GB2032326A

GB2032326A - Nail driving machine

Info

Publication number: GB2032326A
Application number: GB7932364A
Authority: GB
Original assignee: ZAMBAS C
Current assignee: ZAMBAS C
Priority date: 1978-09-19
Filing date: 1979-09-18
Publication date: 1980-05-08
Also published as: GB2032326B; CY1207A

Abstract

An endless conveyor 14 has pusher bars 16 at spaced intervals therealong which transport first components 10 deposited on the conveyor by a first magazine 18 to a second magazine 20 where one or more second components 12 are deposited on the first component or components. Thereafter the conveyor transports the components to a working station where they are clamped by a clamping block 62 and nailed together by driving rods 64 driven by a flywheel 22 in synchronism with the conveyor 14. Nails, pins or the like are dispensed from a storage box 28 to the driving rods 64 along guides (not shown) in synchronism with the operation of the rods 64. <IMAGE>

Description

SPECIFICATION Nail driving machines The present invention relates to a nail driving machine and in particular to such a machine for manufacturing crates, trays, boxes or the like or parts thereof. Such trays may be used for example for the storage and/or transport of fresh fruit and vegetables. The invention relates also to an apparatus for presenting nails, screws or the like to a working station at, for example, a nail driving machine.

Hitherto, the wooden crates used for storage and/or transport of fresh fruit or vegetables have been assembled manually. This is clearly an expensive and time consuming operation.

In accordance with one aspect of the present invention there is provided a nail driving machine which comprises an endless conveyor having a plurality of pusher bars arranged in spaced apart relationship along the length thereof, a first magazine arranged to hold a plurality of first components to be nailed and to discharge the components, one or more at a time, onto said conveyor, a second magazine spaced from the first magazine and arranged to store a plurality of second components to be nailed to said first component or components, and to discharge same one or more at a time onto said conveyor with the second component or components aligned with the first component or components, said components being transportable on said conveyor by way of said pusher bars to a working position, said working position including clamp means operative to hold the first and second components in clamped relationship, nail guiding means for guiding nails, pins or the like into nailing positions, and respective driving rods, one for each nail and operative to drive the nails through the first and second components.

The first magazine may be of inverted V-shape configuration and arranged to deposit two of said first components at a time on either side of the endless conveyor. The deposited first components are then transported by the pusher bars to the second magazine which may deposit a single component across the first two components and in overlying relationship thereto, the pusher bar continuing to transport both the first and second components to the working position of the nail driving machine.Where the first components are of generally triangular cross-section, guide members having an inclined surface profiled to that of the first components may be provided adjacent to the edges of the endless conveyor to guide the first components towards the working position, The nail guiding means may comprise a plurality of tubes, one for each nailing position, arranged to deliver said nails, pins or the like in seriatim fashion from a storage device to the nailing positions in synchronism with mqvement of the endless conveyor.

The driving rods may be resiliently mounted upon a driving block to transmit a driving force smoothly from a drive source, such as a drive head to the driving rods.

In accordance with another aspect of the present invention there is provided apparatus for presenting fastening components.(such as nails, screws or the like) to a working station, said apparatus comprising a storage device forthefastening components which is pivotable between a first position in which the fastening components lie in a storage position and a second position i.n which respective ones of the fastening components are caused to pass along a plurality of slots to a dispensing position, means being provided for retaining a plurality of said fastening components at said dispensing position for dispensing one at a time from each slot, and a profiled member lying transverse to said slots and movable laterally with respect thereto, said profiled member having a plurality of first apertures for receiving respective individual fastening components from said slots when the storage device lies in its second position and for transporting said fastening components to a dispensing location where they are passed through guides to respective fastening positions. In a preferred embodiment of the invention the guides are tubes made, for example, of plastics material.

The invention will now be described further by way of example with reference to the accompanying drawings in which: Figure 1 shows part of a fruit or vegetable tray which may be manufactured by means of the nail driving machine of the present invention, Figure 2 shows a completed tray, Figure 3 is a side elevational view of a nail driving machine in accordance with one embodiment of the present invention, Figure 4 is an elevational view of a nail supply mechanism for use with the nail driving machine shown in Figure 3, Figure 5 is a sectional elevation of part of the nail supply mechanism shown in Figure 4, Figure 6 is a plan view of the mechanism shown in Figures 4 and 5.

Figure 7 and 8 illustrates part of the mechanism shown in Figure 6 to an enlarged scale, and Figure 9 shows the nail driving mechanism as used in the nail driving machine as shown in Figure 3.

The nail driving machine of the present invention may be used to drive nails, pins, screws or the like into blocks, normally wooden blocks, to produce structures such as wooden crates, trays or boxes as used for example for the transportation of fresh fruit and vegetables. Atypical vegetable tray which may be produced with a nail driving machine in accordance with the invention is shown in Figure 2, part of the tray during construction being illustrated in Figure 1.

The nail driving machine consists essentially of three sections: (a) a horizontal chain conveyor 14 having a plurality of pusher bars 16 spaced therealong, each pusher bar being arranged to collect components to be nailed together from respective magazines 18 and 20 therefor and deliverthem to a main nailing section, (b)- a nail supply mechanism which delivers a nail to each of a plurality of nailing positions prior to operation of the main nailing section, and (c) a main nailing or nail driving section which, by means of a vertical downward reciprocating stroke, drives the nails presented by the nail supply mechanism into the components to be nailed which are at that moment clamped in position to a base of the machine.It is to be understood that the horizontal chain conveyor, the nail supply mechanism and the main nailing section are driven in synchronism.

The chain conveyor 14 is driven from a flywheel 22 through a linkage 24 and a ratchet wheel 26 in a step wise manner, the linkage 24 being pivotally connected to the flywheel 22 at a point 40. Forward movement of the conveyor in the direction of the arrow A is brought about during half of the cycle of the ratchet wheel 26, the conveyor being stationary for the other half of the cycle whilst nailing occurs.

The flywheel 22 is itself driven from an electric motor (not shown) by way of a gear speed reducer (not shown) and two sets of V belts. Upon energization of the motor, a drive pulley thereof rotates continuously at a constant speed such as 36 rpm.

The flywheel 22 is coupled to the chain conveyor by way of a clutch (not shown). The clutch is foot-operated via a pedal and a linkage which, when operated, directly engages the drive pulley with a crank shaft of the flywheel. Once the pedal is depressed, the crank shaft remains coupled to the drive pulley for one complete revolution of the crank shaft thus completing one full machine cycle. If the foot pedal is permanently depressed, the machine will run continuously but in a stepwise manner. At the completion of each cycle, the machine reaches a condition in which the nail driving section is at a top dead centre position to be described.

In the illustrated embodiment of the invention the pusher bars 16 are angled iron bars which extend across the full width of the conveyor and which are fixed at right angles to be direction of movement thereof. The Magazine 18 is in the form of an inverted V and, when a pusher bar passes the magazine it collects components, two pegs 10, therefrom which are deposited on either side of the conveyor. The pegs are carried by the relevant pusher bar towards the second magazine 20 where a second component, a single side panel 12, is col lected by the pusher bar so that the side panel lies in overlapping relationship with the previously depo sited pegs 10. The pegs and side panel are then transported towards the nail driving section for nailing.As can be seen to advantage in Figures 1 and 2, the pegs 10 are of generally triangular crosssection; guide members (not shown) having an inclined surface profited to that of the pegs 10 are provided adjacent to the edges of the conveyor to guide the pegs towards the nail driving section.

The nail supply mechanism includes a storage device in the form of a metal box 28 in the base of which there are a plurality of slots 30 (figures 6 and 7) which are each of a width to receive a nail shank as a sliding fit. The box is tiltable between a first position, as shown in Figure 4, in which the nails are held within the body of the box and a second or operative position in which the box is tilted and inclined relative to the position shown in Figure4to free one nail from each slot to enable that nail to be passed to a respective nailing position. Tilting is achieved by means of a linkage which includes two arms 34 which are pivoted together at 36, one end of one arm 34 being pivoted to a projection 38 on the bottom of the box 28 and the other arm being pivoted at 40 to the flywheel 22.A shock absorber 42 extends between the projection 38 and a fixed reference point 44 to dampen vibration of the nail box during movement.

In operation, at the commencement of a nailing cycle the linkage 24 is arranged with the pivot point 40 at the bottom dead centre of the flywheel 22. As the flywheel commences to rotate in an anticlockwise direction as indicated by an arrow in Figure 4, the nail box is gradually raised and tilted forward into a plan of about 45C relative to the horizontal plane. During up and down movement of the box the nails are held at the rear end of the box by a separating plate 46 which may best be seen in FigureS.

Random movement of the nails within the box causes a number of nails to be caught inside the slots 30 with their shanks pointing downwardly thus forming six queues of nails which are required for feeding to the nail driving mechanism. The nails which do not manage to find their correct way in the slots return to the back of the box for subsequent attempts at falling into the slots during the following cycles.

At the front of the box adjacent the separating plate 46 are six small resilient fingers 34 which permit forward movement of the nails in their respective slots but which retain the first 10 to 12 nails in position following tilting to prevent them from returning to store in the nail box.

The separating plate 46 is movable transversely to the direction of the slots 30 as the mechanism moves through one cycle. The mechanism for achieving this is shown in Figure 6 from which it will be seen that a cam profile 48 and a follower 50 transmit the desired position of the plate 46 relative to the nail box through a link 52. Contact of the follower onto the fixed profile is effected by means of a spring 54 which pushes the plate 46 to its leftmost position.

The plate 46 has six semi-circular gaps 56 and adjacent thereto, six further but smaller semicircular gaps 58. There are also six gaps 60 corresponding to the gaps 58 at the interface between the base of the nail box and the plate 46. As will be seen, the nail heads are of a size sufficient to fit within the matched gaps 58, 60 with their shanks depending below whereas the nails, including their nail heads will pass freely through the large semi-circular gaps 56.

When the machine is in its initial position, the position of the plate 46 relative to the queues of nails is as shown in Figure 7. The queues of nails are blocked and there is one nail which has been guided into each gap 60 by the corresponding smail gap 58 in the plate 46. As the machine proceeds through its operating cycle, the box goes through the horizontal position and subsequently tips forward, the plate 46 moves progressively to the right and, at a half cycle position, the large gaps 56 in the plate 46 are aligned with the gaps 60 as may be seen from Figure 8.

This causes the six nails to fall vertically, under gravity, as the nail box is tilted forwards and down corresponding guides or chutes (preferably in the form of plastics tubes) which guide them to the nailing positions. At this instant, the gaps 58 are aligned with the nail queues and each picks up the first nail from the queue. As the mechanism enters its next half cycle, the movements are reversed and the plate 46 guides the picked up nails from the queues into the corresponding gaps 60 on the base of the nail box whilst the box assumes its original position ready for the next cycle.

The nail driving mechanism consists essentially of a clamping block 62 (Figure 3) and driving rods 64 which are received as pistons within the clamping block. As the mechanism moves downwardly by rotation of the flywheel 22, the clamping block 62 clamps the pegs and side panel 10 and 12 respectiveliy which have been presented for nailing. Thus the pegs and side panels are held in a correct position ready for nailing. Six nails are then guided to the positions illustrated at C in Figure 1 and subsequently the driving rods 64 start to press the nails into the blocks at right angles to the wooden surface. More details of this arrangement are shown in Figure 9 from which it will be seen that a driving block 66 which is fixed tithe crank mechanism provides the force needed to drive the nails into the parts 10 and 12.The downward travel of the block 66 is always the same, this being determined by the geometry of the crank mechanism.

Force is transmitted to the driving rods 64 through a modulating member in the form of a rectangular plate 68 and through springs 70. The plate 68 is held in contact with the driving block 66 through a rod 72 approximately in the middle of the plate and which permits swiveling, and through an oval shaped modulating cam 74. The plate 68 exerts a force on the top of the driving springs 70 which is then transmitted to the driving rods by means of an abutment 76 on the driving rods.

The force with which the nails penetrate the wooden parts is determined by the stiffness of the springs and this can be regulated by means of adjusting nuts 78 according to the hardness of the wood being made up into boxes, crates, or the like. It has been found that the correct adjustment for a given wood thickness is such that the force exerted is sufficient to drive the nails right into the wooden block but is insufficient to cause undesirable penetration of the tips of the rods into the block thus causing cracks and damage. However, if a somewhat thicker wooden block is to be nailed, penetration of the tips of the rods would be inevitable since the force exerted on the rods would be determined by the compression of the driving springs.

By incorporating a probe or guide rod 80 and its associated linkage to the modulating cam 74, the above mentioned defect may be overcome. Wherever there is a thicker block to be nailed, as the plate moves downwards, the guide rod 80 senses the extra thickness involved and causes a rotation of the modulating cam thus displacing the plate 68, increasing the distanced, decreasing the distance t, and releasing the force exerted by the plate 68 on the driving springs 70. The new position of the plate 68 regulates the force on the nails according to the extra thickness of the blocks thus avoiding unnecessary nail penetration and damage.

It will be understood that once the pegs and side panel have been nailed together in the manner described, the nailed assembly thus produced is removed by means of the pusher bars. One end of a tray is then complete. The other sides of the tray and the tray base may then be nailed to two of the nailed assemblies to complete a tray.

Claims

1. A nail driving machine comprising an endless conveyor having a plurality of pusher bars arranged in spaced apart relationship along the length thereof, a first magazine arranged to hold a plurality of first components to be nailed and to discharge the components, one or more at a time, onto said conveyor, a second magazine spaced from the first magazine and arranged to store a plurality of second components to be nailed to the first component or components, and to discharge same one or more at a time onto the conveyor with the second component or components aligned with the first component or components, the components being transportable on the conveyor by way of the pusher bars to a working position, the working position including clamp means operative to hold the first and second components in clamped relationship, nail guiding means for guiding nails, pins or the like into nailing positions, and respective driving rods, one for each nail and operative to drive the nails through the first and second components.

2 A nail driving machine as claimed in claim 1, wherein the nail guiding means comprises a plurality oftubes, one for each nailing position, arranged to deliver said nails, pins or the like in seriatim fashion from a storage device to the nailing positions in synchronism with movement of the endless conveyor.

3. A nail driving machine as claimed in claim 1, wherein the tubes are made of plastics material.

4. A nail driving machine as claimed in claim 1,2 or 3, wherein the driving rods are resiliently mounted on a driving block to transmit a driving force smoothly from a drive source.

5. A nail driving machine as claimed in any preceding claim, wherein the working position further includes adjustment means arranged to adjust the driving force of the driving rods automatically in accordance with the thickness of the components to be nailed.

6. A nail driving machine as claimed in claim 5, wherein the driving rods are biassed by springs in a nail driving direction, and the adjustment means is arranged to adjust the biassing force of the springs in accordance with the thickness of said components.

7. A nail driving machine as claimed in claim 6, wherein the driving rods are mounted on a driving block, the springs act between the driving rods and a modulating member, and the adjustment means includes a probe which is arranged to sense the thickness of the components to be nailed and to adjust the position of the modulating member relative to the driving block in accordance therewith.

8. A nail driving machine as claimed in any preceding claim, wherein said nails, pins or the like are fed to the nailing positions from a storage device which is pivotable between a first position in which said nails, pins or the like lie in a storage position and a second position in which respective ones of said nails, pins or the like are caused to pass along a plurality of slots to a dispensing position, means being provided for retaining a plurality of said nails, pins or the like at the dispensing position for dispensing one at a time from each slot and a profiled member lying transverse to the slots and movable laterally with respect thereto, the profiled member having a plurality of first apertures for receiving respective individual nails, pins or the like from the slots when the storage device lies in its second position and for transporting the nails, pins orthe like to a dispensing location upon lateral movement of the profiled member.

9. A nail driving machine as claimed in any preceding claim, wherein the first magazine is of inverted V-shape configuration and is arranged to deposit two of the first components at a time on either side of the conveyor.

10. A nail driving machine as claimed in any preceding claim, wherein guide members having an inclined surface profiled to that of the first components are provided adjacent to the edges of the conveyor to guide the first components towards the working position.

11. Apparatus for presenting fastening components to a working station, comprising a storage device for the fastening components which is pivotable between a first position in which the fastening components lie in a storage position and a second position in which respective ones of the fastening components are caused to pass along a plurality of slots to a dispensing position, means being provided for retaining a plurality of said fastening components at the dispensing position for dispensing one at a time from each slot, and a profiled member lying transverse to the slots and movable laterally with respect thereto, the profiled member having a plurality of first apertures for receiving respective individual fastening components from the slots when the storage device lies in its second position and for transporting said fastening components to a dispensing location where they are passed through guides to respective fastening positions.

12. Apparatus as claimed in claim 11, wherein the guides are tubes.

13. Apparatus as claimed in claim 12, wherein the tubes are made of plastics material.

14. A nail driving machine substantially as hereinbefore described with reference to Figures 3 to 9 of the accompanying drawings.

15. Apparatus for presenting fastening components to a working station, substantially as hereinbefore described with reference to Figures 4 to 8 of the accompanying drawings.