CORKSCREW

Abstract: A corkscrew (10) has a handle (12) mounted to a screw stem (14) rotatably guided within a cap (18) which contains upper ends of two prongs (40). These have semi-circular lower ends (48) that surround a screw (16) and comprise inner shoulder stops (64) for engaging on a bottle-neck; upper prong ends (42) are articulated to a core unit (20) having a guide bush (22) for the screw stem (14). Cap (18) may be integral with the handle (12) or the latter may be screw-fitted to a tapped stem (84) guided by the cap (18). Bearing means for the upper prong ends (42) on which expanding springs (56) bear find stops at a lower peripheral edge of cap (18). A lug (50) supports each upper prong end (42) on a pin (34) that traverses a guiding cheek (30) on the guide bush (22). Radial bell ribs (44) have lower leading edges (45) in each central portion (46) of the prongs (40). Various screw types can be exchangeably used; preferred is a bladed type (16; 16') having wide sharp flares or a round wire hollow helix (16''), either ending in a pointed tip (78). A sleeve (80) may be put first over a captive screw 16' whereupon the screw top can be mounted to handle (12); a widened lower screw end cannot pass beyond sleeve (80) and is thus movably retained therein. The screw (16, 16'; 16'') made of steel may be surface-treated for minimum friction.

Description: The invention relates to a corkscrew according to the generic portion of claim 1. Corkscrews have been known for centuries. A particular type as disclosed in US 310,766 (B. Wilhelm) includes a handle mounted to a cone-shaped part the bottom of which has a circular groove for receiving two semi-circular tongues. These surround a screw and form the upper ends of loose prongs having inner shoulders that are capped by a slidable ring. A screw stem comprising a bearing disk is fixed to the handle so as to axially hold the components together. In operation, the screw tip is turned into a cork and the ring is slid up or down, respectively, so that the lower prong ends will first be spread and then moved together as lower prong shoulders are placed onto the neck of a bottle; further turning of the handle will force the cork up between the prongs while the device is pressed onto the bottle. More modern corkscrews of similar type include a housing or bell that is solid with two prongs. These have inner semi-circular stops to be placed onto a bottle-neck. Under a firm grip to hold the bottle and housing together, a loose screw or worm can be put through a housing top portion that serves for guiding the screw which, upon turning, will enter the cork. As the latter raises between lateral ribs of the housing, it will thereby be held against rotation; once it is lifted out of the bottle, simple counter-turning of the screw handle will eject the cork from the bell. Other corkscrews named after Reissmann have a tapped stem screw borne within a matchingtapped bush of a bell or housing. A tiltable top nut through which a handle rod transversely extends also screws with the stem thread. With the housing bottom put onto a bottle-neck, the handle is turned one way from a first upper position so as to penetrate the cork, and under continued turning the handle will screw down on the stem and the cork is extracted from the bottle; then the nut is tilted, the handle is turned upwards the other way and turning is continued until the cork drops out from between retaining bell ribs. While each of the designs mentioned has its merits, there are specific drawbacks, too. Thus the corkscrew initially described requires precise manufacture and mounting, and the assembly of the various components is critical in that both close fit and rotatability are of the essence for trouble-free use. In addition, there are no centering means for the screw which is thus quite likely to sometimes obliquely enter a cork. Solid bells cannot fit bottle-necks of widely differing sizes. Conventional Reissmann corkscrews, in particular, have a short housing pot that will not readily warrant centered application to a corked bottle so that it may again be possible to penetrate the cork in a slanted direction, resulting in its split-up. The invention aims at overcoming these and other drawbacks of the prior art. It is an object of the invention to create a corkscrew that combines advantages of earlier designs in a simple and economical manner. A particular object of the invention is the creation of a two-prong corkscrew of sturdy design that permits fairly cheap manufacture and easy use, especially with well centered application onto bottle-necks of various sizes. The invention also aims at providing a cork-screw whose screw proper is surface-treated for minimum friction and is designed for easy piercing into a cork and for large engagement area therein. Important features of the invention are stated in claim 1. Specializations form the subject matter of claims 2 to 19. In a corkscrew including a handle mounted to a screw stem rotatably guided within a cap which contains upper ends of two prongs having semi-circular lower ends that surround a screw and comprise inner shoulder stops adapted for engagement on a bottle-neck, the improvement according to the invention is characterized in that the upper prong ends are articulated to a core unit to which a guide bush for the screw stem is associated and in that they are spring-biassed to provide a spreading force towards the perimeter of the cap. This important feature permits very easy application of the corkscrew to bottlenecks of widely varying diameter which are gripped by the prongs for centered engagement of the screw to a cork to be extracted. The cap may be integral with the handle, or the latter may be screw-fitted to a tapped stem which is guided by the cap. The core unit includes bearing means for the upper prong ends on which expanding springs bear and which have and/or find stops in the region of a lower peripheral edge of the cap. Specifically, each of the upper prong ends comprises a lug for support on a pin that traverses guiding cheeks of the core unit on either outward side of the guide bush. Cork retaining and removing means in a bell include radial ribs having lower leading edges in each central portion of the prongs. Various types of screws or worms can be exchangeably used; preferred is a bladed type having wide sharp flares or a round wire hollow helix, either ending in a pointed tip. In particular, the screw is made of steel and is surface-treated for minimum friction, e.g. by plating, enameling or teflon-coating. It may conically widen downwards and thus be captive in respect of the core unit in which it is guided. Further features, particulars and advantages of the invention will become evident from the wording of the claims and from the following description of special embodiments by way of the drawings wherein: Fig. 1 is a side view, partly in longitudinal section, of a novel corkscrew, Fig. 2 is a cross section along line II-II of Fig. 1, Fig. 3 is a side view similar to Fig. 1 but with partly elevated handle and screw, Figs. 4 to 6 are exploded side views of various corkscrew components, Fig. 4 showing three alternatives of screws, Fig. 7 is a side view similar to Fig. 1 but of a different embodiment, Fig. 8 is a cross section along line VIII-VIII of Fig. 7, Fig. 9 is a side view similar to Fig. 3 but of the embodiment shown in Fig. 8 and Fig. 10 is an exploded side view of several corkscrew components. A preferred embodiment of a corkscrew 10 according to the invention will be seen in Figs. 1 to 6. It includes a handle 12 to which a screw stem 14 having a worm or screw 16 is fixed exchangeably. A cap 18 is integral with the handle 12 and tops a core unit 20 as well as a guide bush 22 having a bore 23 (Figs. 5 and 6) in which the screw stem 14 and the screw 16 proper, respectively, are guided. Two prongs 40 preferably of metal have upper ends 42 which are articulated to a socket 26 of core unit 20 and are biassed by springs 56 so that the lower ends 48 of the prongs 40 would easily fit over bottle-necks (not shown) of various sizes. A flange 24 of core unit 20 separates the guide bush 22 from the upper ends 42 and may serve as a stop to these, just as a shoulder 28 of socket 26. The latter includes two pairs of parallel cheeks 30 defining radial chambers 36 and having transverse bores 32 in order to receive pins 34 which also pass through transverse bores 52 in lugs 50 of the upper prong ends 42. The lugs 50 contain blind holes 54 for seating outer ends 58 of compression springs 56 which bear on an outer portion 62 of each of the upper ends 42 for limited spreading of the prongs 40. Inner ends 57 of the springs 56 are each contained in the chamber 36 and bear on a wall 59 therein. A sliding ring 38 (Fig. 4) may snugly encompass the socket 26 as well as the outer portions 62 inside cap 18 for reducing friction during the cork extracting operation. Likewise a sleeve 80 may snugly fit the guide bush 22 inside a handle collet 82. The prongs 40 have a central portion 46 comprising opposite ribs 44 that extend radially from inner prong walls 47. Each rib 44 has a lower leading edge 45 that may be curved or slanted relative to the corkscrew axis A and serves for receiving a rising cork which is then retained between the ribs 44 until, after extraction, the cork is pushed off as handle 12 is counter-turned. The expelled cork will automatically fall out of the corkscrew 10 from between its slightly spreaded prongs 40. Below the central portion 46 that forms a bell-type housing, shoulder stops 64 preferably made of plastics are seated in an inner groove 66 and are anchored by a detent 68; they serve for rather gentle engagement on the bottle-neck. The lower ends 48 are curved outwardly to facilitate gripping a bottle-neck. A preferred worm or screw 16 includes a stem 14 having an upper square 74 which fits into a square hole 72 of handle 12 and which can be fixed thereto by means of a bolt 76 (Fig. 4). The pitched screw 16 is of the bladed type and comprises wide coil flares that are bevelled or cyphered to provide a continuous sharp helical edge ending in a pointed tip 78. The flare area or effective cross section is large and thus warrants ample engagement in a cork so that even if in a deteriorated state, the cork is very likely to be lifted out of the bottle. Alternatively, a steep-pitched center worm or screw 16' may be employed (lefthand in Fig. 4). Yet another worm or screw 16'' of the hollow helical type (righthand in Fig. 4) may also be inserted in handle 12 and likewise be fixed via a square connection 74/72. In a two-part design (Fig. 10), the worm or screw 16 proper may include a bolt portion 90 that screws with a threaded hole 92 in the stem 14 or stem extension 84. Handle 12 and screw 16 may be captive in respect of core unit 20. The example of Fig. 4/lefthand shows that the lower end of screw 16' may slightly widen towards its tip 78, e.g. conically, so that the lower screw end has adjacent tip 78 a somewhat larger outer diameter D than any other screw portion. Moreover, a bore 81 of inner diameter d in sleeve 80, which is put over the top of the screw 16', matches the latter's outer diameter in particular at its top and central portions and is likewise slightly smaller than the outer diameter D of the lower screw end. It will be understood that the handle 12 which is bolted to the screw top of smaller diameter d is thus captively but movably held to the core unit 20. Sleeve 80 serves, in addition, as a bearing inside handle collet 22 (Fig. 4). If, after extraction of a cork, the screw 16' is counter-turned for unscrewing from the cork, whereby the screw 16' usually rises relative to socket 20, the wider lower screw end will clampingly engage the smaller bore 81 so that sleeve 80 will also counter-turn in a bearing bush 83 inside the collet 22 in whose central bore 23 the screw body is guided. This clamping connection between the sleeve 80 and the lower screw end will be released immediately as handle 12 and thus screw 16' is turned again in screwing direction. In any case, the worm or screw 16 (or 16' or 16'') is preferably made of steel and is surface-treated for minimum friction, in particular by a plating process on the basis of copper, nickel, chrome, tin or alloys thereof. Velvet finish nickel-plating, enameling and teflon-coating may also be used. A second corkscrew embodiment is shown in Figs. 7 to 10. It is of the Reissmann type and includes a handle 12 adapted to be inserted in a tiltable nut 86 and provided with a tapped bore 88. Nut 86 and bore 88 match the thread of a tapped extension 84 of stem 14 and screw 16, respectively. The latter here comprises a bolt portion 90 designed to be screwed into a threaded hole 92 of tapped stem extension 84 with a stop ring 85 interposed. In the second embodiment, guide bush 22 is integral with cap 18 rather than with core unit 20. Cap 18 also includes a lower stop edge 60. Guide bush 22 here guides the tapped stem extension 84 the top of which forms a captive screw so that nut 86 previously mounted cannot spin off. A snap ring 70 may be seated, especially in a peripheral flute (merely indicated in Fig. 7), at the lower ends 48 of prongs 40 of either corkscrew embodiment. Snap ring 70 equals or exceeds the spreading force of springs 56 and serves to hold the prongs 40 resiliently together, especially to assist centered application on a bottle-neck, but also to facilitate the grip thereon and/or to retain the device when the corkscrew 10 is stationed on a table or on an extra wooden post (not shown) prior to use. Reference Symbols A axis (of 20; 10) d main stem/screw diameter D lower screw end diameter 10 corkscrew 12 handle 14 screw stem 16,16',16'' screw / worm 18 cap 20 core unit 22 guide bush 23 bore 24 flange 26 socket 28 shoulder 30 cheeks 32 transverse bores 34 pins 36 chamber 38 sliding ring 40 prongs 42 upper end 44 rib 45 leading edge 46 central portion 47 prong wall 48 lower end 50 lug / block 52 transverse bore 54 blind hole 56 compression spring 57 inner end 58 outer end 59 wall 60 stop edge 62 outer portion 64 shoulder stops 66 groove 68 detent 70 snap ring 72 square hole 74 square 76 bolt 78 tip 80 sleeve 81 bore 82 collet 83 bearing bush 84 tapped stem extension 85 stop ring 86 tilting nut 88 tapped bore 90 bolt portion 92 threaded hole

Claims: In a corkscrew (10) including a handle (12) mounted to a screw stem (14) rotatably guided within a cap (18) which contains upper ends (42) of two prongs (40) having semi-circular lower ends (48) that surround a screw (16) and comprise inner shoulder stops (64) adapted for engagement on a bottle-neck, the improvement wherein the upper prong ends (42) are articulated to a core unit (20) to which a guide bush (22) for the screw stem (14) is associated and are spring-biassed to provide a spreading force towards the perimeter of the cap. A corkscrew according to claim 1, wherein the cap (18) is integral with the handle (12). A corkscrew according to claim 1, wherein the cap (18) or a sliding ring (38) housed therein includes a lower peripheral edge (60) serving as a stop to an outer portion (62) of each of the upper prong ends (42). A corkscrew according to claim 1, wherein adjacent the guide bush (22), the core unit (20) comprises two parallel bearing means (30, 32, 34) transverse to the core axis (A) for articulating the prongs (40). A corkscrew according to claim 1, wherein on either side of the guide bush (22), the core unit (20) comprises a bearing face (62) for receiving an inner end (57) each of a compression spring (56) whose opposite outer end (58) is seated in a blind hole (54) of an associated upper prong end (42). A corkscrew according to claim 1, wherein each of the upper ends (42) includes a lug (50) having a transverse bore (52) that matches a transverse bore (32) in parallel cheeks (30) of the core unit (20) and wherein pins (34) extend through the matching bores (32, 52) for support of the lug (50). A corkscrew according to claims 5 and 6, wherein the parallel cheeks (30) define a chamber (36) for receiving a block-shaped lug (50) in a guiding manner and wherein each blind hole (54) is radially arranged in the lug (50) below its associated transverse bore (52). A corkscrew according to claim 1, wherein each prong (40) comprises a radial rib (44) extending from the upper end (42) downwards and having a lower leading edge (45) that is curved or tapered relative to a prong wall (47). A corkscrew according to claim 1, wherein each prong (40) comprises an inner groove (66) with a detent (68) for retaining a shoulder stop (64) of semi-circular shape. A corkscrew according to claim 1, wherein the screw stem (14) is exchangeably mounted to the handle (12). A corkscrew according to claim 10, wherein the screw stem (14) includes an upper square (74) adapted to be inserted into a square hole (72) of the handle (12) and to be bolted thereto. A corkscrew according to claim 1, wherein the handle (12) includes a tapped hole (88) for screw-fitting with a tapped stem (84) whose top forms a captive screw and wherein the cap (18) is integral with the guide bush (22) through which the tapped stem (84) extends. A corkscrew according to claim 12, wherein the screw (16) includes an upper threaded portion for detachable fixing to the tapped stem (84) with a stop ring (85) interposed. A corkscrew according to claim 1, wherein the lower ends (48) of the prongs (42) are adapted to receive a snap ring (90) to provide a contracting force that equals or exceeds the spreading force of the prong springs (56). A corkscrew according to claim 1, comprising a sliding ring (38) for snugly fitting the socket (26) and/or comprising a sliding sleeve (80) for snugly fitting the guide bush (22). A corkscrew according to claim 1, wherein the screw (16') is captive, its lower end near its tip (78) having a larger outer diameter (D) than all other screw portions, and wherein the inner diameter (d) of an upper bore (81) of a sleeve (80) put over the top of the screw (16') is smaller than the outer diameter of the lower screw end and is adapted to engage the latter, whereby the handle bolted to the screw top is captively held to the core unit (20). A corkscrew according to claim 1, wherein the screw (16; 16') is of the bladed type and comprises coil flares that are bevelled or cyphered to provide a continuous sharp helical edge ending in a pointed tip (78). A corkscrew according to claim 1, wherein the screw (16'') is of the hollow type and comprises a round wire helix ending in a pointed tip (78). A corkscrew according to claim 1, wherein the screw (16, 16', 16'') is made of steel and is surface-treated for minimum friction, e.g. by plating, enameling or teflon-coating.

Inventors: USBECK FRIEDRICH WILHELM, USBECK, FRIEDRICH WILHELM
Applicants: USBECK & SOEHNE MONOPOLWERK, MONOPOLWERK USBECK & SOEHNE GMBH & CO.
Application year: 1997
Main classification: B67B7
IPC codes: B67B7