US3864981A

US3864981A - Pretensioning apparatus for cam-driven reciprocating slide assembly

Info

Publication number: US3864981A
Application number: US370295A
Authority: US
Inventors: Kurt Schlegel
Original assignee: Individual
Current assignee: Individual
Priority date: 1973-06-15
Filing date: 1973-06-15
Publication date: 1975-02-11
Anticipated expiration: 1992-02-11

Abstract

A cam-driven reciprocating slide assembly for reciprocating a carriage of a machine, particularly a quilting machine, includes a frame member which is mounted for slidable movement along a linear direction. A pair of opposed contact rollers are mounted on the frame member and positioned to define a space along the predetermined direction for receiving a rotary design or pattern cam disc therebetween. One of the contact rollers is mounted on the frame member and adjustably positionable along the predetermined direction. The other contact roller is mounted on a pretensioning apparatus which comprises a housing mounted on the frame member and a resiliently mounted piston arrangement slidably movable within the housing. The contact roller mounted on the pretensioning apparatus is fixed on the piston. With this arrangement, rotary movement of the design cam disc with the periphery of the latter in contact with the contact rollers imparts reciprocatory motion to the slide assembly. The cam receiving space is variable by the yielding movement of the resiliently mounted contact roller, whereby a design cam disc disposed in operative relation between the rollers causes the resiliently mounted roller to yield in response to peripheral surface imperfections on the cam disc.

Description

United States Patent [191 Schlegel [111 3,864,981 [451 Feb. 11,1975

[ PRETENSIONING APPARATUS FOR CAM-DRIVEN RECIPROCATING SLIDE ASSEMBLY [76] Inventor: Kurt Schlegel, 1 Hastings Rd., Old

Westbury, NY. 11568 [22] Filed: June 15, 1973 [21] Appl. N0.: 370,295

[52] U.S. Cl 74/55, 112/79 R, 74/569 Primary ExaminerWesley S. Ratliff, Jr. Attorney, Agent, or Firm--Friedman & Goodman 57 ABSTRACT A cam-driven reciprocating slide assembly for reciproeating a carriage of a machine, particularly a quilting machine, includes a frame member which is mounted for slidable movement along a linear direction. A pair of opposed contact rollers are mounted on the frame member and positioned to define a space along the predetermined direction for receiving a rotary design or pattern cam disc therebetween. One of the contact rollers is mounted on the frame member and adjustably positionable along the predetermined direction. The other contact roller is mounted on a pretensioning apparatus which comprises a housing mounted on the frame member and a resiliently mounted piston arrangement slidably movable within the housing. The contact roller mounted on the pretensioning apparatus is fixed on the piston. With this arrangement, rotary movement of the design cam disc with the periphery of the latter in contact with the contact rollers imparts reciprocatory motion to the slide assembly. The cam receiving space is variable by the yielding movement of the resiliently mounted contact roller, whereby a design cam disc disposed in operative relation between the rollers causes the resiliently mounted roller to yield in response to peripheral surface imperfections on the cam disc.

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PRETENSIONING APPARATUS FOR CAM-DRIVEN RECIPROCATING SLIDE ASSEMBLY BACKGROUND OF THE INVENTION The present invention generally relates to slide assemblies for reciprocating a carriage of the machine, and more particularly to a slide assembly provided with two contact rollers one of which is resiliently mounted for pretensioning a design cam.

Cam-driven reciprocating slide assemblies are already known for reciprocating a carriage ofa machine. For example, such slide assemblies are utilized in conjunction with quilting machines which are adapted to sew different designs or patterns by interchanging the design cams operatively associated with the slide assembly.

According to one known slide assembly, two opposed contact rollers are mounted on a frame member of the slide assembly to define a space along the reciprocating direction for receiving a rotary pattern or design cam disc therebetween. The rollers span opposed peripheral portions of the cam disc, whereby rotary movement of the cam disc, with the periphery of the latter in contact with the rollers, imparts reciprocatory motion to the slide assembly. One example of such a slide assembly is more fully described in my U. S. Pat. No. 2,838,939

A major disadvantage of most of the cam-driven reciprocating slide assemblies of the prior art is their inability to operate reliably with design or pattern discs whose peripheral surfaces exhibit imperfections or high spots. The contact rollers which span the cam disc are adjustably positioned on the slide assembly frame to each abut against an opposed peripheral portion of the cam disc. At such time, the contact rollers are rigidly fixed in position along the frame member by, for example, tightening a bolt or other conventional fixing means. However, the initial spacing set, between the contact rollers while the design cam is stationary, is not always, due to the peripheral surface imperfections in the cam, a constant or fixed value and may vary slightly depending on the tolerances with which the cam was made. The cam surface imperfections, and the fixed nature of the rollers, once initially positioned fre quently manifests itself in several serious problems which adversely affects the operation of such reciprocating machines, such as quilting machines, and operation is characterized by frequent breakdown.

When the design disc rotates, and the contact rollers do do not closely follow and continuously engage or abut against the cam surface there are created shocks or very large vibrations upon both the cam as well as the slide assembly whenever the cam moves from an engaged to a non-engaged condition or vice versa. These shocks result in very high stresses exerted on the components or elements of the machine, particularly the high mass reciprocating members thereof.

One solution which is attempted is the utilization of shock absorbers which, to some degree, alleviate the shocks or jolts which are produced. However, the utilization of shock absorbers has only served as a partial solution and has not eliminated the basic problem or the cause therefor.

Another problem associated with the above described reciprocating slide assemblies, operated by design cams, is the inability of the conventional slide assembly to properly adjust to all peripheral imperfec- 2 tions of the cam. Frequently, when a high spot is present on the periphery of a design cam, and the distance represented by the "high spot and the opposed peripheral portion of the cam is greater than the initial distance fixed between the contact rollers. the cam cannot continue to rotate and becomes jammed between the contact rollers. This problem is particularly serious since prevention of continued rotation of the design cam can, and frequently does, produce serious damage to either the slide assembly, the design cam, the gear box associated with the design cam, the driving source which drives the gears and the design cam, or a combination of these elements. Once such damage has taken place, the machine becomes disabled and requires a frequently expensive repair. This, of course, is aggravated by the fact that the machine is removed from production until such repair is made.

SUMMARY OF THE INVENTION An object of the present invention is to provide a cam-driven reciprocating slide assembly which is not possessed of the above described disadvantages associ ated with prior art slide assemblies.

It is another object of the present invention to provide a slide assembly of the type under discussion which is simple in construction and economical to manufacture.

It is still another object of the present invention to provide a cam-driven reciprocating slide assembly for reciprocating a carriage ofa machine which cooperates with a design cam without the generation of impulses or shocks which necessitate the utilization of shock absorbers.

It is yet another object of the present invention to provide a slide assembly as above described which provides a pretensioning apparatus which biasses one of two contact rollers into abutment against a design cam during movement thereof the biassed contact roller being adapted to resiliently yield to high points or other surface imperfections of a design cam during rotary movement thereof.

It is a further object of the present invention to provide a cam-driven reciprocating slide assembly which prevents jamming of design cams and driving devices therefor as a result of a design cam being locked in position between two fixed contact rollers.

It is still a further object of the present invention to provide a cam-driven reciprocating slide assembly which avoids the necessity of utilizing design cams manufactured to close or high tolerances.

It is yet a further object of the present invention to provide a slide assembly for reciprocating a carriage of a machine, particularly a quiltingmachine, which does not require a precise initial setting of the cam peripheral portion contact rollers one of the contact rollers being resiliently mounted to yield in response to imperfections in the cam.

It is an additional object of the present invention to provide a cam-driven reciprocating slide assembly for reciprocating the carriage of a machine which is highly reliable and which practically fully eliminates the possibility of damage described above in connection with prior art machines.

In order to achieve the above objects, as well as other objects which will.become apparent hereafter, a camdriven reciprocating slide assembly for reciprocating a carriage of a machine comprises a frame member mounted for free slidable movement along a predetermined linear direction. Said frame member includes means for connecting the latter to the reciprocable carriage of the machine. A pair of opposed contact rollers define a space along said predetermined direction for receiving said rotary cam disc therebetween and for spanning opposed peripheral portions of the cam disc. In this manner, rotary movement of the cam disc with the periphery of the latter in contact with said rollers imparts reciprocatory motion to the slide assembly. A pair of mounting means are provided on said frame member each supporting a roller and mounting a respective roller on said frame member. One of said rollers is resiliently mounted for limited movement relative to its associated mounting means along said predetermined direction, said one roller normally being biassed to an initial position relative to its associated mounting means in the direction of the other roller. Said cam-receiving space is variable by the yielding movement of said one resiliently mounted roller from said initial normal biassed position. With this construction, a cam disc disposed in operative relation between said rollers causes said one roller to resiliently yield in response to peripheral surface imperfections on the cam disc.

Various constructions may be utilized for resiliently mounting the said one contact roller. For example, a support block may be-slidably mounted on said frame member for movement along said predetermined direction. Said one resiliently mounted roller may be mounted on one end portion of said support block facing said other roller. Biassing means are provided acting between an opposed end portion of said support block and said frame member for biassing said support block in a direction of said other roller. Another arrangement entails the utilization of a cylinder-piston arrangement, wherein said cylinder is mounted on said frame member. Said piston is mounted for slidable movement within said cylinder. Said one roller is mounted on a portion of said piston extending beyond said cylinder in the direction of the other roller. Again, biassing means act between said piston and said cylinder for urging said piston in the direction of said other roller.

According to the presently preferred embodiment, the mounting means supporting said one resiliently mounted roller comprises a housing mounted on said frame member. The housing is provided with an elongated cavity extending along said predetermined direc tion and open at one end thereof facing the other of said rollers. A support block is slidably mounted in said cavity and has a projection at least partially extending therefrom in the direction of the other of said rollers. One resiliently mounted roller is mounted on said projection of said support block. Biassing means act between the closed end of the housing cavity and the support block for biassing the latter in the direction of the other roller. In this manner, said one resiliently mounted roller may yield against the action of said biassing means to increase the cam disc receiving space during rotary movement of the cam disc.

The present invention contemplates the utilization of a limit pin mounted on the support block coaxially with said one resiliently mounted roller for movement with the latter. A stop member is provided on the frame mounted in the line of movement of the limit pin and adapted to engage the latter with excessive movement of the support block in the direction of the'other roller." In this manner, the initial position of the said one roller is determined by the position of the limit pin on said frame member. In this connection, the limit pin is provided with a marking as is the frame member. The markings are aligned in the initial position of said one roller. The degree of misalignment of said markings represents the extent of yielding movement on said one roller from said initial position against the action of said biassing means and the extent of pretensioning applied to an operatively disposed cam disc between said rollers.

BRIEF DESCRIPTION OF THE DRAWINGS With the above and additional objects and advantages in view, as will hereinafter appear, this invention comprises the devices, combinations and arrangements of parts hereinafter described and illustrated in the accompanying drawings of a preferred embodiment in which:

FIG. 1 is a front elevational view of a cam-driven reciprocating slide assembly with a design cam operatively positioned thereon, schematically shown to be connected to a carriage of a machine to be reciprocated;

FIG. 2 is a top plan view of the slide assembly shown in FIG. 1;

FIG. 3 is a rear elevational view of the slide assembly shown in FIG. 1;

FIG. 4 is an enlarged fragmented view of the pretensioning apparatus of the slide assembly shown in FIG. 1, taken alone line 4-4;.

FIG. 5 is a fragmented view of the slide assembly frame member, shown with the design cam removed and shown slidably mounted in a guide block;

FIG. 6 is a fragmented enlarged view of the pretensioning apparatus of the slide assembly shown in FIG.

FIG. 7 is an enlarged fragmented view in cross section of the pretensioning apparatus shown in FIG. 2, taken along line 77;

FIG. 8 is-a rear elevational view of the pretensioning apparatus shown in FIG. 6; and

FIG. 9 is a front elevational view of the end block shown in FIG. 1 which does not support the contact roller supported by the pretensioning apparatus, showing the means for adjustably positioning the contact roller.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the FIGURES, wherein the same reference numerals have been utilized to designate identical or similar parts throughout, and first referring to FIGS. 1 and 2, the cam-driven reciprocating slide assembly in accordance with the present invention is generally designated by the reference numeral 10. The slide assembly 10 is provided with means 11, to be described hereafter, for connecting at least a portion thereof to the reciprocable carriage of a machine 12. The present invention will be described, by way of example, as being utilized in conjunction with a quilting machine. However, it will become apparent from the description that follows that the slide assembly 10 may be utilized with any other machine which incorporates a reciprocable carriage to be reciprocated by a camdriven reciprocating slide assembly of the type described.

The slide assembly comprises a frame member 14 which generally includes an upper rod or bar 16 and a lower rod or bar 18. The

bars

16, 18, in the presently preferred embodiment, have a square cross section. However, the precise cross sectional configuration of the bars is not critical for the purposes of the present invention.

The

bars

16 and 18 are spaced from each other and extend parallel to one another.

The spaced and parallel relation of the bars l6, 18 is maintained by an end block 20 at the right end of the bar, as viewed in FIG. 1, and by a pretensioning apparatus 22, spaced from the end block 20 and to be more fully described hereafter.

The end block 20 is generally horseshoe-shaped or U-shaped, and the parallel legs thereof are each rigidly bolted to another of the bars by means of bolts 24. The end block 20 is provided with a slot 26 having a curved or rounded end 28. The slot 26 extends in a direction substantially parallel to that of the bars, which extend along a predetermined reciprocating linear direction to be described hereafter. One longitudinal end of the slot 26 is open in a direction of the pretensioning apparatus 22 while the other longitudinal end thereof is closed.

A cam contact roller 30 is rotatably mounted on mounting means which includes a shaft 31 slidably movable within the slot 26 when a bolt 32 is loosened. [n this manner, the shaft or pin 31 is adjustably positionable along the slot 26. When a desired position therefor has been selected, the bolt 32 is tightened the bolt engaging an enlarged disc or washer 33 which abuts against the end block 20 in pressure relationship, as to be more fully described hereafter.

A pretensioning adjustment screw 34 is provided on the end block 20 which is threadedly meshed with the closed longitudinal end of the slot 26 and adapted to engage the mounting means in the form of the pin or shaft 31, for reasons to be described hereafter.

Referring to FIG. 3, an end block 38, forming part of the pretensioning apparatus 22 and comparable to end block 20, is positioned proximate an opposed end of the bar 18 and at an intermediate portion of the bar 16. The end block 38 is similarly horseshoe-shaped or U- shaped and is provided with an elongate slot 40 similarly disposed along the reciprocating or the predetermined linear direction. The slot 40 is provided with a rounded end 42. The open longitudinal end of the slot 40 is directed toward the end block 20. The end block 38 is fastened to the

bars

16, 18 by means of bolts 24. The width or thickness of the end blocks 20 and 38 are, in the presently preferred embodiment, approximately equal to the widths of the

bars

16, 18.

As best seen in FIG. 2, a spacing plate 44 is provided adjacently to the top bar 16 and extends in a substantially horizontal position, as viewed in P16. 1. A similar spacing plate (not shown) is disposed adjacently to the bar 18. Four bolts 46 attach an end plate 48 to each of the spacing plates 44 to form therewith an open cavity or space to be more fully described hereafter. A cover plate 50 is connected to the end plate 48 and to the end block 38 by means of

bolts

52, 54 respectively. The cover plate 50 closes off one end of the above described cavity or space. The end block 38, the spacing plates 44, the end plate 48 and the cover plate 50 together define a housing defining a cylinder cavity or space 56, shown in FIG. 4. The formation of the above described housing by generally flat planar members defines a space 56 which has a rectangular cross section.

A support block 58 in the nature of a piston, having a rectangular cross section comparable to that of the space 56, is slidably mounted within the space 56 for slidable movement along the predetermined linear reciprocating direction. While the external dimensions of the support block 58 are comparable to the internal dimensions of the housing or the space 56, the dimen' sions of the support block are so selected to provide some clearance between itself and the housing to permit free slidable movement therein.

In accordance with a presently preferred construction, the support block 58 is provided with two spaced

parallel arms

60, 62 which project from the support block to form a yoke or forked structure between which extends a pin or shaft 63, shown in FIG. 6, on which a contact roller 64 may be rotably mounted.

As shown in FIGS. 4 and 7, the support block 58 is provided with an elongate aperture 66 or bore which extends at least through a portion of the longitudinal length of the support block 58 and has a closed or bearing surface 67 proximate the contact roller 64 and has an opening facing the direction of the cover plate 50. A helical spring 68 is provided in the aperture or bore 66 and so dimensioned so as to normally be in a compressed state to thereby resiliently urge or bias the support block 58 in a direction away from the cover plate 50. As should be clear, the further that the support block 58 is moved into the space 56 closer towards the cover plate 50, the more the biassing spring 68 is compressed and the greater pressure or restoring force is exerted upon the support block and thereby upon the contact roller 64. Since the support block 58 is slidably mounted within the housing of the pretensioning apparatus 22, the pretensioning cam contact roller 64 is adapted to resiliently yield in different degrees depending upon the extent to which pressure is applied thereto along the linear reciprocating direction.

As best shown in FIG. 2, the housing of the pretensioning apparatus 22 is disposed on the same vertical sides of the bars 16, 1.8 as is the contact roller 30 the

contact rollers

30 and 64 being spaced and opposed to each other and together defining a space along the predetermined reciprocating direction for receiving a rotary cam disc therebetween and for spanning opposed peripheral portions of the cam disc. In this manner, rotary movement of the cam disc with the periphery of the latter in contact with the

contact rollers

30, 64 imparts reciprocatory motion to the slide assembly 10.

The structure connected to each of the end blocks 20, 38 which supports a respective one of the contact rollers are termed, for the purposes of the present specification and claims, as mounting means. Thus, the mounting means for the contact roller 30 comprises the shaft or pin 31 as well as the fastening means associated therewith, including the bolt 32 and washer 33. The mounting means for supporting the resiliently mounted roller 64 comprises the spacing plates 44, the end plate 48, the cover plate 50, the support block 58 including the

arms

60, 62 and the shaft or pin extending therebetween. By providing a biassing spring 68 in the housing as above described, biassing or resilient movement of the roller 64 may be achieved.

Stop means are provided for limiting movement of the resiliently mounted roller 64 in the direction of the roller 64 under the action of the biassing spring 68. The stop means includes an alignment and limit pin 70 mounted on the support block 58 coaxially with the contact roller 64 for movement with the latter with slidable movement of the support block within the housing of the pretensioning apparatus 22. As best shown in H6. 4, the alignment and limit pin 70 is disposed to the other side of the contact roller 64 with respect to the arm 62. A stop member 72 is provided on the frame member 14. The stop member is best shown in FIGS. 3, 4, 6 and 8. In the presently preferred embodiment, the stop member 72 comprises a sleeve which surrounds an end portion of a bolt 24, best shown in FIG. 3. The alignment and limit pin is generally oriented in a horizontal direction and extends sufficiently beyond the arm 62 to extend into and through a substantial part of the slot 40 of the end block 38. On the other hand, the stop member 72 is disposed entirely within the slot 40 and extends in a substantially vertical direction between opposing surfaces of the slot. Of importance in this connection is that the stop member 72 is mounted in the line of movement of the alignment and limit pin 70 and adapted to engage the latter with excessive movement of the support block 58 in the direction of the roller 30. The alignment and limit pin 70 is disposed between the stop member 72 and the rounded ends 42 of the slots 40. For this reason, the longitudinal movement or reciprocation in the predetermined direction of the contact roller 64 is limited.

When a cam is not positioned between

contact rollers

30, 64, and no other forces are applied to the contact roller 64, the biassing spring 68 is selected to urge the support block 58 to a normal initial position wherein the alignment and limit pin 70 is in contact or in abutment against the stop member 72. For preselected positions of the

end block

20, 38, this normal initial position of the support block 58 represents the smallest cam receiving space between the rollers.

Referring to FIG. 4, it will be noted that according to the presently preferred embodiment, the end surface of the alignment pin and limit pin 70 is flush with or in the same plane as the plane defined by the exposed surface of the end block 38, shown in FIG. 3. As best illustrated in FIGS. 3 and 8, spaced inscribed

lines

74 and 76 are provided on the fixed end block 38 and bars 16, 18. Comparably spaced markings or

lines

78 and 80 are provided on the end surface of the alignment limit pin 70. The

markings

74, 76 are aligned with the

markings

78, 80 respectively in the normal initial position of the roller 64 shown in FIGS. 3, 4 and 6-8. Accordingly, the degree of misalignment of the markings represent the extent of yielding movement of the roller 64 from the normal initial position against the action of the spring 68 and the extent of pretensioning or force which the contact roller could apply to a cam disc operatively disposed between the rollers, as to be described hereafter.

Referring to FlGS. l-3, a design or pattern cam 80 which is provided with a peripheral cam surface 82 is mounted adjacently to the

bars

16, 18, and more particularly a major surface of the cam 80 is disposed adjacently to the surfaces 83 of the

bars

16, 18 which face the cam.

The cam 80 is mounted on a shaft 84, the shaft 84 extending through a bearing 86 which is fixed to the cam 80 in any conventional manner. An extension 84' of the shaft 84 is rotatably journaled through a fixed guide block 88, best shown in FIG. 5. The fixed guide block 88 is provided with spaced parallel slots defining upper guide surfaces 90 and lower guide surfaces 92 which are spaced to slidably receive the outer bar 16 and lower bar 18 respectively.

A set screw 94, shown in FlGS. l and 2, is threadedly mounted on the bearing 86 and can be advanced inwardly towards the shaft 84 to engage the latter in abutting or secure relation. By mounting the cam disc 80 and the bearing 86 fixed to the latter on the shaft 84, and tightening the set screw 94, the cam 80 is caused to rotate about the shaft 84 when the shaft portion 84' is rotated within the guide block 88. The portions of the peripheral cam surface 82 which are simultaneously in abutment or in contact with

respective rollers

30 and 64 are termed, for the purposes of the present application and claims, as opposed peripheral portions along the predetermined reciprocating direction.

In accordance with the presently preferred embodiment, the length of the bar 16 is greater than that of the bar 18 the bar 16 having a portion thereof extending beyond the corresponding end of the bar 18 and being provided with a threaded shank 96. The member or carriage of the machine to be reciprocated 12 is provided with an aperture 98 through which the threaded shank 96 is adapted to pass. A nut 100 or any other suitable connecting means may be utilized to fix the bar 16 to the member 12 to be reciprocated, whereby the reciprocal movement of the frame member 14 of the slide assembly 10 imparts corresponding reciprocatory movement to the member 12.

The operation, to the extent to which it has not been set forth above, will now be described. As well known to those skilled in the art, design or pattern cams 80 are frequently interchanged for the purpose of providing various stitches on quilts or the like. The manner of mounting a cam 80 on the slide assembly 10 first comprises the step of turning the pretensioning adjustment screw 34 to retract a substantial portion thereof from the slot 26. The mounting means on which the contact roller 30 is rotatably mounted may now be slidably moved towards the rounded end 28 by loosening the bolt 32. By sliding the contact roller 30 towards the rounded end 28, it should be clear that the cam receiving space between the

rollers

30 and 64 is correspondingly enlarged. With no cam between the rollers, as described above, the biassing spring 68 urges the support block 58 and therefore the contact roller 64 to a normally initialposition wherein the alignment and limit pin abuts against the stop member 72.

A cam having a desired peripheral cam surface 82 is mounted on the shaft 84 and brought to a position wherein the rearward facing major surface of the cam is disposed adjacently to the surfaces 83 of the bar 16,

18. This is best illustrated in FIG. 2. Once the cam and the bearing 86 are moved to the last mentioned position, wherein the peripheral cam surface 82 has portions thereof which are disposed laterally of the contact rollers, the set screw 94 is tightened to fix the bearing, and consequently the cam 80, relative to the shaft 84 and the shaft portion 84, the latter of which is connected to a suitable drive mechanism.

It should be borne in mind that the guide block 88 is fixed in position. The shaft 84 and shaft portion 84 are rotatably movable within the guide block 88 but are fixed in relation to the linear reciprocating direction. Once the cam 80 and bearing 86 have been mounted on the shaft 84, the frame member 14 is urged towards the right, as viewed in FIGS. 1 and 2, bringing the member 12 to be reciprocated towards the right and bringing the cam contact roller 64 into abutment against a peripheral portion of the cam 80.

When the contact roller 64 abuts against the cam 80, the shaft or pin 31 which comprises the mounting means for the contact roller 30 is slidably moved within the slot 26 towards the left, as viewed in FIGS. 1 and 2. The contact roller 30 is advanced towards the left to bring the same into abutment with a portion of the periphery of the cam80. The bolt 32 is now tightened to sandwich a portion of the end block 20 by means of the washer or disc 33. The tightening of the bolt 32, as suggested above, fixes the pin or shaft 31 within the slot 26. It should be pointed out that the extent of movement of the shaft or pin 31 towards the left is limited by the presence of the cam 80. The biassing spring 68 is advantageously selected to comprise a heavy spring having a high constant. For this this manner, a relatively large force must be exerted on the frame member 14 to advance the same towards the right subsequent to contact between the roller 64 and the cam 80 or with yielding movement or retraction of the support block 58 into the space 56 of the pretensioning apparatus 22. It should be clear, that the greater the frame member 14 is advanced towards the right with increased yielding movement or resilient movement of the support block 58 relative to the

bars

16, 18, the greater will be the restoring force which the biassing spring 68 exerts upon the cam 80 via the cam contact roller 64. Because of the high restoring forces involved, it is generally not possible to manually move the slidable assembly 10 and the member 12 towards the right beyond the point at which the contact roller 64 first engages the cam 80. Such engagement is possible, however, with the support block 58 in the fully extended normal initial position above described wherein the contact roller 64 applies a relatively small force upon the cam.

To increase the pretensioning forces which the

rollers

30 and 64 exert on opposing peripheral portions of the cam 80, the bolt 32 may be loosened and the pretensioning adjustment screw advanced internally of the slot 26 to abut against the roller-30 mounting means including the shaft or pin 31 to thereby effectively urge the frame member 14 to move towards the right, as viewed in FlGS. l and 2 the adjustment or set screw 34 applying a force upon the fixed cam 80 via the contact roller 30. With continued movement of the frame member 14 towards the right, the pretensioning apparatus 22, mounted on the frame member 14, similarly advances towards the right and the support block 58 is urged interiorly of the space 56 against the action of the biassing spring 68. This yielding or resilient movement of the support block 58 is due to the fixed engaging relationship between the contact roller 64 and the cam 80. As mentioned above, increased compression of the biassing spring 68 by movement of the support block 58 further interiorly of the space 56 increases the restoring forces which the contact roller exerts against the cam 80. The degree of pretensioning or entry of the support block 58 interiorly of the space 56 is determinable from the misalignment of the markings or

lines

74, 76, 78 and 80 as described above. lf desired, a scale in numerical markings may be provided which indicate the precise amount of restoring or pretensioning forces generated within the pertensioning apparatus 22. Once the cam 80 has been secured between the

rollers

30 and 64 with sufficient pressure applied thereon at peripheral opposing portions thereof,

the contact roller 30 may be fixed in position within the 2 slot 26 by tightening the bolt 32.

Rotation of the shaft 84 causes the cam to rotate with the contact rollers closely following the peripheral surface 82 thereof. Continued rotation of the cam 80 about the shaft 84 causes the slide assembly 10 to reciprocate in a horizontal direction on the fixed guide block 88. The present invention overcomes several major problems inherent in prior art comparable assemblies. Firstly, it becomes a very simple matter to initially set the positions of the contact rollers by moving the shaft or pin 31 within the slot 26.. pretensioning or. the application of compressing forces upon the cam 80 are easily established by adjustment of the adjustment screw 34 for advancement into the slot 26 for abutment against the pin 31.

An important feature of the present invention is the provision of a resiliently mounted contact roller 64 which is adapted to yield during rotation of the cam to compensate or adjust the space between the

contact rollers

30, 64 for peripheral surface imperfections or.

high points frequently found in the cams. For this reason, the present invention eliminates many problems inherent in prior apparatus such as jamming and damage of cam and gear mechanisms as well as the need to provide careful or precise adjustments of the slide assembly or the provision of expensive cams made to high tolerances.

Although the pin 31, on which the contact roller 30 is mounted for rotation but fixed insofar as linear movement relative thereto, is described as being movable within the slots and the housing of the pretensioning apparatus 22 is described as being fixed on the frame member or relative to the

bar

16, 18, it should be clear that it is also possible to fix the shaft or pin 31 on the frame or member 14 and have the housing of the pretensioning apparatus 22 slidably movable. It is only important that one of the contact rollers be mounted for coarse linear movement along the reciprocating direction to coarsely select a cam receiving space therebetween. Means are provided for further moving one of the rollers to still further decrease the distance somewhat to provide a tensioning or pressure fit relationship between the cam and the rollers. This comprises a fine linear adjustment. When one of the rollers is mounted resiliently as above described for yielding movement, several of the objects associated with imperfectly finished cams may be achieved.

Numerous alterations of the structure herein disclosed will suggest themselves to those skilled in the art. However, it is to be understood that the present disclosure relates to a preferred embodiment of the invention which is for purposes of illustration only and is not to be construed as a limitation of the invention.

What is claimed is:

1. Cam-driven reciprocating slide assembly for reciprocating a carriage of a machine, the slide assembly comprising a frame member mounted for free slidable movement along a predetermined linear direction, said frame member including means for connecting the latter to the reciprocable carriage of the machine; a pair of opposed contact rollers defining a space along said predetermined direction for receiving a rotary cam disc therebetween and for spanning opposed peripheral portions of the cam disc, whereby rotary movement of the cam disc with the periphery of the latter in contact with said rollers imparts reciprocatory motion to the slide assembly; a pair of mounting means provided on said frame member each supporting a roller and mounting a respective roller on said frame member, one of said rollers being resiliently mounted for limited movement relative to its associated mounting means along said predetermined direction; and stop means for limiting movement of said resiliently mounted roller in the direction of said other roller, said one roller normally being biassed to an initial position relative to its associated mounting means and normally being maintained in said initial position by said stop means, said cam-receiving space being variable by the yielding movement of said one resiliently mounted roller from said initial normal biassed position, whereby a cam disc disposed in operative relation between said rollers causes said one roller to resiliently yield in response to peripheral surface imperfections on the cam disc.

2. A slide assembly as defined in claim 1, wherein the mounting means supporting said one resiliently mounted roller comprises a support block slidably mounted on said frame member for movement along said predetermined direction, said one resiliently mounted roller being mounted on an end portion of said support block facing said other roller, and biassing means acting between an opposed end portion of said support block and said frame member for biassing said support block in the direction of said other roller.

3. A slide assembly as defined in claim 1, wherein the mounting means supporting said one resiliently mounted roller comprises a cylinder-piston arrangement, said cylinder being mounted on said frame member, said piston being mounted for slidable movement within said cylinder; and biassing means acting between said piston and said cylinder for urging said piston in the direction of said other roller.

4. A slide assembly as defined in claim 1, wherein the mounting means supporting said one resiliently mounted roller comprises a housing mounted on said frame member, said housing being provided with an elongated cavity extending along said predetermined direction and open at one end thereof facing the other of said rollers, a support block slidably mounted in said cavity and having a projection at least partially extending therefrom in the direction of the other of said rollers, said one resiliently mounted roller being mounted on said projection of said support block, and biasing means acting between the closed end of said housing cavity and said support block for biassing the latter in the direction of said other roller, whereby said one resiliently mounted roller may yield against the action of said biassing means to increase said cam disc receiving space during rotary movement of the cam disc.

5. A slide assembly as defined in claim 4, wherein said housing has an end plate, and the end of said support block in the region of said end plate being pro vided with a bore which partially extends through said support block, said biassing means comprises a helical spring at least partially inserted into said bore and having one end resiliently abutting against said end plate.

6. A slide assembly as defined in claim 1, wherein said stop means comprises a limit pin mounted on said support block coaxially with said one resiliently mounted roller for movement with the latter, and a stop member provided on said frame member mounted in the line of movement of said limit pin and adapted to engage the latter with excessive movement of said support block in the direction of said other roller, whereby said initial position of said one roller is determined by the position of said limit pin on said frame member.

7. A slide assembly as defined in claim 6, wherein said limit pin is provided with a marking, said frame member being provided with a marking, said markings being aligned in said initial position of said one roller. whereby the degree of misalignment of said markings represents the extent of yielding movement of said one roller from said initial position against the action of said biasing means and the extent of pretensioning applied to an operatively disposed cam disc between said rollers.

8. A slide assembly as defined in claim 4, wherein said cavity has a rectangular cross-section, and wherein said support block is configurated to matingly and slidably be mounted in said cavity.

9. A slide assembly as defined in claim 4, wherein said support block projection comprises two spaced arms forming a yoke, and further comprising a pin having an axis oriented generally normally to a plane defined by an operatively positioned cam disc between said rollers, said pin extending between and mounted on said spaced arms, and said one roller being rotatably mounted on said pin.

10. A slide assembly as defined in claim 1, wherein one of said mounting means is adjustably positionable relative to said frame member along said predetermined direction, whereby said cam disc receiving space may be substantially adjusted to thereby closely receive a cam disc between said two rollers in operative position.

11. A slide assembly as defined in claim 10, wherein said one roller is mounted on said other mounting means.

12. A slide assembly as defined in claim 10, wherein said other roller is fixedly mounted relative to said one adjustably positionable mounting means.

13. A slide assembly as defined in claim 12, wherein said frame member comprises two spaced parallel elongate bars, and two spaced end blocks each disposed between and connected to said bars, said one adjustably positionable mounting means being mounted for slidable movement in said predetermined direction on one of said end blocks.

14. A slide assembly as defined in claim 13, wherein said one end block is provided with a slot extending in said predetermined direction, and said adjustably positionable mounting means comprises bolt means, a support pivot pin projecting axially from said bolt means, said other roller being rotatably mounted on said pivot pin, and bolt means including means for adjustably fixing the position thereof against slidable movement within said slot.

15. A slide assembly as defined in claim 14, wherein said portion of said collar provided with said surfaces is shorter than the width of said bars, said collar being further provided with an integrally formed abutment projecting from corresponding ends of each respective surface on one side of said one end block, and a threaded shank which is receivable through said slot, said locking means comprising an apertured disc disposed at corresponding ends of each respective surface on the other side of said one end block, and a -nut threadedly mounted on said threaded shank, whereby tightening of the nut urges said apertured disc towards said abutments with said one end block locked therebetween.

16. A slide assembly as defined in claim 14, further comprising a set screw oriented on said one end block in said predetermined direction and having one end thereof projecting into said slot into abutment against said adjustably positionable mounting means, whereby said one resiliently mounted roller may be displaced from said initial position via an operatively disposed cam-disc by advancing said set screw into said slot and urging said other roller against the cam disc to thereby adjust the pretensioning which said rollers exert against the cam disc.

17. In a quilting machine having a reciprocable carriage and a cam-driven slide assembly connected to the carriage, the slide assembly including a frame member, a pair of opposed contact rollers defining a space along a predetermined linear direction of reciprocation for receiving a rotary cam disc therebetween and for spanning opposed peripheral portions of the cam disc, whereby rotary movement of the cam disc with the periphery of the latter in contact with said rollers imparts reciprocatory motion to the slide assembly, and said slide assembly further including a pair of mounting means provided on said frame member each supporting a contact roller and mounting a respective roller on said frame member, the improvement comprising in that one of said rollers is resiliently mounted for limited movement relative to its associated mounting means along said predetermined direction; and stop means for limiting movement of said resiliently mounted roller in the direction of said other roller, said one roller normally being biassed to an initial position relative to its associated mounting means and normally being maintained in said initial position by said stop means, said cam-receiving space being variable by the yielding movement of said one resiliently mounted roller from said initial normal biassed position, whereby a cam disc disposed in operative relation between said rollers causes said one roller to resiliently yield in response to peripehral surface imperfections on the cam disc.

18. In a quilting machine as defined in claim 17,

wherein the mounting means supporting said one resiliently mounted roller comprises a housing mounted on said frame member, said housing being provided with an elongated cavity extending along said predetermined direction and open at one end therof facing the other of said rollers, a support block slidably mounted in said cavity and having a projection at least partially extending therefrom in the direction of the other of said rollers, said one resiliently mounted roller being mounted on said projection of said support block, and biassing means acting between the closed end of said housing cavity and said support block for biassing the latter in the direction of said other roller, whereby said one resiliently mounted roller may yield against the action of said biassing means to increase said cam disc receiving space during rotary movement of the cam disc.

19. In a quilting machine as defined in claim 18, wherein said support block projection comprises two spaced arms forming a yoke, and further comprising a pin having an axis oriented generally normally to a plane defined by an operatively positioned cam disc between said rollers, said pin extending between and mounted on said spaced arms, and said one roller being rotatably mounted on said pin.

20. In quilting machine as defined in claim 17, wherein one of said mounting means is adjustably positionable relative to said frame member along said predetermined direction, whereby said cam disc receiving space may be substantially adjusted to thereby closely receive a cam disc between said two rollers in operative position.

21. In a quilting machine as defined in claim 20, wherein said one roller is mounted on said other mounting means, and wherein said other roller is fixedly mounted relative to said one adjustably positionable mounting means.

22. Cam-driven reciprocating slide assembly for reciprocating a carriage of a machine, the slide assembly comprising a frame member mounted for free slidable movement along a predetermined linear direction, said frame member including means for connecting the latter to the reciprocable carriage of the machine; a pair of opposed contact rollers defining a space along said predetermined direction for receiving a rotary cam disc therebetween and for spanning opposed peripheral portions of the cam disc, whereby rotary movement of the cam disc with the periphery of the latter in contact with said rollers imparts reciprocatory motion to the slide assembly; a pair of mounting means provided on said frame member each supporting a roller and mounting a respective roller on said frame member, one of said rollers being resiliently mounted for limited movement relative to its associated mounting means along said predetermined direction, said mounting means supporting said one resiliently mounted roller comprising a housing mounted on said frame member, said housing being provided with an elongated cavity extending along said predetermined direction and open at one end thereof facing the other of said rollers, a support block slidably mounted in said cavity and having a projection at least partially extending therefrom in the direction of the other of said rollers, said support block projection comprising two spaced arms forming a yoke, and further comprising a pin having an axis oriented generally normally to a plane defined by an operatively positioned cam disc between said rollers, said pin extending between and mounted on said spaced arms, and said one roller being rotatably mounted on said pin, said one resiliently mounted roller being mounted on said projection of said support block, and biassing means acting between the closed end of said housing cavity and said support block for biassing the latter in the direction of said other roller, said one roller normally being biassed to an initial position relative to its associated mounting means in the direction of the other roller, said cam-receiving space being variable by the yielding movement of said one resiliently mounted roller from said initial normal biassed position, whereby said one resiliently mounted roller may yield against the action of said biassing means to increase said cam disc receiving space during rotary movement of the cam disc, and whereby a cam disc disposed in operative relation between said rollers causes said one roller to resiliently yield in response to peripheral surface imperfections on the cam disc.

23. Cam-driven reciprocating slide assembly for reciprocating a carriage of a machine, the slide assembly comprising a frame member mounted for free slidable movement along a predetermined linear direction, said frame member including means for connecting the latter to the reciprocable carriage of the machine; a pair of opposed contact rollers defining a space along said predetermined direction for receiving a rotary cam disc therebetween and for spanning opposed peripheral '15 portions of the cam disc, whereby rotary movement of the cam disc with the periphery of the latter in contact with said rollers imparts reciprocatory motion to the slide assembly; a pair of mounting means provided on said frame member each supporting a roller and mounting a respective roller on said frame member, one of said rollers being resiliently mounted for limited movement relative to its associated mounting means along said predetermined direction, one of said mounting means being adjustably positionable relative to said frame member along said predetermined direction, whereby said cam disc receiving space may be adjusted to thereby closely receive a cam disc between said two rollers in operative position, and said other roller being substantially fixedly mounted relative to said one adjustably positionable mounting means, said frame member comprising two spaced parallel elongate bars, and two spaced end blocks each disposed between and connected to said bars, said one adjustably positionable mounting means being mounted for slidable movement in said predetermined direction in one of said end blocks, said one end blocks being provided with a slot extending in said predetermined direction, and said adjustably positionable mounting means comprising a bolt means, whereby a portion of said bolt means is slidably receivable in said slot, a support pivot pin projecting axially from said bolt means, said other roller being rotatably mounted on said pivot pin, said bolt means including means for adjustably fixing the position thereof against slidable movement within said slot, said one roller normally being biassed to an initial position relative to its associated mounting means in the direction of the other roller, said cam-receiving space being variable by the yielding movement of said one resiliently mounted roller from said initial normal biassed position, whereby a cam disc disposed in operative relation between said rollers causes said one roller to resiliently yield in response to peripheral surface imperfections on the cam disc.

24. In a quilting machine having a reciprocable carriage and a cam-driven slide assembly connected to the carriage, the slide assembly including a frame member, a pair of opposed contact rollers defining a space along a predetermined linear direction of reciprocation for receiving a rotary cam disc therebetween and for spanning opposed peripheral portions of the cam disc, whereby rotary movement of the cam disc with the periphery of the latter in contact with said rollers imparts reciprocatory motion to the slide assembly, and said slide assembly further including a pair of mounting means provided on said frame member each supporting a contact roller and mounting a respective roller on said frame member, the improvement comprising in that one of said rollers is resiliently mounted for limited movement relative to its associated mounting means along said predetermined direction, said mounting means supporting said one resiliently mounted roller comprising a housing mounted on said frame member, said housing being provided with an elongated cavity extending along said predetermined direction and open at one end thereof facing the other of said rollers. a support block slidably mounted in said cavity and having a projection at least partially extending therefrom in the direction of the other said rollers, said support block projection comprising two spaced arms forming a yoke, and further comprising a pin having an axis oriented generally normally to a plane defined by an operatively positioned cam disc between said rollers, said pin extending between and mounted on said spaced arms, and said one roller being rotatably mounted on said pin, said one resiliently mounted roller being mounted on said projection of said support block, and biassing means acting between the closed end of said housing cavity and said support block for biassing the latter in the direction of said other roller, said one roller normally being biassed to an initial position relative to its associated mounting means in the direction of the other roller, said cam-receiving space being variable by the yielding movement of said one resiliently mounted roller from said initial normal biassed position, whereby said one resiliently mounted roller may yield against the action of said biassing means to increase said cam disc receiving space during rotary movement of the cam disc, and whereby a cam disc disposed in operative relation between said rollers causes said one roller to resiliently yield in response to peripheral surface imperfections on the cam disc.

Claims

1. Cam-driven reciprocating slide assembly for reciprocating a carriage of a machine, the slide assembly comprising a frame member mounted for free slidable movement along a predetermined linear direction, said frame member including means for connecting the latter to the reciprocable carriage of the machine; a pair of opposed contact rollers defining a space along said predetermined direction for receiving a rotary cam disc therebetween and for spanning opposed peripheral portions of the cam disc, whereby rotary movement of the cam disc with the periphery of the latter in contact with said rollers imparts reciprocatory motion to the slide assembly; a pair of mounting means provided on said frame member each supporting a roller and mounting a respective roller on said frame member, one of said rollers being resiliently mounted for limited movement relative to its associated mounting means along said predetermined direction; and stop means for limiting movement of said resiliently mounted roller in the direction of said other roller, said one roller normally being biassed to an initial position relative to its associated mounting means and normally being maintained in said initial position by said stop means, said camreceiving space being variable by the yielding movement of said one resiliently mounted roller from said initial normal biassed position, whereby a cam disc disposed in operative relation between said rollers causes said one roller to resiliently yield in response to peripheral surface imperfections on the cam disc.

5. A slide assembly as defined in claim 4, wherein said housing has an end plate, and the end of said support block in the region of said end plate being provided with a bore which partially extends through said support block, said biassing means comprises a helical spring at least partially inserted into said bore and having one end resiliently abutting against said end plate.

7. A slide assembly as defined in claim 6, wherein said limit pin is provided with a marking, said frame member being provided with a marking, said markings being aligned in said initial position of said one roller, whereby the degree of misalignment of said markings represents the extent of yielding movement of said one roller from said initial position against the action of said biasing means and the extent of pretensioning applied to an operatively disposed cam disc between said rollers.

15. A slide assembly as defined in claim 14, wherein said portion of said collar provided with said surfaces is shorter than the width of said bars, said collar being further provided with an integrally formed abutment projecting from corresponding ends of each respective surface on one side of said one end block, and a threaded shank which is receivable through said slot, said locking means comprising an apertured disc disposed at corresponding ends of each respective surface on the other side of said one end block, and a nut threadedly mounted on said threaded shank, whereby tightening of the nut urges said apertured disc towards said abutments with said one end block locked therebetween.

18. In a quilting machine as defined in claim 17, wherein the mounting means supporting said one resiliently mounted roller comprises a housing mounted on said frame member, said housing being provided with an elongated cavity extending along said predetermined direction and open at one end therof facing the other of said rollers, a support block slidably mounted in said cavity and having a projection at least partially extending therefrom in the direction of the other of said rollers, said one resiliently mounted roller being mounted on said projection of said support block, and biassing means acting between the closed end of said housing cavity and said support block for biassing the latter in the direction of said other roller, whereby said one resiliently mounted roller may yield against the action of said biassing means to increase said cam disc receiving space during rotary movement of the cam disc.

23. Cam-driven reciprocating slide assembly for reciprocating a carriage of a machine, the slide assembly comprising a frame member mounted for free slidable movement along a predetermined linear direction, said frame member including means for connecting the latter to the reciprocable carriage of the machine; a pair of opposed contact rollers defining a space along said predetermined direction for receiving a rotary cam disc therebetween and for spanning opposed peripheral portions of the cam disc, whereby rotary movement of the cam disc with the periphery of the latter in contact with said rollers imparts reciprocatory motion to the slide assembly; a pair of mounting means provided on said frame member each supporting a roller and mounting a respective roller on said frame member, one of said rollers being resiliently mounted for limited movement relative to its associated mounting means along said predetermined direction, one of said mounting means being adjustably positionable relative to said frame member along said predetermined direction, whereby said cam disc receiving space may be adjusted to thereby closely receive a cam disc between said two rollers in operative position, and said other roller being substantially fixedly mounted relative to said one adjustably positionable mounting means, said frame member comprising two spaced parallel elongate bars, and two spaced end blocks each disposed between and connected to said bars, said one adjustably positionable mounting means being mounted for slidable movement in said predetermined direction in one of said end blocks, said one end blocks being provided with a slot extending in said predetermined direction, and said adjustably positionable mounting means comprising a bolt means, whereby a portion of said bolt means is slidably receivable in said slot, a support pivot pin projecting axially from said bolt means, said other roller being rotatably mounted on said pivot pin, said bolt means including means for adjustably fixing the position thereof against slidable movement within said slot, said one roller normally being biassed to an initial position relative to its associated mounting means in the direction of the other roller, said cam-receiving space being variable by the yielding movement of said one resiliently mounted roller from said initiaL normal biassed position, whereby a cam disc disposed in operative relation between said rollers causes said one roller to resiliently yield in response to peripheral surface imperfections on the cam disc.

24. In a quilting machine having a reciprocable carriage and a cam-driven slide assembly connected to the carriage, the slide assembly including a frame member, a pair of opposed contact rollers defining a space along a predetermined linear direction of reciprocation for receiving a rotary cam disc therebetween and for spanning opposed peripheral portions of the cam disc, whereby rotary movement of the cam disc with the periphery of the latter in contact with said rollers imparts reciprocatory motion to the slide assembly, and said slide assembly further including a pair of mounting means provided on said frame member each supporting a contact roller and mounting a respective roller on said frame member, the improvement comprising in that one of said rollers is resiliently mounted for limited movement relative to its associated mounting means along said predetermined direction, said mounting means supporting said one resiliently mounted roller comprising a housing mounted on said frame member, said housing being provided with an elongated cavity extending along said predetermined direction and open at one end thereof facing the other of said rollers, a support block slidably mounted in said cavity and having a projection at least partially extending therefrom in the direction of the other said rollers, said support block projection comprising two spaced arms forming a yoke, and further comprising a pin having an axis oriented generally normally to a plane defined by an operatively positioned cam disc between said rollers, said pin extending between and mounted on said spaced arms, and said one roller being rotatably mounted on said pin, said one resiliently mounted roller being mounted on said projection of said support block, and biassing means acting between the closed end of said housing cavity and said support block for biassing the latter in the direction of said other roller, said one roller normally being biassed to an initial position relative to its associated mounting means in the direction of the other roller, said cam-receiving space being variable by the yielding movement of said one resiliently mounted roller from said initial normal biassed position, whereby said one resiliently mounted roller may yield against the action of said biassing means to increase said cam disc receiving space during rotary movement of the cam disc, and whereby a cam disc disposed in operative relation between said rollers causes said one roller to resiliently yield in response to peripheral surface imperfections on the cam disc.