing the moulding material into a mould or between confining surfaces without significant moulding pressure; Apparatus therefor for making articles of definite length, i.e. discrete articles characterised by the shape of the surface
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Mechanical Engineering (AREA)
Abstract
SPIRAL ORE CONCENTRATING PAD APPARATUS AND METHOD
ABSTRACT
A spiral ore concentrating pad apparatus and fabrication method allows the efficient and inexpensive production of spiral concentrating pads of any size or configuration. A mold for the pad is made using elongated strips of flexible material having a variable cross section. The strips are disposed in planar and spiral orientation and glued tightly together to a backing plate.
A mold is made by forming a hardenable material such as fiberglass over the strips. When strips having sawtoothed cross section are used, the,mold so produced has an internal contour having a sawtoothed-shaped recess spiralling from the center to the periphery of the mold.
Spiral concentrating pads are the made from the mold with a variety of methods. First, material can be compressed into the mold to produce the pad. Second, liquid material may be poured into the mold and allowed -to harden to produce the pad. Third, flexible stripping can be wound into the internal contours of the mold and a backing plate affixed thereto to produce the pad. Fourth, the original stripped pad or negative mold may be used to produce a vacuum formed part from thermodeformable plastic.
ABSTRACT
A spiral ore concentrating pad apparatus and fabrication method allows the efficient and inexpensive production of spiral concentrating pads of any size or configuration. A mold for the pad is made using elongated strips of flexible material having a variable cross section. The strips are disposed in planar and spiral orientation and glued tightly together to a backing plate.
A mold is made by forming a hardenable material such as fiberglass over the strips. When strips having sawtoothed cross section are used, the,mold so produced has an internal contour having a sawtoothed-shaped recess spiralling from the center to the periphery of the mold.
Spiral concentrating pads are the made from the mold with a variety of methods. First, material can be compressed into the mold to produce the pad. Second, liquid material may be poured into the mold and allowed -to harden to produce the pad. Third, flexible stripping can be wound into the internal contours of the mold and a backing plate affixed thereto to produce the pad. Fourth, the original stripped pad or negative mold may be used to produce a vacuum formed part from thermodeformable plastic.
Description
3~
SPIRAL ORE CONCENTRATING PAD APPAR~TUS AND METHOD
The present invention relates in gene~al to lnining equipment and, in par-ticular, to spiral concentrating wheels.
Spiral concentrating wheels are a specific type of automatic panning machines. Such machines have been used Eor many years by both professlonal and amateur gold miners to remove trace amounts of gold flom the ~urface of ~he earth. The principle of operation of these machines is relatively simple~ The ~piral concentrating wheel has a spiral groove running ~rom the center to the periphery of the wheel. The wheel is spun, and earth in elther a wet or dry state is placed upon the wheel. Separation is accomplished when a combination of gravitational and ~Erictional forces act on the material placed in the wheel.
These Eorces cau~e the material to move toward the vertical centerline of the wheel, where the lighter material is washed away he cascading water. While in this off center position/ the heavier material rides the spiral recess toward the center of the concentrating wheel. The center of the wheel general1y has a hole passiny therethrough.
Accordingly, the gold drops through the hole into a collection pan or the like.
,Spiral concentrating wheels have been made from variou~ ma~erial~. Steel, aluminum, rubber, and injected molded pl,~stlc have been used. Few materials have ~urvived the wrath oE the mining community and the test of time~
Those wheels which have survived and proven themselves the mo~t worthy h~ve been th~e con~t~ucted of ~teel. The attrlbute~ oE the ~teel wheels have been high eEficiency, longevity, and good throughput capability. Steel wheels have also characterlstically been as heavy and costly as they have been efficient. The expense of a steel concentrating wheel relates primarily to the fact that modern versions of the wheel have been machined ol~t of ~ 3~
solid steel. This process is expensive both in terms of material~ and labor.
More recent automatic panning machines have used modern technology and materials to recluce the weight and increase the portability and efficiency of the wheel. The most recent addition to the field of spiral concentrating wheels has been a metal wheel which utilizes a one-piece compression molded rubber centerpiece or pad in place of the traditional machined steel spirals. From a production standpoint, a one-piece compression molded rubber centerpiece or pad has tremendous advantages over customized steel machining. Use of the rubber inserts allows lower production costs plus muc'n ligllter weight.
The negative side of the compression molded rubber centerpiece or pad has been the difficulty of fabricating the original metal compression mold from whic~h the rubber pads are Inade. As the size oE the pad being fabricated increases, the cost of the mold goes up exponentially. For example~ a compression mold for a rubber pad on the order oE a foot in diameter can cost several thousand dollars, while a mold for a pad approximately six feet in diameter can cost hundreds of t'nousands o~ dollars. A primary di~ficulty in producing such a mold, even if one has the requisite capital, lies in the fact that the production o such a mold require~ very special tooling which is very die~icult to ~ind.
Accordingly, it i~ the principal object of the pre~ent invention to produce a splral rubber concentrating pads o~ virtually unlimlted size without using the standard compre~slan moldin~ techniques, which generally utilize ne~cll mold~.
Tt is a Eurther object o~ the present invention to produce spiral concentrating pads havlng internal spirals of different cross sectional variation.
Yet another object of the present invention is to produce a spiral concentrating pad utilizing either pour-molding techniques, strip-molding techniques, or vacuum forming techniques adapted to t'nermoplastic.
The present invention provides a novel spiral ore concentrating pad and -~abrication method thereof based upon the recognition of the fact that in any device utilizing spiral rifEles, any given spiral in the device has a nearly triangular cross section which is in the shape of a sawtooth. More specifically, when one of the compression-molded spiral pads is completely cut in halE, the pad appears in cross section as a plurality of sawteeth. Any one of these sawteeth can be thought of a~ a cross section of a long thin piece of extruded material.
Accordingly, in a broad aspect, the invention comprises a technique for making a mold to produce a spiral lS concentrating pad and the production of the pad using the mold. More specifically, the invention comprises a technique for making an original or master pad having strips of indeterminate cross section; making a molded part ~rom the original pad; and making pads ~rom the molded part.
According to the invention, a method for producing a spiral concentrating pad with a planar and spiral yroove between the center and the periphery of the pad utilizes the following steps. First, elongated flexible stripping ls arranged and maintained in a planar and spiral orientation. Next, a hardenable material is formed over the st~ipping. The strips are then removed ~rom the material after it is harclened, thereby expo~ing a molcled part having an internal contour in the image Oe the ~trlpplng. Lastly, ~esilient material i~ formed in the molded part, therehy producing a pad having an outer conkour identical to that oE the stripping originally in the molcded part in the planar and spiral orientation.
In accordance with a further feature of the inven-tion, a novel ore concentrating pad is provided with the latter technic~ue. The pa~ comprises a central open hub, ~ ~ ~3~
resilient stripping dispos~d i~ spiral and planar orien-tation outward ~rom the hub, and a means for maintaining the stripping in that orientation. This produces an ore concentrating pad having stripping spiralling outwardly from the hub. The strips can be of flexible and elongated material and the ~ize of the pad is limited only by the number of strips utilized~ The cross section oE the stripping can vary in accordance with t'ne desired cross sectional shape of the pad.
The present invention is further illustrated in the accompanying drawings, in whicho FIG. 1 is a perspective view of the spiral concentrating wheel portion of an automatic panning machine as known in the prior art;
FIG. 2 is a ~raymentary cross sectional view of the wheel of Fics~ 1, taken through the plane II - II, the view showing a spiral ore concentrating pad as known in the pclor art;
FIG. 3 i~ a plan view of the spiral concentrating pad of Fig. ~, taken through the plane III - III;
FIG. 4 is a perspective view of a section of resilient stripping used to form a molded part for producing a spiral concentrating pad according to the present invention;
FIG. 5 is a plan view o~ elongated flexible stripping dispo~ed in a ~piral and planar orientation for producing the molded part from whlch the spiral concentrating pad is made accordiny to the present invention;
FIG. 6 is a eragmentary cros~ sectional view of the strlpping o~ Fig. 5, taken through the plane VI ~ VI;
FIG. 7 i~ a Eragmentary cro~s ~ectlonal view oE the producti4n oE the molded part Eoc producing a spiral pad according to the present invention, said view showing the ~orming of a hardenable snaterial over the stripping shown in Figs. S and 6;
FIG. 8 shows a fraymentary cro~ sectional view of _5_ the molded part produced in Fig. 7;
FIG. 9 shows a Eragmentary cross sectional view of the forming of a spiral pad according to the present invention using the molded part of Fig. 8 by the pouring of a hardenable material into the molded part and allowing the ~naterial to harden;
FIG. 10 is a fragmentary cross sectional view oE the spiral concentrating pad formed with hardenable material as shown in Fig. 9, after the material has been removed from the molded part;
FIG. ll shows a ~r3gmentary cross sectional view of the forming of a spiral concentrating pad according to the present invention by placing elongated flexible stripping into the molded part of Fig. 8 and bonding the stripping together and to a flexible backing plate placed thereover;
FIG. 12 shows a plan view of Fig. ll;
FIG. 13 shows a fragmentary cross sectional view Oe a sectiorl of the spiral concentrating pad produced according to the present invention, after removal from the molded part shown in ~ig. ll; and Fig. 14 shows an cross sectional view of alternate emboaiment of the flexible stripping used in the production oE the spiral concentrating pad according to the present invention.
ReEerring more particularly to the drawings, Fig. l ~hows a spiral ore concentrating wheel lO as known in the prior art. Such wheels yenerally comprise an open pan h~vlng ln the bottom thereoe a continuou~ .5pkal, between the periphery oE khe pan and a hub or hole in the middle thereo~. In operatlon, the wheel i~ rotated in a tilted orlentation, and material from the surEace oE the earth is placed upon thc wheel in a wet or dry state. As the pan rotatesl the lighter material moves toward the pertphery o~
the pan 14, while the heavier material travels in the spiral groove to the opening ih the center of the pan.
As mentioned hereinabove, varLous materials have been ~3~
used in the prior art to fabricate the spiral concentrating wheel. For example, steel, aluminum, rubber and injection molded plastic have been used~ Of these, only steel wheels have proven successful. Steel wheels are very expensive to fabricate, however, because of both materials and labor.
Fi~s. 1-3 show a more recent design of a spiral concentrating wheel 10. In contrast to the solid, machined steel wheel of the prior art, the design of FigsO 1-3 uses a flat and nongrooved pan 14 into which is placed a compression molded rubber centerpiece or pad 12 having the necessary spiral between the center opening or hub 16 and the edge of the pan 14. As shown in Fig 2, the pad 12 is generally flat on its underside for bonding to the bottom oE the pan. Additionally, in cross section, the continuous spiral between the center opening 16 and the periphery oE
the pan appears as a plurality of sawteeth 12'.
As also discussed hereinabove, while the compression molded rubber centerpiece or pad has a lower production cost than a completely machined steel wheel, the original metal compression mold from which the rubber pads are made ls extremely expen~ive. The cost of the metal compression mold almost increases exponentially as the diameter of the ruhb~r pad increases.
The present invention is directed toward the production o~ a rubber spiral concentrating pad without the need ~or an orlginal metal compression rnold. Referring to Fig. 2, the present lnvention is based upon the recoqnition of the act that, in cross section, the single continuous spiral groove of the rubber concentrating pad 12 appear3 as a plurality o~ sawteeth 12'. IE the vertical line oE each oE the ~awteeth l~' ls envisloned as ex~ending down to the bottom oE the pad, then any one oE the sawteeth can be thought of as a separate section o rubber stripping having generally sawtoothed or triangular cross section.
Therefore, iE a hardenable material is Eor~ed over such stripping, a molded part will be produced which can be used ~83~
, to strip-form, pour-form, or compres~ion mold a spiral concentrating pad to replace tho~e currently manuEactured with metal compression molds.
The present invention therefore comprises both a novel method of forming a molded part rom which a spiral concentrating pad can be fabricated in a number of ways, but also a novel spiral concentrating pad apparat:us made from the ~olded part.
~egarding the molded part, Figs. 4-8 show the production thereof. Several steps are required to make the molded part. First, strips of flexible extruded material 18 are arranged on a flat backing plate 20 in a planar and spiral orientation in a manner whereby they fit together snugly. Wext, the strips 18 are bonded together and also attached ~o the backing plate 20. The stripping 18 is arranged to form a central opening or hub 22 passing through the sections of stripping 18 and the backing plate 20. The arrangement of the stripping 18 on the plate 20 pro~uces a master concentrating pad or template 24 from which the molded part i8 produced.
As shown in Fig. 6l each of the strips is generally triangular or sawtoothed in cross section, in ordar to provi~3e the molded part to be formed thereover with an internal contour identical to that of the outer contour of the prior art spiral concentrating pad 12 shown in Fig. 2.
The ~tripping 18 may be oE any flexible material such as rubher. It ha~ been Eound that rubber extru~ions of approximately lS Eeet in length may be comme~cially ~abrlcated at very low cost. The backing plate 20 may be lik~wl~e eabrlca~e~ ~rom any convenient material which is generally ~tlE~ Wood, metal, or the like may be ~tilized.
As ~een from the foregoing, with the novel technique of the present invention, a template 24 of any diameter may be ~ormed by ~imply adding more lengths of stripping 18.
ThereEore, the cost oE a very large template is only sllghtly more than a Emaller template becau~e oE the ;
extremely low cost of the material comprising the template 24. Moreover, since the outer contour of the tegnplate is determined by the cross sections of the rubber stripping, the template 24 may have an outer contour which i5 deeply grooved by the use of stripping 18 having a sawtooi7led or triahgular cross section. Similarly, the outer contour may comprise a continuous rounded groove by the use of stripping 18 with a rounded cross section.
Once the template 24 has been fabricated as .shown in Fig. 6, a molded part 26 is produced from the template by forming a hardenable material thereover. The internal contour oE the molded part 26 is identical to the outer contour of the template 24. Accordingly, the resulting mold can be used as a guide in producing the novel spiral concentrating pad according to the present invention.
Various materials may be used to form the molded part 26 from the template. In particular, ~iberglass 28 may be laid up over the template 24 and allowed to harden.
Alternately, a sheet of hardenable material may be vacuumed formed over the template. When the template 24 is flberglassed, a stiff backing plate 30 can be attached to the fiberglass material 2~ to increase its rigidity and strength.
Figs~ 8 and ll, respectively, show cross sectional and plan view~ of the molded part 26 produced by forming hardenahle materlal such as Piberglass 2~ over the template 24. As shown in Flg. 8, the interna:L contour oE the molded part 26 is sawtoothed in cross section, corresponding to the outer contour o~ the template 24. Additionally, a li~
por~lon 2~ also b~en ~ormed in the hardenable material to act a~ a vertical guide in the forming of the pad. As ~hown in Fig. ll, the outer shape of the molded part 26 may be generally square in cross section, although this feature is not particularly critical.
Once the molded part 26 has been ~o produced, spiral concentrating pads may be formed from it with a variety of ~3~
g me-thods. Four methods are particularly contemplated. Wikh the Eirst method, the molded part 26 may be used as a compression mold in place of the metal compression mold.
With this method, and as shown in Fig. 9, rubber rnaterial 32 would simply be compressed into the molded part 26 to produce a spiral concentrating pad 34 ( Fig . 10 ) which is substantially identical to the rubber spiral concentrating pad 12 of the prior art (Fig. 2). With the second method, r~silient material could be vacuum formed over the molded part 26. With the third method, a spiral concentrating pad could be formed by pouring a hardenable material into the molded part 26 and allowing the material to harden.
Natural liquid rubber (latex) or some ~orm of two-part catalytic urethane could be used. The pad so produced could be cured or vulcanized either in the mold or after removal for hardening purposes. A pad produced with a such pour molding would be substantially identical in appearance to the pad 34 produced by compression molding, as ~shown in Fig. 10.
With the fourth and particularly contemplated method of the present invention, the molded part 26 may be used to strip-form a spiral concentrating pad as shown in Figs.
11-13. With this method, strips of extruded material 36 substantially identical to those used to form the template 24 are wound into the recessed spLral groove of the molded part 26~ As shown in Figs. 11 and 13, after the strips 36 have been wound into the molded part 26, a flexible thin backing sheet 38 is glued to the spirals, thereby ~orming a spiral concentrating pad 40/ shown in cross section in Fig.
12. The completed pad 40 may be heated prior to removal erom the molded part 26 in order to promote complete and rapid dryiny. A~ter the strlp-formed spiral concentrating pad ha~ been removed from the molded part 26, it may be affixed to a spiral concentrating wheel 14 as known in the prior art and shown in Fig. 1. The use o~ the strips 36 to strip mold a spiral concentrating pad 40 is particularly advantageous because the stripping 36 may be obtained commercially at a very reasonable cost.
Regardless oE the technique used to produce the spiral concentrating pad, the finished pad is substantially identical in appearance and quality to the rubber concentrating pads 12 of the prior art, as shown in Figs.
1-3. Morever, the novel spiral concentrating pad apparatus and method has several advantages over the rubber concentrating pads currently produced with metal compression molds. First, the cost of the molded part 26 is very inexpensive compared to the great expense of the metal compression mold. It is estimated that fabricating time and cost for the molded part 26 are approximately one-tenth the cost of a metal compression mold. Second, the novel spiral concentrating pad of the present invention can be of relatively unlimited size because of the ease with which the molded part 26 may be produced. The ability to produc~ very large concentrating pad will result in increased ore throughput with less labor Third, the cross sectional shape of the novel spiral concentrating pad may be easily changed due to the ease with which the molded part may be produced. The ability to vary the cross section of the molded part also allows the width of the spiral groove to varied. As the processing of larger material requires larger grooves, while the processing of small material is mo3t beneficial with smaller grooves, the configuration Oe the pad ma~ be matched to it~ use.
Fig. 14 ~hows an alternate embodiment oE the rubber stripplng u~ed to ~orm the templa~e 24 Eor the production oE the molded park 26, a~ well as Eor the strlp-Eorming o~
the spical concentratlng pad ~rom khe molded part ~6. ~8 shown therein, the stripping 42 has a cross section with a sawtoothed portion 44 adjacent a dovetail section 46. On the underside of the stripping 42 is a dovetail opening 48.
As can be easil~ envisioned, the forming of the template 24 would be done by simpl~ snapping the dovetail projections --ll--46 into the dovetail opening 48 of an adjacent section o~
stripping. The use of such stripping 42 would resul-t in a semiriyid structure. Accordingly, when the stripping ~2 was used to form the template 24, the backing plate 20 could ~e eliminated. Similarly, when the spiral concentrating pad was strip molded in the molded part 26, the in-terlocking o~ the stripping 42 would also eliminate the necessity for the flexible ~acking sheet 38. While the dovetail stripping 42 will most likely eliminate the backing sheet 38 and the backing plate 20, it is unlikely that use of the molded part 21 could be eliminated.
As an additional contemplated variation of the inven-tion described herein, the pads 34 and 40 may be provided with means to allow thl_ pads to he removably attached to a rigid and generally circular hacking wheel similar to the prior art wheel 10 shol~n in Fig. 1, but without the spirals 12. Such a hacking wheel could have various curvatures to tilt the spirals o~ the pad at difEerent anyles. Moreover, this Eeature would allow the pads to be changed after wear, ~0 and would also a:Llow pads having di~ferent cross sectional conEigurations for the spirals in the pads to be used for ~pecialized applications. Such removal means could be a separabLe hook and loop type ~astener such as is sold under the trade mark VELCRO, bolts or the like, glue, etc.
In the foregoing description of the present invention, several embodiments of the invention have been disclosed. It is to be understood that other mechanical and design varlations are within the scope of -the present invention. ~ccorcl.i~nctl!,7, i:he invent.iorl ls not 1imited to the partlcular arrangemerits w~lich have been illu~trated and described in detai:L herein.
SPIRAL ORE CONCENTRATING PAD APPAR~TUS AND METHOD
The present invention relates in gene~al to lnining equipment and, in par-ticular, to spiral concentrating wheels.
Spiral concentrating wheels are a specific type of automatic panning machines. Such machines have been used Eor many years by both professlonal and amateur gold miners to remove trace amounts of gold flom the ~urface of ~he earth. The principle of operation of these machines is relatively simple~ The ~piral concentrating wheel has a spiral groove running ~rom the center to the periphery of the wheel. The wheel is spun, and earth in elther a wet or dry state is placed upon the wheel. Separation is accomplished when a combination of gravitational and ~Erictional forces act on the material placed in the wheel.
These Eorces cau~e the material to move toward the vertical centerline of the wheel, where the lighter material is washed away he cascading water. While in this off center position/ the heavier material rides the spiral recess toward the center of the concentrating wheel. The center of the wheel general1y has a hole passiny therethrough.
Accordingly, the gold drops through the hole into a collection pan or the like.
,Spiral concentrating wheels have been made from variou~ ma~erial~. Steel, aluminum, rubber, and injected molded pl,~stlc have been used. Few materials have ~urvived the wrath oE the mining community and the test of time~
Those wheels which have survived and proven themselves the mo~t worthy h~ve been th~e con~t~ucted of ~teel. The attrlbute~ oE the ~teel wheels have been high eEficiency, longevity, and good throughput capability. Steel wheels have also characterlstically been as heavy and costly as they have been efficient. The expense of a steel concentrating wheel relates primarily to the fact that modern versions of the wheel have been machined ol~t of ~ 3~
solid steel. This process is expensive both in terms of material~ and labor.
More recent automatic panning machines have used modern technology and materials to recluce the weight and increase the portability and efficiency of the wheel. The most recent addition to the field of spiral concentrating wheels has been a metal wheel which utilizes a one-piece compression molded rubber centerpiece or pad in place of the traditional machined steel spirals. From a production standpoint, a one-piece compression molded rubber centerpiece or pad has tremendous advantages over customized steel machining. Use of the rubber inserts allows lower production costs plus muc'n ligllter weight.
The negative side of the compression molded rubber centerpiece or pad has been the difficulty of fabricating the original metal compression mold from whic~h the rubber pads are Inade. As the size oE the pad being fabricated increases, the cost of the mold goes up exponentially. For example~ a compression mold for a rubber pad on the order oE a foot in diameter can cost several thousand dollars, while a mold for a pad approximately six feet in diameter can cost hundreds of t'nousands o~ dollars. A primary di~ficulty in producing such a mold, even if one has the requisite capital, lies in the fact that the production o such a mold require~ very special tooling which is very die~icult to ~ind.
Accordingly, it i~ the principal object of the pre~ent invention to produce a splral rubber concentrating pads o~ virtually unlimlted size without using the standard compre~slan moldin~ techniques, which generally utilize ne~cll mold~.
Tt is a Eurther object o~ the present invention to produce spiral concentrating pads havlng internal spirals of different cross sectional variation.
Yet another object of the present invention is to produce a spiral concentrating pad utilizing either pour-molding techniques, strip-molding techniques, or vacuum forming techniques adapted to t'nermoplastic.
The present invention provides a novel spiral ore concentrating pad and -~abrication method thereof based upon the recognition of the fact that in any device utilizing spiral rifEles, any given spiral in the device has a nearly triangular cross section which is in the shape of a sawtooth. More specifically, when one of the compression-molded spiral pads is completely cut in halE, the pad appears in cross section as a plurality of sawteeth. Any one of these sawteeth can be thought of a~ a cross section of a long thin piece of extruded material.
Accordingly, in a broad aspect, the invention comprises a technique for making a mold to produce a spiral lS concentrating pad and the production of the pad using the mold. More specifically, the invention comprises a technique for making an original or master pad having strips of indeterminate cross section; making a molded part ~rom the original pad; and making pads ~rom the molded part.
According to the invention, a method for producing a spiral concentrating pad with a planar and spiral yroove between the center and the periphery of the pad utilizes the following steps. First, elongated flexible stripping ls arranged and maintained in a planar and spiral orientation. Next, a hardenable material is formed over the st~ipping. The strips are then removed ~rom the material after it is harclened, thereby expo~ing a molcled part having an internal contour in the image Oe the ~trlpplng. Lastly, ~esilient material i~ formed in the molded part, therehy producing a pad having an outer conkour identical to that oE the stripping originally in the molcded part in the planar and spiral orientation.
In accordance with a further feature of the inven-tion, a novel ore concentrating pad is provided with the latter technic~ue. The pa~ comprises a central open hub, ~ ~ ~3~
resilient stripping dispos~d i~ spiral and planar orien-tation outward ~rom the hub, and a means for maintaining the stripping in that orientation. This produces an ore concentrating pad having stripping spiralling outwardly from the hub. The strips can be of flexible and elongated material and the ~ize of the pad is limited only by the number of strips utilized~ The cross section oE the stripping can vary in accordance with t'ne desired cross sectional shape of the pad.
The present invention is further illustrated in the accompanying drawings, in whicho FIG. 1 is a perspective view of the spiral concentrating wheel portion of an automatic panning machine as known in the prior art;
FIG. 2 is a ~raymentary cross sectional view of the wheel of Fics~ 1, taken through the plane II - II, the view showing a spiral ore concentrating pad as known in the pclor art;
FIG. 3 i~ a plan view of the spiral concentrating pad of Fig. ~, taken through the plane III - III;
FIG. 4 is a perspective view of a section of resilient stripping used to form a molded part for producing a spiral concentrating pad according to the present invention;
FIG. 5 is a plan view o~ elongated flexible stripping dispo~ed in a ~piral and planar orientation for producing the molded part from whlch the spiral concentrating pad is made accordiny to the present invention;
FIG. 6 is a eragmentary cros~ sectional view of the strlpping o~ Fig. 5, taken through the plane VI ~ VI;
FIG. 7 i~ a Eragmentary cro~s ~ectlonal view oE the producti4n oE the molded part Eoc producing a spiral pad according to the present invention, said view showing the ~orming of a hardenable snaterial over the stripping shown in Figs. S and 6;
FIG. 8 shows a fraymentary cro~ sectional view of _5_ the molded part produced in Fig. 7;
FIG. 9 shows a Eragmentary cross sectional view of the forming of a spiral pad according to the present invention using the molded part of Fig. 8 by the pouring of a hardenable material into the molded part and allowing the ~naterial to harden;
FIG. 10 is a fragmentary cross sectional view oE the spiral concentrating pad formed with hardenable material as shown in Fig. 9, after the material has been removed from the molded part;
FIG. ll shows a ~r3gmentary cross sectional view of the forming of a spiral concentrating pad according to the present invention by placing elongated flexible stripping into the molded part of Fig. 8 and bonding the stripping together and to a flexible backing plate placed thereover;
FIG. 12 shows a plan view of Fig. ll;
FIG. 13 shows a fragmentary cross sectional view Oe a sectiorl of the spiral concentrating pad produced according to the present invention, after removal from the molded part shown in ~ig. ll; and Fig. 14 shows an cross sectional view of alternate emboaiment of the flexible stripping used in the production oE the spiral concentrating pad according to the present invention.
ReEerring more particularly to the drawings, Fig. l ~hows a spiral ore concentrating wheel lO as known in the prior art. Such wheels yenerally comprise an open pan h~vlng ln the bottom thereoe a continuou~ .5pkal, between the periphery oE khe pan and a hub or hole in the middle thereo~. In operatlon, the wheel i~ rotated in a tilted orlentation, and material from the surEace oE the earth is placed upon thc wheel in a wet or dry state. As the pan rotatesl the lighter material moves toward the pertphery o~
the pan 14, while the heavier material travels in the spiral groove to the opening ih the center of the pan.
As mentioned hereinabove, varLous materials have been ~3~
used in the prior art to fabricate the spiral concentrating wheel. For example, steel, aluminum, rubber and injection molded plastic have been used~ Of these, only steel wheels have proven successful. Steel wheels are very expensive to fabricate, however, because of both materials and labor.
Fi~s. 1-3 show a more recent design of a spiral concentrating wheel 10. In contrast to the solid, machined steel wheel of the prior art, the design of FigsO 1-3 uses a flat and nongrooved pan 14 into which is placed a compression molded rubber centerpiece or pad 12 having the necessary spiral between the center opening or hub 16 and the edge of the pan 14. As shown in Fig 2, the pad 12 is generally flat on its underside for bonding to the bottom oE the pan. Additionally, in cross section, the continuous spiral between the center opening 16 and the periphery oE
the pan appears as a plurality of sawteeth 12'.
As also discussed hereinabove, while the compression molded rubber centerpiece or pad has a lower production cost than a completely machined steel wheel, the original metal compression mold from which the rubber pads are made ls extremely expen~ive. The cost of the metal compression mold almost increases exponentially as the diameter of the ruhb~r pad increases.
The present invention is directed toward the production o~ a rubber spiral concentrating pad without the need ~or an orlginal metal compression rnold. Referring to Fig. 2, the present lnvention is based upon the recoqnition of the act that, in cross section, the single continuous spiral groove of the rubber concentrating pad 12 appear3 as a plurality o~ sawteeth 12'. IE the vertical line oE each oE the ~awteeth l~' ls envisloned as ex~ending down to the bottom oE the pad, then any one oE the sawteeth can be thought of as a separate section o rubber stripping having generally sawtoothed or triangular cross section.
Therefore, iE a hardenable material is Eor~ed over such stripping, a molded part will be produced which can be used ~83~
, to strip-form, pour-form, or compres~ion mold a spiral concentrating pad to replace tho~e currently manuEactured with metal compression molds.
The present invention therefore comprises both a novel method of forming a molded part rom which a spiral concentrating pad can be fabricated in a number of ways, but also a novel spiral concentrating pad apparat:us made from the ~olded part.
~egarding the molded part, Figs. 4-8 show the production thereof. Several steps are required to make the molded part. First, strips of flexible extruded material 18 are arranged on a flat backing plate 20 in a planar and spiral orientation in a manner whereby they fit together snugly. Wext, the strips 18 are bonded together and also attached ~o the backing plate 20. The stripping 18 is arranged to form a central opening or hub 22 passing through the sections of stripping 18 and the backing plate 20. The arrangement of the stripping 18 on the plate 20 pro~uces a master concentrating pad or template 24 from which the molded part i8 produced.
As shown in Fig. 6l each of the strips is generally triangular or sawtoothed in cross section, in ordar to provi~3e the molded part to be formed thereover with an internal contour identical to that of the outer contour of the prior art spiral concentrating pad 12 shown in Fig. 2.
The ~tripping 18 may be oE any flexible material such as rubher. It ha~ been Eound that rubber extru~ions of approximately lS Eeet in length may be comme~cially ~abrlcated at very low cost. The backing plate 20 may be lik~wl~e eabrlca~e~ ~rom any convenient material which is generally ~tlE~ Wood, metal, or the like may be ~tilized.
As ~een from the foregoing, with the novel technique of the present invention, a template 24 of any diameter may be ~ormed by ~imply adding more lengths of stripping 18.
ThereEore, the cost oE a very large template is only sllghtly more than a Emaller template becau~e oE the ;
extremely low cost of the material comprising the template 24. Moreover, since the outer contour of the tegnplate is determined by the cross sections of the rubber stripping, the template 24 may have an outer contour which i5 deeply grooved by the use of stripping 18 having a sawtooi7led or triahgular cross section. Similarly, the outer contour may comprise a continuous rounded groove by the use of stripping 18 with a rounded cross section.
Once the template 24 has been fabricated as .shown in Fig. 6, a molded part 26 is produced from the template by forming a hardenable material thereover. The internal contour oE the molded part 26 is identical to the outer contour of the template 24. Accordingly, the resulting mold can be used as a guide in producing the novel spiral concentrating pad according to the present invention.
Various materials may be used to form the molded part 26 from the template. In particular, ~iberglass 28 may be laid up over the template 24 and allowed to harden.
Alternately, a sheet of hardenable material may be vacuumed formed over the template. When the template 24 is flberglassed, a stiff backing plate 30 can be attached to the fiberglass material 2~ to increase its rigidity and strength.
Figs~ 8 and ll, respectively, show cross sectional and plan view~ of the molded part 26 produced by forming hardenahle materlal such as Piberglass 2~ over the template 24. As shown in Flg. 8, the interna:L contour oE the molded part 26 is sawtoothed in cross section, corresponding to the outer contour o~ the template 24. Additionally, a li~
por~lon 2~ also b~en ~ormed in the hardenable material to act a~ a vertical guide in the forming of the pad. As ~hown in Fig. ll, the outer shape of the molded part 26 may be generally square in cross section, although this feature is not particularly critical.
Once the molded part 26 has been ~o produced, spiral concentrating pads may be formed from it with a variety of ~3~
g me-thods. Four methods are particularly contemplated. Wikh the Eirst method, the molded part 26 may be used as a compression mold in place of the metal compression mold.
With this method, and as shown in Fig. 9, rubber rnaterial 32 would simply be compressed into the molded part 26 to produce a spiral concentrating pad 34 ( Fig . 10 ) which is substantially identical to the rubber spiral concentrating pad 12 of the prior art (Fig. 2). With the second method, r~silient material could be vacuum formed over the molded part 26. With the third method, a spiral concentrating pad could be formed by pouring a hardenable material into the molded part 26 and allowing the material to harden.
Natural liquid rubber (latex) or some ~orm of two-part catalytic urethane could be used. The pad so produced could be cured or vulcanized either in the mold or after removal for hardening purposes. A pad produced with a such pour molding would be substantially identical in appearance to the pad 34 produced by compression molding, as ~shown in Fig. 10.
With the fourth and particularly contemplated method of the present invention, the molded part 26 may be used to strip-form a spiral concentrating pad as shown in Figs.
11-13. With this method, strips of extruded material 36 substantially identical to those used to form the template 24 are wound into the recessed spLral groove of the molded part 26~ As shown in Figs. 11 and 13, after the strips 36 have been wound into the molded part 26, a flexible thin backing sheet 38 is glued to the spirals, thereby ~orming a spiral concentrating pad 40/ shown in cross section in Fig.
12. The completed pad 40 may be heated prior to removal erom the molded part 26 in order to promote complete and rapid dryiny. A~ter the strlp-formed spiral concentrating pad ha~ been removed from the molded part 26, it may be affixed to a spiral concentrating wheel 14 as known in the prior art and shown in Fig. 1. The use o~ the strips 36 to strip mold a spiral concentrating pad 40 is particularly advantageous because the stripping 36 may be obtained commercially at a very reasonable cost.
Regardless oE the technique used to produce the spiral concentrating pad, the finished pad is substantially identical in appearance and quality to the rubber concentrating pads 12 of the prior art, as shown in Figs.
1-3. Morever, the novel spiral concentrating pad apparatus and method has several advantages over the rubber concentrating pads currently produced with metal compression molds. First, the cost of the molded part 26 is very inexpensive compared to the great expense of the metal compression mold. It is estimated that fabricating time and cost for the molded part 26 are approximately one-tenth the cost of a metal compression mold. Second, the novel spiral concentrating pad of the present invention can be of relatively unlimited size because of the ease with which the molded part 26 may be produced. The ability to produc~ very large concentrating pad will result in increased ore throughput with less labor Third, the cross sectional shape of the novel spiral concentrating pad may be easily changed due to the ease with which the molded part may be produced. The ability to vary the cross section of the molded part also allows the width of the spiral groove to varied. As the processing of larger material requires larger grooves, while the processing of small material is mo3t beneficial with smaller grooves, the configuration Oe the pad ma~ be matched to it~ use.
Fig. 14 ~hows an alternate embodiment oE the rubber stripplng u~ed to ~orm the templa~e 24 Eor the production oE the molded park 26, a~ well as Eor the strlp-Eorming o~
the spical concentratlng pad ~rom khe molded part ~6. ~8 shown therein, the stripping 42 has a cross section with a sawtoothed portion 44 adjacent a dovetail section 46. On the underside of the stripping 42 is a dovetail opening 48.
As can be easil~ envisioned, the forming of the template 24 would be done by simpl~ snapping the dovetail projections --ll--46 into the dovetail opening 48 of an adjacent section o~
stripping. The use of such stripping 42 would resul-t in a semiriyid structure. Accordingly, when the stripping ~2 was used to form the template 24, the backing plate 20 could ~e eliminated. Similarly, when the spiral concentrating pad was strip molded in the molded part 26, the in-terlocking o~ the stripping 42 would also eliminate the necessity for the flexible ~acking sheet 38. While the dovetail stripping 42 will most likely eliminate the backing sheet 38 and the backing plate 20, it is unlikely that use of the molded part 21 could be eliminated.
As an additional contemplated variation of the inven-tion described herein, the pads 34 and 40 may be provided with means to allow thl_ pads to he removably attached to a rigid and generally circular hacking wheel similar to the prior art wheel 10 shol~n in Fig. 1, but without the spirals 12. Such a hacking wheel could have various curvatures to tilt the spirals o~ the pad at difEerent anyles. Moreover, this Eeature would allow the pads to be changed after wear, ~0 and would also a:Llow pads having di~ferent cross sectional conEigurations for the spirals in the pads to be used for ~pecialized applications. Such removal means could be a separabLe hook and loop type ~astener such as is sold under the trade mark VELCRO, bolts or the like, glue, etc.
In the foregoing description of the present invention, several embodiments of the invention have been disclosed. It is to be understood that other mechanical and design varlations are within the scope of -the present invention. ~ccorcl.i~nctl!,7, i:he invent.iorl ls not 1imited to the partlcular arrangemerits w~lich have been illu~trated and described in detai:L herein.
Claims (26)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A method for producing a pad with a generally planar and spiral groove between the center and the periphery of said pad, comprising:
arranging elongated flexible stripping into a planar and spiral orientation and to form a spiralling recess;
maintaining said stripping in said orientation;
forming a hardenable material over said stripping and in said spiralling recess:
removing said stripping from said material after said material has hardened, thereby exposing a molded part having an internal contour in the image of said stripping; and forming resilient material in said molded part, thereby producing a pad having an outer contour identical to that of said stripping when in said planar and spiral orienta-tion.
arranging elongated flexible stripping into a planar and spiral orientation and to form a spiralling recess;
maintaining said stripping in said orientation;
forming a hardenable material over said stripping and in said spiralling recess:
removing said stripping from said material after said material has hardened, thereby exposing a molded part having an internal contour in the image of said stripping; and forming resilient material in said molded part, thereby producing a pad having an outer contour identical to that of said stripping when in said planar and spiral orienta-tion.
2. A method as defined in claim 1, wherein:
said flexible stripping comprises a plurality of elongated strips of resilient material; and said step of arranging said stripping comprises positioning said plurality of strips in a generally concentric and spiral orientation.
said flexible stripping comprises a plurality of elongated strips of resilient material; and said step of arranging said stripping comprises positioning said plurality of strips in a generally concentric and spiral orientation.
3. A method as defined in claim 2, wherein said step of maintaining said stripping in said spiral orientation comprises:
bonding each of said strips to a mutually adjacent strip; and bonding said strips to a rigid backing plate.
bonding each of said strips to a mutually adjacent strip; and bonding said strips to a rigid backing plate.
4. A method as defined in claim 1, wherein:
said stripping is generally sawtoothed in cross section, whereby said outer contour of said pad comprises a continuous and spiral sawtoothed recess disposed between the center and the periphery of said pad.
said stripping is generally sawtoothed in cross section, whereby said outer contour of said pad comprises a continuous and spiral sawtoothed recess disposed between the center and the periphery of said pad.
5. A method as defined in claim 1, wherein said step of forming a hardenable material over said stripping comprises:
fiberglassing said stripping.
fiberglassing said stripping.
6. A method as defined in claim 1, wherein said step of forming a hardenable material over said stripping comprises:
vacuum forming a sheet of hardenable material over said stripping.
vacuum forming a sheet of hardenable material over said stripping.
7. A method as defined in claim 1, wherein said step of forming said resilient material in said molded part comprises:
compressing deformable material into said molded part.
compressing deformable material into said molded part.
8. A method as defined in claim 1, wherein said step of forming said resilient material in said molded part comprises:
pouring a hardenable material into said part and allowing said material to harden.
pouring a hardenable material into said part and allowing said material to harden.
9. A method as defined in claim 8, wherein said step of allowing said material to harden comprises:
vulcanizing said material.
vulcanizing said material.
10. A method as defined in claim 8, wherein said step of allowing said material to harden comprises:
curing said material.
curing said material.
11. A method as defined in claim 1, wherein said step of forming resilient material in said molded part comprises:
vacuum forming resilient material into said molded part.
vacuum forming resilient material into said molded part.
12. A method as defined in claim 1, wherein said step of forming said resilient material in said molded part comprises:
placing elongated and flexible stripping into said internal contour of said molded part; and affixing a backing sheet to said stripping.
placing elongated and flexible stripping into said internal contour of said molded part; and affixing a backing sheet to said stripping.
13. An ore concentrating pad comprising:
central hub means;
resilient stripping means disposed in spiral and planar orientation outwardly from said hub means, said stripping being generally sawtoothed in cross section, whereby said pad comprises a continuous and spiral sawtoothed recess extending outwardly from said hub means; and means for maintaining said stripping means in said orientation, thereby producing an ore concentrating pad of stripping means spiralling outward from said hub means.
central hub means;
resilient stripping means disposed in spiral and planar orientation outwardly from said hub means, said stripping being generally sawtoothed in cross section, whereby said pad comprises a continuous and spiral sawtoothed recess extending outwardly from said hub means; and means for maintaining said stripping means in said orientation, thereby producing an ore concentrating pad of stripping means spiralling outward from said hub means.
14. A pad as defined in claim 13, wherein said resilient stripping means comprises:
a plurality of strips of flexible and elongated material, said strips being disposed in a generally concentric and spiral orientation.
a plurality of strips of flexible and elongated material, said strips being disposed in a generally concentric and spiral orientation.
15. A pad as defined in claim 13, wherein:
said maintaining means comprises a backing plate of flexible material affixed to said stripping means.
said maintaining means comprises a backing plate of flexible material affixed to said stripping means.
16. A pad as defined in claim 13, wherein:
said resilient stripping means comprises a plurality of elongated flexible members, each of said members including a sawtoothed-shaped surface disposed longitudinally along said member; and said maintaining means comprises a dovetail-shaped member projecting from said elongated flexible member and disposed longitudinally adjacent said sawtoothed-shaped surface, and a dovetail-shaped recess disposed longitudinally beneath said sawtoothed-shaped surface, whereby said dovetail-shaped member of one of said elongated flexible members interlocks with said dovetail-shaped recess of an adjacent flexible member as said flexible members are disposed in said spiral and planar orientation.
said resilient stripping means comprises a plurality of elongated flexible members, each of said members including a sawtoothed-shaped surface disposed longitudinally along said member; and said maintaining means comprises a dovetail-shaped member projecting from said elongated flexible member and disposed longitudinally adjacent said sawtoothed-shaped surface, and a dovetail-shaped recess disposed longitudinally beneath said sawtoothed-shaped surface, whereby said dovetail-shaped member of one of said elongated flexible members interlocks with said dovetail-shaped recess of an adjacent flexible member as said flexible members are disposed in said spiral and planar orientation.
17. A pad as defined in claim 13, wherein said hub means comprises:
a generally circular opening at the center of said pad defined by said stripping.
a generally circular opening at the center of said pad defined by said stripping.
18. A method for producing an ore concentrating pad comprising:
producing a molded part having a recessed internal contour which is generally circular and which has a continuous and spiral recess disposed between the center of said part and the periphery of said part; and forming resilient material in said molded part, thereby producing a pad having an outer contour identical to that of said inner contour of said molded part said step of producing comprises the substeps of:
arranging elongated flexible stripping in a planar or spiral orientation;
maintaining said stripping in said orientation;
forming a hardenable material over said stripping;
and removing said stripping from said material after said material has hardened, thereby exposing said molded part with an internal contour in the image of said stripping.
producing a molded part having a recessed internal contour which is generally circular and which has a continuous and spiral recess disposed between the center of said part and the periphery of said part; and forming resilient material in said molded part, thereby producing a pad having an outer contour identical to that of said inner contour of said molded part said step of producing comprises the substeps of:
arranging elongated flexible stripping in a planar or spiral orientation;
maintaining said stripping in said orientation;
forming a hardenable material over said stripping;
and removing said stripping from said material after said material has hardened, thereby exposing said molded part with an internal contour in the image of said stripping.
19. A method as defined in claim 18, wherein:
said recess is generally of a sawtooth shape in cross section.
said recess is generally of a sawtooth shape in cross section.
20. A method as defined in claim 19, wherein:
said flexible stripping comprises a plurality of elongated strips of rubber material; and said step of arranging said stripping comprises placing said plurality of strips in a generally concentric and spiral orientation, with each of said strips being in mutually abutting relation with the immediately adjacent strips.
said flexible stripping comprises a plurality of elongated strips of rubber material; and said step of arranging said stripping comprises placing said plurality of strips in a generally concentric and spiral orientation, with each of said strips being in mutually abutting relation with the immediately adjacent strips.
21. A method as defined in claim 20, wherein said step of maintaining said stripping and said spiral orientation comprises:
attaching each of said strips to a mutually adjacent strip; and affixing said attached strips to a resilient backing plate.
attaching each of said strips to a mutually adjacent strip; and affixing said attached strips to a resilient backing plate.
22. A method as defined in claim 19, wherein:
said stripping is in the shape of a sawtooth in cross section, whereby said recessed internal contour of said molded part comprises a continuous and spiral sawtoothed recess dis-posed between the center and the periphery of said part.
said stripping is in the shape of a sawtooth in cross section, whereby said recessed internal contour of said molded part comprises a continuous and spiral sawtoothed recess dis-posed between the center and the periphery of said part.
23. A method as defined in claim 19, wherein said step of forming a hardenable material over said stripping comprises:
fiberglassing said stripping.
fiberglassing said stripping.
24. A method as defined in claim 18, wherein said step of forming said resilient material in said molded part comprises:
compressing deformable material into said molded part.
compressing deformable material into said molded part.
25. A method as defined in claim 18, wherein said step of forming said resilient material in said molded part comprises:
pouring a hardenable liquid material into said part and allowing said material to harden.
pouring a hardenable liquid material into said part and allowing said material to harden.
26. A method as defined in claim 18, wherein said step of forming said resilient material in said molded part comprises:
placing elongated and flexible stripping into said molded part; and affixing a backing sheet to said stripping.
placing elongated and flexible stripping into said molded part; and affixing a backing sheet to said stripping.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US21290280A | 1980-12-04 | 1980-12-04 | |
| US212,902 | 1980-12-04 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1183491A true CA1183491A (en) | 1985-03-05 |
Family
ID=22792854
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000377641A Expired CA1183491A (en) | 1980-12-04 | 1981-05-14 | Technique of forming a riffled pad by coiling and securing a flexible strip |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP0065985A1 (en) |
| CA (1) | CA1183491A (en) |
| WO (1) | WO1982001830A1 (en) |
| ZA (1) | ZA818373B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SE501773C2 (en) * | 1993-09-30 | 1995-05-15 | Kvaerner Pulp Equipment As | Fractionator comprising a rotatable drum for fractionation of a suspension |
| US7041160B2 (en) * | 2003-12-15 | 2006-05-09 | Kimberly-Clark Worldwide, Inc. | Solubility additive for ink compositions |
| GB2484064B (en) | 2010-08-26 | 2016-01-06 | Rotite Ltd | Connector and method of connecting two items together |
| US20150328803A1 (en) * | 2012-02-24 | 2015-11-19 | George Roland Hill | Device for and method of connecting two items together |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1089134A (en) * | 1913-01-25 | 1914-03-03 | Flexitallic Gasket Co Inc | Gasket. |
| US1236839A (en) * | 1917-06-29 | 1917-08-14 | Harry Hertzberg | Rotary concentrator, classifier, and separator. |
| US2064554A (en) * | 1933-06-21 | 1936-12-15 | Bendix Aviat Corp | Separator |
| US1986778A (en) * | 1933-07-31 | 1935-01-01 | Hinkley Paul | Ore separator |
| US2546056A (en) * | 1948-06-08 | 1951-03-20 | Raybestos Manhattan Inc | Clutch facing and method of making same |
| US3199541A (en) * | 1963-04-03 | 1965-08-10 | Flexible Tubing Corp | Interlocking strip flexible hose |
| US3269538A (en) * | 1963-05-07 | 1966-08-30 | Stephan Joseph | Concentrating table for mineral recovery |
| US4008152A (en) * | 1975-09-15 | 1977-02-15 | Johnny Hilmer Kleven | Metal separating process and apparatus |
-
1981
- 1981-05-14 CA CA000377641A patent/CA1183491A/en not_active Expired
- 1981-12-02 WO PCT/US1981/001603 patent/WO1982001830A1/en unknown
- 1981-12-02 EP EP82900295A patent/EP0065985A1/en not_active Withdrawn
- 1981-12-03 ZA ZA818373A patent/ZA818373B/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| ZA818373B (en) | 1982-12-29 |
| WO1982001830A1 (en) | 1982-06-10 |
| EP0065985A1 (en) | 1982-12-08 |
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