GB2155834A - Rivet presenting apparatus - Google Patents

Abstract

The apparatus presents pull-type blind-riveting assemblies delivered one-by-one along a hose 70 to a uniform position for pick-up by a rivet setting tool H. It includes a venturi arrangement 54, 56, 58, 60 in the base 10 of the apparatus, in which air supplied through a hose 68 draws the assemblies along the hose 70 and a passage 52 and holds them in the presenting position A. Two guide members 18 are pivotally mounted to provide a gate when closed together with a funnel 48 to guide the assemblies into the presenting position. The gate is urged open by a spring-pressed plunger 36 and closed by a bridge piece 22 which is depressed by the nosepiece 4 of the setting tool. <IMAGE>

Description

SPECIFICATION Fastener presenting apparatus This invention is concerned with apparatus for presenting pull-type blind riveting assemblies for pickup by the nosepiece of a rivet setting tool comprising a supporting base having a passage through it along which riveting assemblies travel mandrel stem foremost under the influence of a forwardly flowing air current upon release one-by-one for travel along a hose from a raceway, gate means arranged to arrest each assembly and position it in uniform orientation at a pick-up locality, means for bringing together (or ensuring that they are brought together) the gate means and the nosepiece of a setting tool with the mandrel-receiving hole in the nosepiece in a position to receive a mandrel from the gate means at the pick-up locality, and means responsive to relative movement between the base and a setting tool for opening the gate means and allowing an assembly held thereby to be released for transfer to the tool; it is such apparatus that is meant by the expression "fastener presenting apparatus of the kind referred to" where it is used hereinafter.

Fastener presenting apparatus of the kind referred to has been proposed for supplying blindriveting assemblies to hand-held setting tools and in British patent specification 1278845 for example for supplying them to automatic bench-mounted tools, but such proposals have not generally resulted in widespread use of such apparatus. Contemporary efforts have also been directed to feeding blind-riveting assemblies automatically directly to the rivet setting tools themselves rather than to an independent presenting apparatus with which the tools are to co-operate.

It is desirable that for the automatic feeding of blind-riveting assemblies to hand-held or benchmounted tools, the supply and transfer of assemblies shall be very reliable and the apparatus inexpensive, robust and simple enough not to require undue down-time for maintenance. Reliability of delivery of blind-riveting assemblies depends not only, in the case of a presenting apparatus, on reliability of release of an assembly in the apparatus itself but also on the reliability of delivery of assemblies to the apparatus, which has sometimes hitherto depended on assemblies being blown under air pressure along a length of hose.Blowing of air along a hose to propel blind-riveting assemblies from a hopper to rivet-setting or rivet assembly pick-up means not only involves the possibility of unduly high air consumption or loss of sufficient air flow to maintain propulsion of the assemblies at the delivery end of the apparatus but also the risk of turbulence in the hose resulting in less than full control over the disposition of the assemblies during conveyance.

It is an object of the present invention to provide an improved apparatus for presenting pull-type blind-rivet assemblies to setting tools which includes a hose through which the assemblies travel to the apparatus and which is simple, inexpensive and reliable.

The invention provides fastener presenting apparatus of the kind referred to in which the gate means comprises a pair of guide members individually pivoted upon the supporting base of the apparatus and arranged, when brought into closed abutting engagement with one another, to define a funnel in which an assembly emerging from said passage will be brought to rest with its mandrel confined by the narrow end of the funnel, the apparatus also comprising a spring-pressed plunger arranged to bear against the guide members to urge them resiliently open, and a gate-operating member engageable by the nosepiece to control opening and closing of the gate means.

Preferably, in an apparatus as set out in the last preceding paragraph, the guide members are pivoted about parallel axes lying in a direction at right angles to the stem of a mandrel confined by the members as aforesaid, and the gate-operating member is slidable on said supporting base and has an aperture at one end of which the guide members of the gate means are resiliently urged against the gate-operating member under the influence of the spring-pressed plunger. At the other end of said aperture, the member is conveniently shaped to receive and position the nosepiece of the setting tool.

Preferably also, in apparatus as set out in the last preceding paragraph but one, said passage of the base is provided in a sleeve, and said plunger is slidable on said sleeve and urged towards the guide members by a coiled compression spring surrounding said sleeve, and a stop adjustably mounted on said plunger is arranged, when the plunger retracts upon closing of the guide members, to initiate delivery of an assembly along said passage. Preferably also, where the gate means is closed by movement of the gate-operating member towards its, means is provided for adjustably limiting movement of the gate-operating member towards the gate means so as to vary the separation of the guide members according to the diameter of mandrel stem of the blind-riveting assemblies.

There now follows a detailed description, to be read with reference to the accompanying drawings, of fastener presenting apparatus of the kind referred to embodying the invention. This apparatus has been selected for description to illustrate the invention by way of example and not of limitation.

in the accompanying drawings: Figure l is a side view of the illustrative apparatus with parts broken away; Figure 2 is a view similar to Figure 1 though largely in longitudinal section and showing a blindriveting assembly about to be delivered to a nosepiece of a rivet-setting tool.

The illustrative apparatus comprises a supporting base 10 conveniently mounted on the side of a bench 12 and having two vertical up-standing pil lars 14. The pillars 14 have co-planar vertical faces 16 against which two guide members 18 of gate means of the apparatus are pivoted on pins 20. Reduced diameter upper end portions of the pillars 14 provide vertical sliding support for a gate-operating member in the form of a bridge-piece 22 which rests (as hereinafter described) on the guide members and is prevented from being lifted off the pillars by washers 24 secured by screws 26 at the tops of the pillars.

A central vertical bore 30 in the supporting base 10 accommodates a flange 32 of a vertical sleeve 34 which projects upwardly between the pillars 14 and slidably supports a tubular plunger 36. A coiled compression spring 38 surrounding the sleeve and acting between the flange 32 and the plunger 36 constantly urges the plunger upwardly into engagement with the guide members 18, and thus the guide members into engagement with the bridge-piece 22.

The guide members 18 have a closed condition (shown in Figure 2) in which flat faces 40 (Figure 1) of each abut one another and the two members are disposed to form an inverted "V"; they assume this closed condition when the bridge-piece 22 is depressed against the resilience of the spring 38. A cylindrical hole 42 through the bridge piece 22 terminates at a rounded lower edge 44 for engagement with the outer edges of the guide members, and has a conical mouth 46 at its upper side to receive and position a complementarily shaped nose housing H of a rivet-setting tool. Each guide member 18 is rectangular in cross-section, but its abutment face 40 is relieved by a conical groove 48, narrowing upwardly, so as to provide a funnel to guide the mandrel stem of a blind-riveting assembly A when the members 18 are in their closed condition.

The lower end of the bore 30 is counterbored at 49 to receive a flange of a venturi arrangement in the form of a commercially available vacuum pump, which comprises a flanged sleeve 50 having an upper bore portion 52 of the same diameter as the bore in the sleeve 34 and an enlarged lower bore portion 54. In the lower bore portion 54 is a flanged tubular boss 56 having an upper portion of reduced diameter to provide an annular space 58 between the boss and the sleeve; this annular space is restricted at its upper end by an annular rib 60 of the boss while at its lower end holes 62 in the wall of the sleeve 50 communicate with an annular groove 64 in the wall of the bore 30 of the base 10.To this groove 64 there leads a port 66 through which air under pressure can be supplied through a hose 68.ql The fianges of the sleeve 50 and boss 56 are secured in the counterbore 49, which is screw-threaded, by a nut 65 which also bears on a flange of a tubular nipple 66 on to which is securely pressed an end portion of a delivery hose 70 leading from a raceway and escapement mechanism (not shown, as they may be of conventional construction). The nipple 66 has a splayed mouth 72 which provides an external rim to ensure retention of the hose and a smooth inner surface which merges with that of the hose to facilitate passage of blind-riveting assemblies, mandrel stems leading, to the vacuum pump.

The nipple 66 and the sleeves 50 and 34 provide a continuous passage leading to the plunger 36 and guide members 18 for blind-riveting assemblies. Air admitted through the hose 68 passes through the annular space 58, past the restriction by the rib 60 and into the bore 52, where eddy currents result in a venturi effect drawing air from the hose 70. The air is expelled through holes 74 in a forward portion of the wall of the sleeve 34 near the plunger 36.

Initiation of air flow from the hole 68 occurs, in the operation of the illustrative apparatus, on actuation of a valve (not shown) in response to depression of a plunger 76 (Figure 1) of an electric switch 78 secured to the base 10. This plunger is engaged by an adjustable stop 80 locked by a nut 82 in a tapped hole in a bracket 84 integrai with the plunger 36.

In the operation of the illustrative apparatus, a conical end portion of a nose housing H (Figure 2) of a blind-riveting tool is thrust into the conical mouth 46 of the bridge-piece 22, and the bridgepiece is depressed against the resilience of the spring 38 to close the guide members 18 and actuate the switch 78 both to initiate air flow through the vacuum pump and to release a blind-riveting assembly A into the hose 70. The venturi arrangement, aided by rearward flow of air (as is conventional) in the rivet setting tool conveys the blindriveting assembly mandrel stem leading into the position shown in Figure 2 where it is arrested by engagement of the closed guide members 18 by the rivet head with the mandrel stem in alignment with the nosepiece P of the setting tool, and projecting into it.Alignment is assured by the grooves 48 of the guide members and by the conical mouth 46 of the bridge-piece 22 which positions the housing H.

So long as the bridge-piece 22 remains depressed, the guide members 18 remain closed and the assembly A remains captive in the nosepiece P because of the rearward flow of air in the rivet setting tool. Upon retraction of the setting tool, the bridge-piece rises under the influence of the spring 38 urging the plunger 36 upwards and the guide members 18 apart to allow the rivet head to pass between them. The plunger 36 has converging upper faces which bear on the guide members to facilitate this movement. The now loaded rivet setting tool is thus ready for a rivet setting operation.

The illustrative rivet assembly presenting apparatus is robust, simple enough for economical manufacture and reliable both in ensuring the delivery of assemblies from the hose 70 and their presentation to the setting tool. In particular, there is no obstruction to passage of the assemblies through the apparatus until they are arrested by the guide members 18. The illustrative apparatus is economical in the use of air, which is demanded only during periods of delivery.

The illustrative apparatus can accommodate different sizes of blind-riveting assemblies, being capable of adjustment for different diameters of mandrel stems by varying the distance apart of the abutting faces 40 of the guide members 18 when in their closed condition. For the thinnest mandrel stems, the members 18 abut as shown in Figure 2 and as hereinbefore described. For thicker mandrel stems, annular spacers (not shown) would be placed at the lower ends of the reduced upper end portions of the pillars 14 so as to limit the downward movement of the bridge-piece 22 and thus the extent to which the guide members would close when positioning a nosepiece in the conical mouth 46 of the bridge-piece; the faces 40 of the guide members 18 would thus remain apart by a suitable distance to allow the mandrel stem to pass into the nosepiece of the setting tool.

The illustrative apparatus has been described as being secured on a bench with the sleeves 34, 50 vertical such a disposition is especially convenient where, for example, the setting tool is also mounted on the bench with provision for movement between a loading position in which the nose housing is received in the conical mouth 46 of the bridge-piece 22 and a rivet-setting locality. But it will be realised that the illustrative apparatus does not have to be fixed nor does it have to be vertical.

The base 10 can be held in the hand for manual presentation to a number of static tools, or it can be mounted to move to and away from one or more static tools; or it can be fixed in any suitable disposition.

It will be observed that, because a blind-riveting assembly is released and the air flow to deliver it initiated in the operation of the illustrative apparatus only when the guide members are closed, and the air supply is cut off as soon as they are open, there is no possibility of blind-riveting assemblies being accidentally projected from the apparatus.

Such a safety factor against the risk of injury is especially desirable in an apparatus which propels the assemblies with their mandrel stems, i.e. their sharp ends, leading.

Because, in the illustrative apparatus, the venturi arrangement is located in the base 10 close to the point of presentation of the assembly, not only is delivery of the assemblies through the hose 70 assured, but if desired, to speed up the rate of delivery, the escapement for releasing assemblies one at a time could be located near the base 10 rather than at the other end of the hose 70, and assemblies arranged to advance along the hose to a position close to the escapement at another time in readiness for immediate delivery on actuation of the switch 78.

Claims (11)

1. Apparatus for presenting pull-type blind riveting assemblies for pick-up by the nosepiece of a rivet setting tool comprising a supporting base having a passage through it along which riveting assemblies travel mandrel stem foremost under the influence of a forwardly flowing air current upon release one-by-one for travel along a hose from a raceway, gate means arranged to arrest each assembly and position it in uniform orientation at a pick-up locality, means for bringing together (or ensuring that they are brought together) the gate means and the nosepiece of a setting tool with the mandrel-receiving hole in the nosepiece in a position to receive a mandrel from the gate means at a pick-up locality, and means responsive to relative movement between the base and a setting tool for opening the gate means and allowing an assembly held thereby to be released for transfer to the tool, characterised in that the gate means comprises a pair of guide members individually pivoted upon the base and arranged, when brought into closed abutting engagement with one another to define a funnel in which an assembly emerging from said passage will be brought to rest with its mandrel confined by the narrow end of the funnel, a spring-pressed plunger arranged to bear against the guide members to urge them resiliently open, and a gate-operating member engageable by the nosepiece to control opening and closing of the gate means.

2. Apparatus according to claim 1 in which the guide members are pivoted about parallel axes lying in a direction at right angles to the stem of a mandrel confined by the members as aforesaid.

3. Apparatus according to either one of claims 1 and 2 in which the gate-operating member is slidable on said base and has an aperture at one end of which the guide members of the gate means are resiliently urged against the gate-operating member under the influence of the springpressed plunger.

4. Apparatus according to claim 3 in which, at the other end of said aperture, the member is shaped to receive and position the nosepiece of a setting tool.

5. Apparatus according to any one of claims 1 to 4 in which said passage of the base is provided in a sleeve, and said plunger is slidable on said sleeve and urged towards the guide members by a coiled compression spring surrounding said sleeve.

6. Apparatus according to any one of claims 1 to 5 comprising a stop adjustably mounted on said plunger and arranged, when the plunger retracts upon closing of the guide members, to initiate delivery of an assembly along said passage.

7. Apparatus according to any one of claims 1 to 6 comprising a suction-creating venturi arrangement in said base to create a forward flow of air through said passage.

8. Apparatus according to claim 7 in which at a rear end adjacent a hose through which assemblies are delivered to the base, said sleeve has an enlarged bore in which is accommodated a tubular boss of less length than the enlarged bore so as to provide therearound an annular space through which air can reach the passage from a source of air under pressure, a restriction being provided in said annular space and the arrangement being such that a venturi effect results from the admission of air under pressure creating a forward flow of air through said passage.

9. Apparatus according to claim 8 in which said sleeve has openings in its wall nearer the slidable plunger to facilitate the escape of air.

10. Apparatus according to any one of claims 1 to 9 comprising means for adjusting the limit of movement of the gate-operating member towards the gate means so as to vary the separation of the guide members according to the diameter of mandrel stem of the blind-riveting assemblies.

11. Fastener presenting apparatus constructed arranged and adapted to operate substantially as hereinbefore described with reference to the accompanying drawings.