GB2090646A

GB2090646A - Control for a power shaft for use in a web burster machine

Info

Publication number: GB2090646A
Application number: GB8200177A
Authority: GB
Original assignee: Swingline Inc
Current assignee: Swingline Inc
Priority date: 1981-01-05
Filing date: 1982-01-05
Publication date: 1982-07-14
Also published as: DE3152118A1; GB2090646B; CA1153326A; FR2497550A1

Abstract

A drive and clutch control 21 is provided for a power shaft to enable said shaft to be manually rotated by a control knob 24 and yet render the knob 24 non-rotatably driven while said shaft is being power driven by means of pulley 23. Knob 24 is axially movable with knob shaft 39 away from pulley 23 against biassing provided by spring 41 to engage radial clutch members 37 in cavities 36 in an intermediate housing portion 27 to select a manual drive mode for the shaft, and on release of the knob 24, clutch members 37 are disengaged from cavities 36 and the power drive mode may be selected without rotatably driving knob 24, to provide increased safety. <IMAGE>

Description

SPECIFICATION Control for a power shaft and a web burster machine including one or more such controls This invention relates to a control for a power shaft, of for example, a drive roll of a web burster machine, which control is more particularly a drive and clutch conrol knob assembly and also to such a machine including one or more such controls.

Shafts protruding from equipment which are rotatably power driven during normal operation tend to present safety hazards in that clothing of personnel working near the equipment can be entangled in the rotating shaft and possibly cause serious injury. Where shafts do not require manual operation, for example, for start-up operation, such shafts may be enclosed in housings thereby alleviating such hazards.

Shafts that need to be manually operated at some stage can still be designed, by providing a suitable control, so that the shaft end is not dangerously exposed during powered operation.

A number of arrangements to accomplish this feature have been proposed.

U.S. Patent No. 3,986,409 (Tripp) discloses a control knob which must be depressed to engage the shaft end. When the knob is not depressed it is disengaged from and is not rotatably driven with the shaft.

U.S. Patent No. 4,194,412 (Boyer) discloses a ball-groove arrangement for translating knob movement with respect to shaft movement.

Other related patents include U.S. Patent No.

2,797,592 (Marrapese) and 3,208,302 (Lewis).

According to one aspect of the present invention there is provided a drive and clutch control attachable to a machine shaft comprising (a) a housing; (b) a chamber in the housing; (c) a knob shaft journalled in the housing with one end of the knob shaft positioned in the chamber; (d) a knob at the other end of the knob shaft positioned outside of the chamber; (e) first clutch means on said one end of the knob shaft (f) second clutch means on the interior of the housing, co-operable with the first clutch means; (g) spring means surrounding the knob shaft in the said housing which spring means biasses the first clutch means away from the second clutch means, whereby the machine shaft is capable of being driven in a power-driven mode and in a manual mode; in the power-driven mode the knob is disengaged from the machine shaft and is not rotatably driven, and to adopt the manual mode the knob and knob shaft are capable of being moved against the biasing of the spring means so that the first and second clutch means are engaged and the knob is capable or rotating the machine shaft when it is manually rotated.

According to a second aspect of the present invention there is provided a control knob assembly attachable or attached to one end of a power shaft, comprising a central knob having a knob shaft extending through a housing and into a chamber, the knob shaft being journalled in the housing and biassed in its axial direction, in use, towards the power shaft, by biassing means in the chamber, the knob shaft having a first clutch means cooperable with a second clutch means on the housing, the assembly being such that while the power shaft is being power driven the first clutch means and second clutch means are disengaged so that the control knob is not rotatably driven with the power shaft, and such that the first and second clutch means are capable of being engaged by moving the control knob axially away from the power shaft against said biassing means and the power shaft then being manually rotatable by rotating the control knob.

Further according to the present invention there is provided a web burster machine including at least one drive and clutch control as described in the penultimate paragraph, or including at least one control knob assembly as described in the immediately preceding paragraph.

It is a feature of the present invention that parts which rotate during normal power driving of the power shaft need not be dangerously exposed to the machine operator to cause injury.

The housing may comprise a composite housing of two or more parts. Preferably, the chamber accommodates the first clutch means, knob shaft and spring means and accommodates or forms part of the second clutch means.

An embodiment of a web burster machine including at least one power shaft control in accordance with the present invention will now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 is a partial side elevational view of the web burster machine including a pair of web drive rolls; Figure 2 is a cross-sectional view of a drive and clutch control or control knob assembly for driving either one of the drive rolls; Figure 3 is a cross-sectional view, similar to Figure 2, in which the clutch of the control is engaged with a power shaft by pulling the knob; and Figure 4 is a sectional view taken along lines 4-4 of Figure 3.

Referring to Figure 1, burster machine 10 processes a continuous web 11 of paper forms arranged serially. Web 11 is caused to move in the direction of arrow 1 2 over stationary burster element 13 by pulling action of drive rolls 14, 1 6 rotating in opposite senses about shafts 1 7, 1 8 respectively. Burster element 13 includes apex 19 which acts upon spaced-apart perforations (not shown) in web 11 to separate web 11 into individual sheets, all as well known in the burster art.

Turning to Figure 2, a drive and clutch unit 21 is adapted to be connected to either shaft 1 7 or 18 through connector member 22 to provide shaft drive through pulley 23 and a belt (not shown).

During normal operation of the burster 10, rolls 14 and 1 6 rotate through pulley drives driving one or both of the shafts 17 and 18.

To restrain driven rotation of an adjustment hand knob 24 during normal running operation, while permitting hand operated rotation of shaft 1 7 or 1 8 for threading and initial movement of web 11 into and between rolls 14 and 16, a clutch arrangement is provided which includes a pulley housing part 26, an intermediate housing part 27 and knob housing part 28, all axially aligned. The housing parts 26, 27 and 28 form a composite housing 30 between knob pulley 23 and the exposed end of knob 24. With respect to the clutch arrangement (and particularly Figures 2, 3 and 4), connector member 22 and pulley housing part 26 are affixed to pulley 23 on opposite sides thereof. Pulley housing part 26, which has a recess 29 therein, is bolted to pulley 23 through four threaded bolts 31.Bolt heads 32 are positioned in pulley recesses 33 and bolt stems 34 are secured in threaded recesses in the intermediate housing part 27.

Intermediate housing part 27 also includes a recess 36 which complements recess 29 to accommodate projecting clutch members 37.

Recess 36 includes a plurality of radial clutch receiving cavities 38, opposing parts of which receive and engage projecting clutch members 37 when the knob 24 is moved to its position of Figure 3. Projecting clutch members 37 are secured to knob shaft 39 which is journalled in intermediate housing part 27 for rotation therein.

Helically coiled compression spring 41 positioned in and guided by inner recess 42 of intermediate housing part 27 during normal operation urges and holds the shaft 39 (and the knob secured to it by set screw 43) in the position shown in Figure 2, i.e. out of driven engagement with the pulley 23 and shaft 1 7 or 1 8 respectively. Recesses 29, 36 and 42 together form housing chamber 45.

When the burster is not being power driven and the web is being threaded or adjusted, pulley 23 may be hand driven through hand knob 24 by pulling knob 24 in the direction of arrow 44 (and as necessary rotating the knob full turns or fractions of a turn either clockwise or counterclockwise) until the radially projecting clutch members 37 engage an opposite pair of clutch receiving cavities 38. Knob 24 is then manually rotated, while continuing to exert a pull in the direction of arrow 44, to rotate pulley 23 and rotate either roll 1 4 or 1 6 as necessary to thread and adjust web 11. After this operation is complete, knob 24 is released allowing spring 42 to return knob 24 and associated parts to the disengaged Figure 2 position.

When burster 10 is energised, power driven pulley 23 rotates at high speed but knob 24 is not rotatably driven thus avoiding the danger of an operator or other person being injured by a rotating knob.

The clutch and drive unit 21 may be used on powered-shaft machines other than bursters, for example, to accomplish hand threading through a knob while avoiding the knob being rotatably driven during normal powered operation.

Claims

1. A drive and clutch control attachable to a machine shaft comprising (a) a housing; (b) a chamber in the housing; (c) a knob shaft journalled in the housing with one end of the knob shaft positioned in the chamber; (d) a knob at the other end of the knob shaft positioned outside of the chamber; (e) first clutch means on said one end of the knob shaft; (f) second clutch means on the interior of the housing, co-operable with the first clutch means; (g) spring means surrounding the knob shaft in the said housing which spring means biasses the first clutch means away from the second clutch means, whereby the machine shaft is capable of being driven in a power-driven mode and in a manual mode; in the power-driven mode the knob is disengaged from the machine shaft and is not rotatably driven, and to adopt the manual mode the knob and knob shaft are capable of being moved against the biassing of spring means so that the first and second clutch means are engaged and the knob is capable of rotating the machine shaft when it is manually rotated.

2. A control as claimed in Claim 1 in which the chamber includes cavities which form the second clutch means.

3. A control as claimed in Claim 1 or Claim 2 in which the spring means is a coiled compression spring surrounding the knob shaft.

4. A control as claimed in any one of the preceding claims comprising a pulley attached to the housing to thereby rotate at least part of the housing and a power shaft simultaneously and about a common axis.

5. A control as claimed in any one of the preceding claims in which the knob and knob shaft are each formed individually.

6. A control knob assembly attachable or attached to one end of a power shaft, comprising a control knob having a knob shaft extending through a housing and into a chamber, the knob shaft being journalled in the housing and biased in its axial direction, in use, towards the power shaft, by biassing means in the chamber, the knob shaft having a first clutch means co-operable with a second clutch means on the housing, the assembly being such that while the power shaft is being power driven the first clutch means and second clutch means are disengaged so that the control knob is not rotatably driven with the power shaft, and such that the first and second clutch means are capable of being engaged by moving the control knob axially away from the power shaft against said biassing means and the power shaft then being manually rotatable by rotating the control knob.

7. An assembly as claimed in Claim 6 in which the housing is a composite housing comprised of two or more housing parts.

8. An assembly as claimed in Claim 7 in which the chamber is defined by the two, or by two of the housing parts.

9. An assembly as claimed in any one of Claims 6 to 8 in which the first clutch means comprises one or more radical clutch members or projections on the knob shaft engageable with second clutch means in the form of radial grooves or cavities, the biassing means acting between the first clutch means and the housing and being seated in the chamber radially inwardly of the radical grooves.

10. An assembly as claimed in Claim 9 in which the first clutch means comprises two diametrically opposing radical clutch members or projections engageable in selected pairs of radial grooves or cavities.

11. A drive and clutch control attachable to a shaft substantially as herein described and illustrated with reference to the accompanying drawings.

1 2. Web burster machine including at least one drive and clutch control as claimed in any one of Claims 1 to 5, or Claim 11, or including at least one control knob assembly as claimed in any one of Claims 6 to 10.

13. A drive and clutch device attachable to a normally powered machine shaft of a web burster machine for turning said shaft during periods when the shaft is not power driven comprising (a) a pulley mountable axially to said power shaft and a housing secured to said pulley, (b) a chamber in said housing, (c) a knob shaft journalled in the housing with a first end of the knob shaft positioned in the chamber, (d) a knob secured to the other end of the shaft extending outside of the housing, (e) first clutch means on the first end portion of the knob shaft, (f) second clutch means on the interior of the housing, (g) spring means surrounding said knob shaft in said housing which spring means normally urges the first clutch means away from the second clutch means, whereby the normally powered shaft is rotatable independently of the knob until and unless the knob is moved away from the powered shaft to compress the spring means and engage the first and second clutch means.