GB1572896A

GB1572896A - Diagnostic tendon hammer

Info

Publication number: GB1572896A
Application number: GB9109/76A
Authority: GB
Original assignee: REEVES SAUNDERS R
Current assignee: REEVES SAUNDERS R
Priority date: 1976-03-08
Filing date: 1976-03-08
Publication date: 1980-08-06
Also published as: JPS52115588A; CA1093406A; IT1125759B; FR2343465B1; FR2343465A1; IN143778B; JPS5930093B2; DE2709340A1

Description

(54) DIAGNOSTIC TENDON HAMMER (71) 1, RALPH REEVES-SAUN- DERS, a British Subject, of 175 Parkside Avenue, Bexleyheath, Kent DA7 6NP, formerly of Flat 4/4, International House, Brook Hill Road, Woolwich, London SEIS 6RZ, do hereby declare the invention, for which I pray that a Patent may be granted to me, and the method by which it is to be performed, to be particularly described in and by the following statement: - This invention concerns a diagnostic tendon hammer and has as one objective the pro vision of a diagnostic instrument, in the form of a tendon hammer, that can adopt a configuration in which the hammer is relatively compact and hence relatively easily handled.

Accordingly, one aspect of the present invention provides a tendon hammer comprising a percussive head and shaft having three or more telescopically connected shaft sections, means being provided for retaining adjacent shaft sections in desired relatve axial positions. The shaft of the tendon hammer of the invention may thus be telescopically collapsed to provide a configuration of the hammer that is relatively compact Advantageously, the percussive head is so connected to. the shaft that it may be moved to a stowed position with the or a major dimension thereof in a plane generally parallel to the shaft so as to be alongside the latter. Hence, in a further aspect the present invention provides a tendon hammer comprising a percussive head movably connected to a shaft having three or more telescopically connected shaft sections, the percussive head being moveable from a position d use to a stowed position in which it lies alongside the shaft, with the or a major dimension of the percussive head substantially parallel thereto, means being provided for retaining adjacent shaft sections in desired relative axial positions.

The connection between the percussive head and shaft conveniently includes detent means for locating the percussive head in at least its position of use. Such detent means conveniently comprise a ball catch arrangement adapted to hold the head in position for normal use of the hammer but capable of being overpowered, when required, for movement of the head to its stowed position.

The shaft may comprise any desired number of shaft sections greater than two and these may be of any suitable material, such as metal or rigid plastics material. However, in preferred embodiments of the invention the shaft comprises three or four metal shaft sections the outermost of which is formed as or is fitted with a suitable handle. Thus conveniently the end of the shaft that is remote from the percussive head when the shaft is extended may be fitted with a tubular handle of, for example, rubber, metal or plastics material, the handle conveniently being fitted over the outermost shaft section.

The percussive head advantageously comprises a disc-like member of metal or other dense material, encircled with an impact member. Suitable impact members include, for example, an integral or attached rim of metal or other material, and a ring of plastics (e g. elastomeric) material, solid rubber or air-filled rubber mounted in a circumferential groove in the disc-like member.

The tendon hammer may conveniently be adapted to perform a number of other diagnostic tests in addition to eliding tendon reflexes with the percussive head. For example, the shaft may be provided with a terminal projection of suitable shape for stimulating the skin. Alternatively, the hammer may be adapted to receive and store, for example, in a hollow portion of the shaft and/or of the head, one or more stimulating elements including a skin stimulator, such as a sharp pin or miniature brush.

Although in many cases natural frictional resistance to sliding of overlapping portions of adjacent shaft sections may serve to retain the shaft sections in desired relative axial positions, this frictional resistance may be enhanced, for instance by the provision of one or more shims of resilient flexible material, and/or inserts of plastics or other material engaging overlapping portions of adjacent shaft sections. Further, more positive retention of the shaft section in one or more relative axial positions may be obtained by the provision of detent means, for example, an out wardly extending radially displaceable pro jection disposed on the external surface of a shaft section and adapted to engage releasably one or more holes provided in the adjacent shaft section.

If desired, relative axial rotation between adjacent shaft sections may be prevented, for example bg providing cooperating longitudinal ribs and grooves in adjacent shaft sections.

The invention will be further described, by way of example, with reference to the accompanying drawings, in which: FIGURE 1 is a part-sectional perspective view of a preferred embodiment of a tendon hammer -in accordance with the present invention; FIGURE 2 is a longitudinal section, on an enlarged scale, of the tendor hammer of FIGURE 1; and FIGURE 3 is a par sectional view, on an enlarged scale, of a further tendor hammer anbodying the present invention.

Referring to Figures 1 and 2, the illu- strated tendon hammer comprises a percus sive head, generally designated 1, including a generally circular, disc-like solid metal member 2 formed with a circumferential groove 3. A rubber ring 4 is removably mounted in the groove 3 and provides an im pact member with a yielding surface for eliciting tendon reflexes by percussion.

The head 1 is connected to a telescopic shaft generally designated 5 by a connector 6 of such construction that the head 1 is pivotable about an axis at right angles to the longitudinal axis of the shaft 5. The con nector 6 comprises a circular cylindrical con necting piece 7 having one end mounted, for example by adhesive, or by a screw-threaded connection, as shown, in a circular cylindrical recess 8 formed coaxially in one end surface of the member 2. A diametric slot 9 extends from the other end of the connecting piece 7, forming a pair of opposed, part-circular cylindrical arms 10. The connector 6 addi tionally comprises a central shaft element 11 having a solid circular cylindrical portion 12 mounted coaxially within a first section 13 of the shaft 5, and a projection 14 of rec tangular cross-section extending coaxially from the free end of cylindrical portion 12.

The projection 14 is pivotally mounted be tween the arms 10 by means of a pin 13 extending at right angles to the longitudinal axis of the shaft 5.

A detent ball 16 is located at the base of the slot 9 and is urged into engagement with the adjacent surface of the projection 14 by means of a spring 17 mounted in a bore 18 in the connecting piece 7. The surface of the projection 14 engaged by the ball 16 is formed with five notches 19 so disposed and shaped that when the head 1 is pivoted about the pin 15, the head and shaft can rest and be retained in the five relative positions in which the ball 16 is seated in a notch 19. These five detent-located positions comprise a normal position of use, shown in full lines in Figure 2, in which the head 1 and shaft 5 are coaxial, the major dimension (diameter) of the head being at right angles to the shaft axis, in which the tendon hammer may be used for eliciting tendon reflexes by use of the impact member of the head 1; two stowed positions, shown in part in dot dash lines in Figure 2, in which the axes of the head 1 and shaft 5 are inclined at right angles on either side of the operational position, the major dimension of the head being substan dally parallel to the shaft axis, in which positions the tendon hammer has a relatively compact configuration that facilitates handling and storage; and two intermediate positions, also shown in part in dot dash lines in Figure 2, in which the axes of the head 1 and shaft 5 are inclined at 450 on either side of the normal position of use.

The shaft 5 comprises four coaxial, tubular, telescopically connected, metal shaft sections, including the first shaft section 13 to which the central shaft element 11 of connector 6 is mounted, and second, third and fourth shaft sections 20, 21 and 22 respectively. The shaft sections are of substantially the same length and are adapted to slide axially within or over adjacent shaft sections with a radial clearance taken up by lips (not shown) so that the shaft 5 can assume a number of different configurations, ranging between a fully extended position in which there is only a small overlap between adjacent shaft sections, and a fully collapsed position in which there is substantially complete overlap of adjacent shaft sections. The shaft sections are fitted, in the manner illustrated in the embodiment of Figure 3 but not shown in Figure 2, with shims that take up the radial clearance between the shaft sections and provide frictional restraint upon telescoping movement of the shaft sections, so that the shaft will retain an adjusted length. A tubular plastics handle 23, provided with a pointed conical end 24 for stimulating the skin, is securely fitted over substantially the entire external surface of the fourth shaft section 22, for example by means of adhesive, friction fit or a screwthreaded connection.

When it is required to use the tendon hammer for eliciting tendon reflexes by means of the impact member of the head 1, the shaft 5 is partly or fully extended, as desired, and the head 1 located in the normal position of use. When the tendon hammer is not required for such a purpose, the shaft 5 may be fully collapsed and the head 1 located in one of the stowed positions, providing the hammer with a relatively compact configuration in which the hammer may be easily handled and carried, for example, in a garment pocket.

Figure 3 shows a multi-purpose tendon hammer that is adapted to perform a number of other diagnostic tests in addition to eliciting tendon reflexes. The tendon hammer comprises a percussive head, generally designated 25, including a generally circular, disc-like solid metal member 26 having an axial bore 27, the side surface of the member 27 formed with a circumferential groove 28. A rubber ring 29 is removably mounted in the groove 28 and provides an impact member with a yielding surface for eliciting tendon reflexes by percussion.

The head 25 is pivotally connected to a telescopic shaft generally designated 30 by means of a circular cylindrical connecting piece 31 that is mounted in an enlarged end portion 32 of the bore 27 and that cooperates with an elongate solid circular cylindrical shaft element 33. The end of connecting piece 31 remote from the head 25 is provided with a diametric projection 34 that fits into a cor responding diametric slot 35 formed between a pair of oppposed part-circular-cylindrical arms 36 at the opposing end of shaft element 33. A pin 37 extends at right angles to the longitudinal axis of the shaft 30 through the arms 36 and the projection 34 and provides a pivotal connection between the head 25 and the shaft 30. The pivotal connection may be stabilised against undesirable play between the head 25 and shaft 30, for example by providing for dose frictional engagement be tween the projection 34 and arms 36, or by the provision of suitable detent means.

The telescopic shaft 30 additionally com prises first and second coaxial, tubular metal shaft sections 38 and 39 respectively, the end of shaft element 33 remote from the head 25 being slidably mounted within the first shaft section 38, that is, in turn, slidably mounted within the second shaft section 39. The ends of shaft element 33 remote from the head 25 are prwided with respective inwardly extend ing flanges 40 and 41 having an internal diameter substantially equal to the external diameter of the element 33 or shaft section 38 borne within the respective shaft sections.

The outer surface of the ends of the element 33 and first shaft section 38 remote from the head 25 are provided with one or more resi lient flexible metal shims 42 that bear against the internal surface of the adjacent shaft section and serve to retain the element 33 and shaft sections 38 and 39 in desired rela tive positions and, in addition, contribute axial rigidity to the shaft when the shaft is partly or fully extended. Alternatively, these functions may be served by projetcions of plastics or other materials extending from the outer surface of the element 33 and first shaft section 38 and bearing on the internal surface of the adjacent shaft section. In addition, detent means are provided for retaining the shaft sections in one or more relative axial positions, the detent means comprising a resilient, flexible rod 43 extending from the end of the element 33 remote from the head 25, and including a radial projection 44 that engages one or more holes 45 in the first shaft section 38. The rod 43 also prevents relative axial rotation of the element 33 and first shaft section 38: such rotation may also be prevented by providing corresponding longitudinal ribs and grooves in the surfaces of the element 33 and shaft sections 38 and 39.

A tubular plastics handle 46 is secured to substantially the entire external surface of second shaft section 39, for example, by means of adhesive, friction fit or a screw-threaded connection. An axial bore 47, having a narrower inner portion 48 and a wider outer portion 49, passes through a conical end portion 50 of the handle 46.

There may be provided one or more dual purpose stimulating elements 51 comprising a circular cylindrical plastics plug 52 having a pointed conical end 53 for stimulating the surface of skin, and including a sharp metal pin 54, a miniature brush or other skin stimu lator. The illustrated hammer is adapted to store two such elements with their pins pro tected when not required for use. As shown in Figure 3, one element 51 is stored with the pin 54 extending within the handle 46, the plug 52 being removably mounted in the outer portion 49 of bore 47 and retained in position, for example by frictional engage ment or a screw threaded connection. If de sired, the element 51 may be further secured by inserts of metal, rubber or plastics material mounted in the handle and bearing on the pin 54. A second element 51 is stored in the head 25, with the pin 54 extending through the bore 27 in member 26 and into a contiguous bore 55 provided in connecting piece 31. The element 51 is secured in position by means of frictional engagement between the pin 54 and inserts mounted on the inside of bore 27 and/or bore 55.

WHAT I CLAIM IS: 1. A tendon hammer comprising a percussive head and a shaft having three or more telescopically connected shaft sections, means being provided for retaining adjacent shaft sections in desired relative axial positions.

2. A tendon hammer comprising a percussive head movably connected to a shaft having three or more telescopically connected shaft sections, the percussive head being movable from a position of use to a stowed position in which it lies alongside the shaft, with the or a major dimension of the percussive head substantially parallel thereto, means being

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **.

hammer with a relatively compact configuration in which the hammer may be easily handled and carried, for example, in a garment pocket.

Figure 3 shows a multi-purpose tendon hammer that is adapted to perform a number of other diagnostic tests in addition to eliciting tendon reflexes. The tendon hammer comprises a percussive head, generally designated 25, including a generally circular, disc-like solid metal member 26 having an axial bore 27, the side surface of the member 27 formed with a circumferential groove 28. A rubber ring 29 is removably mounted in the groove 28 and provides an impact member with a yielding surface for eliciting tendon reflexes by percussion.

The head 25 is pivotally connected to a telescopic shaft generally designated 30 by means of a circular cylindrical connecting piece 31 that is mounted in an enlarged end portion 32 of the bore 27 and that cooperates with an elongate solid circular cylindrical shaft element 33. The end of connecting piece

31 remote from the head 25 is provided with a diametric projection 34 that fits into a cor responding diametric slot 35 formed between a pair of oppposed part-circular-cylindrical arms 36 at the opposing end of shaft element 33. A pin 37 extends at right angles to the longitudinal axis of the shaft 30 through the arms 36 and the projection 34 and provides a pivotal connection between the head 25 and the shaft 30. The pivotal connection may be stabilised against undesirable play between the head 25 and shaft 30, for example by providing for dose frictional engagement be tween the projection 34 and arms 36, or by the provision of suitable detent means.

The telescopic shaft 30 additionally com prises first and second coaxial, tubular metal shaft sections 38 and 39 respectively, the end of shaft element 33 remote from the head 25 being slidably mounted within the first shaft section 38, that is, in turn, slidably mounted within the second shaft section 39. The ends of shaft element 33 remote from the head 25 are prwided with respective inwardly extend ing flanges 40 and 41 having an internal diameter substantially equal to the external diameter of the element 33 or shaft section 38 borne within the respective shaft sections.

The outer surface of the ends of the element

33 and first shaft section 38 remote from the head 25 are provided with one or more resi lient flexible metal shims 42 that bear against the internal surface of the adjacent shaft section and serve to retain the element 33 and shaft sections 38 and 39 in desired rela tive positions and, in addition, contribute axial rigidity to the shaft when the shaft is partly or fully extended. Alternatively, these functions may be served by projetcions of plastics or other materials extending from the outer surface of the element 33 and first shaft section 38 and bearing on the internal surface of the adjacent shaft section. In addition, detent means are provided for retaining the shaft sections in one or more relative axial positions, the detent means comprising a resilient, flexible rod 43 extending from the end of the element 33 remote from the head 25, and including a radial projection 44 that engages one or more holes 45 in the first shaft section 38. The rod 43 also prevents relative axial rotation of the element 33 and first shaft section 38: such rotation may also be prevented by providing corresponding longitudinal ribs and grooves in the surfaces of the element 33 and shaft sections 38 and 39.

A tubular plastics handle 46 is secured to substantially the entire external surface of second shaft section 39, for example, by means of adhesive, friction fit or a screw-threaded connection. An axial bore 47, having a narrower inner portion 48 and a wider outer portion 49, passes through a conical end portion 50 of the handle 46.

There may be provided one or more dual purpose stimulating elements 51 comprising a circular cylindrical plastics plug 52 having a pointed conical end 53 for stimulating the surface of skin, and including a sharp metal pin 54, a miniature brush or other skin stimu lator. The illustrated hammer is adapted to store two such elements with their pins pro tected when not required for use. As shown in Figure 3, one element 51 is stored with the pin 54 extending within the handle 46, the plug 52 being removably mounted in the outer portion 49 of bore 47 and retained in position, for example by frictional engage ment or a screw threaded connection. If de sired, the element 51 may be further secured by inserts of metal, rubber or plastics material mounted in the handle and bearing on the pin 54. A second element 51 is stored in the head 25, with the pin 54 extending through the bore 27 in member 26 and into a contiguous bore 55 provided in connecting piece 31. The element 51 is secured in position by means of frictional engagement between the pin 54 and inserts mounted on the inside of bore 27 and/or bore 55.

WHAT I CLAIM IS: 1. A tendon hammer comprising a percussive head and a shaft having three or more telescopically connected shaft sections, means being provided for retaining adjacent shaft sections in desired relative axial positions.
2. A tendon hammer comprising a percussive head movably connected to a shaft having three or more telescopically connected shaft sections, the percussive head being movable from a position of use to a stowed position in which it lies alongside the shaft, with the or a major dimension of the percussive head substantially parallel thereto, means being

provided for retaining adjacent shaft sections in desired relative axial positions.
3. A tendon hammer according to claim 2, wherein the connection between the percussive head and shaft includes detent means for locating the percussive head in at least its position of use.
4. A tendon hammer according to claim 3, wherein the detent means comprise a ball catch arrangement adapted to hold the head in its position of use, but capable of being overpowered, when required, for movement of the head to its stowed position.
5. A tendon hammer according to any one of the preceding claims, wherein the shaft comprises four metal shaft sections.
6. A tendon hammer according to any one of the preceding claims, wherein a tubular handle of plastics material is fitted over the outermost shaft section.
7. A tendon hammer according to claim 6, wherein the handle is formed with a terminal conical projection of suitable shape for stimulating the skin.
8. A tendon hammer according to any one of claims 1 to 5, wherein the outermost shaft section constitutes a handle and terminates in a terminal conical projection for skin stimulation.
9. A tendon hammer according to any one of the preceding claims, wherein the percussive head comprises a disc-like metal member encircled with an impact member.
10. A tendon hammer according to claim 9, wherein the impact member comprises a rubber ring mounted in a circuuiferential groove in the disc-like member.
11. A tendon hammer according to any one of the preceding claims, including at least one detachable skin stimulating element
12. A tendon hammer according to any one of the preceding claims, wherein the means for retaining adjacent shaft sections in desired relative axial position comprise at least one shim of resilinet, flexible material and/or at least one insert of plastics or other material engaging overlapping portions of adjacent shaft sections.
13. A tendon hammer according to any one of claims 1 to 12, wherein detent means are provided for retaining the shaft sections in one or more relative axial positions.
14. A tendon hammer according to claim 13, wherein the detent means comprise an outwardly extending, radially displaceable projection disposed on the external surface of a shaft section and adapted to engage releasably one or more holes provided in the adjacent shaft section.
15. A tendon hammer according to any one of the preceding claims, wherein adjacent shaft sections are provided with cooperating longitudinal ribs and grooves.
16. A tendon hammer substantially as described with reference to, and as shown in, Figures 1 and 2 of the accompanying drawings.
17. A tendon hammer substantially as des; cribed with reference to, and as shown in, Figure 3 of the accompanying drawings.