GB2062791A - Torque featured screw thread - Google Patents
Torque featured screw thread Download PDFInfo
- Publication number
- GB2062791A GB2062791A GB7938457A GB7938457A GB2062791A GB 2062791 A GB2062791 A GB 2062791A GB 7938457 A GB7938457 A GB 7938457A GB 7938457 A GB7938457 A GB 7938457A GB 2062791 A GB2062791 A GB 2062791A
- Authority
- GB
- United Kingdom
- Prior art keywords
- screw member
- plastics
- torque screw
- metal part
- member according
- 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.)
- Granted
Links
- 239000004033 plastic Substances 0.000 claims abstract description 38
- 229920003023 plastic Polymers 0.000 claims abstract description 38
- 239000002184 metal Substances 0.000 claims abstract description 20
- 239000000463 material Substances 0.000 claims description 7
- 239000004677 Nylon Substances 0.000 claims description 5
- 229920001778 nylon Polymers 0.000 claims description 5
- 238000001746 injection moulding Methods 0.000 claims description 2
- 238000004519 manufacturing process Methods 0.000 claims 1
- 239000011248 coating agent Substances 0.000 description 3
- 238000000576 coating method Methods 0.000 description 3
- 239000004020 conductor Substances 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
- F16B39/00—Locking of screws, bolts or nuts
- F16B39/22—Locking of screws, bolts or nuts in which the locking takes place during screwing down or tightening
- F16B39/28—Locking of screws, bolts or nuts in which the locking takes place during screwing down or tightening by special members on, or shape of, the nut or bolt
- F16B39/34—Locking by deformable inserts or like parts
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M3/00—Idling devices for carburettors
- F02M3/08—Other details of idling devices
- F02M3/10—Fuel metering pins; Nozzles
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
- F16B35/00—Screw-bolts; Stay-bolts; Screw-threaded studs; Screws; Set screws
- F16B35/005—Set screws; Locking means therefor
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Injection Moulding Of Plastics Or The Like (AREA)
- Shafts, Cranks, Connecting Bars, And Related Bearings (AREA)
- Transmission Devices (AREA)
Abstract
A screw has a cylindrical portion 13 with a plastics insert 14 to provide a torque feature. As shown both metal portion 13 and insert 14 are threaded and the screw is used as an idler adjusting screw for a carburettor. In a second embodiment (Fig. 2 not shown) the plastics insert is unthreaded. In a third embodiment (Fig. 3 not shown) the plastics insert constitutes the entire threaded surface of the screw. <IMAGE>
Description
SPECIFICATION
Torque featured screw thread
The present invention relates to torque screw arrangements in which it is required that a screw is really adjustable to a desired position but remains in that position when the adjustment has finished.
In prior art arrangements it is known to provide a torque feature by applying a coating of powder to part of a screw thread. When the coated thread engages another thread resistance to relative rotation increases and, to continue screwing, it is necessary to apply increased torque. The prior art arrangement suffers from the disadvantage that the life of the coating is short, because it is stripped from the screw by repeated adjustment, and so is not reusable. Furthermore, where the screw thread is exposed to harmful environments it is possible for the coating to be damaged.
In accordance with the present invention there is provided a torque screw member which comprises a generally cylindrical metal part having a plastics insert extending along part or all of its cylindrical surface, the cylindrical surface of the member being threaded along at least a substantial part of its length.
The present invention will now be described by way of the example only with reference to the accompanying drawings of which;
Fig. 1 shows a partially-sectioned view of a first embodiment of a torque screw member in accordance with the present invention;
Fig. 2 shows a partially-sectioned view of a second embodiment of the invention; and
Fig. 3 shows a partially-sectioned view of a third embodiment of the invention.
Referring to Fig. 1 of the drawings there is shown a carburettor idler adjusting screw 10 having a torque feature. This type of screw is often called a "set screw". The screw comprises a head 12, a threaded cylindrical portion 13, a stepped shank portion 1 5 and an end portion 16. All the above mentioned parts are integrally formed of metal. An annular groove 17 is formed in cylindrical portion 13, in which is provided a threaded plastics insert 14 which extends.
completely around the circumference of portion 13. The insert 14 is preferably of nylon applied by an injection moulding process. In Fig. 1 the thread of the nylon insert is indicated in broken lines.
In use the screw 10 is mounted in a female threaded portion of a carburettor with the end portion 1 6 projecting into a passageway for fuel and/or air. It is so arranged that the plastics insert 14 engages the female thread when end portion 1 6 lies in its operating range of positions. Thus when end portion 16 is adjusted to one of these positions, by screwing head 12, the torque screw member is held in this adjusted position by the
relatively high frictional engagement between the
threads.
An advantage of the above embodiment is that
by appropriate selection of the plastics material a
very accurate degree of torque may be introduced
into the screws member over a wide range,
depending upon the required application. In
addition by selecting the size and shape of the
threads on the plastics insert with respect to those
on the metal portion there is provided a further
method of consistently controlling the torque over
a very close tolerance band. Furthermore the
plastics material may be selected to withstand exposure to harmful environments; for example a grade of nylon may be chosen which is resistant to petrol, oil, water and/or gases etc., as well as heat.
Fig. 2 shows a second embodiment of the invention in which there is provided an unthreaded plastics insert 18. By appropriate selection of the hardness of the plastics material and the depth to which it fills annular groove 17 the degree of the torque provided may be adjusted. It may be arranged that when the torque screw member is first inserted in its corresponding female member a thread is cut in the plastics insert 18 by the thread of the female member.
Fig. 3 shows a third embodiment in which a plastics sleeve 1 9 is provided along the entire length of portion 13, so that all the threads are provided by the plastics material. The threads are shown in broken lines in the Figure. This embodiment provides a relatively high torque feature throughout its entire range of movement.
It may be arranged that the size and/or shape of the threads vary along the length of portion 13 so that there are provided regions of low and high torque.
The plastics insert may extend for any desired length along the cylindrical portion 13 from one thread, or even part of a thread, to the entire length as shown in Fig. 3. In addition a plurality of plastics inserts may be provided along portion 13, and to satisfy particular torque requirements, these inserts may be of different materials.
Moreover one or more of the inserts may be unthreaded, as shown in Fig. 2.
In further modifications the plastics inserts extend around only a part of the circumference to cylindrical portion 13. By varying the proportion of the circumference covered by the plastics inserts, additional control of the amount of torque is achieved.
Any dimension of screw thread up to 1 inch diameter can be manufactured with the inbuilt torque feature, or any standard screw can be adapted and given a torque loading to any specified requirement.
The torque screw members of the present invention are not limited to use in carburettors, but may be employed in set screw arrangements, and especially in set screw arrangements, where it is desired to retain a screw member in an adjusted position.
In particular, the embodiment of Figure 3 can be employed in electrical devices with advantage, when a conductor (the portion 13) is also insulated by the threaded sleeve from the member in which it is fitted.
Claims (12)
1. A torque screw member which comprises a generally cylindrical metal part having a plastics member extending along part or all of its cylindrical surface, the cylindrical surface of the screw member being threaded along at least a substantial part of its length.
2. A torque screw member accordingto Claim 1, wherein the cylindrical metal part and the plastics member are both threaded.
3. A torque screw member according to Claim 1, wherein the cylindrical metal part is threaded and the plastics member is unthreaded.
4. A torque screw member according to Claim
1, wherein the cylindrical metal part is unthreaded and the plastics member is threaded.
5. A torque screw member according to any preceding claim wherein the plastics member extends around the entire circumference of the cylindrical metal part.
6. A torque screw member according to any of claims 1 to 4 wherein the plastics member extends around only a part of the circumference of the cylindrical metal part.
7. A torque screw member according to any preceding Claim, wherein the plastics member is made of nylon.
8. A torque screw member according to any preceding Claim, wherein a plurality of plastics members are provided in the cylindrical metal part.
9. A torque screw member according to Claim 8, wherein the plastics members are of different materials.
10. A torque screw member according to any preceding Claim, wherein the cylindrical metal part is provided with one or more grooves and the plastics member or members are provided as inserts in said groove(s).
11. A torque screw member substantially as herein described with reference to the accompanying drawings.
12. A method of manufacturing a torque screw member which comprises providing a generally cylindrical metal part with a plastics insert by an injection moulding process, the plastics insert being provided so that it extends along an axially central region of the cylindrical surface of the metal part, the cylindrical surface of the screw member being threaded along at least a substantial part of its length.
12. A carburettor having as an idler adjusting screw a torque screw member according to any preceding claim.
New claims or amendments to claims filed on 23rd October, 1980.
Superseded claims 1-12.
New or amended claims: 1-12.
1. A torque screw member which comprises a generally cylindrical metal part having a plastics insert extending along an axially central region of its cylindrical surface and around substantially all of its circumference, the cylindrical surface of the screw member being threaded along at least a substantial part of the its length.
2. A torque screw member according to Claim 1, wherein the cylindrical metal part is threaded and the plastics insert are both threaded.
3. A torque screw member according to Claim 1, wherein the cylindrical metal part is threaded and the plastics insert is unthreaded.
4. A torque screw member according to Claim 1, wherein the cylindrical metal part is unthreaded and the plastics insert is threaded.
5. A torque screw member according to any preceding claim wherein the plastics insert extends around the entire circumference of the cylindrical metal part.
6. A torque screw member according to any preceding claim, wherein the plastics insert is made of nylon.
7. A torque screw member according to any preceding claim, wherein a plurality of plastics inserts are provided in the cylindrical metal part.
8. A torque screw member according to Claim 7, wherein the plastics inserts are of different materials.
9. A torque screw member according to any preceding claim, wherein the or each insert is an injection-moulded insert.
10. A torque screw member substantially as herein described with reference to the accompanying drawings.
1 A carburettor having as an idler adjusting screw a torque screw member according to any preceding claim.
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB7938457A GB2062791B (en) | 1979-11-06 | 1979-11-06 | Torque featured screw thread |
DE19803041371 DE3041371A1 (en) | 1979-11-06 | 1980-11-03 | TORQUE SCREW |
ES1980254546U ES254546Y (en) | 1979-11-06 | 1980-11-06 | TORQUE SCREW ORGAN |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB7938457A GB2062791B (en) | 1979-11-06 | 1979-11-06 | Torque featured screw thread |
Publications (2)
Publication Number | Publication Date |
---|---|
GB2062791A true GB2062791A (en) | 1981-05-28 |
GB2062791B GB2062791B (en) | 1984-01-11 |
Family
ID=10509013
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB7938457A Expired GB2062791B (en) | 1979-11-06 | 1979-11-06 | Torque featured screw thread |
Country Status (3)
Country | Link |
---|---|
DE (1) | DE3041371A1 (en) |
ES (1) | ES254546Y (en) |
GB (1) | GB2062791B (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8152427B2 (en) | 2006-01-24 | 2012-04-10 | Puku Limited | Threaded fastener shaft having a deformable threaded portion |
Families Citing this family (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE29510122U1 (en) * | 1995-06-22 | 1995-08-31 | TRW Fahrwerksysteme GmbH & Co KG, 40547 Düsseldorf | Lid for a pressure piece housing of a steering gear |
DE19823746C2 (en) * | 1998-05-27 | 2001-04-26 | Ejot Kunststofftech Gmbh | Method for producing a device for adjusting the distance between two components |
DE10044025B4 (en) * | 2000-09-06 | 2012-04-05 | Andreas Stihl Ag & Co. | Carburetor for an internal combustion engine with at least one adjusting screw |
DE10244010A1 (en) * | 2002-09-21 | 2004-04-01 | Hensoldt Ag | adjusting screw |
DE202020005509U1 (en) | 2020-06-01 | 2021-06-29 | Viktor Hegedüs GmbH | Self-locking screw |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE1085127B (en) * | 1958-01-02 | 1960-07-14 | Walter Ziehr | Process for the production of a threaded bolt with an annular locking member |
US3285310A (en) * | 1964-08-11 | 1966-11-15 | United Shoe Machinery Corp | Self-locking male threaded fasteners |
DE1975535U (en) * | 1967-10-07 | 1967-12-21 | Suedd Kolbendolzenfabrik G M B | SCREW, NUT OD. DGL. |
DE2327285A1 (en) * | 1973-05-29 | 1975-01-02 | Hermann Winker Kg Metallwarenf | Reusable self-locking screw, motion and vibration proof - with nylon ring held in circular groove by knurling |
-
1979
- 1979-11-06 GB GB7938457A patent/GB2062791B/en not_active Expired
-
1980
- 1980-11-03 DE DE19803041371 patent/DE3041371A1/en active Granted
- 1980-11-06 ES ES1980254546U patent/ES254546Y/en not_active Expired
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8152427B2 (en) | 2006-01-24 | 2012-04-10 | Puku Limited | Threaded fastener shaft having a deformable threaded portion |
Also Published As
Publication number | Publication date |
---|---|
DE3041371C2 (en) | 1992-06-25 |
ES254546Y (en) | 1981-12-16 |
DE3041371A1 (en) | 1981-05-14 |
ES254546U (en) | 1981-07-16 |
GB2062791B (en) | 1984-01-11 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
727 | Application made for amendment of specification (sect. 27/1977) | ||
727A | Application for amendment of specification now open to opposition (sect. 27/1977) | ||
727B | Case decided by the comptroller ** specification amended (sect. 27/1977) | ||
SPAC | Amended specification published ** copy of the specification now available | ||
PE20 | Patent expired after termination of 20 years |
Effective date: 19991105 |