US3733070A

US3733070A - Floating jogger

Info

Publication number: US3733070A
Application number: US00228032A
Authority: US
Inventors: D Obenshain
Original assignee: Westvaco Corp
Current assignee: Westvaco Corp
Priority date: 1972-02-22
Filing date: 1972-02-22
Publication date: 1973-05-15
Anticipated expiration: 1990-05-15
Also published as: IT977382B; JPS517903B2; GB1397872A; DE2307224B2; CA1002976A; DE2307224C3; DE2307224A1; FR2173548A5; JPS4894162A

Abstract

A paper jogging device is presented for stacking sheets of paper or the like into precise alignment as the sheets are piled directly onto a shipping skid. The device comprises an oscillating paddle, arranged in substantially a vertical plane, that is pivoted at its bottom edge through a flexible hinge element to a more-or-less horizontally disposed hinge plate. The hinge plate rests on and stays in contact with the shipping skid during the initial stages of the stacking operation, and the entire device is mounted so as to float downward with the shipping skid as the stacking operation continues and until the stack reaches a height that is near the top of the oscillating paddle. When the jogging device reaches the level of its lowest downward movement, jogging action continues as the stack increases in height and the shipping skid continues to move downward.

Description

United States Patent 1 Obenshain FLOATING JOGGER [75] Inventor: David Noel Obenshain, Swanton,

[73] Assignee: Westvaco Corporation, New York,

[22] Filed: Feb. 22, 1972 [21] Appl. No.: 228,032

Primary ExaminerEdward A. Sroka Att0rney- Larry C. Hall et al.

[57] ABSTRACT A paper jogging device is presented for stacking sheets of paper or the like into precise alignment as the sheets are piled directly onto a shipping skid. The device comprises an oscillating paddle, arranged in substantially a vertical plane, that is pivoted at its bottom edge through a flexible hinge element to a moreor-less horizontally disposed hinge plate. The hinge plate rests on and stays in contact with the shipping skid during the initial stages of the stacking operation, and the entire device is mounted so as to float downward with the shipping skid as the stacking operation continues and until the stack reaches a height that is near the top of the oscillating paddle. When the jogging device reaches the level of its lowest downward movement, jogging action continues as the stack increases in height and the shipping skid continues to move downward.

11 Claims, 10 Drawing Figures PATENTED m1 5197s SHEET 1 0F 4 PATENIEB HAY] 51973 SHEET 2 0F 4 FIG.

FIG.

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awk-Q5 FIG.

PA] [NIH] W 1 51975 SHEET 3 BF 4 PATENTEDNAY 1 5W3 SHEET H []F 4 FIG. 9.

FIG.

1 FLOATINGJOGGER,

SUMMARY OF THE INVENTION The present invention relates to novel improvements in an attachment for a sheet cutting and stacking apparat us, and more particularly to a paper stacking device which is adapted to receive the cut sheets as they are discharged from the sheet cutting apparatus. The device of the present invention aids in stacking the cut sheets directly onto a shipping skid and includes provisions for receiving a great number of the cut sheets while insuring that the sheets remain evenly stacked prior to removing the shipping skid from the sheet cutting apparatus. Accordingly, it is a specific object of the present invention to provide, adjacent to a receiving skid for out sheets of paper or the like, an improved floating jogger which permits the sheets stacked on the receivingskid to be immediately wrapped and prepared for shipment without the necessity of performing subsequent operations on the sheets.

Another object of the invention lies in the provision of means associated with the jogging device which permits a limited, automatic vertical movement of the jogging device as the stack of cut sheets being deposited on the shipping skid grows in height.

A still further object of the present invention is the provision of a device that is simple in construction so that it may be quickly and readily placed into position adjacent the sheet receiving end of a sheet cutting and stacking apparatus.

The present invention is designed to provide a reliable and relatively inexpensive mechanically operating, electrically actuated, jogging device for stacking sheets of cut paper in a neat and even pile on a shipping skid. The unit requires very little power to operate and is adapted to impart a sufficient rate of actuation to the jogging paddle to maintain the cut sheets in precise alignment with only a limited amount of pivotal movement of the paddle. The device is primarily intended for use with a paper sheeting operation, however, it should be obvious that the apparatus of the'present invention would be capable of use on any other kind of sheeting operation including a printing press.

With the paper sheeters disclosed in the prior art, the cut sheets of paper are not stacked directly onto a shipping skid because generally the sheets are cut to oversize dimensions and later guillotine trimmed to the desired size. Moreover, to prevent damage to the edges of the stacked sheets of paper by the strapping material used to bind the stack to the skid, the shipping skids are made larger all around, and, this requirement effectively prohibits the positioning of a shipping skid directly between the fixed paper joggers used in the prior art. Thus, when paper is sheeted and stacked using one of the prior art sheeters referred to above, the sheets are initially stacked on a temporary shipping skid the same size as the cut sheets, and then, after guillotine trimming to the desired size, transferred to a shipping skid of overall larger dimensions.

However, along with the development of new high speed precision sheeters, as disclosed in applicants prior US. Pat Nos. 3,203,326; 3,222,964; 3,272,044 and 3,363,520, including other related patents, all assigned to the present Assignee herein, it became highly desirable to develope a jogging device for stacking the machine finished paper directly on its shipping skid. Applicants prior US. Pat. No. 3,062,539 describes a high speed jogging mechanism that gives the necessary precision for jogging, however it proved to be not adaptable for starting the stack of cut sheets on their own-shipping skid. Accordingly the invention disclosed herein was developed for use with the high speed precision sheeters described in applicant's prior patents mentioned hereinbefore.

The invention described herein includes, among its unique characteristics, the following novel features, 1 the provision of a jogging paddle pivoted at its bottom edge, (2) the use of an infinitely flexible, yet extremely durable hinge element between the jogger paddle and its hinge plate, and (3) the provision of a mounting means for the joggerpaddle and its actuating mechanism which permits the jogger paddle to rest on the shipping skid when the stacking operation begins, and then continue to automatically float with the shipping 'skid for a limited distance during the initial stages of the stacking operation, or, until the stack reaches a height that is near the top of the oscillating jogger paddle.

Accordingly, withthe above and other objects in mind, the invention herein is deemed to consist of the novel features of construction and the combination and arrangement of parts hereinafter more fully set forth, as recited in the claims appended hereto, and as shown in the accompanying drawing.

IN THE DRAWING the edge of a shipping skid;

FIG. 4 is a view similar to FIG. 2 showing the side floating joggers following a shipping skid downward as the stack of cut sheets is building up;

FIG. 5 is a view similar to FIGS. 2 and 4 showing the side floating joggers at the bottom of their limited amount of vertical travel;

FIG. 6 is a view similar to FIGS. 2, 4 and 5 showing the stack of cut sheets continuing to build up with the side floating joggers at the bottom limit of their vertical travel;

FIG. 7 is a top view of the mounting means for one of the floating joggers showing the eccentric device which actuates the jogger paddle;

FIG. 8 is a front view taken along lines 88 in FIG. 7 showing the floating mounting means for the jogger paddle actuation mechanism;

FIG. 9 is a side view taken along lines 9-9 of FIG. 8, but with the jogger paddle attached, showing the jogger paddle actuating mechanism; and,

FIG. 10 is an enlarged partial cross section showing the hinge connection between the jogger paddle and the hinge plate.

DETAILED DESCRIPTION A preferred embodiment of the floating jogging device according to the present invention, includes a rigid frame having a pair of cylindrical elements mounted thereon, which in turn slidably receive a pair of rods having fixed thereto the actuation mechanism, including the jogger paddle, for carrying out the desired results, i.e., precisely aligning a stack of cut sheets directly onto a shipping skid. It should also be noted that a preferred requirement of the present invention lies in the provision of three such floating joggers on the sides and back of a stack of cut sheets for the purpose of achieving the desired results.

In this regard, FIG. 1 illustrates the preferred application of the novel floating joggers of the present invention wherein there is shown a skid lift platform with a shipping skid 11 resting thereon. The stacked sheets are indicated at 12 with three

floating jogger devices

13, 14 and 15 arranged at the back and two sides of the stack. A non-floating jogger 16 is illustrated at the front of the stack where the sheets 17 and 18 are shown to be coming onto the stack 12. Since the cut sheets 17 and 18, for example, arrive at the stack 12 substantially at the existing stack level, a floating jogger cannot be employed at the front of the stack. However, it has been found that a floating jogger is not required at the front of the stack when sheeting paper with applicants prior patented sheet cutting and stacking apparatus. It is conceivable, however, that under certain circumstances a floating jogger would be needed, and could be installed at each of the four sides of a stackof cut sheets. Accordingly, the present description should not be considered limiting in this regard. The floating jogger oscillating mechanisms and mounting means are not shown in detail in FIG. 1 but are described in more detail hereinafter.

With further reference to FIG. 1, and with particular reference to the preferred embodiment disclosed herein, it may be noted that since a floating jogger is not used at the front of the stack 12, nor can the skid 11 project in front of the stacked sheets. To account for this hiatus, the skid 11 is shown as projecting beyond the rear end of the stack 12 a distance equal to twice the normal amount of that distance left at each side of the stack. Thus, for the preferred embodiment, after the stack is finished and removed from the stacking mechanism, the skid 11 is driven under the stack 12 by means of hammer blows on the projecting rear end of the skid 11. The result of the realignment of the skid 1 1 with respect to the stack 12 is to insure that the amount of skid 11 which projects from the stack 12 at each of the four sides thereof will be uniform. However, as noted before, the projection of the skid 11 at each side of the stack 12 should be correct from the beginning.

FIG. 2 shows how the'two side joggers l4 and 15 rest on the shipping skid 11 when the stack of cut sheets is started. The rear end jogger 13 would rest on the shipping skid 11 in a similar manner, but with twice the normal skid projection as set forth above. Note that as shown only schematically, the two

side joggers

14, 15 are each mounted on rod like elements 20 which are slidably received in cylindrical guide housings 21 that are in turn mounted to fixed side rails 22. The two fixed side rails 22 are mounted adjacent the area in which the skid lift platform 10 is positioned. The skid lift platform 10 is hydraulically actuated in accordance with the delivery rate of the sheeter stacker apparatus (not shown) to move downwardly to accept the cut sheets as the stack 12 grows in height. FIGS. 4-6 illustrate the relative movement of the skid lift platform 10 as the sheet delivery and stacking continues.

FIG. 3 shows an enlarged detailed view of how the wrapper 30 for the stack 12, including the paperboard liner 31, are positioned on the shipping skid 11. Of course, the wrapper 30 and liner 31 are placed in position on the skid 11 prior to starting the sheeting operation. Then the skid lift platform is raised into contact with the floating

jogger devices

13, 14 and 15, and, finally raised an additional amount to move the jogging devices to their uppermost position as shown in FIG. 2. Subsequently, after the sheeting operation is finished and stack 12 completed, the skid 11 is repositioned under the stack 12 as explained hereinbefore, and, the wrapper 30 is folded up and around the stack in the final skid wrapping operation.

FIG. 4 illustrates how the

jogger devices

14 and 15 float downwardly as the stack 12 builds up, and, as the skid lift platform 10 is lowered to keep the stacking level constant. Similarly FIG. 5 shows the

jogger devices

14 and 15 at the lower limit of their prescribed amount of vertical travel.

FIG. 6 illustrates how the stacking operation is continued with the joggers l4 and 15 remaining at their lowest level. It was found that the joggers were only effective in the first several inches of the stack. Thus, as the stack 12 grows in height, and the weight of the stacked sheets forces the air out from between the sheets, the stack 12 becomes stabilized and resists further shifting on its own. However, to insure that no subsequent shifting of the stacked sheets does occur, the

jogger devices

13, 14 and 15 are provided with sufficient vertical movement to give a safety factor to the operation. In addition, to assure that the stack starts in precise alignment and remains precisely aligned, the jogger paddles 40 are carefully adjusted so that as they each pivot forward about their lower hinged connection, their extreme forward movement ends in exactly a vertical plane. In this manner the jogger paddles 40 act to define very precisely the edges of the stack while insuring that the edges of the stack remain precise until the sheets become firmly stabilized on the stack. The resulting stacks of sheeted paper have thus become known for their superior quality and appearance.

It should be noted, however, that the novel floating jogger devices disclosed herein are not limited to use on shipping skids Obviously the joggers could be arranged adjacent oversized skids for subsequent in-plant operation. Moreover, by using the novel floating joggers described, a limited number of skid sizes could easily be used to handle a large number of different sheet sizes.

From the foregoing description of the novel floating jogger devices, it is obvious that since the bottom edges of the jogger paddles 40 rest on the skid during the initial phase of the stacking operation, the jogger paddles 40 must be restrained against any form of unwanted movement. To satisfy this requirement, various schemes involving external pivoting mechanisms were considered, but none appeared to be practical. Then, and only quite recently, a plastic hinge became commercially available, to make the present invention practical and effective.

Thus, for the purpose of pivotally connecting the jogger paddles 40 to their hinge plates 41, a plastic hinge 42 made from polypropylene was chosen. The hinge material selected was 1 inches wide and approximately three-thirty-two of an inch thick, with a thinner portion at three thirty-seconds center where the hinge would pivot or bend. It was found that the polypropylene hinge just described had unusually good fatigue properties, permitting millions of flexures before failing, and moreover, the hinge satisfied the requirement of providing a connection between the jogger paddle 40 and the hinge plate 41 that would permit pivotal movement while limiting unwanted deflections to a minimum. FIG. 3 and also FIG. show the preferred hinge connection in detail.

With particular reference to FIG. 10, note that both the lower end of the jogger paddle 40 and the outer end of the hinge plate 41 are each machined as shown to accept the plastic hinge element 42. A pair of hinge clamps 43 are positioned tohold the hinge element 42 against the jogger paddle 40, and hinge plate 41, and the hinge element 42 is then firmly clamped in place by means of screws 44. It was found that a more than satisfactory arrangement could be achieved by spacing the screws 44 at approximately 1% inch centers along the hinge clamps 43 without weakening the hinge element 42. Another bonus achieved with the above described configuration was the fact that the hinge element 42 could be replaced easily and quickly when failure did occur. No holes were required in the hinge element itself, and the desired length of hinge material could be cut from a coil of hinge material on hand and inserted in the clamps before retightening the screws.

FIG. 7 shows an example of one scheme for mounting a floating jogger on the side frame provided therefor. The mounting means illustrated in FIG. 7 represents a construction that may be used with the jogger paddle drive mechanism 50 fixed to the top of a floating platform and should not be considered as limiting as regards the type of mounting means preferred. It has been found that each installation must be more-or-less tailored for the particular apparatus to which the jogger is applied. Hence FIG. 7 shows rather schematically a top view of a typical installation.

In regard, the jogger paddle 40 is shown as being connected to an eccentric drive device 51 by a connecting link 52. One end of the eccentric device 51 has a slot for receiving the end of the connecting link 52 with two screws 53 located therein for closing the slot to firmly grip the end of the connecting link. For the purpose of this invention, it was found that the same polypropylene material that was used for the hinge material 42 could also be used for the connecting link 52. The outer end of the connecting link 52 is attached to the jogger paddle 40 by means of a clamp 54 and two screws 55. In addition, bearing adjustments are provided at 56 between the clamp 54 and the connecting link 52 to permit adjustment of the jogger paddle 40 to exactly vertical plane in its most extended position.

The eccentric shaft 45 has integral therewith-a circular land 46, larger than the shaft 45 and with its center offset one-sixteenth inch. This arrangement gives approximately a 5/32 inch pivotal movement of the top edge of the jogger paddle 40 during operation of the device. In tests run with the arrangement disclosed herein, motions of from one-eighth to one-fourth inch were found to be satisfactory for efficient jogging action. On the circular land 46, there is an inner race of a roller bearing press fitted thereto with the roller bearing fitted into the eccentric 51 and held in place by snap rings at either side. In addition, the eccentric 51 has mounted therein a grease fitting for lubrication purposes. At each side of the eccentric 51, there is a ball bearing pillow block 47 for supporting the eccentric shaft 45 and at one end of the eccentric shaft 45 there is atiming belt pulley 48 through which a timing belt 49.is passed from the driving motor 60.

All of the assembled components mentioned above for supporting the eccentric 51 and the eccentric shaft 45 are rigidly attached to an upper bracket 57. The upper bracket 57 is in turn attached to the two rod like elements 20 and move with the rod like elements within the before mentioned cylindrical housings 21. Further, as shown in FIG. 7, and in other figures, the cylindrical housings 21 are attached to the rigid side rails 22 by brackets 23 at each side thereof.

FIG. 8 is a front view of one of the floating jogger devices with the jogger paddle removed, but, illustrated by dotted lines. In this view, the cylindrical slide housings 21 are shown in cross section and comprise an outer housing spaced from the rod like elements 20 by a plurality of bearings 24. The bearings 24 are press fitted into the outer housings and are separated from one another by spacer rings with grease seals located at each end. The grease seals are preferably made over size and when press fitted into the housings, hold the bearings in place. The particular features of the different bearings, spacer rings and grease seals mentioned above, and their manner of attachment to the cylindrical housings 21, are matters of mechanical skill and not deemed to be pertinent to the disclosure herein, except that it will be noted that the housings 21 are of a different length at each side of the mechanism. The difference in size of the two housings was chosen to more readily accommodate the vertical movement of the shafts 20 within the cylindrical housings 21. It was found that if the cylindrical housings 21 were made of equal size at each side of a jogger device, the vertical movement thereof sometimes became erratic when the jogger devices were following the skid platform 10. This malfunction was traced to the slight variation in spacing and alignment of the rods 20, which could be expected in assemblies of this type. However, to remove the possibility of such malfunctions, it was discovered that a smooth and predictable vertical movement could be assured by simply making one of the housings 21 of a length different than the first.

FIG. 8 also shows the motor mounting scheme that was found to be suitable for the particular embodiment disclosed herein. It is to be remembered, of course, that the illustrated embodiment should not be considered limiting to the present invention since a custom built installation is required in almost every environment. However, for the purpose of illustration, the motor 60 for driving the eccentric shaft and eccentric 51, is shown as being mounted on a motor mounting bracket 61 with screws 62. The motor bracket 61 is in turn attached to the upper platform 57 by vertical members 63. In addition, the entire installation is made more rigid by attaching the upper platform 57 to a lower plat- A form 58 through a connection at the lower end of the rods 20.

A typical motor installation that was found to be adequate for the present invention was a standard 1/15 horsepower, 1,725 rpm AC. motor. Mounted on the motor at one end thereof is a 12-tooth timing belt pulley 64, and through a timing belt 49, a 26-tooth pulley 48 is attached to the eccentric drive shaft 45. This arrangement gives the eccentric drive shaft 45 a speed of 796 rpm thereby yielding an adequate jogging action to the stack. Additional tests of the jogger devices disclosed herein illustrated that satisfactory jogging action could be obtained at from 500 to 1,000 oscillations per minute of the jogger paddle 40, with around 800 oscillations per minute being optimum.

FIG. 8 also shows the mounting brackets 23 provided between the cylindrical slide housings 21 and the jogger side rail 22. Only a schematic showing is illustrated however, since the particular mounting means chosen would vary from installation to installation. Obviously, however, the cylindrical slide housings 21 should be of a type exhibiting very low friction as set forth hereinbefore, to permit free and easy movement of the slide rods 20 therethrough. On the other hand, the arrangement and location of the side rails 22 and the cylindrical slide housings 21 should be such as to hold the slid-' ing mechanism firmly in all lateral directions. This latter requirement is imperative for the precise stacking ability demonstrated by the novel jogging device described herein. The side rail 22 extends the full length of the jogger mechanism and supports near each end thereof the slide housings 21 on the arms 23.

The jogger hinge plate 65 is attached to the motor support element 61 by means of several screws, with precise alignment provided by a key element (not shown). Thus by removing the screws and the attachment screws 55 at the top of the jogger paddle 40, the entire paddle assembly may be removed, and another paddle assembly of the same, or different length, may be installed simply and quickly by the machine operator. Spare paddle assemblies can be kept in stock so that in case of a hinge failure, a new paddle assembly can be installed quickly and with a minimum of machine down time. However, it should be noted that hinges as described herein have been found to last 6 months or longer when in operation 24 hours a day.

The jogger supporting structure comprises the top platform 57, the bottom platform 58, the end plates 63 and the motor support plate 61. These are each mortised as shown and held in position by socket head screws. The material is preferably aluminum plate to minimize weight, but other materials of fabrication could be used as desired to suit the particular installatron.

ln addition, the jogger paddle 40 is preferably made of aluminum and may be cast or fabricated from aluminum plate. The jogger paddle 40 must be stiff and very straight. Also, aluminum is chosen as the preferred material of construction in order to minimize load on the motor 60 and eccentric mechanism. Further, when aluminum is used, the surface contacting the paper is preferably anodized to prevent wear.

Many variations in materials and structural relationships may be employed in carrying out the invention without departing from the scope thereofas set forth in the following claims.

I claim:

1. A floating jogger device for precisely aligning cut sheets of material on a stack comprising:

a. ajogger paddle element pivoted at its bottom edge to a hinge plate;

b. means for actuating said jogger paddle element;

and,

c. means for mounting said jogger paddle element and actuation means for limited vertical movement wherein said jogger paddle element and hinge plate rest on top of the stacking skid initially and follow the stacking skid for a limited distance during the initial stage of operation. 2. The floating jogger device of claim 1 wherein said jogger paddle element is pivotally connected by an infinitely flexible hinge element to said hinge plate.

3. The floating jogger device of claim 2 wherein said flexible hinge element is fabricated from a plastic material such as polypropylene.

4. The floating jogger device of claim 3 wherein the means for actuating said jogger paddle element comprises an eccentric device connected to a driving motor.

5. The floating jogger device of claim 4 wherein the mounting means for said jogger paddle element and said jogger paddle actuating means further comprises:

1. a rigid side rail which extends the entire length of said jogger device;

2. a pair of cylindrical guide housings attached to said side rail near the ends thereof; and,

3. a floating jogger platform attached to a pair of rodlike elements slidably received in said cylindrical guide housings.

6. The floating jogger device of claim 5 wherein the mounting means for said jogger paddle element and actuation means further comprises:

1. a pair of spaced apart upper and lower support plates connected to one another by said rod-like elements; and

2. a pair of spaced vertical side elements attached to said upper support plate and having attached to the lower ends thereof an intermediate motor support plate.

7. The floating jogger device of claim 6 wherein a driving motor is attached to said motor support plate and the jogger paddle element eccentric device is attached to said upper support platform.

8. The floating jogger device of claim 7 wherein said driving motor is connected to said eccentric device by a timing belt.

9. The floating jogger device of claim 8 wherein said jogger paddle element is adjustably connected to said eccentric device so that its extreme forward movement ends in exactly a vertical plane.

10. A device for precisely aligning cut sheets of material directly on a shipping skid comprising a plurality of floating jogger devices positioned at the sides and the back of said shipping skid, said jogger devices each further comprising:

a. a jogger paddle element pivoted at its bottom edge to a hinge plate resting on said shipping skid;

b. means for actuating each of said jogger paddle elements; and,

0. means for mounting said jogger paddle elements and actuation means for limited vertical downward movement with said shipping skid.

11. A floating jogger device comprising:

a. ajogger paddle element pivotally connected at the bottom edge thereof to a hinge plate, said pivotal connection comprising a length of infinitely flexible hinge material fixedly attached to both the jogger paddle element and the said hinge plate;

b. means for actuating said jogger paddle element to produce oscillating movement of the jogger paddle element about said pivotal connection; and,

0. means for mounting said jogger paddle element and actuation means for limited vertical movement.

Claims

1. A floating jogger device for precisely aligning cut sheets of material on a stack comprising: a. a jogger paddle element pivoted at its bottom edge to a hinge plate; b. means for actuating said jogger paddle element; and, c. means for mounting said jogger paddle element and actuation means for limited vertical movement wherein said jogger paddle element and hinge plate rest on top of the stacking skid initially and follow the stacking skid for a limited distance during the initial stage of operation.

2. The floating jogger device of claim 1 wherein said jogger paddle element is pivotally connected by an infinitely flexible hinge element to said hinge plate.

3. a floating jogger platform attached to a pair of rod-like elements slidably received in said cylindrical guide housings.

10. A device for precisely aligning cut sheets of material directly on a shipping skid comprising a plurality of floating jogger devices positioned at the sides and the back of said shipping skid, said jogger devices each further comprising: a. a jogger paddle element pivoted at its bottom edge to a hinge plate resting on said shipping skid; b. means for actuating each of said jogger paddle elements; and, c. means for mounting said jogger paddle elements and actuation means for limited vertical downward movement with said shipping skid.

11. A floating jogger device comprising: a. a jogger paddle element pivotally connected at the bottom edge thereof to a hinge plate, said pivotal connection comprising a length of infinitely flexible hinge material fixedly attached to both the jogger paddle element and the said hinge plate; b. means for actuating said jogger paddle element to produce oscillating movement of the jogger paddle element about said pivotal connection; and, c. means for mounting said jogger paddle element and actuation means for limited vertical movement.