AU2013204196A1 - A retractable pin coupling - Google Patents

Abstract

A retractable pin coupling may be used in a telescopic post, the coupling 13 surrounds tubes and includes retractable pin means in the form of opposed pins 14 and 15 and a manually operable pin retraction mechanism 16. The pin retraction mechanism 16 includes a pushbutton 17 and lever arms 18 and 19 so that when the pushbutton 17 is depressed the lever arms 18 and 19 pivot about pivot pins 20 and 21 and the arms 18 and 19 operate to radially retract the pins 14 and 15 thereby releasing the coupling of the tubes 11 and 12. Torsion springs 22 and 23 are used to bias the arms 18 and 19 so that the pins 14 and 15 are normally biased to the extended "'coupled" position shown.

Description

1 A retractable pin coupling TECHNICAL FIELD [0001] THIS INVENTION relates to a retractable pin coupling and in particular but not limited to a retractable pin coupling for securing telescopic members in releasable fixed relation. BACKGROUND [0002] There are certain advantages with quick couplings for all manner of devices including interchangeable tools, tool heads and fittings in general that may require coupling to another device, handle or the like. Many of these include the use of mated sockets and pins as well as various detents including spring biased ball detents, clamps and the like. [0003] In the case of telescopic members there are many arrangements that serve to arrest movement of one member relative to the other including simple mated sockets and pins and also various clamps. Examples are as used in camera tripods and tent poles which might use the common threaded cross bolt which may screw through an outer tube and directly against an inner tube sliding inside the outer tube. [0004] While all of these work for the particular application for which they are designed many lack strength and are not robust enough for more heavy duty applications. [0005] An object of the present invention is to provide a retractable pin coupling which may be used in many circumstances where the prior art is generally unsuitable but also in these applications as well. [0006] A further object is to provide a useful alternative to the prior art which facilitates rapid coupling employing mated pin and socket arrangement that provides a robust assembly. In the present specification "pin" will be understood to include any mechanical device that blocks movement of one part relative to another. Thus all that is required is an extension that serves to arrest the relative movement as by clamping, plugging aligned holes and similarly mechanical 2 equivalents that perform these functions. SUMMARY [0007] In one aspect therefore there is provided a retractable pin coupling comprising retractable pin means and a manually operable pin retraction/extension mechanism, the coupling being adapted to be pin coupled to pin mated means on a device to which the coupler is connected with the pin means being in an extended position and being releasable upon operation of the pin retraction mechanism to retract the pin means to a retracted position. [0008] Preferably, the retractable pin means includes at least two retractable pins. Typically, the pins are set in a pincer configuration and are biased to an extended position by suitable biasing means, the pin extended position being a pin coupled position. [0009] The manually operable pin retraction mechanism may include a lever, button, linkage or other means directly or indirectly operating on the pin. Typically there is a manually operable button, switch, or other manual actuator and an intermediate link between the actuator and the pin. The actuator may be lockable in position corresponding to a pin extended position. The actuator may be manually released or require a key or code for release. [0010] The pin mated means may be a surface or alignable pin receivers. Typically, it may include a socket means but may be any recess, hole, slot, groove or any surface that serves to sufficiently engage the pin or be engaged by the pin for the desired level of engagement. In the case where the coupling is in sliding engagement along an object or device the engagement may be continuously variable along the device if enough clamping force is applied so that the pin coupling may occur at any position along the device or the arrangement may be of discrete intervals as in the case of spaced alignable holes. [0011] Ordinarily, the pin means will be automatically biased to a pin extended position and manually retracted using the pin retraction mechanism but this need not be the case, it could be manually extended and automatically retracted upon operation of a button, switch or the like or it could be progressively extended and/or retracted under a manual in and out action. For 3 example, the pin means may be extended and retracted using a winding action or a combination of winding and spring actions. [0012] In one preferred embodiment the manually operable pin retraction mechanism uses an actuator, typically a push button, applied to a lever arm so that when the button is pushed the lever arm operates to retract the pin and thereby release the coupling. Preferably, the coupling employs bilateral lever arms and pins so that two opposing pins are simultaneously extended and retracted. The actuator may itself require release as a prequel to its operation to retract the pin means so that the pin means may not be inadvertently retracted by accident. [0013] In one preferred form the actuator is biased to a locked position. Typically, where the actuator is a push button, the button may be turned or twisted to release the button which can then be depressed providing the required manual force to retract the pin(s). In this embodiment the actuator is biased to the locked position. [0014] In a preferred form the coupling comprises a main body with bilateral coupling pins, the main body being formed with a button housing and bilateral lever arm slots, the button being adapted to travel against biasing force provided by springs, respective lever arms being located in the slots, the retraction mechanism being adapted to transmit force applied to the button through the arms to the coupling pins, the lever arms being adapted to pivot about pivot pins, against a biasing force provided by springs so the net effect of the springs is to bias the coupling pins toward a coupled position. Preferably, the main body has a central passage with bilateral coupling pins adapted to extend radially into the passage, the button being adapted to travel radially so that the coupling pins are biassed toward a coupled position and radially toward each other in a pincer action along radial guideways. In a still further prefered embodiment the button is blocked against axial travel until released by a manual release. Preferably, the manual release comprises initial rotation of the button about its axis to a released position where it may then move axially. BRIEF DESCRIPTION OF THE DRAWINGS [0015] In order that the present invention may be more readily understood and put into practical 4 effect reference will now be made to the accompanying drawings which illustrate preferred embodiments of the invention and wherein: Figure 1 is a drawing showing application of a pin coupler according to the invention to a telescopic pole assembly; Figure 2 is a transverse section (with some detail omitted for clarity) through the coupler and telescopic pole assembly of Figure 1; Figure 3 is a is a drawing illustrating another coupler according to the present invention; Figure 4 is an exploded view of the coupler of Figure 3; Figure 5 is a transverse section through an isometric view of the coupler of Figures 3 and 4; Figure 6 is another embodiment of a coupler according to the present invention; Figure 7 is an exploded view of the coupler of Figure 6; Figure 8 is a transverse section shown in isometric view of the coupler of Figures 6 and 7; Figures 9-13 are respective bottom, side, end, isometric and top views of a release mechanism suitable for use with a coupler according to the invention; and Figure 14 is a coupler according to the present invention suitable for use with the release mechanism of Figures 9-13. DESCRIPTION OF EMBODIMENTS [0016] Referring to the drawings and initially to Figures 1 and 2 there is illustrated a telescopic pole assembly 10 comprising an outer tube 11, an inner tube 12 mounted for telescopic movement inside outer tube 11. A retractable pin coupling 13 surrounds the tubes and includes retractable pin means in the form of opposed pins 14 and 15 and a manually operable pin retraction mechanism 16. The pins are cylindrical bodies with rounded ends and can be short long and made from rod material, may have spongy or frictional exterior if used to clamp. The pin retraction mechanism 16 includes a pushbutton 17 and lever arms 18 and 19 so that when the pushbutton 17 is depressed the lever arms 18 and 19 pivot about pivot pins 20 and 21 and the arms 18 and 19 operate to radially retract the pins 14 and 15 thereby releasing the coupling of the tubes 11 and 12. In the illustrated embodiment torsion springs 22 and 23 are used to bias the arms 18 and 19 so that the pins 14 and 15 are normally biased to the extended "coupled" position shown in Figure 2.

5 [0017] In this embodiment the "device" which is being coupled, is a telescopic pole but it will be appreciated that other devices may be coupled using a coupler according to the teachings of the present invention. Likewise the shape of the coupler may be any shape as may be the members or devices being coupled. All that is required is that there be pin mated coupling and a mechanism to operate it. [0018] Each of poles 11 and 12 are shaped or otherwise keyed to one another and/or to the coupling using either flats as at 24 and 25 or otherwise so that pin mated means, in this case holes 26, 27 and 28,29 line up so that pins 14,15 may move to the operative extended position illustrated in Figure 2. [0019] Ordinarily, the outer tube 11 would be fixed in the coupling using concealed screws and the inner tube 12 would have spaced holes 26, 28 at predetermined positions along the inner pole so that it could be adjusted accordingly. On the other hand if the pole was made for a specific purpose as in a transportable structure then there may be only one pair of holes 26,28 and one predesigned position of the inner tube. [0020] Referring now to Figures 3-5 a more detailed description of a second embodiment 30 will be undertaken. In Figures 3-5 a square shaped button 31 is employed, but generally speaking the parts and operation of the embodiment of Figures 1 and 2 are substantially the same as the embodiment of Figure 3. While ever sufficient finger pressure is applied to the buttons the pins will be retracted and as soon as pressure is released the pins will extend through the holes in the tubes as soon as they are aligned, thus there is automatic coupling as soon as the holes come into register. At all other times, the inner tube is free to slide in the outer tube. [0021] As shown, the coupler 30 comprises a main body 32 (half being shown in Figure 5) having a through passage 33 carrying marginal internally threaded sections 34 and 35 so that externally threaded upper and lower collars 36 and 37 may be connected to the main body 32. The collars are optional. This configuration enables the main body to be used with different collars and hence different tubes or other fittings matched to the collars.

6 [0022] An example of this is shown in Figure 4 compared with Figure 1. In Figure 4 the lower collar 37 is different to the lower collar depicted in Figure 1. The lower collar in Figure 1 is suited to a permanently fitted inner and outer tube whereas in Figure 4 the lower collar is configured for engaging a fully extended inner tube but also a releasable inner tube that may be removed from the outer tube and collar. This will be described in greater detail below. [0023] The main body 32 is formed with a button housing 38 and bilateral lever arm slots 39 and 40. The button 31 has a centre plug section 41 which travels in a blind hole or spring well 42 against a compression spring 43. The plug section 41 has a flared end 44 and a slot 45 and the spring 43 and the flared end are retained in hole 42 by a sleeve 46. The slot 45 permits the plug section 41 to compress and be pushed through the hole in the sleeve 46 and be retained therein. The button 31 has a peripheral edge or shoulder 47 part of which abuts the ends 48 and 49 of the respective lever arms 50 and 51. The lever arms 50 and 51 pivot about pivot pins 52 and 53 respectively, against torsion springs 54 and 55 so the net effect of the springs 43, 54 and 55 is to bias pins 56 and 57 radially toward each other in a pincer action along radial guideways 58 and 59. [0024] Each of the pins 56 and 57 has a stub 60, 61 that slides in the slotted ends 62 and 63 of the respective lever arms 50 and 51 as the pins extend and retract. [0025] Referring to Figures 6-8 a third embodiment 64 is illustrated. In general configuration this embodiment is the same as the previous embodiment (where appropriate like numerals illustrated like features) and generally the pins 56 and 57 are extended and retracted using the same mechanical arrangements as described above except for the operation of the button 65. In this embodiment in order to depress the button 65 it must first rotate about its axis 90" giving rise to a twist and push action. Upon release it pops out radially and then spins back 90" to a locked position. [0026] Button 65 has a finger tab 66 which can be gripped to rotate the button while at the same time pushing on it in a radial direction. [0027] In this embodiment the blind hole 42 of the previous embodiment is replaced by an 7 annular hole 67 with a central tongue 68. The button plug 69 has a slot (not visible in the drawings) corresponding to and adapted to slide on the tongue 68 but normally set at 90" to it, when the button is in the rest or locked position and the pins are extended as shown in Figure 8. In this position the button can not be depressed as it is blocked by the tongue 68. The button 65 includes a spring end retainer 70 holding an end of coil spring 71 which operates as a torsion spring so as the button 65 is rotated clockwise, the spring 71 will bias it anti-clockwise. Thus the button is rotated and while under radial finger pressure the slot in the plug 69 will align with the tongue 68 and the button will, under continued radial finger pressure, slide radially tongue in slot and the pins 56 and 57 will retract thereafter, in exactly the same way as previously described in Figures 3-5. As soon as manual pressure is released from button 65 the whole mechanism will be automatically biased back to the locked position with the tongue 68 blocking the button 65. [0028] As mentioned above the lower collar 37 differs from the embodiment of Figures 1 and 2 insofar as the collar 37 has the capacity for a release mechanism 72 according to Figures 9-13 to operate inside the collar 3 and inside inner tube 12. [0029] The release mechanism 72 fits inside the lower end of inner tube 12 and has pins 73 and 74 keyed to project from body 75 through holes in the outer tube and project into holes 76 and 77 of collar 37. Thus the inner tube 12 when fully extended is retained in the collar 37 and automatically locks in place. [0030] A compression spring 78 forces the pins 73 and 74 radially outward against release buttons 79 and 80 which are located beneath release button cover 81. The release buttons have respective springs 82 and 83 so the buttons pop back against the flexible windows 84 and 85 in the release button cover 81. [0031] Each of the pins 73 and 74 has a bevel 86,87 so that as the inner tube is pushed down into the outer tube the bevels cause the pins 73, 74 to retract and the inner tube is free to slide. [0032] If one wishes to completely remove the inner tube the release buttons 79 and 80 are simultaneously depressed thereby pushing in the pins 73 and 74 and the inner tube can be removed. Figure 14 illustrates a modification to the main body exemplified by opposed grooves 8 86 and 87 that are aligned with the previously described embodiments and the grooves 88 and 89 that are aligned with the pins 73 and 74. The main body 90 in Figure 14 operates in all respects in accordance with the previously described embodiments and the grooves 88 and 89 may also be incorporated into the twist lock embodiment of Figures 6-8. [0033] There are many variations on the present invention, and it will be appreciated that the collars are optional and are employed merely to adapt. In addition the main body configuration may slide freely and be used to couple at any location of appropriate pin mating holes. [0034] Likewise if the main body or collars are to be fixed this could be accomplished in any manner. However, it is preferred that concealed fasteners be employed and in the embodiments illustrated grub screws 91, 92 and passing through threaded inserts 93, 94 located behind the push buttons is an example in Figure 4 of how the outer tube may be secured in the main body 32. [0035] Whilst the above has been given by way of illustrative example many variations and modifications will be apparent to those skilled in the art without departing from the broad ambit and scope of the invention as set out in the appended claims.

Claims (17)

1. A retractable pin coupling comprising retractable pin means and a manually operable pin retraction/extension mechanism, the coupling being adapted to be pin coupled to pin mated means on a device to which the coupler is connected when the pin means is in an extended coupling position and the coupling being releasable upon operation of the pin retraction mechanism to retract the pin means to a retracted uncoupled position.

2. A retractable pin coupling according to claim 1 wherein the retractable pin means includes at least two retractable pins.

3. A retractable pin coupling according to any one of the preceding claims wherein, the pins are set in a pincer configuration and are biased to an extended position by biasing means.

4. A retractable pin coupling according to any one of the preceding claims wherein the manually operable pin retraction mechanism comprises a manually operable actuator and an intermediate link between the actuator and the pin(s).

5. A retractable pin coupling according to any one of the preceding claims wherein the manually operable pin retraction mechanism comprises a manually operable actuator lockable in a position corresponding to a pin extended position.

6. A retractable pin coupling according to any one of the preceding claims wherein the pin mated means comprises alignable pin receivers.

7. A retractable pin coupling according to any one of the preceding claims where the coupling is in sliding engagement along an object or device, the engagement being continuously variable along the device using alignable pin receivers located at spaced intervals.

8. A retractable pin coupling according to any one of the preceding claims wherein the pin means is automatically biased to a pin extended position and manually retracted using the pin retraction mechanism. 10

9. A retractable pin coupling according to any one of the preceding claims wherein the coupler comprises a main body having a through passage and upper and lower collars connected to the main body.

10. A retractable pin coupling according to any one of claims 1-8 wherein the coupler comprises a main body with bilateral coupling pins, the main body being formed with a button housing and bilateral lever arm slots, the button being adapted to travel against biasing force provided by springs, respective lever arms being located in the slots, the retraction mechanism being adapted to transmit force applied to the button through the arms to the coupling pins, the lever arms being adapted to pivot about pivot pins, against a biasing force provided by springs so the net effect of the springs is to bias the coupling pins toward a coupled position.

11. A retractable pin coupling according to any one of claims 1-8 wherein the coupler comprises a main body with bilateral coupling pins, the main body being formed with a button housing and bilateral lever arm slots, the button being adapted to travel against biasing force provided by springs, respective lever arms being located in the slots, the retraction mechanism being adapted to transmit force applied to the button through the arms to the coupling pins, the lever arms being adapted to pivot about pivot pins, against a biasing force provided by springs so the net effect of the springs is to bias the coupling pins toward a coupled position.

12. A retractable pin coupling according to any one of claims 1-8 wherein the coupler comprises a main body having a central passage with bilateral coupling pins adapted to extend radially into the passage, the main body being formed with a button housing and bilateral lever arm slots, the button being adapted to travel radially against biasing force provided by springs, respective lever arms being located in the slots, the retraction mechanism being adapted to transmit force applied to the button through the arms to the coupling pins, the lever arms being adapted to pivot about pivot pins, against a biasing force provided by springs so the net effect of the springs is to bias the coupling pins toward a coupled position and radially toward each other in a pincer action along radial guideways.

13. A retractable pin coupling according to any one of the preceding claims wherein the retraction mechanism includes a press button and the button is blocked against travel until 11 released by a manual release.

14. A retractable pin coupling according to any one of claims 1-11 wherein the retraction mechanism includes a press button and the button is blocked against axial travel until released by a manual release, the manual release comprising an initial rotation of the button about its axis to a released position where it may then move axially.

15. A telescopic post assembly comprising inner and outer telescopic sections, each section having alignable pin mated means and a retractable pin coupling according to any one of the preceding claims.

16. A retractable pin coupling substantially described with reference to any one of the accompanying drawings.

17. A telescopic post assembly substantially as described with reference to Figures 1 and 2 of the accompanying drawings. DATED this 12th day of April 2013 Hany Salama By his Patent Attorneys INTELLEPRO