AU599507B2

AU599507B2 - Missile having collapsible flight

Info

Publication number: AU599507B2
Application number: AU20668/88A
Authority: AU
Inventors: Kenneth Cass Morris
Original assignee: Individual
Current assignee: Individual
Priority date: 1987-08-14
Filing date: 1988-08-14
Publication date: 1990-07-19
Anticipated expiration: 2008-08-10
Also published as: AU2066888A

Description

COMMONWEALTH OF AUSTRALIA Patents Act 1952 COMPLETE SPECIFICATION (original) FOR OFFICE USE Application Number: PI 3777 Lodged: 14/08/87 Class Int. Class t Complete Specification Lodged: Accepted: Published: Priority: Related Art: TO BE COMPLETED BY APPLICANT 0 5 9 0 DO 0060 Name of Applicant: KENNETH CASS MOR:RIS Address of Applicant: 21 Frances Road, Gelorup, in the State of Western Australia, Commonwealth of Australia Actual Inventor: KENNETH CASS MORRIS Address for Service:- Wray Associates Primary Industry House 239 Adelaide Terrace Perth Western Australia 6000.

41 Complete Specification for the invention entitled: "MISSILE HAVING COLLAPSIBLE FLIGHT" 9 10/08/8 The following statement is a full description invention, including the best method of performing to me:p00OC)39 of this i t known 1r t 10 I I I I I I U I 10 'lit It tO I I t U I U $1 I U I I t it U It I I I I II I 0.0 I I 4 I i.

I 90 I 4 I 14 20 444444 4 4 -2- THIS INVENTION relates to a missile having a collapsible flight.

The invention has been devised particularly, although not solely, as a missile in the form of a dart.

In playing the game of darts, it is usual for each player to throw three darts at each turn. On occasions, the flight of a previously thrown dart may obstruct a succeeding dart.

The present invention seeks to overcome the abovementioned difficulty by providing a dart with a flight which collapses on impact with the dart board. In this way, the flight of the impacted dart does not impede the path of any subsequently thrown dart.

In one form the invention resides in a missile comprising a body defining a longitudinal axis and having a leading end, a trailing end and a cavity within the body, a flight mounted on the body for movement between an operative condition in which the flight extends laterally of the body at or near the trailing end thereof for assisting the missile in flight and a collapsed condition in which the flight is received in the cavity, the flight being adapted to move from said operative condition to said collapsed condition upon impact of the missile on a target surface.

Preferably, the missile includes means releasably locking the flight in the operative condition and an inertia means responsive to impact of the missile on the target surface to effect release of said flight whereby to allow -the flight to move from the operative condition to the collapsed condition.

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-4 3 Preferably, means are provided for biasing the flight towards the collapsed condition. The biasing means may comprise a spring secured between the flight and a portion of the body.

c ct cc C C C C CC t C C CT C c cC r r C C C C CC C FC LC CC C CE' C c C r cc 'c C CC C C Preferably, the flight is constructed of resiliently flexible material which is constricted by the cavity when in the collapsed condition.

Preferably, the locking means includes an elongated member axially movable in the body between first and second 10 positions corresponding to the operative and collapsed conditions of the flight and having a lateral protrusion movable between extended and retracted positions, the lateral protrusion being engagable with a stop when in the extended position whereby to lock the elongated member in said first position and being clear of the stop when in the retracted position whereby to allow the elongated member to move from the first position to the second position and wherein said inertia means is adapted to cause retraction of the lateral protrusion upon impact of 20 the missile on the target surface.

Preferably, the elongated member includes a longitudinally split portion supporting the protrusion, the longitudinally split portion being movable radially to effect movement of the protrusion between the extended and retracted positions, and wherein the inertia means comprises an element which surrounds and is mounted on the elongated member for movement therealong whereby forward movement of the element on the elongated member radially compresses the longitudinal split portion to cause 30 contraction of the protrusion.

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6 99 94 9 9 4 Preferably, the stop comprises an annular face defining an opening through which the elongated members each pass when the lateral protrusion is in the retracted position.

The invention will be better understood by reference to the following description of one specific embodiment thereof as shown in the accompanying drawings in which:- Fig. 1 is a sectional side view of a missile according to the embodiment in an operative condition; Fig. 2 is a sectional side view of the missile in a collapsed condition; Fig. 3 is a sectional view of part of the missile, showing use of a tool designed to facilitate assembly of the missile; Fig. 4 is a fragmentary view on an enlarged scale of the missile in the operative condition; Fig. 5 is a fragmentary view on an enlarged scale of the missile in a collapsed condition; and Fig. 6 is an exploded view of the missile.

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The embodiment shown in the drawings is directed to a missile in the form of a dart of the type used in the game of darts.

The dart comprises an elongated hollow body 11 defining an elongated cavity 13. The body 11 includes a leading end and a trailing end 17. The leading end 15 of the body is fitted with a removable dart point 18. The dart point 18 1~ 5 is releasably attached to the leading end of the body to permit replacement of the dart point with any one of various dart points of different weight.

The body 11 is formed in three parts being a leading part 19, an intermediate part 20 and a trailing part 21. The leading and intermediate parts 19 and 20 are threadedly interconnected at 22. Similarly, the intermediate and trailing parts are threadedly interconnected at 23.

A flight 25 is mounted on the elongated body 11 adjacent the trailing end thereof and is provided to assist the missile in flight when in an operative condition as shown 9£ -v in Fig. 1. The flight is collapsible whereby it can assume a collapsed condition within the cavit-y 13 in the body, as best seen in Fig. 3 oif the drawings. The flight is constructed of resiliently flexible material which is t constricted when the flight is received within the cavity z t 13.

A tubular part 24 is provided within the cavity 13. The part 24 has a male thread formation 26 at its leading end which is received in an internally threaded bore 28 in leading part 19 for engagement therewith.

A tubular elongated member 27 is slidably mounted in the cavity 13 within the body. The flight 25 is coupled to the elongated mem'ber 27, as best seen in Fig. 1 of the.

drawings. The coupling is by way of a male coupling member 30 provided on the flight 25 co-operating with a female coupling member 31 provided on member 27.

The elongated member 27 is movable between a first (rearward) position in which it is disposed rearwardly of tubular part 24 and a second (forward) position in which L- -i I:I 6 it is received within tubular part 24. In moving between the-first and second positions, the elongated member moves the flight 25 between its operative and collapsed conditions. The elongated member 27 is biased toward the second (forward) position by way of a tension spring 29 which extends between coupling member 31 at the trailing end of the elongated member and member 33 located in bore 28 and retained in position by tubular part 24. The forward end of the elongated member is provided with a protrusion 35 defined by the radially outer -most end of a flared section 37 on the forward end of the elongated C member. The forward end section of the elongated member is also provided with a pair of diametrally opposed slits 39 which facilitate movement of the protrusion between radially extended and radially retracted positions. When t the protrusion 35 is in the radially extended position, it locates against a stop 41 defined by the trailing end of St, tubular part 24. Co-operation between the protrusion 37 on the elongated member and the stop 41 serves to retain the elongated member in said first (rearward) position in tr. which the flight 25 is in the operative condition. The t .r stop 41 is provided by an annular face which defines an opening through which the elongated member can pass on forward movement thereof when the protrusion is in the ti..

retracted position.

srism An inertia member 43 is provided to effect contraction of the radial protrusion thereby to allow the elongated member to move forwardly past the stop on impact of the dart with a target surface. The inertia member 43 comprises a tubular element disposed around tubular part I 24 within the elongated body 13. The tubular element 43 has at its trailing end an internal circumferential flange which surrounds the elongated member 27. The inertia member 43 is movable between forward and rearward .ii -7positions and is biased towards a rearward position by a spring 47 acting between the forward end of the inertia member and a face 49 defined at the rear end of threaded formation 26 on part. 24. The spring 47 acts to bias the inertia member 43 towards its rearmost position at which the rear end of the inertia member locates against a stop defined by a tapered section 50 of the body 11. The spring force of the spring 47 is such that the inertia member is biased to the rearward position under normal conditions but is overcome by inertia of the inertia i ,member upon impact of the dart with a target surface. On impact of the dart, inertia of the inertia member causes the latter to slide forwardly against the biasing effect trig ,ttt, of the spring 47 bringing the in-turned flange 45 to It C contact the flared section 37 on the elongated member 27.

The action of the in-turned flange 45 engaging on the flared section 37 causes the latter to contract thereby moving the protrusion 35 from the extended position to the contracted position. As a consequence of this, the protrusion 35 is moved clear of the stop 41 and the elongated member 27 is caused to move from the first (rearward) position to the second (forward) position under the influence of the spring 29. Forward movement of the tee._ elongated member 27 has the effect of moving the flight forwardly into the cavity 13. As the flight 25 moves into the cavity 27, it is caused to collapse into the collapsed position as seen in Fig. 2 of the drawings.

The rear end of the flight 25 is provided with a part 51 which serves as a finger grip by means of which a user can 'F 30 grasp the flight and pull it rearwardly so as to manually move the flight from the collapsed position to the P 1* I operative position. This causes the elongated member 27 to also move rearwardly until such time as the protrusion i |I is disposed rearwardly of the stop 41 whereby cooperation 1 3 i l -8between the protrusion and stop again maintains the elongated member in the first (rearward) position.

With reference to Figures 3 and 6 of the drawings, a tool 53 is provided to releasably engage the elongated member 27 during assembly of the dart so that the elongated member can be retracted against the biasing force of the spring 29 to permit attachment of the flight 25 onto the rear end of the elongated member.

operation of the dart will now be described. When the flight is in the operative condition as shown in Fig. 1, the dart can be thrown in the manner of a conventional dart. Upon the dart impacting the target surface, the flight 25 is caused to collapse intothe cavity 13 in the manner described previously. Consequently, the flight is no longer exposed so as to obstruct the flight path of any subsequently thrown dart.

C z It should be appreciated that the scope of the invention is not limited to the scope of the embodiment described.

In particular, it should be appreciated that the invention may be applied to missiles other than darts, such as goes. arrows shot from bows.

Claims

1. A missile comprising a body defining a longitudinal axis and having a leading end, a trailing end and a cavity within the body, a flight mounted on the body for movement between an operative condition in which the flight extends laterally of the body at or near the trailing end thereof for assisting the missile in flight and a collapsed condition in which the flight is received in the cavity, the flight being adapted to move from said operative condition to said collapsed condition upon impact of the e 'r missile on a target surface. C c t

2. A missile according to claim 2 further comprising locking means for releasably locking .the flight in the t e operative condition and an inertia means responsive to impact of the missile on the target surface to effect C¢ release of said flight whereby to allow the flight to move C C from the operative condition to the collapsed condition. V

3. A missile according to claim 1 or 2 further C CU comprising biasing means for biasing the flight towards the collapsed condition. S tt

4. A missile according to claim 3 wherein the biasing S t means comprise a spring secured between the flight and a portion of the body.

A missile according to any one of the preceding claims wherein the flight is constructed of resiliently flexible material which is constricted by the cavity when r- I in the collapsed condition. *1

6. A missile according to any one of claims 2 to wherein the locking means includes an elongated member 91; i. 10 axially movable in the body between first and second positions corresponding to the operative and collapsed conditions of the flight and having a lateral protrusion movable between extended and retracted positions, the lateral protrusion being engagable with a stop when in the extended position whereby to lock the elongated member in said first position and being clear of the stop when in the retracted position whereby to allow the elongated member to move from the first position to the second position and wherein said inertia means is adapted to S*r cause retraction of the lateral protrusion upon impact of the missile on the target surface. t t

7. A missile according to claim 6 wherein the elongated member includes a longitudinally split portion supporting the protrusion, the longitudinally split portion being movable radially to effect movement of the protrusion between the extended and retracted positions, and wherein the inertia means comprises an element which surrounds and 'C C t is mounted on the elongated member for movement therealong «t whereby forward movement of the element on the elongated member radially compresses the longitudinal split portion to cause contraction of the protrusion.

8. A missile according to claim 6 or 7 wherein the stop comprises an annular face defining an opening through which the elongated member can pass when the lateral protrusion is in the retracted position. I;; ''t 'fI i te ii ;U)I lit 11

9. A missile substantially as herein described with reference to the accompanying drawings. DATED this tenth day of August, 1988 KENNETH CASS MORRIS Applicant A 4 SC t 44 WRAY ASSOCIATES, Perth, Western Australia, Patent Attorneys for the Applicant. t- t t 4i t t IS t v 'rt t1I I ji ife^ i' r rl