US3735935A

US3735935A - Reel hub assembly

Info

Publication number: US3735935A
Application number: US00212318A
Authority: US
Inventors: R A Nordmeyer
Original assignee: PERTEC CHATSWORTH
Current assignee: PERTEC PERIPHERALS CORP
Priority date: 1971-12-27
Filing date: 1971-12-27
Publication date: 1973-05-29
Anticipated expiration: 1990-05-29
Also published as: GB1385259A; JPS4877819A; JPS5534105B2

Abstract

A hub assembly actuatable to selectively lock and unlock a reel thereon. The hub assembly is particularly useful with magnetic tape reels for enabling a reel to be locked onto the hub for rotation therewith. With the hub assembly unlocked, the reel can be easily placed on or removed from the hub assembly. The hub assembly includes a cylindrical drive plate secured to a drive shaft. The circumferential surface of the drive plate is formed by an inclined plane terminating in a flange defining a radially extending reference surface. A pressure plate is mounted substantially parallel to the drive plate for limited axial movement with respect thereto in response to the movement of an actuator handle coupled to the pressure plate. As the actuator handle is moved from an unlocked to a locked position, the pressure plate moves toward the drive plate exhibiting a travel stroke on the order of 0.120 inches. The pressure plate bears against an expansion ring which expands as it moves axially up the drive plate inclined plane to press outwardly against the inner surface of a tape reel. The expansion ring is provided with several protrusions beveled to define inclined planes for forcing the tape reel axially against the flange reference surface as the ring expands. The linkage coupling the actuator handle to the pressure plate is designed to assure stable retention of the actuator handle in either the locked or unlocked position.

Description

ttes

Nordmeyer REEL HUB ASSEMBLY Robert A. Nordmeyer, Los Angeles, Calif.

[73] Assignee: Pei-tee, Chatsworth, Calif.

[22] Filed: Dec. 27, 1971 [21] Appl. No.: 212,318

[75] Inventor:

Abraham Wasserman et al.

[57] ABSTRACT A hub assembly actuatable to selectively lock and unlock a reel thereon. The hub assembly is particularly useful with magnetic tape reels for enabling a reel to be locked onto the hub for rotation therewith. With the hub assembly unlocked, the reel can be easily placed on or removed from the hub assembly. The hub assembly includes a cylindrical drive plate secured to a drive shaft. The circumferential surface of the drive plate is formed by an inclined plane terminating in a flange defining a radially extending reference surface. A pressure plate is mounted substantially parallel to the drive plate for limited axial movement with respect thereto in response to the movement of an actuator handle coupled to the pressure plate. As the actuator handle is moved from an unlocked to a locked position, the pressure plate moves toward the drive plate exhibiting a travel stroke on the order of 0.120 inches. The pressure plate bears against an expansion ring which expands as it moves axially up the drive plate inclined plane to press outwardly against the inner surface of a tape reel. The expansion ring is provided with several protrusions beveled to define inclined planes for forcing the tape reel axially against the flange reference surface as the ring expands. The linkage coupling the actuator handle to the pressure plate is designed to assure stable retention of the actuator handle in either the locked or unlocked position.

9 Claims, 5 Drawing Figures Patented May 29, 1973 2 Sheets-Sheet l REEL HUB ASSEMBLY FIELD OF THE INVENTION This invention relates generally to a hub mechanism for driving a reel and more particularly to a hub mechanism actuatable to selectively lock and unlock a reel with respect thereto.

DESCRIPTION OF THE PRIOR ART The prior art is replete with various hub designs suitable for selectively locking a reel thereon; e.g. see the following U. S. Pat. Nos.:

SUMMARY OF THE INVENTION The present invention is directed to an improved hub assembly suitable for driving reels such as magnetic tape reels. Such reels normally have an open central core portion having about a 3% inch diameter for receiving a hub. In accordance with the present invention, the hub is capable of being selectively expanded within the reel so as to lock the hub against the inner reel surface.

More particularly, the hub assembly in accordance with a preferred'embodiment of the invention includes a substantially cylindrical drive plate fixedly secured to an axial drive shaft. The drive plate circumferential surface is inclined, i.e. diverges, from its front to rear edge in an axial direction. The inclined surface terminates in a radially extending reference surface defined by a flange extending around the drive plate.

An expansion ring is fitted around the drive plate circumferential surface and keyed thereto for positive torque coupling t-herebetween. The expansion ring is free, however, to move a limited distance in an axial direction relative to the drive plate. As the expansion ring moves up the inclined plane from the front toward the rear edge of the drive plate, it expands radially and bears against the reel inner surface. In accordance with a significant feature of the invention, the expansion ring is provided with radially extending protrusions which fit through the open reel core area when the ring is contracted. Each protrusion is beveled so as to define its own inclined plane so that when the ring expands radially, the reel is forced axially tight against the reference surface.

The axial movement of the expansion ring is directly controlled by a pressure plate mounted for limited axial travel. As the pressure plate moves toward the drive plate, it bears against the expansion ring to force the ring up to the drive plate inclined plane.

The axial position of the pressure plate is controlled by an actuator handle which rocks about a rock shaft fixed in relation to the drive plate. The actuator handle is coupled to the pressure plate such that for a first or unlocked position of the handle, the pressure plate will be spaced from the drive plate by a relatively large axial distance and for a second or locked position of the handle, the pressure will be axially closer toward the drive plate thereby forcing the expansion ring up the drive plate inclined plane.

The linkage coupling the pressure plate to the drive plate includes the actuator handle which has a pair of rocker arms mounted on the rock shaft fixed relative to the drive plate. Each rocker arm is pivotally connected to a link at a point spaced from the rock shaft. The other ends of the links are pivotally connected to the pressure plate. In the locked actuator handle position, the links are articulated to the rocker arms by a small angle in one direction with respect to a straight line and in the unlocked position by an angle in the opposite direction with respect to that straight line.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a reel hub assembly in accordance with the present invention;

FIG. 2 is a perspective view of the three primary components of the hub assembly of FIG. 1, i.e. the drive plate, expansion ring, and pressure plate, shown in telescoping fashion;

DESCRIPTION OF THE PREFERRED EMBODIMENTS Attention is now called to FIG. 1 of the drawing which illustrates a perspective view of a hub assembly 10 in accordance with the present invention. The hub assembly 10 is useful for rotationally driving a reel, such as a magnetic tape reel, having an open center core area for receiving the hub assembly therethrough. The hub assembly 10 in accordance with the present invention enables such a tape reel to be easily placed on and locked to the hub assembly as well as being easily unlocked and removed therefrom. A reel can be selectively locked on or unlocked from the hub assembly by selective actuation of an actuator handle 12 by rocking it about a fixed rock shaft (not shown in FIG. 1).

The hub assembly 10 of FIG. 1 is comprised of four major structural elements. These elements will be identified here and later described in greater detail in connection with FIGS. 2, 3 and 4. The four elements are: (1) the drive plate 16 which is permanently secured to a drive shaft (n0t shown in FIG. 1); (2) an expansion ring 18 mounted for limited axial movement over the inclined circumferential surface of the drive plate 16; (3) a pressure plate 20, also mounted for limited axial movement, which bears against the expansion ring for forcing it up the inclined surface of the drive plate; and (4) an actuator mechanism including the actuator handle l2 coupling the pressure plate 20 t0 the fixed drive plate 16 for selectively moving the pressure plate in both axial directions with respect to the drive plate 16.

Attention is now called to FIG. 2 which illustrates the drive plate 16, expansion ring 18, and pressure plate 20 in a dissassembled telescopic fashion. The drive plate 16 consists of a back wall 22 having a forwardly projecting stud 24 extending therefrom. A drive shaft 26 extends into the stud 24 and is permanently fixed thereto as by any suitable technique. For example, it has been found convenient to provide the drive shaft with a knurled end which is then directly cast into the drive plate casting.

The drive plate 16 is provided with a circumferential surface 28. For convenience, the axial boundaries of the surface 28 will respectively be referred to as a front edge 30 and a rear edge 32. The circumferential surface 28 is inclined so that its diameter increases from the front edge 30 to the rear edge 32. The rear edge 32 of the circumferential surface 28 is contiguous with a radially extending reference surface 34 defined by a flange 36. As will be seen hereinafter, this reference surface 34 is provided for the purpose of assuring a precise orientation of the reel relative to the drive shaft.

Further, the circumferential surface 28 of the drive plate 16 is provided with axially extending keyways 38 which, as will be seen hereinafter, mate with keys formed on the expansion ring 18 for enabling torque to be positively coupled from the drive plate 16 to the expansion ring 18.

Still further, the drive plate 16 is provided with a pair of axially extending

studs

40 and 42 which are equally radially spaced from the drive shaft center line. The

studs

40 and 42 are recessed for retaining springs, as will be seen hereinafter, for cooperating with the pressure plate tending to urge the hub assembly to an unlocked condition.

The expansion ring 18, as shown in FIG. 2, comprises an open ring dimensioned to fit closely around in contact with the drive plate circumferential surface 28. The expansion ring 18 is formed of a flexible compliant material such as a suitable plastic. In order to enable the diameter of the ring to expand, the ring is slotted at several points along its circumference. More particularly, consider the expansion ring 18 as having a front edge 46 and a rear edge 48. A series of spaced slots 50 are provided along the circumference of the ring 18 extending inwardly from the rear edge 48 toward the front edge 46. In addition to the slots 50, a plurality of pairs of slots are provided around the circumference extending from the front edge 46 toward the rear edge 48. More particularly, each pair of slots consists of closely spaced

parallel slots

52 and 54 which define a cantilevered tab 56 therebetween. As a consequence of the slots 50 extending from the rear edge 48 toward the front edge 46 and the

slots

52 and 54 extending from the front edge 46 toward the rear edge 48, the diameter of the ring 18 has the capability of expanding, as the ring 18 is forced up the inclined surface 28 of the drive plate 16.

The inner surface of the expansion ring 18 is provided with the previously mentioned axially extending keys 58 which are adapted to be received in the keyways 38 formed on the drive plate circumferential surface 28. The keys 58 are able to axially slide within the keyways 38 to permit relative axial movement between the expansion ring 18 and drive plate 16. However, engagement of the keys 58 within the keyways 38 prevents any relative rotation between the expansion ring 18 and drive plate 16, thus serving to positively couple the torque developed on the drive shaft 26 to the expansion ring 18.

Further, the expansion ring 18 is provided with a flange 60 adjacent its front edge 46. The flange 60 defines a rear surface 62 which, as will be seen hereinafter, defines an edge for positioning a high friction band around the expansion ring 18. The high friction band (shown at 94 in FIG. 3) can be formed of rubber for example and is utilized to assure good frictional contact between the expansion ring 18 and the inner surface of a reel.

Each of the previously mentioned tabs 56 in the expansion ring 18 is provided with a protrusion 64. Each protrusion 64 has front and rear

beveled surfaces

66 and 68. As will be seen hereinafter, the beveled surface 68 functions to force a reel rearwardly against the drive plate reference surface 34 when a reel is locked to the hub assembly.

The previously mentioned pressure plate 20 functions to carry the expansion ring 18. More particularly, the pressure plate 20 constitutes an open ring having a circumferential surface 72. The front edge of the circumferential surface 72 is contiguous with a flange 74 which has a rear edge 76 adapted to bear against the front edge 46 of the expansion ring. The circumferential surface 72 of the pressure plate 20 is provided with at least two square recesses 78 for receiving square protrusions 80 formed on the inner surface of the expansion ring 18. Engagement of the protrusions 80 in the recesses 78 assures identical axial movement of the pressure plate 20 and expansion ring 18.

The pressure plate 20 is additionally provided with a front wall 82 having an opening 84 therein dimensioned so as to receive the actuator handle 12 previously mentioned in the discussion of FIG. 1. The rear side of the pressure plate front wall 82 is provided with a pair of recesses 86 and 88 aligned with the

studs

40 and 42 in the drive plate 16. As noted, springs (shown at 98 in FIG. 3) are received between the recesses 86 and 88 of the pressure plate 20 and the

studs

40 and 42 of the drive plate 16 to urge the pressure plate away from the drive plate to thereby urge the expansion ring to its contracted or unlocked position.

Attention is now called to FIG. 3 which comprises a vertical sectional view taken substantially along the plane 3-3 of FIG. 1. FIG. 3 illustrates the drive shaft 26 having a knurled end 90 case within the stud 24 of the drive plate 16. The recessed

studs

40 and 42 can be readily seen in FIG. 3 spaced radially inwardly from the inner surface 92 of the circumferential wall of the drive plate 16. Note in FIG. 3, the circumferential surface of the drive plate which is of increasing diameter from the forward edge 30 to the rearward edge 32. Note that the rearward edge of the drive plate circumferential surface is contiguous with the reference surface 36 formed on the flange 34.

FIG. 3 readily illustrates how the expansion ring 18 fits around the circumferential surface of the drive plate 16. The expansion ring has a band 94 of high friction material, such as rubber, wrapped around the other surface thereof. When the expansion ring 18 is moved rearwardly up the inclined circumferential surface of the drive plate 16, the expansion ring 18 will expand thus forcing the rubber band 94 outwardly against the inner surface of a reel 96 illustrated in FIG. 3.

The previously mentioned square protrusions 80 formed on the inner surface of the expansion ring 18 fit within recesses 78 defined within the wall of the pressure plate 20. Thus, as the pressure plate is moved axially rearwardly toward the drive plate, the expansion ring 18 is forced to expand as it moves up the inclined circumferential surface of the drive plate. Springs 98 supported between the forwardly projecting studs on the drive plate 16 and the rearwardly opening recesses on the pressure plate 20 urge the pressure plate away from the drive plate to thereby urge the expansion ring into a contracted condition in which of course it unlocks the reel 96 permitting it to be axially withdrawn from the hub assembly past the protrusions 64 on the expansion ring.

The pressure plate 20 is moved under the influence of the previously mentioned actuator handle 12 which is mounted so as to be rocked about a rock shaft 104. More particularly, the actuator handle 12 is provided with a pair of depending rocker arms 100 and 102. Arms 100 and 102 rock about rock shaft 104 supported by mounting block 106. Mounting block 106 is secured in fixed relationship to the drive shaft 26 by screw 108. The ends of the arms 100 and 102 are respectively pivotally coupled to

links

110 and 112 by

pins

114 and 116. In turn, the

links

110 and 112 are pivotally connected to the pressure plate 20 by pins 118 and 120. When the actuator handle 12 is locked in one direction, the

links

110 and 112 are articulatedso as to move the expansion ring 118 up the drive plate inclined plane to thereby lock the high friction band 94 against the inner surface of the reel 96. When the handle 12 is rocked in the opposite direction, the

links

110 and 112 are articulated so as to permit the expansion ring 18 to move down the drive plate inclined plane'to thus contract and unlock the reel 96.

For a better understanding of the manner in which the actuator handle operates to control the axial movement of the pressure plate 20, attention is now called to FIG. 4 which constitutes a sectional view taken sub stantially along the plane 44 of FIG. 3. Note that with the actuator handle 12 rocked about the shaft 104 to the position shown in FIG. 4, the link 112 will be articulated so as to pull the pressure plate away from the drive plate 16. In this position, of course, the expansion ring will be contracted and will thereby permit the reel 96 to be axially withdrawn from the hub assembly over the protrusions 64. In order to lock the reel 96 onto the hub assembly, the actuator handle 12 must be pivoted from the position shown in FIG. 4 to the position shown in FIG. 5. Note that the link 112 in FIG. 5 more nearly constitutes a straight line between the rock shaft 104 and the pin 120 thereby meaning that the pressure plate 20 is forced rearwardly closer to the drive plate 16 as shown. This action of course moves the expansion ring up the drive plate inclined surface thereby forcing the rubber band 94 outwardly against the inner surface of the reel. In addition, as the expansion ring extends radially, the inclined surfaces 68 on the protrusions 64 expand to force the reel rearwardly against the reference surface 36 of the drive plate. In order to unlock the reel, it is merely necessary to manually force the actuator handle 12 from the position shown in FIG. 5 back to the position shown in FIG. 4. Note that the link 112 is articulated by a large angle in one direction in FIG.4 and by a smaller angle in the opposite direction in FIG. 5. That is, the pin 116 lies above a straight line between the shaft 104 and pin 120 in FIG. 4 and below that straight line in FIG. '5. Thus, the actuator handle 12 is stable ineither position and requires manual forcing in order to change the position.

From the foregoing, it should be apparent that a hub assembly has been disclosed herein useful for selectively locking and unlocking a reel, such as a magnetic tape reel, to a hub.

What is claimed is:

l. A hub assembly useful for driving a reel having a open core'area defined by an inner reel surface, said hub assembly comprising:

a substantially cylindrical drive plate mounted for rotation with respect to an axis therethrough, said drive plate having a circumferential surface of increasing diameter from the front to the rear edge thereof in an axial direction, said circumferential surface rear edge being contiguous with a radially extending reference surface;

an expansion ring supported around drive plate circumferential surface for relative movement with respect thereto in an axial direction only;

a plurality of radially extending protrusions formed on said expansion ring, each of said protrusions having a rear surface, opposed to said reference surface, inclined in a direction from said rear toward said front edge of said circumferential surface; and

means for selectively axially moving said expansion ring relative to said drive plate whereby said expansion ring will expand radially as it is moved from said front toward said rear edge of said circumferential surface to engage the inner surface of a reel and to cause said protrusions rear surfaces to force the reel against said reference surface.

2. The hub assembly of claim 1 wherein said expansion ring is formed of resilient material and has slots extending inwardly from the front and rear edges thereof toward the opposite edge.

3. The hub assembly of claim 1 wherein said expansion ring is formed of resilient material and includes spaced parallel slots extending inwardly from the front edge thereof to form cantilevered tabs; and wherein each of said radially extending protrusions is carried by one of said tabs.

4. The hub assembly of claim 3 wherein each of said protrusions has a front surface which is inclined in a direction from said front toward said rear edge to facilitate a reel being moved therepast.

5. The hub assembly of claim 4 including a band of resilient high friction material supported around said expansion ring.

6. The hub assembly of claim 1 including a plurality of axial extending keyways formed in said drive plate circumferential surface anda plurality of axially extending keys formed on the inner surface of said expansion ring for mating with said keyways.

7. The hub assembly of claim 1 wherein said means for moving said expansion ring includes an actuator handle mounted for rocking movement between first and second positions about a rock shaft fixed relative to said drive plate; and

means coupling said actuator handle to said expansion ring for moving said expansion ring toward said drive plate rear edge when said actuator handle is rocked into said second position and toward said drive plate front edge when said actuator handle is rocked into said first position.

8. The hub assembly of claim 7 wherein said means coupling said actuator handle to said expansion ring includes a pressure plate bearing against said expansion ring and supported for axial movement relative to said and lengthening the axial distance between said drive plate; pressure plate and drive plate when said actuator said actuator handle including a rocker arm; and handle is in said first position. link means pivotally connected between said rocker 9. The hub assembly of claim 8 including spring arm and pressure plate for shortening the axial dismeans acting between said pressure plate and drive tance between said pressure plate and drive plate plate for urging them apart. when said actuator handle is in said second position

Claims

1. A hub assembly useful for driving a reel having a open core area defined by an inner reel surface, said hub assembly comprising: a substantially cylindrical drive plate mounted for rotation with respect to an axis therethrough, said drive plate having a circumferential surface of increasing diameter from the front to the rear edge thereof in an axial direction, said circumferential surface rear edge being contiguous with a radially extending reference surface; an expansion ring supported around drive plate circumferential surface for relative movement with respect thereto in an axial direction only; a plurality of radially extending protrusions formed on said expansion ring, each of said protrusions having a rear surface, opposed to said reference surface, inclined in a direction from said rear toward said front edgE of said circumferential surface; and means for selectively axially moving said expansion ring relative to said drive plate whereby said expansion ring will expand radially as it is moved from said front toward said rear edge of said circumferential surface to engage the inner surface of a reel and to cause said protrusions rear surfaces to force the reel against said reference surface.

6. The hub assembly of claim 1 including a plurality of axial extending keyways formed in said drive plate circumferential surface and a plurality of axially extending keys formed on the inner surface of said expansion ring for mating with said keyways.

7. The hub assembly of claim 1 wherein said means for moving said expansion ring includes an actuator handle mounted for rocking movement between first and second positions about a rock shaft fixed relative to said drive plate; and means coupling said actuator handle to said expansion ring for moving said expansion ring toward said drive plate rear edge when said actuator handle is rocked into said second position and toward said drive plate front edge when said actuator handle is rocked into said first position.

8. The hub assembly of claim 7 wherein said means coupling said actuator handle to said expansion ring includes a pressure plate bearing against said expansion ring and supported for axial movement relative to said drive plate; said actuator handle including a rocker arm; and link means pivotally connected between said rocker arm and pressure plate for shortening the axial distance between said pressure plate and drive plate when said actuator handle is in said second position and lengthening the axial distance between said pressure plate and drive plate when said actuator handle is in said first position.

9. The hub assembly of claim 8 including spring means acting between said pressure plate and drive plate for urging them apart.