Automatic rivet loading module

An automatic rivet loading module which includes a pusher mechanism, a gripper mechanism, a mandrel receptacle, mechanisms for moving mandrels in the mandrel receptacle, and a tool activation device. The gripper mechanism receives a rivet, and a mandrel is moved through the rivet such that the rivet threads onto the mandrel. The gripper mechanism moves out of the way while the pusher mechanism pushes the mandrel down. The pusher mechanism then retracts, and the gripper mechanism closes and is ready to receive another rivet. This process is repeated until the mandrel is full of rivets. The mandrel receptacle is rotatable such that the loaded mandrel swings to a position under the tool activation device to be loaded into a rivet tool. As the loaded mandrel is swung under the tool activation block, a new mandrel is swung under the gripper mechanism, in position for loading with rivets.

BACKGROUND

This invention generally relates to tools and methods for loading rivets into a rivet gun, and more specifically relates to an automatic rivet loading device and a method of automatically loading rivets.

A speed rivet is a tubular fastener consisting of a flange and a stem. The fastener is placed on a mandrel, which is a wire with a bulb on the end. The speed rivet is strung on the mandrel with the stem directed towards the bulb of the mandrel. The rivet tool is a device that holds the mandrel and pulls the mandrel through the rivet, causing the rivet to expand in diameter. The expansion process causes the rivet to expand in a hole in a workpiece, causing the components to lock together. The significance of the speed rivet is that it can be used and installed from one side of the assembly. The speed rivet is also special in that it does not incorporate a break stem which leaves part of the broken off mandrel in the rivet. A typical rivet tool holds a string of up to 60 rivets on one 20 inch long mandrel, and as one rivet is “broached” at the nose of the gun, the next rivet is moved up, ready to use. Hence, a typical rivet tool needs to be reloaded by stringing a new load of rivets on the mandrel.

Despite the fact that it is advantageous to be able to load rivets into a rivet gun, especially in the case where the rivet gun is a manual tool, the methods which are typically used to insert rivets into a rivet gun are time consuming for the operator. Typical methods which have been used to load rivets into a rivet gun have been unsuccessful due to one or more of the following, depending on the method: the high cost of replacement parts; the high maintenance time and high custom component costs; the high maintenance down time of the tooling; the long length of time it takes to reload the rivet gun; the weight of the tool is too heavy and is at the top end of ergonomic specifications; and the distance from the reload station to the placing tool is too great.

OBJECTS AND SUMMARY

An object of an embodiment of the present invention is to provide a rivet loading module which is fully automatic, highly reliable, lightweight and very fast.

Another object of an embodiment of the present invention is to provide a rivet loading module which allows twelve inches of rivets (such as forty to sixty rivets, depending on length) to be inserted into a rivet tool in four to six seconds.

Another object of an embodiment of the present invention is to provide a rivet loading module which allows an operator to make more joint fastenings in a given amount of time, compared to a typical rivet loading mechanism.

Briefly, and in accordance with at least one of the foregoing objects, an embodiment of the present invention provides an automatic rivet loading module which includes a pusher mechanism, a gripper mechanism, a mandrel receptacle, mechanisms for moving mandrels in the mandrel receptacle, and a tool activation device or block. The gripper mechanism is configured to receive a rivet, and a mandrel is moved in the mandrel receptacle through the rivet such that the rivet threads onto the mandrel. The gripper mechanism is configured to move out of the way while the pusher mechanism pushes the mandrel down. The pusher mechanism then retracts, the gripper mechanism closes and is ready to receive another rivet. This process is repeated until the mandrel is full of rivets. The mandrel receptacle is rotatable such that the loaded mandrel swings to a position under a tool activation block to be reloaded into the rivet tool. As the loaded mandrel is swung under the tool activation block, a new, empty mandrel is swung under the gripper mechanism, position for loading with rivets using the gripper and pusher mechanisms.

DESCRIPTION

While the present invention may be susceptible to embodiment in different forms, there is shown in the drawings, and herein will be described in detail, an embodiment thereof with the understanding that the present description is to be considered an exemplification of the principles of the invention and is not intended to limit the invention to that as illustrated and described herein.

The automatic rivet loading module20shown in the FIGURES is in accordance with an embodiment of the present invention, and as shown inFIGS. 1 and 2, is configured to operate in connection with a rivet feed module22and a tool actuation module24. The three modules can exist in a common cabinet, or each module can work independently and be interrelated via electrical, pneumatic, and/or blow tube connections. The automatic rivet loading module20is fully automatic, highly reliable, lightweight and very fast. It is preferably configured to provide that twelve inches of rivets (such as forty to sixty rivets, depending on length) can be inserted into a rivet tool (i.e., in a rivet actuation module) in four to six seconds. As such, the automatic rivet loading module allows an operator to make more joint fastenings in a given amount of time, compared to a typical rivet loading mechanism. Additionally, the rivet loading module is configured such that a mandrel can be loaded with rivets while the rivet gun is being used elsewhere.

As shown inFIG. 2, the automatic rivet loading module20includes a gripper mechanism26, a pusher mechanism28, a mandrel receptacle30, a rotary actuator32for rotating the mandrel receptacle30, mandrel drive mechanisms34,36for moving mandrels within the mandrel receptacle30, and a tool activation device or block37.

The automatic rivet loading module20, and specifically the gripper mechanism26, is configured to receive rivets from a rivet feed mechanism or rivet feed module22, one rivet at a time. As shown inFIG. 3, the gripper mechanism26consists of two gripper components38,40which are configured to pivot relative to each other, such as about axes42shown inFIG. 3(wherein the pivoting is represented inFIG. 3using arrows44). A gripper actuating mechanism46is preferably associated with the gripper components38,40, and is configured to facilitate pivoting of the gripper components38,40relative to each other, at the appropriate times in the overall rivet loading process (to be described in more detail later herein). As shown inFIG. 3, each of the gripper components38,40may be provided in the form of a rectangular block, although other shapes and configurations may be used.

Preferably, the rivet feed module22is configured to feed rivets to the gripper mechanism26one rivet at a time. As shown inFIG. 3, the rivet feed module22may include a hose48, such as a twenty foot hose made of a relatively soft urethane plastic. The end50of the hose48through which the rivets52exit may be positioned twenty thousandths of an inch away from the side54of the gripper mechanism26. Preferably, the hose48is extruded, and a desired shape throughbore56is formed in the hose48, wherein the throughbore56generally corresponds to the shape of the rivets52to be fed to the automatic rivet loading module20using the rivet feed module22. Preferably, the rivet feed module22is configured to air feed rivets52one at a time to the gripper mechanism26. While the end portion of a hose48is shown inFIG. 3, other types of rivet feed modules may be used in connection with the present invention.

As shown inFIGS. 3–5, each gripper component38,40includes a cut out or profile such that, when the gripper components are pivoted together, they provide a receptacle58which is shaped to receive, and retain, a rivet52from the rivet feed module22. More specifically, as shown, a top edge60,62of each of the gripper components38,40may provide a cut out which, when the gripper components are pivoted together, define a U-shaped cut out64. A side edge66,68of each of the gripper components38,40may provide a cut out which, when the gripper components are pivoted together, define a T-shaped cut out70(the T-shaped cut out70is clearly seen inFIGS. 4,5and9). Regardless, preferably the gripper components38,40are configured such that, when they are pivoted together, they can receive and retain a rivet52.

FIGS. 4–9show the gripper components38,40in cross section, along line4—4ofFIG. 3. As shown, preferably each of the gripper components38,40includes an inclined surface72,74such that when the gripper components38,40are pivoted together (seeFIGS. 4,5and9), the incline surfaces72,74define a lead cone area76. Preferably, a space exists between the gripper components38,40(when the gripper components38,40are pivoted together), and the space defines a guide tube78which is disposed between the rivet receptacle58and the lead cone76. The guide tube78is wide enough to allow a mandrel80to pass therethrough (see the progression fromFIG. 4toFIG. 5), as will be described more fully later herein.

As shown inFIG. 4(see alsoFIGS. 5–9), the pusher mechanism28preferably consists of a pusher82and a pusher actuating mechanism84, such as an air cylinder, which is operably associated with the pusher82. An end86of the pusher82includes a profile which provides a recess88, and the pusher actuating mechanism84is configured to translate the pusher82back and forth along its longitudinal axis90(seeFIG. 4which identifies the axis90), i.e., in an up and down direction as shown inFIGS. 5–9. As will be described more fully later herein, the recess88in the end86of the pusher82is configured to receive the end92of a mandrel80when the pusher82is moved in a downward direction as shown inFIGS. 5–7.

As shown inFIG. 10, preferably the mandrel receptacle30is shaped generally as a rectangular block, but other shapes can be used. For ease of manufacture, the mandrel receptacle30may be provided in the form of two like components (seeFIG. 11) which are secured together. Alternatively, a one piece construction can be used. Preferably, the mandrel receptacle30includes two longitudinal chambers98,100therein, each configured to receive and retain a mandrel, as will be described more fully later herein. Preferably, the two longitudinal chambers98,100are identical, and the mandrel receptacle30is symmetrical about its longitudinal, central axis102. Each chamber extends from a hole104at the top108of the mandrel receptacle30to a hole110at the bottom114of the mandrel receptacle30.

Rivet retaining structure is provided in each chamber, wherein the rivet retaining structure is configured to prevent the travel of rivets therepast, along a mandrel, in the respective chamber in the mandrel receptacle. The rivet retaining structure may consist of spring blades116. Specifically, as shown inFIGS. 10,11,13and14(the spring blades have been left out ofFIG. 12for clarity), two openings118may be provided in both the front120and back122of the mandrel receptacle30(four openings total), wherein each opening118provides an inclined surface124to which is attached a spring blade116. As shown inFIG. 13, each spring blade116extends into the respective chamber and is configured to prevent rivets52from sliding therepast along a mandrel.

As shown inFIGS. 11 and 15, a slotted portion126and a closed portion128are provided along each side of the mandrel receptacle30. Each slotted portion126extends from the bottom114of the mandrel receptacle30to the closed portion128which is on that respective side of the mandrel receptacle30, and each closed portion128extends from the slotted portion126on that respective side of the mandrel receptacle30to the top108of the mandrel receptacle30. Each slotted portion126provides that an opening130extends from the side of the mandrel receptacle30into the respective chamber from its side.

Mandrel drive mechanisms34,36are provided to move mandrels in each of the two chambers98,100provided in the mandrel receptacle30. Specifically, as shown inFIG. 14, a first drive mechanism34includes a stitch cylinder130which enters and translates in the left-most chamber98(seeFIGS. 10 and 12) through left-most hole110on the bottom114of the mandrel receptacle30. The stitch cylinder130is connected to a stitch cylinder drive mechanism132, such as an air cylinder with a relief valve, which is selectively controllable to move the stitch cylinder130up into the left-most chamber98in the mandrel receptacle30.

A second drive mechanism36includes a bullet-shaped member134which enters and translates in the right-most chamber in the mandrel receptacle30(seeFIG. 14; see alsoFIG. 16which shows the bullet-shaped member134isolated). Each of the stitch cylinder130and bullet-shaped member134has a magnetic end portion or a magnet136,138at its end which is configured to magnetically attract a mandrel80. A blade140extends from the bullet-shaped member134and is connected to a bullet drive mechanism142, such as an air cylinder, which is selectively controllable to move the bullet-shaped member134into, and along (i.e., up and down therein), the right-most chamber100in the mandrel receptacle30. Each of the slotted portions126in the mandrel receptacle30(along each side thereof) is configured to receive the blade140and allow the blade140to slide therein. The blade140extends from the side of the bullet-shaped member134and slides in the slotted portion126as the bullet-shaped member134translates in the chamber100. The bullet drive mechanism142is configured to drive the bullet-shaped member134up and down, selectively, in the chamber100in the mandrel receptacle30. As discussed, one end of the bullet-shaped member134provides a magnet or magnetic portion138. The opposite end of the bullet-shaped member preferably provides a conical surface144or some other configuration which is configured to open the spring blades116when the bullet-shaped member134is moving downward, so the bullet-shaped member134can slide past the spring blades116.

Preferably, the stitch cylinder130is moveable through a stroke distance wherein at the bottom of the stroke, the top edge146of the stitch cylinder130is flush with the bottom surface114of the mandrel receptacle30(seeFIGS. 14 and 15), and at the top of the stroke, the stitch cylinder130is extended a desired distance into the mandrel receptacle30, such that the top92of the mandrel80travels to a desired position.

Preferably, the bullet-shaped member134is moveable through a stroke distance wherein at the bottom of the stroke, the top edge148of the bullet-shaped member134is flush with the bottom surface114of the mandrel receptacle30, and at the top of the stroke, the top edge148of the bullet-shaped member134is flush with the top surface108of the mandrel receptacle30and the blade140contacts the end of the slotted portion126(i.e., contacts the closed portion128on the side of the mandrel receptacle30). As such, the distance150(seeFIG. 16) from the top of the blade140to the end of the bullet-shaped member134(i.e., the end of the magnet or magnetic end portion138) is approximately the same length as the length of the closed portions128which are provided on the sides of the mandrel receptacle30.

As shown inFIGS. 14 and 15, the mandrel receptacle30is preferably rotatable and is positioned on, and in, a cup152(see alsoFIG. 18which provides a top plan view of the cup, isolated). The cup152is preferably securely mounted to a support structure (not specifically shown) and includes: a first opening154, perhaps in the form of a circular hole155, through which the stitch cylinder134can pass; a second opening156, perhaps in the form of a circular hole158and slot160extending therefrom, through which the bullet-shaped member134and blade140can pass, respectively; and a third opening162, perhaps in the form of a circular hole164through which a shaft166from a rotary actuator32extends, wherein the shaft166connects the rotary actuator32to the mandrel receptacle30, and the rotary actuator32is controllable to selectively rotate the mandrel receptacle30, such as one hundred eighty degrees one way and the other.

As shown inFIG. 15, in addition to providing a stop for the stroke of the bullet-shaped member134, the closed portions128in the sides of the mandrel receptacle30stabilize mandrels which are retained therein. The cup152in which the mandrel receptacle30is positioned includes an upwardly extending, circumferential side wall168, and the wall also effectively provides a closed portion which functions to stabilize the mandrels which are retained in the mandrel receptacle30, particularly when the mandrel receptacle is being rotated one hundred eighty degrees.

As discussed, preferably the rivet loading module20includes a tool activation device or block37. Preferably, the tool activation block37is configured to receive the tool actuation module24, and specifically the nose of the rivet gun, and sense when the tool actuation module24is received. Preferably, the tool activation block37includes one or more sensors which sense when the tool actuation module24is received.

FIG. 17illustrates a control system which can be used to control the automatic rivet loading module20. As shown, a controller170may be connected to the pusher actuating mechanism84such that the controller170can control the pusher mechanism28and receive feedback therefrom (i.e., whether the pusher82fails to travel through its entire downstroke). Additionally, the controller170is operably connected to the gripper actuating mechanism46, the stitch cylinder drive mechanism132, the bullet drive mechanism142and the rotary actuator32for rotating the mandrel receptacle30. The controller170is preferably connected to the one or more sensors of the tool activation block37, such that the controller170can determine when the tool actuation module24is received and control the components of the rivet loading module20accordingly. In this way, the automatic rivet loading module20is highly automated and controllable from a single controller170.

In operation, a rivet52is fed from the rivet feed module22to the gripper mechanism26as shown inFIG. 3. Specifically, the gripper components38,40are pivoted closed, as shown inFIG. 4, as a rivet52is delivered to the rivet receptacle58. When the rivet52is initially delivered to the gripper mechanism26, the pusher82is in the up position and the mandrel80is down in the chamber98in the mandrel receptacle30. Then, as shown inFIG. 5, the stitch cylinder130pushes the mandrel80up, into the lead cone76, through the guide tube78, through the rivet52, and into the recess88in the end86of the pusher82. Basically, the stitch cylinder130is moved to the end of its upward stroke, wherein the end of the upward stroke has been pre-selected to be such that the end92of the mandrel80moves to a desired position. Then, as shown inFIG. 6, the gripper components38,40are opened (i.e., pivoted away from each other), and the pusher82moves the mandrel80downward as shown inFIG. 7, possibly also pushing the rivet52down on the mandrel80(if the rivet52did not already drop down the mandrel80as a result of gravity). Once the pusher82reaches the end of its stroke, it retracts upward as shown inFIG. 8, and the gripper components38,40close again as shown inFIG. 9to receive another rivet52.

As rivets are threaded onto the mandrel80using the gripper mechanism26and pusher mechanism28, eventually the mandrel80becomes full of rivets as shown inFIG. 13, at which time the bottom-most rivet in the chain contacts the blade springs116in the mandrel receptacle30and the top-most rivet in the chain is high enough that the pusher82cannot complete its down stroke. When the pusher82cannot complete its down stroke, the controller170which is connected to the pusher actuating mechanism84(seeFIG. 17) senses as such, and determines that the mandrel is full. Preferably, the other chamber100in the mandrel receptacle30has an empty mandrel disposed therein, and the mandrel receptacle30is rotated 180 degrees such that the empty mandrel is positioned beneath the gripper mechanism26(seeFIG. 4), and the full mandrel is positioned beneath the tool actuation module24(seeFIG. 14). Then, as shown inFIG. 14, the bullet-shaped member134is moved upward to expel the full mandrel to the tool actuation module24. Subsequently, the rivet gun (part of the tool actuation module24) can be used to install the rivets which are disposed on the mandrel. When the rivet gun is being used, rivets can be installed on the empty mandrel in the opposite chamber96in the mandrel receptacle30as described above, using the gripper mechanism26and pusher mechanism28. After all the rivets have been installed such that the mandrel in the rivet gun is empty again (or a different tool with an empty mandrel can be used), the empty mandrel is installed in the mandrel receptacle30. To do so, the bullet-shaped member134is moved into the upmost position, wherein the end of the bullet-shaped member134(i.e., the magnet or magnetic portion thereof138) is flush with the top108of the mandrel receptacle30. The bullet-shaped member134is then moved downward while the magnet or magnetic portion138attracts the mandrel and pulls the mandrel down into the mandrel receptacle30. Once the bullet-shaped member134has been moved to its down most position, wherein the top end of the bullet-shaped member134is flush with the bottom114of the mandrel receptacle30, the mandrel receptacle can be rotated 180 degrees to move the empty mandrel under the gripper mechanism26and pusher mechanism28, and move the full mandrel under the tool actuation module24.

FIG. 19provides a simplified series of views which illustrates the method of operation of the automatic rivet loading module. Initially, an empty mandrel is loaded into the right-most chamber of the mandrel receptacle using the bullet-shaped member134. Specifically, the bullet-shaped member134is raised to its top-most position (view A inFIG. 19) and then is lowered to pull the mandrel into the mandrel receptacle30(view B inFIG. 19). Then, the mandrel receptacle30is rotated 180 degrees (to the position shown in view C inFIG. 19) and the mandrel is loaded with rivets as described above (view D inFIG. 19), using the gripper mechanism26and the pusher mechanism28. Then, the bullet-shaped member134is raised (view D inFIG. 19) and lowered to pull another empty mandrel into the mandrel receptacle30(view E inFIG. 19). Then, the mandrel receptacle30is rotated 180 degrees (to the position shown in view F inFIG. 19), and the bullet-shaped member134is raised to expel the full mandrel (view G inFIG. 19). While the full mandrel is being expelled, or after the full mandrel has been expelled, rivets can be loaded onto the empty mandrel as described above (view D inFIG. 19), using the gripper mechanism26and the pusher mechanism28. Thereafter, another empty mandrel can be installed in the mandrel receptacle30(i.e., the progression from view D to view E inFIG. 19), and the process repeated.

The automatic rivet loading module which has been described is fully automatic, highly reliable, lightweight and very fast. It is preferably configured to provide that twelve inches of rivets (such as forty to sixty rivets, depending on length) can be inserted into a rivet tool (i.e., in a rivet actuation module) in four to six seconds. As such, the automatic rivet loading module allows an operator to make more joint fastenings in a given amount of time, compared to a typical rivet loading mechanism. Additionally, the rivet loading module is configured such that a mandrel can be loaded with rivets while the rivet gun is being used elsewhere.

While an embodiment of the present invention is shown and described, it is envisioned that those skilled in the art may devise various modifications of the present invention without departing from the spirit and scope of the disclosure.